Sample records for ultrasound tissue typing

  1. Ultrasound RF time series for tissue typing: first in vivo clinical results

    NASA Astrophysics Data System (ADS)

    Moradi, Mehdi; Mahdavi, S. Sara; Nir, Guy; Jones, Edward C.; Goldenberg, S. Larry; Salcudean, Septimiu E.

    2013-03-01

    The low diagnostic value of ultrasound in prostate cancer imaging has resulted in an effort to enhance the tumor contrast using ultrasound-based technologies that go beyond traditional B-mode imaging. Ultrasound RF time series, formed by echo samples originating from the same location over a few seconds of imaging, has been proposed and experimentally used for tissue typing with the goal of cancer detection. In this work, for the first time we report the preliminary results of in vivo clinical use of spectral parameters extracted from RF time series in prostate cancer detection. An image processing pipeline is designed to register the ultrasound data to wholemount histopathology references acquired from prostate specimens that are removed in radical prostatectomy after imaging. Support vector machine classification is used to detect cancer in 524 regions of interest of size 5×5 mm, each forming a feature vector of spectral RF time series parameters. Preliminary ROC curves acquired based on RF time series analysis for individual cases, with leave-one-patient-out cross validation, are presented and compared with B-mode texture analysis.

  2. Tissue identification by ultrasound

    NASA Technical Reports Server (NTRS)

    Lecroissette, D. H.; Heyser, R. C.; Gammell, P. M.; Wilson, R. L.

    1978-01-01

    The ultrasonic properties of animal and human soft tissue were measured over the frequency range of 1.5 to 10.0 MHz. The method employed a swept-frequency, coherent technique known as time delay spectrometry. Measurements of attenuation versus frequency on liver, backfat, kidney, pancreas, spleen, breast, and other tissue were made. Considerable attention was paid to tissue handling and in determining the effects of fixing on the attenuation of ultrasound in the tissue.

  3. Ultrasound-triggered Release of Recombinant Tissue-type Plasminogen Activator from Echogenic Liposomes

    PubMed Central

    Smith, Denise A.B.; Vaidya, Sampada S.; Kopechek, Jonathan A.; Huang, Shao-Ling; Klegerman, Melvin E.; McPherson, David D.; Holland, Christy K.

    2009-01-01

    Echogenic liposomes (ELIP) were developed as ultrasound-triggered targeted drug or gene delivery vehicles (Lanza et al., 1997; Huang et al., 2001). Recombinant tissue-type Plasminogen Activator (rt-PA), a thrombolytic, has been loaded into ELIP (Tiukinhoy-Laing et al., 2007). These vesicles have the potential to be used for ultrasound-enhanced thrombolysis in the treatment of acute ischemic stroke, myocardial infarction, deep vein thrombosis, or pulmonary embolus. A clinical diagnostic ultrasound scanner (Philips HDI 5000) equipped with a linear array transducer (L12-5) was employed for in vitro studies using rt-PA-loaded ELIP (T-ELIP). The goal of this study was to quantify ultrasound-triggered drug release from rt-PA-loaded echogenic liposomes. T-ELIP samples were exposed to 6.9-MHz B-mode pulses at a low pressure amplitude (600 kPa) to track the echogenicity over time under four experimental conditions: 1) flow alone to monitor gas diffusion from the T-ELIP, 2) pulsed 6.0-MHz color Doppler exposure above the acoustically driven threshold (0.8 MPa) to force gas out of the liposome gently, 3) pulsed 6.0-MHz color Doppler above the rapid fragmentation threshold (2.6 MPa), or 4) Triton X-100 to rupture the T-ELIP chemically as a positive control. Release of rt-PA for each ultrasound exposure protocol was assayed spectrophotometrically. T-ELIP were echogenic in the flow model (5 ml/min) for thirty minutes. The thrombolytic drug remained associated with the liposome when exposed to low-amplitude B-mode pulses over 60 min and was released when exposed to color Doppler pulses or Triton X-100. The rt-PA released from the liposomes had similar enzymatic activity as the free drug. These T-ELIP are robust and echogenic during continuous fundamental 6.9-MHz B-mode imaging at a low exposure output level (600 kPa). Furthermore, a therapeutic concentration of rt-PA can be released by fragmenting the T-ELIP with pulsed 6.0-MHz color Doppler ultrasound above the rapid fragmentation threshold (1.59 MPa). PMID:19900755

  4. HOW DOES PERFORMANCE OF ULTRASOUND TISSUE TYPING AFFECT DESIGN OF PROSTATE IMRT DOSE-PAINTING PROTOCOLS?

    PubMed Central

    Zhang, Pengpeng; Osterman, K. Sunshine; Liu, Tian; Li, Xiang; Kessel, Jack; Wu, Leester; Schiff, Peter; Kutcher, Gerald J.

    2010-01-01

    Purpose To investigate how the performance characteristics of ultrasound tissue typing (UTT) affect the design of a population-based prostate dose-painting protocol. Methods and Materials The performance of UTT is evaluated using the receiver operating characteristic curve. As the imager’s sensitivity increases, more tumors are detected, but the specificity worsens, causing more false-positive results. The UTT tumor map, obtained with a specific sensitivity and specificity setup, was used with the patient’s CT image to guide intensity-modulated radiotherapy (IMRT) planning. The optimal escalation dose to the UTT positive region, as well as the safe dose to the negative background, was obtained by maximizing the uncomplicated control (i.e., a combination of tumor control probability and weighted normal tissue complication probability). For high- and low-risk tumors, IMRT plans guided by conventional ultrasound or UTT with a one-dimensional or two-dimensional spectrum analysis technique were compared with an IMRT plan in which the whole prostate was dose escalated. Results For all imaging modalities, the specificity of 0.9 was chosen to reduce complications resulting from high false-positive results. If the primary tumors were low risk, the IMRT plans guided by all imaging modalities achieved high tumor control probability and reduced the normal tissue complication probability significantly compared with the plan with whole gland dose escalation. However, if the primary tumors were high risk, the accuracy of the imaging modality was critical to maintain the tumor control probability and normal tissue complication probability at acceptable levels. Conclusion The performance characteristics of an imager have important implications in dose painting and should be considered in the design of dose-painting protocols. PMID:17236962

  5. Ultrasound tissue analysis and characterization

    NASA Astrophysics Data System (ADS)

    Kaufhold, John; Chan, Ray C.; Karl, William C.; Castanon, David A.

    1999-07-01

    On the battlefield of the future, it may become feasible for medics to perform, via application of new biomedical technologies, more sophisticated diagnoses and surgery than is currently practiced. Emerging biomedical technology may enable the medic to perform laparoscopic surgical procedures to remove, for example, shrapnel from injured soldiers. Battlefield conditions constrain the types of medical image acquisition and interpretation which can be performed. Ultrasound is the only viable biomedical imaging modality appropriate for deployment on the battlefield -- which leads to image interpretation issues because of the poor quality of ultrasound imagery. To help overcome these issues, we develop and implement a method of image enhancement which could aid non-experts in the rapid interpretation and use of ultrasound imagery. We describe an energy minimization approach to finding boundaries in medical images and show how prior information on edge orientation can be incorporated into this framework to detect tissue boundaries oriented at a known angle.

  6. Whole breast tissue characterization with ultrasound tomography

    NASA Astrophysics Data System (ADS)

    Duric, Neb; Littrup, Peter; Li, Cuiping; Roy, Olivier; Schmidt, Steve; Seamans, John; Wallen, Andrea; Bey-Knight, Lisa

    2015-03-01

    A number of clinical trials have shown that screening ultrasound, supplemental to mammography, detects additional cancers in women with dense breasts. However, labor intensity, operator dependence and high recall rates have limited adoption. This paper describes the use of ultrasound tomography for whole-breast tissue stiffness measurements as a first step toward addressing the issue of high recall rates. The validation of the technique using an anthropomorphic phantom is described. In-vivo applications are demonstrated on 13 breast masses, indicating that lesion stiffness correlates with lesion type as expected. Comparison of lesion stiffness measurements with standard elastography was available for 11 masses and showed a strong correlation between the 2 measures. It is concluded that ultrasound tomography can map out the 3 dimensional distribution of tissue stiffness over the whole breast. Such a capability is well suited for screening where additional characterization may improve the specificity of screening ultrasound, thereby lowering barriers to acceptance.

  7. Fuzzy similarity measures for ultrasound tissue characterization

    Microsoft Academic Search

    Salem M. Emara; Ahmed M. Badawi; Abou-Bakr M. Youssef

    1995-01-01

    Computerized ultrasound tissue characterization has become an objective means for diagnosis of diseases. It is difficult to differentiate diffuse liver diseases, namely cirrhotic and fatty liver from a normal one, by visual inspection from the ultrasound images. The visual criteria for differentiating diffused diseases is rather confusing and highly dependent upon the sonographer's experience. The need for computerized tissue characterization

  8. Ultrasound-responsive thrombus treatment with zinc-stabilized gelatin nano-complexes of tissue-type plasminogen activator

    E-print Network

    Takada, Shoji

    is undertaken to design zinc-stabilized gelatin nano-complexes of tissue-type plasminogen activator (t In acute myocardial infarction, treatment strategies aimed at rapidly restoring complete and2 persistent deeply penetrate into the interior of body. Seve

  9. Therapeutic ultrasound for dental tissue repair.

    PubMed

    Scheven, B A A; Shelton, R M; Cooper, P R; Walmsley, A D; Smith, A J

    2009-10-01

    Dental disease affects human health and the quality of life of millions worldwide. Tooth decay (caries) and diseases of the dental pulp result in loss of tooth vitality and function requiring invasive treatment to restore the tooth to health. "Therapeutic" low intensity pulsed ultrasound has been shown to accelerate bone fracture healing indicating that ultrasound may be used as a tool to facilitate hard tissue regeneration. We have shown recently that low frequency ultrasound is able to exert biological effects on odontoblast-like cells. In this paper, we postulate that low frequency, low intensity ultrasound may stimulate endogenous coronal tooth repair by stimulating dentine formation from existing odontoblasts or by activating dental pulp stem cells to differentiate into new reparative dentine-producing cells. Ultrasound therapy promoting dentine formation and repair may also have the potential benefit of alleviating dentine hypersensitivity by inducing occlusion of dentinal tubules. It is envisaged that therapeutic ultrasound may be used in future to facilitate dental tissue engineering and stem cell therapy applications for dental tissue regeneration. Further research is warranted in this clinically important area and we envisage that novel strategies in dental therapy will be realised that may ultimately lead to the development of novel non-invasive, multifunctional ultrasound devices for dental diagnostics, repair and regeneration. PMID:19553029

  10. Ultrasound Tissue Characterization of Vulnerable Atherosclerotic Plaque

    PubMed Central

    Picano, Eugenio; Paterni, Marco

    2015-01-01

    A thrombotic occlusion of the vessel fed by ruptured coronary atherosclerotic plaque may result in unstable angina, myocardial infarction or death, whereas embolization from a plaque in carotid arteries may result in transient ischemic attack or stroke. The atherosclerotic plaque prone to such clinical events is termed high-risk or vulnerable plaque, and its identification in humans before it becomes symptomatic has been elusive to date. Ultrasonic tissue characterization of the atherosclerotic plaque is possible with different techniques—such as vascular, transesophageal, and intravascular ultrasound—on a variety of arterial segments, including carotid, aorta, and coronary districts. The image analysis can be based on visual, video-densitometric or radiofrequency methods and identifies three distinct textural patterns: hypo-echoic (corresponding to lipid- and hemorrhage-rich plaque), iso- or moderately hyper-echoic (fibrotic or fibro-fatty plaque), and markedly hyperechoic with shadowing (calcific plaque). Hypoechoic or dishomogeneous plaques, with spotty microcalcification and large plaque burden, with plaque neovascularization and surface irregularities by contrast-enhanced ultrasound, are more prone to clinical complications than hyperechoic, extensively calcified, homogeneous plaques with limited plaque burden, smooth luminal plaque surface and absence of neovascularization. Plaque ultrasound morphology is important, along with plaque geometry, in determining the atherosclerotic prognostic burden in the individual patient. New quantitative methods beyond backscatter (to include speed of sound, attenuation, strain, temperature, and high order statistics) are under development to evaluate vascular tissues. Although not yet ready for widespread clinical use, tissue characterization is listed by the American Society of Echocardiography roadmap to 2020 as one of the most promising fields of application in cardiovascular ultrasound imaging, offering unique opportunities for the early detection and treatment of atherosclerotic disease. PMID:25950760

  11. Fuzzy similarity measures for ultrasound tissue characterization

    NASA Astrophysics Data System (ADS)

    Emara, Salem M.; Badawi, Ahmed M.; Youssef, Abou-Bakr M.

    1995-03-01

    Computerized ultrasound tissue characterization has become an objective means for diagnosis of diseases. It is difficult to differentiate diffuse liver diseases, namely cirrhotic and fatty liver from a normal one, by visual inspection from the ultrasound images. The visual criteria for differentiating diffused diseases is rather confusing and highly dependent upon the sonographer's experience. The need for computerized tissue characterization is thus justified to quantitatively assist the sonographer for accurate differentiation and to minimize the degree of risk from erroneous interpretation. In this paper we used the fuzzy similarity measure as an approximate reasoning technique to find the maximum degree of matching between an unknown case defined by a feature vector and a family of prototypes (knowledge base). The feature vector used for the matching process contains 8 quantitative parameters (textural, acoustical, and speckle parameters) extracted from the ultrasound image. The steps done to match an unknown case with the family of prototypes (cirr, fatty, normal) are: Choosing the membership functions for each parameter, then obtaining the fuzzification matrix for the unknown case and the family of prototypes, then by the linguistic evaluation of two fuzzy quantities we obtain the similarity matrix, then by a simple aggregation method and the fuzzy integrals we obtain the degree of similarity. Finally, we find that the similarity measure results are comparable to the neural network classification techniques and it can be used in medical diagnosis to determine the pathology of the liver and to monitor the extent of the disease.

  12. Physics of tissue harmonic imaging by ultrasound

    NASA Astrophysics Data System (ADS)

    Jing, Yuan

    Tissue Harmonic Imaging (THI) is an imaging modality that is currently deployed on diagnostic ultrasound scanners. In THI the amplitude of the ultrasonic pulse that is used to probe the tissue is large enough that the pulse undergoes nonlinear distortion as it propagates into the tissue. One result of the distortion is that as the pulse propagates energy is shifted from the fundamental frequency of the source pulse into its higher harmonics. These harmonics will scatter off objects in the tissue and images formed from the scattered higher harmonics are considered to have superior quality to the images formed from the fundamental frequency. Processes that have been suggested as possibly responsible for the improved imaging in THI include: (1) reduced sensitivity to reverberation, (2) reduced sensitivity to aberration, and (3) reduction in side lobes. By using a combination of controlled experiments and numerical simulations, these three reasons have been investigated. A single element transducer and a clinical ultrasound scanner with a phased array transducer were used to image a commercial tissue-mimicking phantom with calibrated targets. The higher image quality achieved with THI was quantified in terms of spatial resolution and "clutter" signals. A three-dimensional model of the forward propagation of nonlinear sound beams in media with arbitrary spatial properties (a generalized KZK equation) was developed. A time-domain code for solving the KZK equation was validated with measurements of the acoustic field generated by the single element transducer and the phased array transducer. The code was used to investigate the impact of aberration using tissue-like media with three-dimensional variations in all acoustic properties. The three-dimensional maps of tissue properties were derived from the datasets available through the Visible Female project. The experiments and simulations demonstrated that second harmonic imaging (1) suffers less clutter associated with reverberation; (2) is not immune to aberration effects and (3) suffers less clutter due to reduced side-lobe levels. The results indicate that side lobe suppression is the most significant reason for the improvement of second harmonic imaging.

  13. Thermal model of local ultrasound heating of biological tissue

    NASA Astrophysics Data System (ADS)

    Nedogovor, V. A.; Sigal, V. L.; Popsuev, E. I.

    1996-09-01

    Possibilities of creation of controlled temperature fields in deep-seated biological tissue with the use of an endocavity ultrasound applicator with surface cooling are considered. Mathematical models are proposed and calculated that make it possible to construct acoustic and thermal fields in biotissues depending on the thermophysical and ultrasound characteristics of the medium being irradiated and to reveal situations and effects that are important for solving problems of practical medicine in the field of local ultrasound hyperthermia and thermotherapy of tissue.

  14. Thermal model of local ultrasound heating of biological tissue

    Microsoft Academic Search

    V. A. Nedogovor; V. L. Sigal; E. I. Popsuev

    1996-01-01

    Possibilities of creation of controlled temperature fields in deep-seated biological tissue with the use of an endocavity ultrasound applicator with surface cooling are considered. Mathematical models are proposed and calculated that make it possible to construct acoustic and thermal fields in biotissues depending on the thermophysical and ultrasound characteristics of the medium being irradiated and to reveal situations and effects

  15. Classification of kidney and liver tissue using ultrasound backscatter data

    NASA Astrophysics Data System (ADS)

    Aalamifar, Fereshteh; Rivaz, Hassan; Cerrolaza, Juan J.; Jago, James; Safdar, Nabile; Boctor, Emad M.; Linguraru, Marius G.

    2015-03-01

    Ultrasound (US) tissue characterization provides valuable information for the initialization of automatic segmentation algorithms, and can further provide complementary information for diagnosis of pathologies. US tissue characterization is challenging due to the presence of various types of image artifacts and dependence on the sonographer's skills. One way of overcoming this challenge is by characterizing images based on the distribution of the backscatter data derived from the interaction between US waves and tissue. The goal of this work is to classify liver versus kidney tissue in 3D volumetric US data using the distribution of backscatter US data recovered from end-user displayed Bmode image available in clinical systems. To this end, we first propose the computation of a large set of features based on the homodyned-K distribution of the speckle as well as the correlation coefficients between small patches in 3D images. We then utilize the random forests framework to select the most important features for classification. Experiments on in-vivo 3D US data from nine pediatric patients with hydronephrosis showed an average accuracy of 94% for the classification of liver and kidney tissues showing a good potential of this work to assist in the classification and segmentation of abdominal soft tissue.

  16. Thermal model of local ultrasound heating of biological tissue

    Microsoft Academic Search

    V. A. Nedogovor; V. L. Sigal; E. I. Popsuev

    1996-01-01

    Possibilities of creation of controlled temperature fields in deep-seated biological tissue with the use of an endocavity\\u000a ultrasound applicator with surface cooling are considered. Mathematical models are proposed and calculated that make it possible\\u000a to construct acoustic and thermal fields in biotissues depending on the thermophysical and ultrasound characteristics of the\\u000a medium being irradiated and to reveal situations and effects

  17. Ultrasound strain imaging for quantification of tissue function: cardiovascular applications

    NASA Astrophysics Data System (ADS)

    de Korte, Chris L.; Lopata, Richard G. P.; Hansen, Hendrik H. G.

    2013-03-01

    With ultrasound imaging, the motion and deformation of tissue can be measured. Tissue can be deformed by applying a force on it and the resulting deformation is a function of its mechanical properties. Quantification of this resulting tissue deformation to assess the mechanical properties of tissue is called elastography. If the tissue under interrogation is actively deforming, the deformation is directly related to its function and quantification of this deformation is normally referred as `strain imaging'. Elastography can be used for atherosclerotic plaques characterization, while the contractility of the heart or skeletal muscles can be assessed with strain imaging. We developed radio frequency (RF) based ultrasound methods to assess the deformation at higher resolution and with higher accuracy than commercial methods using conventional image data (Tissue Doppler Imaging and 2D speckle tracking methods). However, the improvement in accuracy is mainly achieved when measuring strain along the ultrasound beam direction, so 1D. We further extended this method to multiple directions and further improved precision by using compounding of data acquired at multiple beam steered angles. In arteries, the presence of vulnerable plaques may lead to acute events like stroke and myocardial infarction. Consequently, timely detection of these plaques is of great diagnostic value. Non-invasive ultrasound strain compounding is currently being evaluated as a diagnostic tool to identify the vulnerability of plaques. In the heart, we determined the strain locally and at high resolution resulting in a local assessment in contrary to conventional global functional parameters like cardiac output or shortening fraction.

  18. The thresholds and mechanisms of tissue injury by focused ultrasound

    NASA Astrophysics Data System (ADS)

    Simon, Julianna

    Therapeutic ultrasound is used in clinics around the world to treat ailments such as uterine fibroids, kidney stones, and plantar fasciitis. While many of the therapeutic effects of ultrasound are elicited by hyperthermia, bubbles can also interact with tissue to produce beneficial effects. For example, bubbles are used in boiling histotripsy to de-bulk tissue and are used in shock wave lithotripsy to break kidney stones. However, the same bubbles that break the kidney stones also damage the kidney, which is why bubble damage is a concern in every ultrasound application including fetal imaging. Whether the aim is to emulsify a tumor or image a fetus, understanding the thresholds and mechanisms of tissue injury by bubbles in an ultrasound field is important for all ultrasound applications and was the goal of this dissertation. One specific application of therapeutic ultrasound, known as boiling histotripsy, uses shock wave heating to explosively expand a millimeter-size boiling bubble at the transducer focus and fractionate bulk tissue. Yet it was unclear how the millimeter-size boiling or vapor bubble broke down the tissue into its submicron components. In this dissertation, we experimentally tested the hypothesis that ultrasonic atomization, or the emission of fine droplets from an acoustically excited liquid film, is the mechanism by which the millimeter-size boiling bubble in boiling histotripsy fractionates tissue into its submicron components. Using high speed photography, we showed that tissue can behave as a liquid such that a miniature acoustic fountain forms and atomization occurs within a millimeter-size cavity that approximates the boiling or vapor bubble produced by boiling histotripsy. The end result of tissue atomization was a hole in the tissue surface. After showing that tissue can be eroded by atomization, a series of experiments were conducted to determine the tissue properties that influence atomization. The results indicated that highly collagenous tissues such as the liver capsule were difficult to atomize; however it was also shown that surface wetting could be used to enhance atomization by changing the focus of the inverted and reflected ultrasound wave. Finally, the role of bubbles in tissue atomization was investigated using a high static pressure chamber, where it was determined that bubbles are necessary for tissue fractionation. While the investigation into the mechanism of boiling histotripsy was the primary focus of this dissertation, we also established thermal and mechanical injury thresholds for renal tissue injury. This work was driven by the need to determine the safety of a specific therapeutic ultrasound application - renal stone repositioning by ultrasonic propulsion - for FDA approval to begin clinical trials. The end result of this dissertation was an increased understanding of how and at what levels bubbles in an ultrasound field can damage tissue, which is important for developing safe and reliable therapies.

  19. Ultrasonic tissue characterization of prostate biopsy tissues by ultrasound speed microscope

    Microsoft Academic Search

    Hideki Tanoue; Yoshihiro Hagiwara; Kazuto Kobayashi; Yoshifumi Saijo

    2011-01-01

    Ultrasound speed microscope was developed for quantitative measurement of ultrasonic parameters of soft tissues. The system can measure the ultrasonic attenuation and sound speed in the tissue using fast Fourier transform of a single pulsed wave instead of burst waves used in conventional acoustic microscopy. Prostate biopsy tissues were formalin-fixed and sectioned approximately 5–6 ?m in thickness. They were mounted

  20. Therapeutic Ultrasound Enhancement of Drug Delivery to Soft Tissues

    NASA Astrophysics Data System (ADS)

    Lewis, George; Wang, Peng; Lewis, George; Olbricht, William

    2009-04-01

    Effects of exposure to 1.58 MHz focused ultrasound on transport of Evans Blue Dye (EBD) in soft tissues are investigated when an external pressure gradient is applied to induce convective flow through the tissue. The magnitude of the external pressure gradient is chosen to simulate conditions in brain parenchyma during convection-enhanced drug delivery (CED) to the brain. EBD uptake and transport are measured in equine brain, avian muscle and agarose brain-mimicking phantoms. Results show that ultrasound enhances EBD uptake and transport, and the greatest enhancement occurs when the external pressure gradient is applied. The results suggest that exposure of the brain parenchyma to ultrasound could enhance penetration of material infused into the brain during CED therapy.

  1. Breast tissue composition and breast density measurements from ultrasound tomography

    NASA Astrophysics Data System (ADS)

    Sak, Mark; Duric, Neb; Boyd, Norman; Littrup, Peter; West, Erik; Li, Cuiping

    2012-03-01

    It is known that breast cancer risk is greater in women with higher breast densities. Currently, breast density is measured using mammographic percent density, defined as the ratio of fibroglandular to total breast area on a two dimensional mammogram. Alternatively, systems that use ultrasound tomography (UST) create tomographic sound speed images of the patient's breast. These volumetric images can be useful as a diagnostic aid because it is also known that sound speed of tissue is proportional to the density of the tissue. The purpose of this work is to expand on the comparisons of the two imaging modalities by introducing new ultrasound tomography measurements that separate and quantify the fatty and dense tissue distributions within the breast. A total of 249 patients were imaged using both imaging modalities. By using k-means clustering, correlations beyond the volume averaged sound speed of the ultrasound images and the mammographic percent density were investigated. Both the ultrasound and mammographic images were separated into dense and fatty regions. Various associations between the global breast properties as well as separate tissue components were found.

  2. Slow light for deep tissue imaging with ultrasound modulation

    PubMed Central

    Zhang, Huiliang; Sabooni, Mahmood; Rippe, Lars; Kim, Chulhong; Kröll, Stefan; Wang, Lihong V.; Hemmer, Philip R.

    2012-01-01

    Slow light has been extensively studied for applications ranging from optical delay lines to single photon quantum storage. Here, we show that the time delay of slow-light significantly improves the performance of the narrowband spectral filters needed to optically detect ultrasound from deep inside highly scattering tissue. We demonstrate this capability with a 9?cm thick tissue phantom, having 10?cm?1 reduced scattering coefficient, and achieve an unprecedented background-free signal. Based on the data, we project real time imaging at video rates in even thicker phantoms and possibly deep enough into real tissue for clinical applications like early cancer detection. PMID:22509069

  3. TissuesTissues TissuesTissues group of similar cell types thatgroup of similar cell types that

    E-print Network

    Cochran-Stafira, D. Liane

    has four basic types of tissue:tissue: EpithelialEpithelial ConnectiveConnective Muscle TissuesTissues­­ Connective TissueConnective Tissue Loosely organized and composed ofLoosely organizedUsually binds organs or tissues to one anotherone another #12;3 TissuesTissues ­­ Connective TissueConnective

  4. Tissue Macrostructure Determination with Swept-Frequency Ultrasound

    Microsoft Academic Search

    R. C. Waag; R. M. Lerner

    1973-01-01

    A general analysis is provided showing how ultrasound may be used to determine the acoustic structure of tissue on a scale corresponding to the wavelengths employed. since the sL3tt-;-d signal amplitude as a function of frequency is related to the Fourier transform of the acoustic impedance ,variations, the scattered signal may be processed to yield structure information. although similar to

  5. Ultrasonic atomization of tissue and its role in tissue fractionation by high intensity focused ultrasound

    PubMed Central

    Simon, Julianna C.; Sapozhnikov, Oleg A.; Khokhlova, Vera A.; Wang, Yak-Nam; Crum, Lawrence A.; Bailey, Michael R.

    2012-01-01

    Atomization and fountain formation is a well-known phenomenon that occurs when a focused ultrasound wave in liquid encounters an air interface. High intensity focused ultrasound (HIFU) has been shown to fractionate tissue into submicron-size fragments in a process termed boiling histotripsy, wherein the focused ultrasound wave superheats the tissue at the focus, producing a millimetre-size boiling or vapour bubble in several milliseconds. Yet the question of how this millimetre-size boiling bubble creates submicron-size tissue fragments remains. The hypothesis of this work is that tissue can behave as a liquid such that it forms a fountain and atomization within the vapour bubble produced in boiling histotripsy. We describe an experiment, in which a 2-MHz HIFU transducer (maximum in situ intensity of 24,000 W/cm2) was aligned with an air-tissue interface meant to simulate the boiling bubble. Atomization and fountain formation were observed with high-speed photography and resulted in tissue erosion. Histological examination of the atomized tissue showed whole and fragmented cells and nuclei. Air-liquid interfaces were also filmed. Our conclusion was that HIFU can fountain and atomize tissue. Although this process does not entirely mimic what was observed in liquids, it does explain many aspects of tissue fractionation in boiling histotripsy. PMID:23159812

  6. Quantitative ultrasound (QUS) assessment of tissue properties for Achilles tendons

    NASA Astrophysics Data System (ADS)

    Du, Yi-Chun; Chen, Yung-Fu; Chen, Pei-Jarn; Lin, Yu-Ching; Chen, Tainsong; Lin, Chii-Jeng

    2007-09-01

    Quantitative ultrasound (QUS) techniques have recently been widely applied for the characterization of tissues. For example, they can be used for the quantification of Achilles tendon properties based on the broadband ultrasound attenuation (BUA) and the speed of sound (SOS) when the ultrasound wave passes through the tissues. This study is to develop an integrated system to investigate the properties of Achilles tendons using QUS images from UBIS 5000 (DMS, Montpellier, France) and B-mode ultrasound images from HDI 5000 (ATL, Ultramark, USA). Subjects including young (32 females and 17 males; mean age: 23.7 ± 2.0) and middle-aged groups (8 female and 8 males; mean age: 47.3 ± 8.5 s) were recruited and tested for this study. Only subjects who did not exercise regularly and had no record of tendon injury were studied. The results show that the BUA is significantly higher for the young group (45.2 ± 1.6 dB MHz-1) than the middle-age group (40.5 ± 1.9 dB MHz-1), while the SOS is significantly lower for the young (1601.9 ± 11.2 ms-1) compared to the middle-aged (1624.1 ± 8.7 m s-1). On the other hand, the thicknesses of Achilles tendons for both groups (young: 4.31 ± 0.23 mm; middle age: 4.24 ± 0.23 mm) are very similar. For one patient who had an Achilles tendon lengthening (ATL) surgery, the thickness of the Achilles tendon increased from 4 mm to 4.33 mm after the surgery. In addition, the BUA increased by about 7.2% while the SOS decreased by about 0.6%. In conclusion, noninvasive ultrasonic assessment of Achilles tendons is useful for assisting clinical diagnosis and for the evaluation of a therapeutic regimen.

  7. Types of muscle tissue (image)

    MedlinePLUS

    ... types of muscle tissue are cardiac, smooth, and skeletal. Cardiac muscle cells are located in the walls of the heart, appear striated, and are under involuntary control. Smooth muscle ... Skeletal muscle fibers occur in muscles which are attached ...

  8. Measuring tissue blood flow using ultrasound modulated diffused light

    NASA Astrophysics Data System (ADS)

    Ron, A.; Racheli, N.; Breskin, I.; Metzger, Y.; Silman, Z.; Kamar, M.; Nini, A.; Shechter, R.; Balberg, M.

    2012-02-01

    We demonstrate the ability of a novel device employing ultrasound modulation of near infrared light (referred as "Ultrasound tagged light" or UTL) to perform non-invasive monitoring of blood flow in the microvascular level in tissue. Monitoring microcirculatory blood flow is critical in clinical situations affecting flow to different organs, such as the brain or the limbs. . However, currently there are no non-invasive devices that measure microcirculatory blood flow in deep tissue continuously. Our prototype device (Ornim Medical, Israel) was used to monitor tissue blood flow on anesthetized swine during controlled manipulations of increased and decreased blood flow. Measurements were done on the calf muscle and forehead of the animal and compared with Laser Doppler (LD). ROC analysis of the sensitivity and specificity for detecting an increase in blood flow on the calf muscle, demonstrated AUC = 0.951 for 23 systemic manipulations of cardiac output by Epinephrine injection, which is comparable to AUC = 0.943 using laser Doppler. Some examples of cerebral blood flow monitoring are presented, along with their individual ROC curves. UTL flowmetry is shown to be effective in detecting changes in cerebral and muscle blood flow in swine, and has merit in clinical applications.

  9. Pulsed-ultrasound tagging of light in living tissues

    NASA Astrophysics Data System (ADS)

    Lev, Aner; Rubanov, E.; Pomerantz, Ami; Sfez, Bruno G.

    2004-07-01

    Ultrasound can be used in order to locally modulate, or tag, light in a turbid medium. This tagging process is made possible due to the extreme sensitivity of laser speckle distribution to minute changes within the medium. This hybrid technique presents several advantages compared to all-optical tomographic techniques, in that the image resolution is fixed by the ultrasound focus diameter. To our best knowledge, only in vitro experiments have been performed, either on tissue-like phantoms or meat. However a strong difference exists between these sample and living tissues. In living tissues, different kind of liquids flow through the capillaries, strongly reducing the sspeckle autocorrelation time. We have performed experiments on both mice and humans, showing that the autocorrelation time is much shorter than what was previously thought. We show however that it is possible to obtain signal with acceptable signal to noise ratio down to a few cm depth. We will also discuss the origin and characteristics of the speckle noise.

  10. DUAL-FOCUS THERAPEUTIC ULTRASOUND TRANSDUCER FOR PRODUCTION OF BROAD TISSUE LESIONS

    PubMed Central

    Jeong, Jong Seob; Cannata, Jonathan M.; Shung, K. Kirk

    2011-01-01

    In noninvasive high-intensity focused ultrasound (HIFU) treatment, formation of a large tissue lesion per sonication is desirable for reducing the overall treatment time. The goal of this study is to show the feasibility of enlarging tissue lesion size with a dual-focus therapeutic ultrasound transducer (DFTUT) by increasing the depth-of-focus (DOF). The proposed transducer consists of a disc- and an annular-type element of different radii of curvatures to produce two focal zones. To increase focal depth and to maintain uniform beamwidth of the elongated DOF, each element transmits ultrasound of a different center frequency: the inner element at a higher frequency for near field focusing and the outer element at a lower frequency for far field focusing. By activating two elements at the same time with a single transmitter capable of generating a dual-frequency mixed signal, the overall DOF of the proposed transducer may be extended considerably. A prototype transducer composed of a 4.1 MHz inner element and a 2.7 MHz outer element was fabricated to obtain preliminary experimental results. The feasibility the proposed technique was demonstrated through sound field, temperature and thermal dose simulations. The performance of the prototype transducer was verified by hydrophone measurements and tissue ablation experiments on a beef liver specimen. When several factors affecting the length and the uniformity of elongated DOF of the DFTUT are optimized, the proposed therapeutic ultrasound transducer design may increase the size of ablated tissues in the axial direction and, thus, decreasing the treatment time for a large volume of malignant tissues especially deep-seated targets. PMID:20870346

  11. CONTRAST-TO-TISSUE RATIO IMPROVEMENT BY TRANSMITTED OPTIMIZED BINARY SIGNAL IN ULTRASOUND PULSE INVERSION IMAGING

    E-print Network

    Paris-Sud XI, Université de

    .6556590 ABSTRACT Ultrasound contrast imaging has provided more accurate medical diagnoses. One of the most used. INTRODUCTION Since the 1960s, medical ultrasound imaging has become an essential tool for clinical diagnosisCONTRAST-TO-TISSUE RATIO IMPROVEMENT BY TRANSMITTED OPTIMIZED BINARY SIGNAL IN ULTRASOUND PULSE

  12. Quantification of freshly-excised human lymph node tissue using high-frequency ultrasound

    E-print Network

    Paris-Sud XI, Université de

    Quantification of freshly-excised human lymph node tissue using high-frequency ultrasound J. Mamoua 2012 Nantes Conference 23-27 April 2012, Nantes, France 3887 #12;Quantitative ultrasound (QUS) methods Introduction Typical B-mode ultrasound images are mostly qualita- tive and simply display relative changes

  13. Optimal conditions for tissue perforation using high intensity focused ultrasound

    NASA Astrophysics Data System (ADS)

    Mochizuki, Takashi; Kihara, Taizo; Ogawa, Kouji; Tanabe, Ryoko; Yosizawa, Shin; Umemura, Shin-ichiro; Kakimoto, Takashi; Yamashita, Hiromasa; Chiba, Toshio

    2012-10-01

    To perforate tissue lying deep part in body, a large size transducer was assembled by combining four spherical-shaped transducers, and the optimal conditions for tissue perforation have studied using ventricle muscle of chicken as a target. The ex vivo experiments showed that ventricle muscle was successfully perforated both when it was exposed to High Intensity Focused Ultrasound (HIFU) directly and when it was exposed to HIFU through atrial muscle layer. Moreover, it was shown that calculated acoustic power distributions are well similar to the perforation patterns, and that the acoustic energy distributes very complexly near the focus. Lastly, perforation on the living rabbit bladder wall was demonstrated as a preliminary in vivo experiment.

  14. 3D Ultrasound to Stereoscopic Camera Registration through an Air-Tissue Boundary

    Microsoft Academic Search

    Michael C. Yip; Troy K. Adebar; Robert Rohling; Septimiu E. Salcudean; Christopher Y. Nguan

    2010-01-01

    \\u000a A novel registration method between 3D ultrasound and stereoscopic cameras is proposed based on tracking a registration tool\\u000a featuring both ultrasound fiducials and optical markers. The registration tool is pressed against an air-tissue boundary where\\u000a it can be seen both in ultrasound and in the camera view. By localizing the fiducials in the ultrasound volume, knowing the\\u000a registration tool geometry,

  15. INVESTIGATION OF INTENSITY THRESHOLDS FOR ULTRASOUND TISSUE EROSION

    PubMed Central

    Xu, Zhen; Fowlkes, J. Brian; Ludomirsky, Achi; Cain, Charles A.

    2009-01-01

    Our previous studies have shown that short intense pulses delivered at certain pulse repetition frequencies (PRF) can achieve localized, clean erosion in soft tissue. In this paper, the intensity thresholds for ultrasound induced erosion and the effects of pulse intensity on erosion characterized by axial erosion rate, perforation area and volume erosion rate were investigated on in vitro porcine atrial wall tissue. Ultrasound pulses with a 3-cycle pulse duration and a 20-kHz PRF were delivered by a 788-kHz single element focused transducer. ISPPA values of 1000 to 9000 W/cm2 were tested. Results show the following: (1) the estimated intensity threshold for generating erosion was at ISPPA of 3220 W/cm2; (2) the axial erosion rate increased with higher intensity at ISPPA ? 5000 W/cm2, while decreased with higher intensity at ISPPA ? 5000 W/cm2; and (3) the perforation area and the volume erosion rate increased with higher intensity. PMID:16344129

  16. Probability of cavitation for single ultrasound pulses applied to tissues and tissue-mimicking materials.

    PubMed

    Maxwell, Adam D; Cain, Charles A; Hall, Timothy L; Fowlkes, J Brian; Xu, Zhen

    2013-03-01

    In this study, the negative pressure values at which inertial cavitation consistently occurs in response to a single, two-cycle, focused ultrasound pulse were measured in several media relevant to cavitation-based ultrasound therapy. The pulse was focused into a chamber containing one of the media, which included liquids, tissue-mimicking materials, and ex vivo canine tissue. Focal waveforms were measured by two separate techniques using a fiber-optic hydrophone. Inertial cavitation was identified by high-speed photography in optically transparent media and an acoustic passive cavitation detector. The probability of cavitation (P(cav)) for a single pulse as a function of peak negative pressure (p(-)) followed a sigmoid curve, with the probability approaching one when the pressure amplitude was sufficient. The statistical threshold (defined as P(cav) = 0.5) was between p(-) = 26 and 30 MPa in all samples with high water content but varied between p(-) = 13.7 and >36 MPa in other media. A model for radial cavitation bubble dynamics was employed to evaluate the behavior of cavitation nuclei at these pressure levels. A single bubble nucleus with an inertial cavitation threshold of p(-) = 28.2 megapascals was estimated to have a 2.5 nm radius in distilled water. These data may be valuable for cavitation-based ultrasound therapy to predict the likelihood of cavitation at various pressure levels and dimensions of cavitation-induced lesions in tissue. PMID:23380152

  17. Probability of cavitation for single ultrasound pulses applied to tissues and tissue-mimicking materials

    PubMed Central

    Maxwell, Adam D.; Cain, Charles A.; Hall, Timothy L.; Fowlkes, J. Brian; Xu, Zhen

    2012-01-01

    In this article, the negative pressure values at which inertial cavitation consistently occurs in response to a single, 2-cycle, focused ultrasound pulse were measured in several media relevant to cavitation-based ultrasound therapy. The pulse was focused into a chamber containing one of the media, which included liquids, tissue-mimicking materials, and ex-vivo canine tissue. Focal waveforms were measured by two separate techniques using a fiber-optic hydrophone. Inertial cavitation was identified by high-speed photography in optically transparent media and an acoustic passive cavitation detector. The probability of cavitation (Pcav) for a single pulse as a function of peak negative pressure (p?) followed a sigmoid curve, with the probability approaching 1 when the pressure amplitude was sufficient. The statistical threshold (defined as Pcav = 0.5) was between p? = 26.0–30.0 MPa in all samples with a high water content, but varied between p? = 13.7 to > 36 MPa for other media. A model for radial cavitation bubble dynamics was employed to evaluate the behavior of cavitation nuclei at these pressure levels. A single bubble nucleus with an inertial cavitation threshold of p? = 28.2 MPa was estimated to have a 2.5 nm radius in distilled water. These data may be valuable for cavitation-based ultrasound therapy to predict the likelihood of cavitation at different pressure levels and dimensions of cavitation-induced lesions in tissue. PMID:23380152

  18. Study of ultrasound stiffness imaging methods using tissue mimicking phantoms.

    PubMed

    Manickam, Kavitha; Machireddy, Ramasubba Reddy; Seshadri, Suresh

    2014-02-01

    A pilot study was carried out to investigate the performance of ultrasound stiffness imaging methods namely Ultrasound Elastography Imaging (UEI) and Acoustic Radiation Force Impulse (ARFI) Imaging. Specifically their potential for characterizing different classes of solid mass lesions was analyzed using agar based tissue mimicking phantoms. Composite tissue mimicking phantom was prepared with embedded inclusions of varying stiffness from 50 kPa to 450 kPa to represent different stages of cancer. Acoustic properties such as sound speed, attenuation coefficient and acoustic impedance were characterized by pulse echo ultrasound test at 5 MHz frequency and they are ranged from (1564 ± 88 to 1671 ± 124 m/s), (0.6915 ± 0.123 to 0.8268 ± 0.755 db cm(-1)MHz(-1)) and (1.61 × 10(6) ± 0.127 to 1.76 × 10(6) ± 0.045 kg m(-2)s(-1)) respectively. The elastic property Young's Modulus of the prepared samples was measured by conducting quasi static uni axial compression test under a strain rate of 0.5mm/min upto 10 % strain, and the values are from 50 kPa to 450 kPa for a variation of agar concentration from 1.7% to 6.6% by weight. The composite phantoms were imaged by Siemens Acuson S2000 (Siemens, Erlangen, Germany) machine using linear array transducer 9L4 at 8 MHz frequency; strain and displacement images were collected by UEI and ARFI. Shear wave velocity 4.43 ± 0.35 m/s was also measured for high modulus contrast (18 dB) inclusion and X.XX m/s was found for all other inclusions. The images were pre processed and parameters such as Contrast Transfer Efficiency and lateral image profile were computed and reported. The results indicate that both ARFI and UEI represent the abnormalities better than conventional US B mode imaging whereas UEI enhances the underlying modulus contrast into improved strain contrast. The results are corroborated with literature and also with clinical patient images. PMID:24083832

  19. Viscoelastic Property Measurement in Thin Tissue Constructs Using Ultrasound

    PubMed Central

    Liu, Dalong; Ebbini, Emad S.

    2010-01-01

    We present a dual-element concave ultrasound transducer system for generating and tracking of localized tissue displacements in thin tissue constructs on rigid substrates. The system is comprised of a highly focused PZT-4 5-MHz acoustic radiation force (ARF) transducer and a confocal 25-MHz polyvinylidene fluoride imaging transducer. This allows for the generation of measurable displacements in tissue samples on rigid substrates with thickness values down to 500 µm. Impulse-like and longer duration sine-modulated ARF pulses are possible with intermittent M-mode data acquisition for displacement tracking. The operations of the ARF and imaging transducers are strictly synchronized using an integrated system for arbitrary waveform generation and data capture with a shared timebase. This allows for virtually jitter-free pulse-echo data well suited for correlation-based speckle tracking. With this technique we could faithfully capture the entire dynamics of the tissue axial deformation at pulse-repetition frequency values up to 10 kHz. Spatio-temporal maps of tissue displacements in response to a variety of modulated ARF beams were produced in tissue-mimicking elastography phantoms on rigid substrates. The frequency response was measured for phantoms with different modulus and thickness values. The frequency response exhibited resonant behavior with the resonance frequency being inversely proportional to the sample thickness. This resonant behavior can be used in obtaining high-contrast imaging using magnitude and phase response to sinusoidally modulated ARF beams. Furthermore, a second order forced harmonic oscillator (FHO) model was shown to capture this resonant behavior. Based on the FHO model, we used the extended Kalman filter (EKF) for tracking the apparent modulus and viscosity of samples subjected to dc and sinusoidally modulated ARF. The results show that the stiffness (apparent modulus) term in the FHO is largely time-invariant and can be estimated robustly using the EKF. On the other hand, the damping (apparent viscosity) is time varying. These findings were confirmed by comparing the magnitude response of the FHO (with parameters obtained using the EKF) with the measured ones for different thin tissue constructs. PMID:18334343

  20. Window-modulated compounding Nakagami imaging for ultrasound tissue characterization.

    PubMed

    Tsui, Po-Hsiang; Ma, Hsiang-Yang; Zhou, Zhuhuang; Ho, Ming-Chih; Lee, Yu-Hsin

    2014-08-01

    Ultrasound Nakagami parametric imaging is a useful tool for tissue characterization. Previous literature has suggested using a square with side lengths corresponding to 3 times the transducer pulse length as the minimum window for constructing the Nakagami image. This criterion does not produce sufficiently smooth images for the Nakagami image to characterize homogeneous tissues. To improve image smoothness, we proposed window-modulated compounding (WMC) Nakagami imaging based on summing and averaging the Nakagami images formed using sliding windows with varying window side lengths from 1 to N times the transducer pulse length in 1 pulse length step. Simulations (the number densities of scatterers: 2-16 scatterers/mm(2)) and experiments on fully developed speckle phantoms (the scatterer diameters: 20-106 ?m) were conducted to suggest an appropriate number of frames N and to evaluate the image smoothness and resolution by analyzing the full width at half maximum (FWHM) of the parameter distribution and the widths of the image autocorrelation function (ACF), respectively. In vivo ultrasound measurements on rat livers without and with cirrhosis were performed to validate the practical performance of the WMC Nakagami image in tissue characterization. The simulation results showed that using a range of N from 7 to 10 as the number of frames for image compounding reduces the estimation error to less than 5%. Based on this criterion, the Nakagami parameter obtained from the WMC Nakagami image increased from 0.45 to 0.95 after increasing the number densities of scatterers from 2 to 16 scatterers/mm(2). The FWHM of the parameter distribution (bins=40) was 13.5±1.4 for the Nakagami image and 9.1±1.43 for the WMC Nakagami image, respectively (p-value<.05). The widths of the ACF for the Nakagami and WMC Nakagami images were 454±5.36 and 458±4.33, respectively (p-value>.05). In the phantom experiments, we also found that the FWHM of the parameter distribution for the WMC Nakagami image was smaller than that of the conventional Nakagami image (p-value<.05), and there was no significant difference of the ACF width between the Nakagami and WMC Nakagami images (p-value>.05). In the animal experiments, the Nakagami parameters obtained from the WMC Nakagami image for normal and cirrhotic rat livers were 0.62±0.08 and 0.92±0.07, respectively (p-value<.05). The results demonstrated that the WMC technique significantly improved the image smoothness of Nakagami imaging without resolution degradation, giving Nakagami model-based imaging the ability to visualize scatterer properties with enhanced image quality. PMID:24835004

  1. Intense focused ultrasound preferentially stimulates subcutaneous and focal neuropathic tissue: preliminary results

    PubMed Central

    McClintic, Abbi M.; Dickey, Trevor C.; Gofeld, Michael; Kliot, Michel; Loeser, John D.; Richebe, Philippe; Mourad, Pierre D.

    2012-01-01

    Objective Potential peripheral sources of pain from subcutaneous tissue can require invasive evocative tests for their localization and assessment. Here we describe studies whose ultimate goal is development of a non-invasive evocative test for subcutaneous, painful tissue. Design We used a rat model of a focal and subcutaneous neuroma to test the hypothesis that intense focused ultrasound can differentiate focal and subcutaneous neuropathic tissue from control tissue. To do so we first applied intense focused ultrasound (2 MHz, with individual pulses of 0.1 seconds in duration) to the rat’s neuroma while the rat was under light anesthesia. We started with low values of intensity which we increased until intense focused ultrasound stimulation caused the rat to reliably flick its paw. We then applied that same intense focused ultrasound protocol to control tissue away from the neuroma and assayed for the rat’s response to that stimulation. Results Intense focused ultrasound of sufficient strength (I_sata of 600 +/? 160 W/cm^2) applied to the neuroma caused the rat to flick its paw, while the same intense focused ultrasound applied millimeters to a centimeter away failed to induce a paw flick. Conclusion Successful stimulation of the neuroma by intense focused ultrasound required co-localization of the neuroma and intense focused ultrasound, supporting our hypothesis. PMID:23137045

  2. Developing High-Frequency Quantitative Ultrasound Techniques to Characterize Three-Dimensional Engineered Tissues

    NASA Astrophysics Data System (ADS)

    Mercado, Karla Patricia E.

    Tissue engineering holds great promise for the repair or replacement of native tissues and organs. Further advancements in the fabrication of functional engineered tissues are partly dependent on developing new and improved technologies to monitor the properties of engineered tissues volumetrically, quantitatively, noninvasively, and nondestructively over time. Currently, engineered tissues are evaluated during fabrication using histology, biochemical assays, and direct mechanical tests. However, these techniques destroy tissue samples and, therefore, lack the capability for real-time, longitudinal monitoring. The research reported in this thesis developed nondestructive, noninvasive approaches to characterize the structural, biological, and mechanical properties of 3-D engineered tissues using high-frequency quantitative ultrasound and elastography technologies. A quantitative ultrasound technique, using a system-independent parameter known as the integrated backscatter coefficient (IBC), was employed to visualize and quantify structural properties of engineered tissues. Specifically, the IBC was demonstrated to estimate cell concentration and quantitatively detect differences in the microstructure of 3-D collagen hydrogels. Additionally, the feasibility of an ultrasound elastography technique called Single Tracking Location Acoustic Radiation Force Impulse (STL-ARFI) imaging was demonstrated for estimating the shear moduli of 3-D engineered tissues. High-frequency ultrasound techniques can be easily integrated into sterile environments necessary for tissue engineering. Furthermore, these high-frequency quantitative ultrasound techniques can enable noninvasive, volumetric characterization of the structural, biological, and mechanical properties of engineered tissues during fabrication and post-implantation.

  3. Broadband miniature optical ultrasound probe for high resolution vascular tissue imaging.

    PubMed

    Colchester, Richard J; Zhang, Edward Z; Mosse, Charles A; Beard, Paul C; Papakonstantinou, Ioannis; Desjardins, Adrien E

    2015-04-01

    An all-optical ultrasound probe for vascular tissue imaging was developed. Ultrasound was generated by pulsed laser illumination of a functionalized carbon nanotube composite coating on the end face of an optical fiber. Ultrasound was detected with a Fabry-Pérot (FP) cavity on the end face of an adjacent optical fiber. The probe diameter was < 0.84 mm and had an ultrasound bandwidth of ~20 MHz. The probe was translated across the tissue sample to create a virtual linear array of ultrasound transmit/receive elements. At a depth of 3.5 mm, the axial resolution was 64 µm and the lateral resolution was 88 µm, as measured with a carbon fiber target. Vascular tissues from swine were imaged ex vivo and good correspondence to histology was observed. PMID:25909031

  4. Optical and acoustic monitoring of bubble cloud dynamics at a tissue-fluid interface in ultrasound tissue erosion

    PubMed Central

    Xu, Zhen; Hall, Timothy L.; Fowlkes, J. Brian; Cain, Charles A.

    2009-01-01

    Short, high-intensity ultrasound pulses have the ability to achieve localized, clearly demarcated erosion in soft tissue at a tissue-fluid interface. The primary mechanism for ultrasound tissue erosion is believed to be acoustic cavitation. To monitor the cavitating bubble cloud generated at a tissue-fluid interface, an optical attenuation method was used to record the intensity loss of transmitted light through bubbles. Optical attenuation was only detected when a bubble cloud was seen using high speed imaging. The light attenuation signals correlated well with a temporally changing acoustic backscatter which is an excellent indicator for tissue erosion. This correlation provides additional evidence that the cavitating bubble cloud is essential for ultrasound tissue erosion. The bubble cloud collapse cycle and bubble dissolution time were studied using the optical attenuation signals. The collapse cycle of the bubble cloud generated by a high intensity ultrasound pulse of 4–14 ?s was ~40–300 ?s depending on the acoustic parameters. The dissolution time of the residual bubbles was tens of ms long. This study of bubble dynamics may provide further insight into previous ultrasound tissue erosion results. PMID:17471753

  5. Detection of Multiple Electrical Sources in Tissue Using Ultrasound Current Source Density Imaging

    E-print Network

    Witte, Russell S.

    Detection of Multiple Electrical Sources in Tissue Using Ultrasound Current Source Density Imaging disorders. Ultrasound current source density imaging (UCSDI) is a new technique that maps electrical current electrical current and pressure as acoustic waves propagate through a conducting material. In [4] and [5

  6. Ultrasound evidence of altered lumbar connective tissue structure in human subjects with chronic low back pain

    Microsoft Academic Search

    Helene M Langevin; Debbie Stevens-Tuttle; James R Fox; Gary J Badger; Nicole A Bouffard; Martin H Krag; Junru Wu; Sharon M Henry

    2009-01-01

    BACKGROUND: Although the connective tissues forming the fascial planes of the back have been hypothesized to play a role in the pathogenesis of chronic low back pain (LBP), there have been no previous studies quantitatively evaluating connective tissue structure in this condition. The goal of this study was to perform an ultrasound-based comparison of perimuscular connective tissue structure in the

  7. Safety and tissue yield for percutaneous native kidney biopsy according to practitioner and ultrasound technique

    PubMed Central

    2014-01-01

    Background Although percutaneous renal biopsy remains an essential tool in the diagnosis and treatment of renal diseases, in recent times the traditional procedure of nephrologists has been performed by non-nephrologists rather than nephrologists at many institutions. The present study assessed the safety and adequacy of tissue yield during percutaneous renal biopsy according to practitioners and techniques based on ultrasound. Methods This study included 658 native renal biopsies performed from 2005 to 2010 at a single centre. The biopsies were performed by nephrologists or expert ultrasound radiologists using the ultrasound-marked blind or real-time ultrasound-guided techniques. Results A total of 271 ultrasound-marked blind biopsies were performed by nephrologists, 170 real-time ultrasound-guided biopsies were performed by nephrologists, and 217 real-time ultrasound-guided biopsies were performed by radiologists during the study period. No differences in post-biopsy complications such as haematoma, need for transfusion and intervention, gross haematuria, pain, or infection were observed among groups. Glomerular numbers of renal specimens from biopsies performed by nephrologists without reference to any technique were higher than those obtained from real-time ultrasound-guided biopsies performed by expert ultrasound radiologists. Conclusions Percutaneous renal biopsy performed by nephrologists was not inferior to that performed by expert ultrasound radiologists as related to specimen yield and post-biopsy complications. PMID:24957046

  8. Modeling transversely isotropic, viscoelastic, incompressible tissue-like materials with application in ultrasound shear wave elastography

    NASA Astrophysics Data System (ADS)

    Qiang, Bo; Brigham, John C.; Aristizabal, Sara; Greenleaf, James F.; Zhang, Xiaoming; Urban, Matthew W.

    2015-02-01

    In this paper, we propose a method to model the shear wave propagation in transversely isotropic, viscoelastic and incompressible media. The targeted application is ultrasound-based shear wave elastography for viscoelasticity measurements in anisotropic tissues such as the kidney and skeletal muscles. The proposed model predicts that if the viscoelastic parameters both across and along fiber directions can be characterized as a Voigt material, then the spatial phase velocity at any angle is also governed by a Voigt material model. Further, with the aid of Taylor expansions, it is shown that the spatial group velocity at any angle is close to a Voigt type for weakly attenuative materials within a certain bandwidth. The model is implemented in a finite element code by a time domain explicit integration scheme and shear wave simulations are conducted. The results of the simulations are analyzed to extract the shear wave elasticity and viscosity for both the spatial phase and group velocities. The estimated values match well with theoretical predictions. The proposed theory is further verified by an ex vivo tissue experiment measured in a porcine skeletal muscle by an ultrasound shear wave elastography method. The applicability of the Taylor expansion to analyze the spatial velocities is also discussed. We demonstrate that the approximations from the Taylor expansions are subject to errors when the viscosities across or along the fiber directions are large or the maximum frequency considered is beyond the bandwidth defined by radii of convergence of the Taylor expansions.

  9. Pulmonary ultrasound elastography: a feasibility study with phantoms and ex-vivo tissue

    NASA Astrophysics Data System (ADS)

    Nguyen, Man Minh; Xie, Hua; Paluch, Kamila; Stanton, Douglas; Ramachandran, Bharat

    2013-03-01

    Elastography has become widely used for minimally invasive diagnosis in many tumors as seen with breast, liver and prostate. Among different modalities, ultrasound-based elastography stands out due to its advantages including being safe, real-time, and relatively low-cost. While lung cancer is the leading cause of cancer mortality among both men and women, the use of ultrasound elastography for lung cancer diagnosis has hardly been investigated due to the limitations of ultrasound in air. In this work, we investigate the use of static-compression based endobronchial ultrasound elastography by a 3D trans-oesophageal echocardiography (TEE) transducer for lung cancer diagnosis. A water-filled balloon was designed to 1) improve the visualization of endobronchial ultrasound and 2) to induce compression via pumping motion inside the trachea and bronchiole. In a phantom study, we have successfully generated strain images indicating the stiffness difference between the gelatin background and agar inclusion. A similar strain ratio was confirmed with Philips ultrasound strain-based elastography product. For ex-vivo porcine lung study, different tissue ablation methods including chemical injection, Radio Frequency (RF) ablation, and direct heating were implemented to achieve tumor-mimicking tissue. Stiff ablated lung tissues were obtained and detected with our proposed method. These results suggest the feasibility of pulmonary elastography to differentiate stiff tumor tissue from normal tissue.

  10. Histological and Ultrastructural Effects of Ultrasound-induced Cavitation on Human Skin Adipose Tissue

    PubMed Central

    Li, Alessandro Quattrini; Freschi, Giancarlo; Russo, Giulia Lo

    2013-01-01

    Background: In aesthetic medicine, the most promising techniques for noninvasive body sculpturing purposes are based on ultrasound-induced fat cavitation. Liporeductive ultrasound devices afford clinically relevant subcutaneous fat pad reduction without significant adverse reactions. This study aims at evaluating the histological and ultrastructural changes induced by ultrasound cavitation on the different cell components of human skin. Methods: Control and ultrasound-treated ex vivo abdominal full-thickness skin samples and skin biopsies from patients pretreated with or without ultrasound cavitation were studied histologically, morphometrically, and ultrastructurally to evaluate possible changes in adipocyte size and morphology. Adipocyte apoptosis and triglyceride release were also assayed. Clinical evaluation of the effects of 4 weekly ultrasound vs sham treatments was performed by plicometry. Results: Compared with the sham-treated control samples, ultrasound cavitation induced a statistically significant reduction in the size of the adipocytes (P < 0.001), the appearance of micropores and triglyceride leakage and release in the conditioned medium (P < 0.05 at 15 min), or adipose tissue interstitium, without appreciable changes in microvascular, stromal, and epidermal components and in the number of apoptotic adipocytes. Clinically, the ultrasound treatment caused a significant reduction of abdominal fat. Conclusions: This study further strengthens the current notion that noninvasive transcutaneous ultrasound cavitation is a promising and safe technology for localized reduction of fat and provides experimental evidence for its specific mechanism of action on the adipocytes. PMID:25289235

  11. Modeling and Predicting Tissue Movement and Deformation for High Intensity Focused Ultrasound Therapy

    PubMed Central

    Liao, Xiangyun; Yuan, Zhiyong; Lai, Qianfeng; Guo, Jiaxiang; Zheng, Qi; Yu, Sijiao; Tong, Qianqian; Si, Weixin; Sun, Mingui

    2015-01-01

    Purpose In ultrasound-guided High Intensity Focused Ultrasound (HIFU) therapy, the target tissue (such as a tumor) often moves and/or deforms in response to an external force. This problem creates difficulties in treating patients and can lead to the destruction of normal tissue. In order to solve this problem, we present a novel method to model and predict the movement and deformation of the target tissue during ultrasound-guided HIFU therapy. Methods Our method computationally predicts the position of the target tissue under external force. This prediction allows appropriate adjustments in the focal region during the application of HIFU so that the treatment head is kept aligned with the diseased tissue through the course of therapy. To accomplish this goal, we utilize the cow tissue as the experimental target tissue to collect spatial sequences of ultrasound images using the HIFU equipment. A Geodesic Localized Chan-Vese (GLCV) model is developed to segment the target tissue images. A 3D target tissue model is built based on the segmented results. A versatile particle framework is constructed based on Smoothed Particle Hydrodynamics (SPH) to model the movement and deformation of the target tissue. Further, an iterative parameter estimation algorithm is utilized to determine the essential parameters of the versatile particle framework. Finally, the versatile particle framework with the determined parameters is used to estimate the movement and deformation of the target tissue. Results To validate our method, we compare the predicted contours with the ground truth contours. We found that the lowest, highest and average Dice Similarity Coefficient (DSC) values between predicted and ground truth contours were, respectively, 0.9615, 0.9770 and 0.9697. Conclusion Our experimental result indicates that the proposed method can effectively predict the dynamic contours of the moving and deforming tissue during ultrasound-guided HIFU therapy. PMID:25993644

  12. Tissue characterisation from intravascular ultrasound using texture analysis 

    E-print Network

    Nailon, William H

    Intravascular ultrasound has, over the past decade, significantly changed the clinical diagnosis and therapeutic strategy of coronary and vascular disease assessment, as it not only allows visualisation of the vessel ...

  13. A pilot study using Tissue Velocity Ultrasound Imaging (TVI) to assess muscle activity pattern in patients with chronic trapezius myalgia

    Microsoft Academic Search

    Michael Peolsson; Britt Larsson; Lars-Åke Brodin; Björn Gerdle

    2008-01-01

    BACKGROUND: Different research techniques indicate alterations in muscle tissue and in neuromuscular control of aching muscles in patients with chronic localized pain. Ultrasound can be used for analysis of muscle tissue dynamics in clinical practice. AIM: This study introduces a new muscle tissue sensitive ultrasound technique in order to provide a new methodology for providing a description of local muscle

  14. Registration of 3D ultrasound computer tomography and MRI for evaluation of tissue correspondences

    NASA Astrophysics Data System (ADS)

    Hopp, T.; Dapp, R.; Zapf, M.; Kretzek, E.; Gemmeke, H.; Ruiter, N. V.

    2015-03-01

    3D Ultrasound Computer Tomography (USCT) is a new imaging method for breast cancer diagnosis. In the current state of development it is essential to correlate USCT with a known imaging modality like MRI to evaluate how different tissue types are depicted. Due to different imaging conditions, e.g. with the breast subject to buoyancy in USCT, a direct correlation is demanding. We present a 3D image registration method to reduce positioning differences and allow direct side-by-side comparison of USCT and MRI volumes. It is based on a two-step approach including a buoyancy simulation with a biomechanical model and free form deformations using cubic B-Splines for a surface refinement. Simulation parameters are optimized patient-specifically in a simulated annealing scheme. The method was evaluated with in-vivo datasets resulting in an average registration error below 5mm. Correlating tissue structures can thereby be located in the same or nearby slices in both modalities and three-dimensional non-linear deformations due to the buoyancy are reduced. Image fusion of MRI volumes and USCT sound speed volumes was performed for intuitive display. By applying the registration to data of our first in-vivo study with the KIT 3D USCT, we could correlate several tissue structures in MRI and USCT images and learn how connective tissue, carcinomas and breast implants observed in the MRI are depicted in the USCT imaging modes.

  15. Subtraction procedure for the registration of tissue perfusion with Doppler ultrasound

    Microsoft Academic Search

    A. Büher; U. T. Moser; P. M. Schumacher; T. Pasch; M. Anliker

    1996-01-01

    Tissue perfusion, i.e., in muscles or parenchymatous organs, is of both physiological and pathophysiological interest. The measurement of tissue perfusion is an unsolved problem. The Doppler ultrasound method is well suited to this purpose. However, measurements using this technique may be disturbed by movements or vibrations such as heart motion, muscle trembling or vibration of the subsoil (i.e. the examination

  16. Independent Component Analysis Applied to Ultrasound Speckle Texture Analysis and Tissue Characterization

    Microsoft Academic Search

    Di Lai; Navalgund Rao; Chung-hui Kuo; Shweta Bhatt; Vikram Dogra

    2007-01-01

    Analysis of ultrasound speckle texture will provide us information about the underlying properties of tissue, could find applications in early lesion detection and tissue characterization. Traditional first and second order statistics based approaches ignore the higher order statistics information in the texture. On the other hand, conventional multichannel filtering or multiresolution analysis approaches rely on the predefined analytical bases which

  17. Real-Time Monitoring Of Regional Tissue Elasticity During FUS Focused Ultrasound Therapy Using Harmonic Motion Imaging

    Microsoft Academic Search

    Caroline Maleke; Mathieu Pernot; Elisa Konofagou

    2006-01-01

    The feasibility of the Harmonic Motion Imaging (HMI) technique for simultaneous monitoring and generation of focused ultrasound therapy using two separate focused ultrasound transducer elements has previously been shown. In this study, a new HMI technique is described that images tissue displacement induced by a harmonic radiation force induced using a single focused ultrasound element. First, wave propagation simulation models

  18. Doppler ultrasound for diagnosis of soft tissue sarcoma: efficacy of ultrasound-based screening score

    PubMed Central

    Nagano, Satoshi; Yahiro, Yuhei; Yokouchi, Masahiro; Setoguchi, Takao; Ishidou, Yasuhiro; Sasaki, Hiromi; Shimada, Hirofumi; Kawamura, Ichiro; Komiya, Setsuro

    2015-01-01

    Background. The utility of ultrasound imaging in the screening of soft-part tumours (SPTs) has been reported. We classified SPTs according to their blood flow pattern on Doppler ultrasound and re-evaluated the efficacy of this imaging modality as a screening method. Additionally, we combined Doppler ultrasound with several values to improve the diagnostic efficacy and to establish a new diagnostic tool. Patients and methods. This study included 189 cases of pathologically confirmed SPTs (122 cases of benign disease including SPTs and tumour-like lesions and 67 cases of malignant SPTs). Ultrasound imaging included evaluation of vascularity by colour Doppler. We established a scoring system to more effectively differentiate malignant from benign SPTs (ultrasound-based sarcoma screening [USS] score). Results. The mean scores in the benign and malignant groups were 1.47 ± 0.93 and 3.42 ± 1.30, respectively. Patients with malignant masses showed significantly higher USS scores than did those with benign masses (p < 1 × 10?10). The area under the curve was 0.88 by receiver operating characteristic (ROC) analysis. Based on the cut-off value (3 points) calculated by ROC curve analysis, the sensitivity and specificity for a diagnosis of malignant SPT was 85.1% and 86.9%, respectively. Conclusions. Assessment of vascularity by Doppler ultrasound alone is insufficient for differentiation between benign and malignant SPTs. Preoperative diagnosis of most SPTs is possible by combining our USS score with characteristic clinical and magnetic resonance imaging findings. PMID:26029024

  19. Shearwave Dispersion Ultrasound Vibrometry (SDUV) for Measuring Tissue Elasticity and Viscosity

    PubMed Central

    Chen, Shigao; Urban, Matthew W.; Pislaru, Cristina; Kinnick, Randall; Zheng, Yi; Yao, Aiping; Greenleaf, James F.

    2009-01-01

    Characterization of tissue elasticity (stiffness) and viscosity has important medical applications because these properties are closely related to pathological changes. Quantitative measurement is more suitable than qualitative measurement (i.e., mapping with a relative scale) of tissue viscoelasticity for diagnosis of diffuse diseases where abnormality is not confined to a local region and there is no normal background tissue to provide contrast. Shearwave dispersion ultrasound vibrometry (SDUV) uses shear wave propagation speed measured in tissue at multiple frequencies (typically in the range of hundreds of Hertz) to solve quantitatively for both tissue elasticity and viscosity. A shear wave is stimulated within the tissue by an ultrasound push beam and monitored by a separate ultrasound detect beam. The phase difference of the shear wave between 2 locations along its propagation path is used to calculate shear wave speed within the tissue. In vitro SDUV measurements along and across bovine striated muscle fibers show results of tissue elasticity and viscosity close to literature values. An intermittent pulse sequence is developed to allow one array transducer for both push and detect function. Feasibility of this pulse sequence is demonstrated by in vivo SDUV measurements in swine liver using a dual transducer prototype simulating the operation of a single array transducer. PMID:19213632

  20. Fine-Needle Biopsy: Should This Be the First Choice in Endoscopic Ultrasound-Guided Tissue Acquisition?

    PubMed Central

    2014-01-01

    Endoscopic ultrasound (EUS)-guided tissue acquisition is an indispensable technique for the diagnosis of many diseases of the gastrointestinal tract and adjacent structures. EUS-guided fine-needle aspiration (EUS-FNA) is known for its high accuracy and low complication rate. However, the outcome of EUS-FNA highly depends on several factors such as the location and characteristics of the lesion, endosonographer's experience, technique of sampling and sample preparation, type and size of the needle used, and presence of a cytopathologist for rapid on-site examination. EUS-guided fine-needle biopsy is useful to obtain core tissue samples with relatively fewer passes. Aspiration of core tissue with preserved architecture is beneficial for the diagnosis of certain diseases and the performance of ancillary testing such as tumor molecular profiling. Issues related to needle size, type, and their acquired samples for cytologic and histologic evaluation are discussed here. PMID:25325002

  1. Acoustically accessible window determination for ultrasound mediated treatment of glycogen storage disease type Ia patients

    NASA Astrophysics Data System (ADS)

    Wang, Shutao; Raju, Balasundar I.; Leyvi, Evgeniy; Weinstein, David A.; Seip, Ralf

    2012-10-01

    Glycogen storage disease type Ia (GSDIa) is caused by an inherited single-gene defect resulting in an impaired glycogen to glucose conversion pathway. Targeted ultrasound mediated delivery (USMD) of plasmid DNA (pDNA) to liver in conjunction with microbubbles may provide a potential treatment for GSDIa patients. As the success of USMD treatments is largely dependent on the accessibility of the targeted tissue by the focused ultrasound beam, this study presents a quantitative approach to determine the acoustically accessible liver volume in GSDIa patients. Models of focused ultrasound beam profiles for transducers of varying aperture and focal lengths were applied to abdomen models reconstructed from suitable CT and MRI images. Transducer manipulations (simulating USMD treatment procedures) were implemented via transducer translations and rotations with the intent of targeting and exposing the entire liver to ultrasound. Results indicate that acoustically accessible liver volumes can be as large as 50% of the entire liver volume for GSDIa patients and on average 3 times larger compared to a healthy adult group due to GSDIa patients' increased liver size. Detailed descriptions of the evaluation algorithm, transducer-and abdomen models are presented, together with implications for USMD treatments of GSDIa patients and transducer designs for USMD applications.

  2. MODEL-BASED CORRECTION OF TISSUE COMPRESSION FOR TRACKED ULTRASOUND IN SOFT TISSUE IMAGE-GUIDED SURGERY

    PubMed Central

    Pheiffer, Thomas S.; Thompson, Reid C.; Rucker, Daniel C.; Simpson, Amber L.; Miga, Michael I.

    2014-01-01

    Acquisition of ultrasound data negatively affects image registration accuracy during image-guided therapy because of tissue compression by the probe. We present a novel compression correction method that models sub-surface tissue displacement resulting from application of a tracked probe to the tissue surface. Patient landmarks are first used to register the probe pose to pre-operative imaging. The ultrasound probe geometry is used to provide boundary conditions to a biomechanical model of the tissue. The deformation field solution of the model is inverted to non-rigidly transform the ultrasound images to an estimation of the tissue geometry before compression. Experimental results with gel phantoms indicated that the proposed method reduced the tumor margin modified Hausdorff distance (MHD) from 5.0 ± 1.6 to 1.9 ± 0.6 mm, and reduced tumor centroid alignment error from 7.6 ± 2.6 to 2.0 ± 0.9 mm. The method was applied to a clinical case and reduced the tumor margin MHD error from 5.4 ± 0.1 to 2.6 ± 0.1 mm and the centroid alignment error from 7.2 ± 0.2 to 3.5 ± 0.4 mm. PMID:24412172

  3. Combined chirp coded tissue harmonic and fundamental ultrasound imaging for intravascular ultrasound: 20–60 MHz phantom and ex vivo results

    PubMed Central

    Park, Jinhyoung; Li, Xiang; Zhou, Qifa; Shung, K. Kirk

    2013-01-01

    The application of chirp coded excitation to pulse inversion tissue harmonic imaging can increase signal to noise ratio. On the other hand, the elevation of range side lobe level, caused by leakages of the fundamental signal, has been problematic in mechanical scanners which are still the most prevalent in high frequency intravascular ultrasound imaging. Fundamental chirp coded excitation imaging can achieve range side lobe levels lower than –60 dB with Hanning window, but it yields higher side lobes level than pulse inversion chirp coded tissue harmonic imaging (PI-CTHI). Therefore, in this paper a combined pulse inversion chirp coded tissue harmonic and fundamental imaging mode (CPI-CTHI) is proposed to retain the advantages of both chirp coded harmonic and fundamental imaging modes by demonstrating 20–60 MHz phantom and ex vivo results. A simulation study shows that the range side lobe level of CPI-CTHI is 16 dB lower than PI-CTHI, assuming that the transducer translates incident positions by 50 ?m when two beamlines of pulse inversion pair are acquired. CPI-CTHI is implemented for a proto-typed intravascular ultrasound scanner capable of combined data acquisition in real-time. A wire phantom study shows that CPI-CTHI has a 12 dB lower range side lobe level and a 7 dB higher echo signal to noise ratio than PI-CTHI, while the lateral resolution and side lobe level are 50 ?m finer and –3 dB less than fundamental chirp coded excitation imaging respectively. Ex vivo scanning of a rabbit trachea demonstrates that CPI-CTHI is capable of visualizing blood vessels as small as 200 ?m in diameter with 6 dB better tissue contrast than either PI-CTHI or fundamental chirp coded excitation imaging. These results clearly indicate that CPI-CTHI may enhance tissue contrast with less range side lobe level than PI-CTHI. PMID:22871273

  4. Quasi-static elastography and its application in investigation of focused ultrasound induced tissue lesions

    NASA Astrophysics Data System (ADS)

    Wang, Bin; Ling, Tao; Shen, Yong; Wang, Yan; Zheng, Hairong; Li, Faqi

    2012-10-01

    Monitoring of Focused Ultrasound (FUS) therapy has always been a key factor for a successful therapy. Although B-mode ultrasound has long been used for monitoring FUS therapy, the gray scale changes can not precisely reflect the lesion formation inside the tissue, while MR thermometry is considered to be too expensive. In this study, elastography had been performed using a commercial ultrasound system to investigate lesions produced by FUS irradiation in vitro. Several motion detection algorithms had been performed to improve the motion detection accuracy in the elastography. The effects of different algorithms on the motion detection accuracy were compared. Experimental results on the FUS induced lesion in swine muscle were introduced. The results indicated that lesions induced by small dosage of FUS inside the tissue can be successfully detected, which has a profound clinical meaning for the monitoring of FUS therapy.

  5. HIGH-INTENSITY FOCUSED ULTRASOUND IN THE TREATMENT OF PROSTATIC TISSUE*

    E-print Network

    Illinois at Urbana-Champaign, University of

    !S- patient pilot clinical study was undertaken at Indiana University in the fall of 1992. This pilot studies demonstrated that prostatic tissue could be reliably ablated in the therapy zone. The dosimetry number of human patients with deep-seated brain tumors were treated with focused ultrasound after r

  6. Dynamic morphometric characterization of local connective tissue network structure in humans using ultrasound

    Microsoft Academic Search

    Helene M Langevin; Donna M Rizzo; James R Fox; Gary J Badger; Junru Wu; Elisa E Konofagou; Debbie Stevens-Tuttle; Nicole A Bouffard; Martin H Krag

    2007-01-01

    BACKGROUND: In humans, connective tissue forms a complex, interconnected network throughout the body that may have mechanosensory, regulatory and signaling functions. Understanding these potentially important phenomena requires non-invasive measurements of collagen network structure that can be performed in live animals or humans. The goal of this study was to show that ultrasound can be used to quantify dynamic changes in

  7. Ultrasound screening of periarticular soft tissue abnormality around metal-on-metal bearings.

    PubMed

    Nishii, Takashi; Sakai, Takashi; Takao, Masaki; Yoshikawa, Hideki; Sugano, Nobuhiko

    2012-06-01

    Although metal hypersensitivity or pseudotumors are concerns for metal-on-metal (MoM) bearings, detailed pathologies of patterns, severity, and incidence of periprosthetic soft tissue lesions are incompletely understood. We examined the potential of ultrasound for screening of periarticular soft tissue lesions around MoM bearings. Ultrasound examinations were conducted in 88 hips (79 patients) with MoM hip resurfacings or MoM total hip arthroplasties with a large femoral head. Four qualitative ultrasound patterns were shown, including normal pattern in 69 hips, joint-expansion pattern in 11 hips, cystic pattern in 5 hips, and mass pattern in 3 hips. Hips with the latter 3 abnormal patterns showed significantly higher frequency of clinical symptoms, without significant differences of sex, duration of implantation, head sizes, and cup abduction/anteversion angles, compared with hips with normal pattern. Ultrasound examination provides sensitive screening of soft tissue reactions around MoM bearings and may be useful in monitoring progression and defining treatment for periarticular soft tissue abnormalities. PMID:22047978

  8. In vivo tissue sampling of embryonic resorption sites using ultrasound guided biopsy

    Microsoft Academic Search

    K. Schroeder; B. Drews; K. Roellig; B. R. Menzies; F. Goeritz; T. B. Hildebrandt

    2011-01-01

    In the polytocous European brown hare (Lepus europaeus) more than 23% of all successful implantations undergo embryonic resorption. The objective of the study was to establish a minimally invasive ultrasound guided biopsy technique to collect embryonic resorption tissue in vivo. The sampled material was genetically analysed to determine paternity and the sex of the embryo. Female hares were either mated

  9. Independent component analysis applied to ultrasound speckle texture analysis and tissue characterization.

    PubMed

    Di, Lai; Rao, Navalgund; Kuo, Chung-hui; Bhatt, Shweta; Dogra, Vikram

    2007-01-01

    Analysis of ultrasound speckle texture will provide us information about the underlying properties of tissue, could find applications in early lesion detection and tissue characterization. Traditional first and second order statistics based approaches ignore the higher order statistics information in the texture. On the other hand, conventional multichannel filtering or multiresolution analysis approaches rely on the predefined analytical bases which are not fully adaptive to the data being analyzed. In this paper Independent Component Analysis (ICA), which is based on higher order statistics, is proposed to deal with the ultrasound speckle texture analysis problem. ICA image bases obtained from the training images are applied as a filter bank to the testing images. Then the independent features containing higher order statistics information can be extracted from the marginal distributions of the filtered images. ICA is used here as a dimensionality reduction tool to overcome the difficulty of estimating high dimensional joint density of texture. Support Vector Machine (SVM) is then used as a classifier to classify the tissues. By using the digitally simulated tissues and corresponding B-scan images, we can further correlate the change of tissue microstructure or change of imaging conditions with the change of the ICA feature vectors. Our numerical simulation has shown ICA to be a promising technique for ultrasound speckle texture analysis and tissue characterization compared with some traditional methods such as PCA and Gabor transform. PMID:18003520

  10. Ultrasound-modulated optical tomography in soft biological tissues 

    E-print Network

    Sakadzic, Sava

    2007-09-17

    Optical imaging of soft biological tissues is highly desirable since it is nonionizing and provides sensitive contrast information which enables detection of physiological functions and abnormalities, including potentially early cancer detection...

  11. Controlled tissue emulsification produced by high intensity focused ultrasound shock waves and millisecond boiling

    PubMed Central

    Khokhlova, Tatiana D.; Canney, Michael S.; Khokhlova, Vera A.; Sapozhnikov, Oleg A.; Crum, Lawrence A.; Bailey, Michael R.

    2011-01-01

    In high intensity focused ultrasound (HIFU) applications, tissue may be thermally necrosed by heating, emulsified by cavitation, or, as was recently discovered, emulsified using repetitive millisecond boiling caused by shock wave heating. Here, this last approach was further investigated. Experiments were performed in transparent gels and ex vivo bovine heart tissue using 1, 2, and 3 MHz focused transducers and different pulsing schemes in which the pressure, duty factor, and pulse duration were varied. A previously developed derating procedure to determine in situ shock amplitudes and the time-to-boil was refined. Treatments were monitored using B-mode ultrasound. Both inertial cavitation and boiling were observed during exposures, but emulsification occurred only when shocks and boiling were present. Emulsified lesions without thermal denaturation were produced with shock amplitudes sufficient to induce boiling in less than 20 ms, duty factors of less than 0.02, and pulse lengths shorter than 30 ms. Higher duty factors or longer pulses produced varying degrees of thermal denaturation combined with mechanical emulsification. Larger lesions were obtained using lower ultrasound frequencies. The results show that shock wave heating and millisecond boiling is an effective and reliable way to emulsify tissue while monitoring the treatment with ultrasound. PMID:22088025

  12. Mechanical Model Analysis for Quantitative Evaluation of Liver Fibrosis Based on Ultrasound Tissue Elasticity Imaging

    NASA Astrophysics Data System (ADS)

    Shiina, Tsuyoshi; Maki, Tomonori; Yamakawa, Makoto; Mitake, Tsuyoshi; Kudo, Masatoshi; Fujimoto, Kenji

    2012-07-01

    Precise evaluation of the stage of chronic hepatitis C with respect to fibrosis has become an important issue to prevent the occurrence of cirrhosis and to initiate appropriate therapeutic intervention such as viral eradication using interferon. Ultrasound tissue elasticity imaging, i.e., elastography can visualize tissue hardness/softness, and its clinical usefulness has been studied to detect and evaluate tumors. We have recently reported that the texture of elasticity image changes as fibrosis progresses. To evaluate fibrosis progression quantitatively on the basis of ultrasound tissue elasticity imaging, we introduced a mechanical model of fibrosis progression and simulated the process by which hepatic fibrosis affects elasticity images and compared the results with those clinical data analysis. As a result, it was confirmed that even in diffuse diseases like chronic hepatitis, the patterns of elasticity images are related to fibrous structural changes caused by hepatic disease and can be used to derive features for quantitative evaluation of fibrosis stage.

  13. Mathematical modeling of ultrasound in tissue engineering: From bioreactors to the cellular scale

    NASA Astrophysics Data System (ADS)

    Louw, Tobias M.

    Tissue engineering seeks to provide a means to treat injuries that are beyond the body's natural ability to repair without the issues associated with allografts. Autologous cells are cultured in a bioreactor which controls the cellular environment (including mechanical stimulation) for optimal tissue growth. We investigate ultrasound as an effective means of mechanical stimulation by predicting the ultrasonic field in a bioreactor, as well as ultrasonic bioeffects at the cellular level. The Transfer Matrix Angular Spectrum Approach was found to be the most accurate and computationally efficient bioreactor model. Three critical factors influence experimental results: (1) the diameter of the tissue engineering scaffold greatly affects the ultrasonic field; (2) the position of the ultrasonic transducer and liquid level in the tissue culture well determines the maximum pressure amplitude in the bioreactor, but the pressure can be controlled by measuring the transducer input electrical impedance and manipulating the applied voltage; and (3) the position of pressure nodes are influenced by ultrasonic frequency and liquid level; this will affect the response of cells to applied ultrasound. On the cellular level, it was shown that chondrocytes respond to ultrasound with frequency dependence. A predicted resonance frequency near 5MHz matched experimental results showing maximum expression of load inducible genes at 5MHz. Mechanical stresses are concentrated near the nucleus at resonance, alluding to the possibility that the nucleus may directly sense ultrasonic stimulation. We postulate that ultrasound influences the transport of p-ERK to the nucleus or causes minor chromatin reorganization, leading to the observed frequency dependent gene expression. We linked in vitro ultrasonic stimulation to in vivo mechanical stimulation generated by natural movement. The chondrocyte's response to impact is under-damped, and the cell oscillates with a frequency close to the model predicted resonance. It appears that ultrasound applied close to the cell's resonant frequency effectively recreates the mechanical stimulation experienced by cells during natural movement. Ultrasonic bioreactors may therefore reproduce physiological conditions just as well as more complex bioreactors.

  14. Observation of a cavitation cloud in tissue using correlation between ultrafast ultrasound images.

    PubMed

    Prieur, Fabrice; Zorgani, Ali; Catheline, Stefan; Souchon, Remi; Mestas, Jean-Louis; Lafond, Maxime; Lafon, Cyril

    2015-07-01

    The local application of ultrasound is known to improve drug intake by tumors. Cavitating bubbles are one of the contributing effects. A setup in which two ultrasound transducers are placed confocally is used to generate cavitation in ex vivo tissue. As the transducers emit a series of short excitation bursts, the evolution of the cavitation activity is monitored using an ultrafast ultrasound imaging system. The frame rate of the system is several thousands of images per second, which provides several tens of images between consecutive excitation bursts. Using the correlation between consecutive images for speckle tracking, a decorrelation of the imaging signal appears due to the creation, fast movement, and dissolution of the bubbles in the cavitation cloud. By analyzing this area of decorrelation, the cavitation cloud can be localized and the spatial extent of the cavitation activity characterized. PMID:26168172

  15. Detection of tissue harmonic motion induced by ultrasonic radiation force using pulse-echo ultrasound and kalman filter

    Microsoft Academic Search

    Yi Zheng; Shigao Chen; Wei Tan; Randall Kinnick; James F. Greenleaf

    2007-01-01

    A method using pulse echo ultrasound and the Kalman filter is developed for detecting submicron harmonic motion induced by ultrasonic radiation force. The method estimates the amplitude and phase of the motion at desired locations within a tissue region with high sensitivity. The harmonic motion generated by the ultrasound radiation force is expressed as extremely small oscillatory Doppler frequency shifts

  16. Effects of tissue stiffness, ultrasound frequency, and pressure on histotripsy-induced cavitation bubble behavior

    NASA Astrophysics Data System (ADS)

    Vlaisavljevich, Eli; Lin, Kuang-Wei; Warnez, Matthew T.; Singh, Rahul; Mancia, Lauren; Putnam, Andrew J.; Johnsen, Eric; Cain, Charles; Xu, Zhen

    2015-03-01

    Histotripsy is an ultrasound ablation method that controls cavitation to fractionate soft tissue. In order to effectively fractionate tissue, histotripsy requires cavitation bubbles to rapidly expand from nanometer-sized initial nuclei into bubbles often larger than 50?µm. Using a negative pressure high enough to initiate a bubble cloud and expand bubbles to a sufficient size, histotripsy has been shown capable of completely fractionating soft tissue into acelluar debris resulting in effective tissue removal. Previous work has shown that the histotripsy process is affected by tissue mechanical properties with stiffer tissues showing increased resistance to histotripsy fractionation, which we hypothesize to be caused by impeded bubble expansion in stiffer tissues. In this study, the hypothesis that increases in tissue stiffness cause a reduction in bubble expansion was investigated both theoretically and experimentally. High speed optical imaging was used to capture a series of time delayed images of bubbles produced inside mechanically tunable agarose tissue phantoms using histotripsy pulses produced by 345?kHz, 500?kHz, 1.5?MHz, and 3?MHz histotripsy transducers. The results demonstrated a significant decrease in maximum bubble radius (Rmax) and collapse time (tc) with both increasing Young’s modulus and increasing frequency. Furthermore, results showed that Rmax was not increased by raising the pressure above the intrinsic threshold. Finally, this work demonstrated the potential of using a dual-frequency strategy to modulate the expansion of histotripsy bubbles. Overall, the results of this study improve our understanding of how tissue stiffness and ultrasound parameters affect histotripsy-induced bubble behavior and provide a rational basis to tailor acoustic parameters for treatment of the specific tissues of interest.

  17. Effects of tissue stiffness, ultrasound frequency, and pressure on histotripsy-induced cavitation bubble behavior.

    PubMed

    Vlaisavljevich, Eli; Lin, Kuang-Wei; Warnez, Matthew T; Singh, Rahul; Mancia, Lauren; Putnam, Andrew J; Johnsen, Eric; Cain, Charles; Xu, Zhen

    2015-03-21

    Histotripsy is an ultrasound ablation method that controls cavitation to fractionate soft tissue. In order to effectively fractionate tissue, histotripsy requires cavitation bubbles to rapidly expand from nanometer-sized initial nuclei into bubbles often larger than 50?µm. Using a negative pressure high enough to initiate a bubble cloud and expand bubbles to a sufficient size, histotripsy has been shown capable of completely fractionating soft tissue into acelluar debris resulting in effective tissue removal. Previous work has shown that the histotripsy process is affected by tissue mechanical properties with stiffer tissues showing increased resistance to histotripsy fractionation, which we hypothesize to be caused by impeded bubble expansion in stiffer tissues. In this study, the hypothesis that increases in tissue stiffness cause a reduction in bubble expansion was investigated both theoretically and experimentally. High speed optical imaging was used to capture a series of time delayed images of bubbles produced inside mechanically tunable agarose tissue phantoms using histotripsy pulses produced by 345?kHz, 500?kHz, 1.5?MHz, and 3?MHz histotripsy transducers. The results demonstrated a significant decrease in maximum bubble radius (Rmax) and collapse time (tc) with both increasing Young's modulus and increasing frequency. Furthermore, results showed that Rmax was not increased by raising the pressure above the intrinsic threshold. Finally, this work demonstrated the potential of using a dual-frequency strategy to modulate the expansion of histotripsy bubbles. Overall, the results of this study improve our understanding of how tissue stiffness and ultrasound parameters affect histotripsy-induced bubble behavior and provide a rational basis to tailor acoustic parameters for treatment of the specific tissues of interest. PMID:25715732

  18. Effects of ultrasound frequency and tissue stiffness on the histotripsy intrinsic threshold for cavitation.

    PubMed

    Vlaisavljevich, Eli; Lin, Kuang-Wei; Maxwell, Adam; Warnez, Matthew T; Mancia, Lauren; Singh, Rahul; Putnam, Andrew J; Fowlkes, Brian; Johnsen, Eric; Cain, Charles; Xu, Zhen

    2015-06-01

    Histotripsy is an ultrasound ablation method that depends on the initiation of a cavitation bubble cloud to fractionate soft tissue. Previous work has indicated that a cavitation cloud can be formed by a single pulse with one high-amplitude negative cycle, when the negative pressure amplitude directly exceeds a pressure threshold intrinsic to the medium. We hypothesize that the intrinsic threshold in water-based tissues is determined by the properties of the water inside the tissue, and changes in tissue stiffness or ultrasound frequency will have a minimal impact on the histotripsy intrinsic threshold. To test this hypothesis, the histotripsy intrinsic threshold was investigated both experimentally and theoretically. The probability of cavitation was measured by subjecting tissue phantoms with adjustable mechanical properties and ex vivo tissues to a histotripsy pulse of 1-2 cycles produced by 345-kHz, 500-kHz, 1.5-MHz and 3-MHz histotripsy transducers. Cavitation was detected and characterized by passive cavitation detection and high-speed photography, from which the probability of cavitation was measured versus pressure amplitude. The results revealed that the intrinsic threshold (the negative pressure at which probability = 0.5) is independent of stiffness for Young's moduli (E) <1 MPa, with only a small increase (?2-3 MPa) in the intrinsic threshold for tendon (E = 380 MPa). Additionally, results for all samples revealed only a small increase of ?2-3 MPa when the frequency was increased from 345 kHz to 3 MHz. The intrinsic threshold was measured to be between 24.7 and 30.6 MPa for all samples and frequencies tested in this study. Overall, the results of this study indicate that the intrinsic threshold to initiate a histotripsy bubble cloud is not significantly affected by tissue stiffness or ultrasound frequency in the hundreds of kilohertz to megahertz range. PMID:25766571

  19. Elastography: Imaging the elastic properties of soft tissues with ultrasound

    Microsoft Academic Search

    Jonathan Ophir; S. Kaisar Alam; Brian S. Garra; Faouzi Kallel; Elisa E. Konofagou; Thomas Krouskop; Christopher R. B. Merritt; Raffaella Righetti; Remi Souchon; Seshadri Srinivasan; Tomy Varghese

    2002-01-01

    Elastography is a method that can ultimately generate several new kinds of images, called elastograms. As such, all the properties\\u000a of elastograms are different from the familiar properties of sonograms. While sonograms convey information related to the\\u000a local acoustic backscatter energy from tissue components, elastograms relate to its local strains, Young's moduli or Poisson's\\u000a ratios. In general, these elasticity parameters

  20. Numerical simulation of ultrasound-thermotherapy combining nonlinear wave propagation with broadband soft-tissue absorption.

    PubMed

    Ginter, S

    2000-07-01

    Ultrasound (US) thermotherapy is used to treat tumours, located deep in human tissue, by heat. It features by the application of high intensity focused ultrasound (HIFU), high local temperatures of about 90 degrees C and short treating time of a few seconds. Dosage of the therapy remains a problem. To get it under control, one has to know the heat source, i.e. the amount of absorbed US power, which shows nonlinear influences. Therefore, accurate simulations are essential. In this paper, an improved simulation model is introduced which enables accurate investigations of US thermotherapy. It combines nonlinear US propagation effects, which lead to generation of higher harmonics, with a broadband frequency-power law absorption typical for soft tissue. Only the combination of both provides a reliable calculation of the generated heat. Simulations show the influence of nonlinearities and broadband damping for different source signals on the absorbed US power density distribution. PMID:10950353

  1. Methods for using 3-D ultrasound speckle tracking in biaxial mechanical testing of biological tissue samples.

    PubMed

    Yap, Choon Hwai; Park, Dae Woo; Dutta, Debaditya; Simon, Marc; Kim, Kang

    2015-04-01

    Being multilayered and anisotropic, biological tissues such as cardiac and arterial walls are structurally complex, making the full assessment and understanding of their mechanical behavior challenging. Current standard mechanical testing uses surface markers to track tissue deformations and does not provide deformation data below the surface. In the study described here, we found that combining mechanical testing with 3-D ultrasound speckle tracking could overcome this limitation. Rat myocardium was tested with a biaxial tester and was concurrently scanned with high-frequency ultrasound in three dimensions. The strain energy function was computed from stresses and strains using an iterative non-linear curve-fitting algorithm. Because the strain energy function consists of terms for the base matrix and for embedded fibers, spatially varying fiber orientation was also computed by curve fitting. Using finite-element simulations, we first validated the accuracy of the non-linear curve-fitting algorithm. Next, we compared experimentally measured rat myocardium strain energy function values with those in the literature and found a matching order of magnitude. Finally, we retained samples after the experiments for fiber orientation quantification using histology and found that the results satisfactorily matched those computed in the experiments. We conclude that 3-D ultrasound speckle tracking can be a useful addition to traditional mechanical testing of biological tissues and may provide the benefit of enabling fiber orientation computation. PMID:25616585

  2. Ultrasound

    MedlinePLUS

    ... findings that might indicate an increased risk for Down syndrome A pregnancy ultrasound may also be done in ... weeks of pregnancy to look for signs of Down syndrome or other problems in the developing baby. This ...

  3. Ultrasound

    MedlinePLUS

    ... reflect off body structures. A computer receives the waves and uses them to create a picture. Unlike with an x-ray or CT scan, this test does not use ionizing radiation. The test is done in the ultrasound ...

  4. Coregistered three-dimensional ultrasound and photoacoustic imaging system for ovarian tissue characterization

    PubMed Central

    Aguirre, Andres; Guo, Puyun; Gamelin, John; Yan, Shikui; Sanders, Mary M.; Brewer, Molly; Zhu, Quing

    2009-01-01

    Ovarian cancer has the highest mortality of all gynecologic cancers, with a five-year survival rate of only 30% or less. Current imaging techniques are limited in sensitivity and specificity in detecting early stage ovarian cancer prior to its widespread metastasis. New imaging techniques that can provide functional and molecular contrasts are needed to reduce the high mortality of this disease. One such promising technique is photoacoustic imaging. We develop a 1280-element coregistered 3-D ultrasound and photoacoustic imaging system based on a 1.75-D acoustic array. Volumetric images over a scan range of 80 deg in azimuth and 20 deg in elevation can be achieved in minutes. The system has been used to image normal porcine ovarian tissue. This is an important step toward better understanding of ovarian cancer optical properties obtained with photoacoustic techniques. To the best of our knowledge, such data are not available in the literature. We present characterization measurements of the system and compare coregistered ultrasound and photoacoustic images of ovarian tissue to histological images. The results show excellent coregistration of ultrasound and photoacoustic images. Strong optical absorption from vasculature, especially highly vascularized corpora lutea and low absorption from follicles, is demonstrated. PMID:19895116

  5. High frequency ultrasound measurements of the attenuation and backscatter from biological tissues

    NASA Astrophysics Data System (ADS)

    Maruvada, Subha

    There are now diagnostic ultrasonic imaging devices that operate at very high frequencies (VHF) of 20 MHz and beyond for clinical applications in ophthalmology, dermatology, and vascular surgery. To be able to better interpret these images and to further the development of these devices, knowledge of ultrasonic attenuation and scattering of biological tissues in this high frequency range is crucial. Though currently VHF ultrasound is applied mostly to the eye and skin tissue, in this thesis, VHF experiments were performed on porcine red blood cell suspensions and bovine myocardium, liver, and kidney because these tissues are easy to obtain, are similar in structure to their human counterparts and have been used in ultrasound experiments by many investigators but in a lower frequency range. Attenuation and backscatter coefficients of porcine blood and bovine tissues were measured, respectively, using substitution methods. Unfocused and focused transducers were employed in the experiments and corresponding results were compared. This dissertation presents the results of measurements of acoustic attenuation and backscatter from various biological materials (bovine myocardium, liver, and kidney, and porcine blood) in a wide frequency range (10 to 90 MHz) and compares them to previous lower frequency results. Based on the methods used to calculate the acoustic parameters, the frequency limits of the measurements are also defined.

  6. Quantitative assessment of photoacoustic tomography systems integrating clinical ultrasound transducers using novel tissue-simulating phantoms

    NASA Astrophysics Data System (ADS)

    Vogt, William C.; Jia, Congxian; Wear, Keith A.; Garra, Brian S.; Pfefer, Joshua

    2015-03-01

    Photoacoustic Tomography (PAT) systems based on commercial ultrasound instruments have the benefit of dualmodality imaging, which increases their appeal from a clinical standpoint. However, factors that influence PAT system performance have not been thoroughly investigated and standardized test methods have not been established for image quality evaluation. To address these issues we have adapted phantom-based approaches from ultrasound imaging standards and implemented them to assess a PAT system developed for vascular imaging. Our system comprises a tunable near-infrared pulsed laser and a commercial ultrasound imaging system, including four interchangeable linear array clinical ultrasound transducers with varying center frequencies, acoustic bandwidths and geometries. Phantoms consisted of a customized polyvinyl chloride (PVC) plastisol gel that simulates both optical and acoustic properties of breast tissue. One phantom incorporates a sub-resolution filament array suitable for bimodal ultrasound-photoacoustic imaging, while another contains an array of hemoglobin-filled cylindrical inclusions at various depths. Key performance characteristics were evaluated, including spatial resolution, signal uniformity, contrast, and penetration depth. These characteristics were evaluated at 750 nm at radiant exposures below ANSI safety limits. Effects of transducer properties on imaging performance were evaluated. Axial and lateral resolution ranged from 0.27-0.83 mm and 0.28-1.8 mm, respectively, and penetration depths from 1.9-4.2 cm were achieved. These results demonstrate variation in PAT system performance based on clinical transducer selection, as well as the utility of realistic phantom-based test methods in performing benchtop evaluations of system performance.

  7. Experimental study on low intensity ultrasound and tissue engineering to repair segmental bone defects.

    PubMed

    Ye, Fagang; Xia, Changsuo; Xia, Renyun

    2006-01-01

    In order to evaluate the efficacy of low intensity ultrasound and tissue engineering technique to repair segmental bone defects, the rabbit models of 1.5-cm long rabbit radial segmental osteoperiosteum defects were established and randomly divided into 2 groups. All defects were implanted with the composite of calcium phosphate cement and bone mesenchymal stem cells, and additionally those in experimental group were subjected to low intensity ultrasound exposure, while those in control group to sham exposure. The animals were killed on the postoperative week 4, 8 and 12 respectively, and specimens were harvested. By using radiography and the methods of biomechanics, histomorphology and bone density detection, new bone formation and material degradation were observed. The results showed that with the prolongation of time after operation, serum alkaline phosphatase (AKP) levels in both groups were gradually increased, especially in experimental group, reached the peak at 6th week (experimental group: 1.26 mmol/L; control group: 0.58 mmol/L), suggesting the new bone formation in both two group, but the amount of new bone formation was greater and bone repairing capacity stronger in experimental group than in control group. On the 4th week in experimental group, chondrocytes differentiated into woven bone, and on the 12th week, remodeling of new lamellar bone and absorption of the composite material were observed. The mechanical strength of composite material and new born density in experimental group were significantly higher than in control group, indicating that low intensity ultrasound could not only effectively increase the formation of new bone, but also accelerate the calcification of new bone. It was concluded that low intensity ultrasound could evidently accelerate the healing of bone defects repaired by bone tissue engineering. PMID:17219979

  8. Deep-tissue focal fluorescence imaging with digitally time-reversed ultrasound-encoded light

    PubMed Central

    Wang, Ying Min; Judkewitz, Benjamin; DiMarzio, Charles A.; Yang, Changhuei

    2012-01-01

    Fluorescence imaging is one of the most important research tools in biomedical sciences. However, scattering of light severely impedes imaging of thick biological samples beyond the ballistic regime. Here we directly show focusing and high-resolution fluorescence imaging deep inside biological tissues by digitally time-reversing ultrasound-tagged light with high optical gain (~5×105). We confirm the presence of a time-reversed optical focus along with a diffuse background—a corollary of partial phase conjugation—and develop an approach for dynamic background cancellation. To illustrate the potential of our method, we image complex fluorescent objects and tumour microtissues at an unprecedented depth of 2.5 mm in biological tissues at a lateral resolution of 36 ?m×52 ?m and an axial resolution of 657 ?m. Our results set the stage for a range of deep-tissue imaging applications in biomedical research and medical diagnostics. PMID:22735456

  9. The effect of refraction and assumed speeds of sound in tissue and blood on doppler ultrasound blood velocity measurements

    Microsoft Academic Search

    D. A. Christopher; P. N. Burns; J. W. Hunt; F. S. Foster

    1995-01-01

    The combined effect of three assumptions relating to refraction, the speed of sound in tissue and the speed of sound in blood on the accuracy of Doppler ultrasound blood velocity measurements has been investigated. A theoretical relationship giving the net velocity measurement error introduced by these three assumptions has been derived using a model in which tissue and blood layers

  10. Ultrasound

    MedlinePLUS

    ... couldn't see my baby at my 7 week ultrasound. Why? At the 7th week of pregnancy, your baby is about ½ an ... 1 in 120 pregnancies at 15 to 20 weeks gestation. Most disappear during pregnancy or within several ...

  11. Effects of acoustic parameters on bubble cloud dynamics in ultrasound tissue erosion (histotripsy)

    PubMed Central

    Xu, Zhen; Hall, Timothy L.; Fowlkes, J. Brian; Cain, Charles A.

    2009-01-01

    High intensity pulsed ultrasound can produce significant mechanical tissue fractionation with sharp boundaries (“histotripsy”). At a tissue-fluid interface, histotripsy produces clearly demarcated tissue erosion and the erosion efficiency depends on pulse parameters. Acoustic cavitation is believed to be the primary mechanism for the histotripsy process. To investigate the physical basis of the dependence of tissue erosion on pulse parameters, an optical method was used to monitor the effects of pulse parameters on the cavitating bubble cloud generated by histotripsy pulses at a tissue-water interface. The pulse parameters studied include pulse duration, peak rarefactional pressure, and pulse repetition frequency (PRF). Results show that the duration of growth and collapse (collapse cycle) of the bubble cloud increased with increasing pulse duration, peak rarefactional pressure, and PRF when the next pulse arrived after the collapse of the previous bubble cloud. When the PRF was too high such that the next pulse arrived before the collapse of the previous bubble cloud, only a portion of histotripsy pulses could effectively create and collapse the bubble cloud. The collapse cycle of the bubble cloud also increased with increasing gas concentration. These results may explain previous in vitro results on effects of pulse parameters on tissue erosion. PMID:17614482

  12. Localization of focused-ultrasound beams in a tissue phantom, using remote thermocouple arrays.

    PubMed

    Hariharan, Prasanna; Dibaji, Seyed Ahmad Reza; Banerjee, Rupak K; Nagaraja, Srinidhi; Myers, Matthew R

    2014-12-01

    In focused-ultrasound procedures such as vessel cauterization or clot lysis, targeting accuracy is critical. To investigate the targeting accuracy of the focused-ultrasound systems, tissue phantoms embedded with thermocouples can be employed. This paper describes a method that utilizes an array of thermocouples to localize the focused ultrasound beam. All of the thermocouples are located away from the beam, so that thermocouple artifacts and sensor interference are minimized. Beam propagation and temperature rise in the phantom are simulated numerically, and an optimization routine calculates the beam location that produces the best agreement between the numerical temperature values and those measured with thermocouples. The accuracy of the method was examined as a function of the array characteristics, including the number of thermocouples in the array and their orientation. For exposures with a 3.3-MHz source, the remote-thermocouple technique was able to predict the focal position to within 0.06 mm. Once the focal location is determined using the localization method, temperatures at desired locations (including the focus) can be estimated from remote thermocouple measurements by curve fitting an analytical solution to the heat equation. Temperature increases in the focal plane were predicted to within 5% agreement with measured values using this method. PMID:25474777

  13. Optical measurement of adipose tissue thickness and comparison with ultrasound, magnetic resonance imging, and callipers

    NASA Astrophysics Data System (ADS)

    Geraskin, Dmitri; Boeth, Heide; Kohl-Bareis, Matthias

    2009-07-01

    Near-infrared spectroscopy is used to quantify the subcutaneous adipose tissue thickness (ATT) over five muscle groups (vastus medialis, vastus lateralis, gastrocnemius, ventral forearm and biceps brachii muscle) of healthy volunteers (n=20). The optical lipid signal (OLS) was obtained from the second derivative of broad band attenuation spectra and the lipid absorption peak (?=930 nm). Ultrasound and MR imaging as well as mechanical calliper readings were taken as reference methods. The data show that the OLS is a good predictor for ATT (<16 mm) with absolute and relative errors of <0.8 mm and <24%, respectively. The optical method compares favourably with calliper reading. The finding of a non-linear relationship of optical signal vs. ultrasound is explained by a theoretical two-layer model based on the diffusion approximation for the transport of photons. The crosstalk between the OLS and tissue hemoglobin concentration changes during an incremental cycling exercise was found to be small, indicating the robustness of OLS. Furthermore, the effect of ATT on spatially-resolved spectroscopy measurements is shown to decrease the calculated muscle hemoglobin concentration and to increase oxygen saturation.

  14. FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): Modeling of Nonlinear Propagation in Multi-layer Biological Tissues for Strong Focused Ultrasound

    NASA Astrophysics Data System (ADS)

    Fan, Ting-Bo; Liu, Zhen-Bo; Zhang, Zhe; Zhang, Dong; Gong, Xiu-Fen

    2009-08-01

    A theoretical model of the nonlinear propagation in multi-layered tissues for strong focused ultrasound is proposed. In this model, the spheroidal beam equation (SBE) is utilized to describe the nonlinear sound propagation in each layer tissue, and generalized oblique incidence theory is used to deal with the sound transmission between two layer tissues. Computer simulation is performed on a fat-muscle-liver tissue model under the irradiation of a 1 MHz focused transducer with a large aperture angle of 35°. The results demonstrate that the tissue layer would change the amplitude of sound pressure at the focal region and cause the increase of side petals.

  15. Ultrasound backscatter tensor imaging (BTI): analysis of the spatial coherence of ultrasonic speckle in anisotropic soft tissues.

    PubMed

    Papadacci, Clement; Tanter, Mickael; Pernot, Mathieu; Fink, Mathias

    2014-06-01

    The assessment of fiber architecture is of major interest in the progression of myocardial disease. Recent techniques such as magnetic resonance diffusion tensor imaging (MR-DTI) or ultrasound elastic tensor imaging (ETI) can derive the fiber directions by measuring the anisotropy of water diffusion or tissue elasticity, but these techniques present severe limitations in a clinical setting. In this study, we propose a new technique, backscatter tensor imaging (BTI), which enables determination of the fiber directions in skeletal muscles and myocardial tissues, by measuring the spatial coherence of ultrasonic speckle. We compare the results to ultrasound ETI. Acquisitions were performed using a linear transducer array connected to an ultrasonic scanner mounted on a motorized rotation device with angles from 0° to 355° by 5° increments to image ex vivo bovine skeletal muscle and porcine left ventricular myocardial samples. At each angle, multiple plane waves were transmitted and the backscattered echoes recorded. The coherence factor was measured as the ratio of coherent intensity over incoherent intensity of backscattered echoes. In skeletal muscle, maximal/minimal coherence factor was found for the probe parallel/perpendicular to the fibers. In myocardium, the coherence was assessed across the entire myocardial thickness, and the position of maxima and minima varied transmurally because of the complex fibers distribution. In ETI, the shear wave speed variation with the probe angle was found to follow the coherence variation. Spatial coherence can thus reveal the anisotropy of the ultrasonic speckle in skeletal muscle and myocardium. BTI could be used on any type of ultrasonic scanner with rotating phased-array probes or 2-D matrix probes for noninvasive evaluation of myocardial fibers. PMID:24859662

  16. Ex Vivo characterization of canine liver tissue viscoelasticity after high-intensity focused ultrasound ablation.

    PubMed

    Shahmirzadi, Danial; Hou, Gary Y; Chen, Jiangang; Konofagou, Elisa E

    2014-02-01

    The potential of elasticity imaging to detect high-intensity focused ultrasound (HIFU) lesions on the basis of their distinct biomechanical properties is promising. However, information on the quantitative mechanical properties of the tissue and the optimal intensity at which to determine the best contrast parameters is scarce. In this study, fresh canine livers were ablated using combinations of ISPTA intensities of 5.55, 7.16 and 9.07 kW/cm(2) and durations of 10 and 30 s ex vivo, resulting in six groups of ablated tissues. Biopsy samples were then interrogated using dynamic shear mechanical testing within the range of 0.1-10 Hz to characterize the tissue's post-ablation viscoelastic properties. All mechanical parameters were found to be frequency dependent. Compared with unablated cases, all six groups of ablated tissues had statistically significant higher complex shear modulus and shear viscosity. However, among the ablated groups, both complex shear modulus and shear viscosity were found to monotonically increase in groups 1-4 (5.55 kW/cm(2) for 10 s, 7.16 kW/cm(2) for 10 s, 9.07 kW/cm(2) for 10 s, and 5.55 kW/cm(2) for 30 s, respectively), but to decrease in groups 5 and 6 (7.16 kW/cm(2) for 30 s, and 9.07 kW/cm(2) for 30 s, respectively). For groups 5 and 6, the temperature was expected to exceed the boiling point, and therefore, the decreased stiffening could be due to the compromised integrity of the tissue microstructure. Future studies will entail estimation tissue mechanical properties in vivo and perform real-time monitoring of tissue alterations during ablation. PMID:24315395

  17. Ex Vivo Characterization of Canine Liver Tissue Viscoelasticity Following High Intensity Focused Ultrasound (HIFU) Ablation

    PubMed Central

    Shahmirzadi, Danial; Hou, Gary Y.; Chen, Jiangang; Konofagou, Elisa E.

    2014-01-01

    Elasticity imaging has shown great promise in detecting High Intensity Focused Ultrasound (HIFU) lesions based on their distinct biomechanical properties. However, quantitative mechanical properties of the tissue and the optimal intensity for obtaining the best contrast parameters remain scarce. In this study, fresh canine livers were ablated using combinations of ISPTA intensities of 5.55, 7.16 and 9.07 kW/cm2 and time durations of 10 and 30 s ex vivo; leading to six groups of ablated tissues. Biopsy samples were then interrogated using dynamic shear mechanical testing within the range of 0.1-10 Hz to characterize the post-ablation tissue viscoelastic properties. All mechanical parameters were found to be frequency dependent. Compared to the unablated cases, all six groups of ablated tissues showed statistically-significant higher complex shear modulus and shear viscosity. However, among the ablated groups, both complex shear modulus and shear viscosity were found to monotonically increase in groups 1-4 (5.55 kW/cm2 for 10 s, 7.16 kW/cm2 for 10 s, 9.07 kW/cm2 & 10 s, and 5.55 kW/cm2 & 30 s, respectively), but decrease in groups 5 and 6 (7.16 kW/cm2 for 30 s, and 9.07 kW/cm2 for 30 s, respectively). For groups 5 and 6, the temperature was expected to exceed the boiling point, and therefore, the decreased stiffening could be due to the compromised integrity of the tissue microstructure. Future studies are needed to estimate the tissue mechanical properties in vivo and perform real-time monitoring of tissue alterations during ablation. PMID:24315395

  18. Biomechanics-Based Curvature Estimation for Ultrasound-guided Flexible Needle Steering in Biological Tissues.

    PubMed

    Moreira, Pedro; Misra, Sarthak

    2015-08-01

    Needle-based procedures are commonly performed during minimally invasive surgery for treatment and diagnosis. Accurate needle tip placement is important for the success of the procedures. Misplacement of the needle tip might cause unsuccessful treatment or misdiagnosis. Robot-assisted needle insertion systems have been developed in order to steer flexible bevel-tipped needles. However, current systems depend on the information of maximum needle curvature, which is estimated by performing prior insertions. This work presents a new three-dimensional flexible needle steering system which integrates an optimal steering control, ultrasound-based needle tracking system, needle deflection model, online needle curvature estimation and offline curvature estimation based on biomechanics properties. The online and the offline curvature estimations are used to update the steering control in real time. The system is evaluated by experiments in gelatin phantoms and biological tissues (chicken breast tissues). The average targeting error in gelatin phantoms is 0.42 ± 0.17 mm, and in biological tissues is 1.63 ± 0.29 mm. The system is able to accurately steer a flexible needle in multi-layer phantoms and biological tissues without performing prior insertions to estimate the maximum needle curvature. PMID:25465619

  19. Imaging monitored loosening of dense fibrous tissues using high-intensity pulsed ultrasound.

    PubMed

    Yeh, Chia-Lun; Li, Pai-Chi; Shih, Wen-Pin; Huang, Pei-Shin; Kuo, Po-Ling

    2013-10-01

    Pulsed high-intensity focused ultrasound (HIFU) is proposed as a new alternative treatment for contracture of dense fibrous tissue. It is hypothesized that the pulsed-HIFU can release the contracted tissues by attenuating tensile stiffness along the fiber axis, and that the stiffness reduction can be quantitatively monitored by change of B-mode images. Fresh porcine tendons and ligaments were adapted to an ex vivo model and insonated with pulsed-HIFU for durations ranging from 5 to 30 min. The pulse length was 91 µs with a repetition frequency of 500 Hz, and the peak rarefactional pressure was 6.36 MPa. The corresponding average intensities were kept around 1606 W cm(-2) for ISPPA and 72.3 W cm(-2) for ISPTA. B-mode images of the tissues were acquired before and after pulsed-HIFU exposure, and the changes in speckle intensity and organization were analyzed. The tensile stiffness of the HIFU-exposed tissues along the longitudinal axis was examined using a stretching machine. Histology examinations were performed by optical and transmission electron microscopy. Pulsed-HIFU exposure significantly decreased the tensile stiffness of the ligaments and tendons. The intensity and organization of tissue speckles in the exposed region were also decreased. The speckle changes correlated well with the degree of stiffness alteration. Histology examinations revealed that pulsed-HIFU exposure probably damages tissues via a cavitation-mediated mechanism. Our results suggest that pulsed-HIFU with a low duty factor is a promising tool for developing new treatment strategies for orthopedic disorders. PMID:24018912

  20. In vivo tissue sampling of embryonic resorption sites using ultrasound guided biopsy.

    PubMed

    Schroeder, K; Drews, B; Roellig, K; Menzies, B R; Goeritz, F; Hildebrandt, T B

    2011-09-01

    In the polytocous European brown hare (Lepus europaeus) more than 23% of all successful implantations undergo embryonic resorption. The objective of the study was to establish a minimally invasive ultrasound guided biopsy technique to collect embryonic resorption tissue in vivo. The sampled material was genetically analysed to determine paternity and the sex of the embryo. Female hares were either mated or artificially inseminated and pregnancy was confirmed by ultrasound on day six post ovulation. Subsequent embryonic development was ultrasonographically monitored on a regular basis to detect embryos undergoing resorption. Cell material of the resorption site was collected under ultrasonographic control via transabdominal biopsy of the placenta or aspiration of resorption fluid. To avoid breathing movements during the biopsy, the animals were intubated and a short apnoea was evoked by assisted ventilation. The presence of embryonic cells in the biopsy material was confirmed by microsatellite analysis in 11 of the fluid samples (n = 28) and six of the placental samples (n = 8). The lower success rate in the fluid samples was attributed to the abundance of maternal cells which was confirmed by the analysis of fluid sample smears. Male sex of the embryos undergoing resorption was detected by SRY analysis for ten of the fluid samples and for one of the placental samples. The two biopsy techniques did not have any negative impact on the prenatal development of the healthy siblings nor did it influence the future breeding performance of the females that were biopsied. PMID:21601265

  1. Analysis of cooling effect by blood vessel on temperature rise due to ultrasound radiation in tissue phantom

    NASA Astrophysics Data System (ADS)

    Shimizu, Kazuma; Tsuchiya, Takenobu; Fukasawa, Kota; Hatano, Yuichi; Endoh, Nobuyuki

    2015-07-01

    Ultrasound diagnostic equipment using ultrasound pulse–echo techniques is considered minimally invasive and highly versatile. However, one of the causes of damage due to ultrasound radiation is temperature rise caused by the absorption of sound energy. Therefore, it is very important to estimate the temperature rise caused by the radiation of ultrasound. Sound intensity in a medium is analyzed by the finite-difference time-domain (FDTD) method, and the temperature distribution caused by sound is estimated by the heat conduction equation (HCE) method in this study. Because blood vessels keep the temperature constant in tissues, the cooling effect of blood flow has to be taken into account for the precise estimation of temperature rise in human tissues. In general, it is well known that capillary vessels are mainly responsible for the cooling effect in tissues and their effect can be estimated as a function of bloodstream ratio. In this paper, a preliminary study on the cooling effect by a large vessel is described for the precise estimation of temperature rise. Blood flow in blood vessels is analyzed using the Navier–Stokes equation. To confirm the precision of the numerical analysis, the results of the numerical analysis are compared with the experimental results using a soft tissue phantom.

  2. Hybrid optoacoustic and ultrasound biomicroscopy monitors’ laser-induced tissue modifications and magnetite nanoparticle impregnation

    NASA Astrophysics Data System (ADS)

    Estrada, Héctor; Sobol, Emil; Baum, Olga; Razansky, Daniel

    2014-12-01

    Tissue modification under laser radiation is emerging as one of the advanced applications of lasers in medicine, with treatments ranging from reshaping and regeneration of cartilage to normalization of the intraocular pressure. Laser-induced structural alterations can be studied using conventional microscopic techniques applied to thin specimen. Yet, development of non-invasive imaging methods for deep tissue monitoring of structural alterations under laser radiation is of great importance, especially for attaining efficient feedback during the procedures. We developed a fast scanning biomicroscopy system that can simultaneously deliver both optoacoustic and pulse-echo ultrasound contrast from intact tissues and show that both modalities allow manifesting the laser-induced changes in cartilage and sclera. Furthermore, images of the sclera samples reveal a crater developing around the center of the laser-irradiated spot as well as a certain degree of thickening within the treated zone, presumably due to pore formation. Finally, we were able to observe selective impregnation of magnetite nanoparticles into the cartilage, thus demonstrating a possible contrast enhancement approach for studying specific treatment effects. Overall, the new imaging approach holds promise for development of noninvasive feedback control systems that could guarantee efficacy and safety of laser-based medical procedures.

  3. A Hertzian contact mechanics based formulation to improve ultrasound elastography assessment of uterine cervical tissue stiffness.

    PubMed

    Briggs, Brandi N; Stender, Michael E; Muljadi, Patrick M; Donnelly, Meghan A; Winn, Virginia D; Ferguson, Virginia L

    2015-06-25

    Clinical practice requires improved techniques to assess human cervical tissue properties, especially at the internal os, or orifice, of the uterine cervix. Ultrasound elastography (UE) holds promise for non-invasively monitoring cervical stiffness throughout pregnancy. However, this technique provides qualitative strain images that cannot be linked to a material property (e.g., Young's modulus) without knowledge of the contact pressure under a rounded transvaginal transducer probe and correction for the resulting non-uniform strain dissipation. One technique to standardize elastogram images incorporates a material of known properties and uses one-dimensional, uniaxial Hooke's law to calculate Young's modulus within the compressed material half-space. However, this method does not account for strain dissipation and the strains that evolve in three-dimensional space. We demonstrate that an analytical approach based on 3D Hertzian contact mechanics provides a reasonable first approximation to correct for UE strain dissipation underneath a round transvaginal transducer probe and thus improves UE-derived estimates of tissue modulus. We validate the proposed analytical solution and evaluate sources of error using a finite element model. As compared to 1D uniaxial Hooke's law, the Hertzian contact-based solution yields significantly improved Young's modulus predictions in three homogeneous gelatin tissue phantoms possessing different moduli. We also demonstrate the feasibility of using this technique to image human cervical tissue, where UE-derived moduli estimations for the uterine cervix anterior lip agreed well with published, experimentally obtained values. Overall, UE with an attached reference standard and a Hertzian contact-based correction holds promise for improving quantitative estimates of cervical tissue modulus. PMID:26003483

  4. Adipose tissue lymphocytes: types and roles.

    PubMed

    Caspar-Bauguil, S; Cousin, B; Bour, S; Casteilla, L; Castiella, L; Penicaud, L; Carpéné, C

    2009-12-01

    Besides adipocytes, specialized in lipid handling and involved in energy balance regulation, white adipose tissue (WAT) is mainly composed of other cell types among which lymphocytes represent a non-negligible proportion. Different types of lymphocytes (B, alphabetaT, gammadeltaT, NK and NKT) have been detected in WAT of rodents or humans, and vary in their relative proportion according to the fat pad anatomical location. The lymphocytes found in intra-abdominal, visceral fat pads seem representative of innate immunity, while those present in subcutaneous fat depots are part of adaptive immunity, at least in mice. Both the number and the activity of the different lymphocyte classes, except B lymphocytes, are modified in obesity. Several of these modifications in the relative proportions of the lymphocyte classes depend on the degree of obesity, or on leptin concentration, or even fat depot anatomical location. Recent studies suggest that alterations of lymphocyte number and composition precede the macrophage increase and the enhanced inflammatory state of WAT found in obesity. Lymphocytes express receptors to adipokines while several proinflammatory chemokines are produced in WAT, rendering intricate crosstalk between fat and immune cells. However, the evidences and controversies available so far are in favour of an involvement of lymphocytes in the control of the number of other cells in WAT, either adipocytes or immune cells and of their secretory and metabolic activities. Therefore, immunotherapy deserves to be considered as a promising approach to treat the endocrino-metabolic disorders associated to excessive fat mass development. PMID:20358356

  5. Comparative study of temperature measurements in ex vivo swine muscle and a tissue-mimicking material during high intensity focused ultrasound exposures

    NASA Astrophysics Data System (ADS)

    Maruvada, S.; Liu, Y.; Pritchard, W. F.; Herman, B. A.; Harris, G. R.

    2012-01-01

    Tissue-mimicking materials (TMMs) can provide a convenient, stable, and reproducible means for testing high intensity focused ultrasound (HIFU) devices. When TMMs containing thermal sensors are used to measure ultrasound-induced temperature rise, it is important that measurement results reasonably represent those that occur in biological tissue. Therefore the aim of this paper is to compare the thermal behavior of the TMM under HIFU exposure to that of ex vivo tissue. This was accomplished using both a previously developed TMM and fresh ex vivo swine muscle that were instrumented with bare 50 µm thin wire thermocouples. HIFU at 825 kHz was focused at the thermocouple junction. 30 s exposures of increasing peak negative pressure (1 to 5 MPa) were applied and the temperature profile during and after sonication was recorded. B-mode imaging was used to monitor bubble activity during sonication. If bubble formation was noted during the sonication, the sonication was repeated at the same pressure levels two more times at 20 min intervals. Temperature traces obtained at various pressure levels demonstrated similar types of heating profiles in both the tissue and TMM, the exact nature of which depended on whether bubbles formed during the HIFU exposure. The onset of bubble activity occurred at lower ultrasonic pressures in the TMM, but the basic temperature rise features due to HIFU exposure were essentially the same for both materials.

  6. Metachronous bilateral segmental testicular infarction: multi-parametric ultrasound imaging with grey-scale ultrasound, Doppler ultrasound, contrast-enhanced ultrasound (CEUS) and real-time tissue elastography (RTE).

    PubMed

    Patel, Ketul V; Huang, Dean Y; Sidhu, Paul S

    2014-09-01

    Segmental testicular infarction is a rare cause of acute scrotal pain. The appearances on grey-scale sonography are often indistinguishable from that of a testicular tumour, resulting in unnecessary orchiectomy. We report a case of acute bilateral testicular infarction, of unknown etiology, which was conservatively managed to resolution following a confident diagnosis achieved with the aid of contrast-enhanced ultrasound (CEUS) and real-time tissue elastography (RTE) along with conventional grey-scale and Doppler sonography. The evolving appearances on each of the sonographic modalities are described. We discuss the importance of complementing conventional sonography with CEUS and RTE in order to make a confident diagnosis and avoid unnecessary surgical intervention. PMID:25177399

  7. Intraoperative ultrasound for guidance and tissue shift correction in image-guided neurosurgery.

    PubMed

    Comeau, R M; Sadikot, A F; Fenster, A; Peters, T M

    2000-04-01

    We present a surgical guidance system that incorporates pre-operative image information (e.g., MRI) with intraoperative ultrasound (US) imaging to detect and correct for brain tissue deformation during image-guided neurosurgery (IGNS). Many interactive IGNS implementations employ pre-operative images as a guide to the surgeons throughout the procedure. However, when a craniotomy is involved, tissue movement during a procedure can be a significant source of error in these systems. By incorporating intraoperative US imaging, the target volume can be scanned at any time, and two-dimensional US images may be compared directly to the corresponding slice from the pre-operative image. Homologous points may be mapped from the intraoperative to the pre-operative image space with an accuracy of better than 2 mm, enabling the surgeon to use this information to assess the accuracy of the guidance system along with the progress of the procedure (e.g., extent of lesion removal) at any time during the operation. Anatomical features may be identified on both the pre-operative and intraoperative images and used to generate a deformation map, which can be used to warp the pre-operative image to match the intraoperative US image. System validation is achieved using a deformable multi-modality imaging phantom, and preliminary clinical results are presented. PMID:10798702

  8. Transmural Ultrasound-based Visualization of Patterns of Action Potential Wave Propagation in Cardiac Tissue

    PubMed Central

    Luther, Stefan; Singh, Rupinder; Gilmour, Robert F.

    2010-01-01

    The pattern of action potential propagation during various tachyarrhythmias is strongly suspected to be composed of multiple re-entrant waves, but has never been imaged in detail deep within myocardial tissue. An understanding of the nature and dynamics of these waves is important in the development of appropriate electrical or pharmacological treatments for these pathological conditions. We propose a new imaging modality that uses ultrasound to visualize the patterns of propagation of these waves through the mechanical deformations they induce. The new method would have the distinct advantage of being able to visualize these waves deep within cardiac tissue. In this article, we describe one step that would be necessary in this imaging process—the conversion of these deformations into the action potential induced active stresses that produced them. We demonstrate that, because the active stress induced by an action potential is, to a good approximation, only nonzero along the local fiber direction, the problem in our case is actually overdetermined, allowing us to obtain a complete solution. Use of two- rather than three-dimensional displacement data, noise in these displacements, and/or errors in the measurements of the fiber orientations all produce substantial but acceptable errors in the solution. We conclude that the reconstruction of action potential-induced active stress from the deformation it causes appears possible, and that, therefore, the path is open to the development of the new imaging modality. PMID:20499183

  9. Spectral hole burning for ultrasound-modulated optical tomography of thick tissue.

    PubMed

    Xu, Xiao; Kothapalli, Sri-Rajasekhar; Liu, Honglin; Wang, Lihong V

    2010-01-01

    We apply spectral hole burning (SHB)-aided detection in ultrasound-modulated optical tomography (UOT) to image optical heterogeneities in thick tissue-mimicking phantom samples and chicken breast tissue. The efficiency of SHB is improved by using a Tm(3+):YAG crystal of higher doping concentration (2.0-atomic%) and a double-pass pumping configuration, in which the pump beam is transmitted through the crystal twice to burn a deeper spectral hole with the available optical intensity. With the improved SHB-UOT system, we image absorbing, scattering, and phase objects that are embedded in the middle plane of a 30-mm-thick phantom sample. The imaging resolution was 0.5 mm in the lateral direction, as defined by the focal width of the ultrasonic transducer, and 1.5 mm in the axial direction, as determined by the ultrasonic burst length. We also image two absorbing objects embedded in a 32-mm-thick chicken breast sample. The results suggest that the improved SHB-UOT system is one step closer to the practical optical imaging application in biological and clinical studies. PMID:21198192

  10. High-frequency ultrasound M-mode monitoring of HIFU ablation in cardiac tissue

    NASA Astrophysics Data System (ADS)

    Kumon, R. E.; Gudur, M. S. R.; Zhou, Y.; Deng, C. X.

    2012-10-01

    Effective real-time HIFU lesion detection is important for expanded use of HIFU in interventional electrophysiology (e.g., epicardial ablation of cardiac arrhythmia). The goal of this study was to investigate rapid, high-frequency M-mode ultrasound imaging for monitoring spatiotemporal changes in tissue during HIFU application. The HIFU application (4.33 MHz, 1000 Hz PRF, 50% duty cycle, 1 s exposure, 6100 W/cm2) was perpendicularly applied to porcine cardiac tissue with a high-frequency imaging system (Visualsonics Vevo 770, 55 MHz, 4.5 mm focal distance) confocally aligned. Radiofrequency (RF) M-mode data (1 kHz PRF, 4 s × 7 mm) was acquired before, during, and after HIFU treatment. Gross lesions were compared with M-mode data to correlate lesion and cavity formation. Integrated backscatter, echo-decorrelation parameters, and their cumulative extrema over time were analyzed for automatically identifying lesion width and bubble formation. Cumulative maximum integrated backscatter showed the best results for identifying the final lesion width, and a criterion based on line-to-line decorrelation was proposed for identification of transient bubble activity.

  11. Nonlinear inversion modeling for Ultrasound Computer Tomography: transition from soft to hard tissues imaging

    NASA Astrophysics Data System (ADS)

    Lasaygues, Philippe; Mensah, Serge; Guillermin, Régine; Rouyer, Julien; Franceschini, Emilie

    2012-03-01

    Ultrasound Computer Tomography (UCT) is an imaging technique which has proved effective for soft-tissue (breast, liver,...) characterization. More recently, the use of UCT has been envisaged for bone imaging. In this field, the large variations of impedance distribution (high contrast) require that a finer model of wave propagation be integrated into the reconstruction scheme. Here, the tomographic procedure used is adapted to broadband data acquired in scattering configurations while the heterogeneous objects (Born approximation) are probed by spherical waves. An "elliptical" Fourier transform has been derived to solve the near-field inverse problem. This transform differs from the standard Fourier Transform in that, instead of plane waves, families of harmonic ellipsoidal waves are considered. For soft tissues it is possible to separate the impedance and speed of sound contributions and to reconstruct their cartographies using dedicated near-field Radon transforms. In the case of highly heterogeneous media such as bones, iterative inversion schemes are proposed. The various reconstruction procedures are set against experiments.

  12. Spectroscopic measurement of adipose tissue thickness and comparison with ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Geraskin, Dmitri; Boeth, Heide; Kohl-Bareis, Matthias

    2007-07-01

    Near-infrared spectroscopy (NIRS) is widely applied for applications monitoring skeletal muscle oxygenation. However, this method is obstructed by the subcutaneous adipose tissue thickness (ATT) which might vary between < 1 mm to more than 12 mm. Though diffuse optical imaging can be applied to measure ATT, the objective here is to get this measure from spectroscopic data of a single source-detector distance. For the measurement of the optical lipid signal we used a broad band spatially resolved system (SRS), which is based on measurements of the wavelength dependence of the attenuation A for source detector distances ? between 29 mm and 39 mm. Ultrasound images served as an anatomical reference of the lipid layer. The measurements were taken on 5 different muscle groups of 20 healthy volunteers, each for left and right limbs, e.g. vastus medialis, vastus lateralis and gastrocnemius muscle on the leg and ventral forearm muscles and biceps brachii muscle on the arm. Different analysis strategies were tested for the best calculation of ATT. There is a good non-linear correlation between optical lipid signal and ultrasound data, with an overall error in ATT prediction of about 0.5 mm. This finding is supported experimentally by additional MRI measurements as well as a multi-layer Monte Carlo (MC) model. Based on this data of the ATT thickness, a newly developed algorithm which exploits the wavelength dependence of the slope in attenuation with respect to source-detector distance and MC simulation for these parameters as a function of absorption and scattering coefficients delivers a considerably better fit of reflectance spectra when fitting haemoglobin concentrations. Implications for the monitoring of muscle oxygen saturation are discussed.

  13. 3-D visualization and non-linear tissue classification of breast tumors using ultrasound elastography in vivo.

    PubMed

    Sayed, Ahmed; Layne, Ginger; Abraham, Jame; Mukdadi, Osama M

    2014-07-01

    The goal of the study described here was to introduce new methods for the classification and visualization of human breast tumors using 3-D ultrasound elastography. A tumor's type, shape and size are key features that can help the physician to decide the sort and extent of necessary treatment. In this work, tumor type, being either benign or malignant, was classified non-invasively for nine volunteer patients. The classification was based on estimating four parameters that reflect the tumor's non-linear biomechanical behavior, under multi-compression levels. Tumor prognosis using non-linear elastography was confirmed with biopsy as a gold standard. Three tissue classification parameters were found to be statistically significant with a p-value < 0.05, whereas the fourth non-linear parameter was highly significant, having a p-value < 0.001. Furthermore, each breast tumor's shape and size were estimated in vivo using 3-D elastography, and were enhanced using interactive segmentation. Segmentation with level sets was used to isolate the stiff tumor from the surrounding soft tissue. Segmentation also provided a reliable means to estimate tumors volumes. Four volumetric strains were investigated: the traditional normal axial strain, the first principal strain, von Mises strain and maximum shear strain. It was noted that these strains can provide varying degrees of boundary enhancement to the stiff tumor in the constructed elastograms. The enhanced boundary improved the performance of the segmentation process. In summary, the proposed methods can be employed as a 3-D non-invasive tool for characterization of breast tumors, and may provide early prognosis with minimal pain, as well as diminish the risk of late-stage breast cancer. PMID:24768484

  14. Ultrasound -Assisted Gene Transfer to Adipose Tissue-Derived Stem/Progenitor Cells (ASCs)

    NASA Astrophysics Data System (ADS)

    Miyamoto, Yoshitaka; Ueno, Hitomi; Hokari, Rei; Yuan, Wenji; Kuno, Shuichi; Kakimoto, Takashi; Enosawa, Shin; Negishi, Yoichi; Yoshinaka, Kiyoshi; Matsumoto, Yoichiro; Chiba, Toshio; Hayashi, Shuji

    2011-09-01

    In recent years, multilineage adipose tissue-derived stem cells (ASCs) have become increasingly attractive as a promising source for cell transplantation and regenerative medicine. Particular interest has been expressed in the potential to make tissue stem cells, such as ASCs and marrow stromal cells (MSCs), differentiate by gene transfection. Gene transfection using highly efficient viral vectors such as adeno- and sendai viruses have been developed for this purpose. Sonoporation, or ultrasound (US)-assisted gene transfer, is an alternative gene manipulation technique which employs the creation of a jet stream by ultrasonic microbubble cavitation. Sonoporation using non-viral vectors is expected to be a much safer, although less efficient, tool for prospective clinical gene therapy. In this report, we assessed the efficacy of the sonoporation technique for gene transfer to ASCs. We isolated and cultured adipocyets from mouse adipose tissue. ASCs that have the potential to differentiate with transformation into adipocytes or osteoblasts were obtained. Using the US-assisted system, plasmid DNA containing beta-galactosidase (beta-Gal) and green fluorescent protein (GFP) genes were transferred to the ASCs. For this purpose, a Sonopore 4000 (NEPAGENE Co.) and a Sonazoid (Daiichi Sankyo Co.) instrument were used in combination. ASCs were subjected to US (3.1 MHz, 50% duty cycle, burst rate 2.0 Hz, intensity 1.2 W/cm2, exposure time 30 sec). We observed that the gene was more efficiently transferred with increased concentrations of plasmid DNA (5-150 ?g/mL). However, further optimization of the US parameters is required, as the gene transfer efficiency was still relatively low. In conclusion, we herein demonstrate that a gene can be transferred to ASCs using our US-assisted system. In regenerative medicine, this system might resolve the current issues surrounding the use of viral vectors for gene transfer.

  15. A new nonlinear parameter in the developed strain-to-applied strain of the soft tissues and its application in ultrasound elasticity imaging

    PubMed Central

    Xu, Jingping; Tripathy, Sakya.; Rubin, Jonathan. M.; Stidham, Ryan. W.; Johnson, Laura. A.; Higgins, Peter. D.; Kim, Kang.

    2011-01-01

    Strain developed under quasi-static deformation has been mostly used in ultrasound elasticity imaging (UEI) to determine the stiffness change of tissues. However, the strain measure in UEI is often less sensitive to a subtle change of stiffness. This is particularly true for Crohn’s disease where we have applied strain imaging to the differentiation of acutely inflamed bowel from chronically fibrotic bowel. In this study, a new nonlinear elastic parameter of the soft tissues is proposed to overcome this limit. The purpose of this study is to evaluate the newly proposed method and demonstrate its feasibility in the UEI. A non-linear characteristic of soft tissues over a relatively large dynamic range of strain was investigated. A simplified tissue model based on a finite element (FE) analysis was integrated with a laboratory developed ultrasound radio frequency (RF) signal synthesis program. Two dimensional speckle tracking was applied to this model to simulate the nonlinear behavior of the strain developed in a target inclusion over the applied average strain to the surrounding tissues. A nonlinear empirical equation was formulated and optimized to best match the developed strain-to-applied strain relation obtained from the FE simulation. The proposed nonlinear equation was applied to in vivo measurements and nonlinear parameters were further empirically optimized. For an animal model, acute and chronic inflammatory bowel disease was induced in Lewis rats with trinitrobenzene sulfonic acid (TNBS)-ethanol treatments. After UEI, histopathology and direct mechanical measurements were performed on the excised tissues. The extracted non-linear parameter from the developed strain-to-applied strain relation differentiated the three different tissue types with 1.96 ± 0.12 for normal, 1.50 ± 0.09 for the acutely inflamed, and 1.03 ± 0.08 for the chronically fibrotic tissue. T-tests determined that the non-linear parameters between normal, acutely inflamed and fibrotic tissue types were statistically significantly different (normal/fibrotic (P = 0.0000185), normal/acutely inflamed (P = 0.0013), and fibrotic/acutely inflamed (P = 0.0029)). This technique may provide a sensitive and robust tool to assess subtle stiffness changes in tissues such as in acutely inflamed bowel wall. (E-mail: kangkim@upmc.edu) PMID:22266232

  16. Ex vivo viscoelastic characterization of head and neck tissue abnormalities using ultrasound-stimulated vibro-acoustography (USVA)

    NASA Astrophysics Data System (ADS)

    Maccabi, Ashkan; Garritano, James; Arshi, Armin; Saddik, George; Tajudeen, Bobby A.; St. John, Maie; Grundfest, Warren S.; Taylor, Zachary D.

    2014-03-01

    In the absence of an imaging technique that offers a highly dynamic range detection of malignant tissue intra-operatively, surgeons are often forced to excise excess healthy tissue to ensure clear margins of resection. Techniques that are currently used in the detection of tumor regions include palpation, optical coherence tomography (OCT) elastography, dye injections, and conventional ultrasound to pinpoint the affected area. However, these methods suffer from limitations such as minimal specificity, low contrast, and limited depth of penetration. Lack of specificity and low contrast result in the production of vague disease margins and fail to provide a reliable guidance tool for surgeons. The proposed work presents an alternative diagnostic technique, ultrasound-stimulated vibro-acoustography (USVA), which may potentially provide surgeons with detailed intra-operative imagery characterized by enhanced structural boundaries and well-defined borders based on the viscoelastic properties of tissues. We demonstrate selective imaging using ex vivo tissue samples of head and neck squamous cell carcinoma (HNSCC) with the presence of both malignant and normal areas. Spatially resolved maps of varying acoustic properties were generated and show good contrast between the areas of interest. While the results are promising, determining the precision and sensitivity of the USVA imaging system in identifying boundary regions as well as intensities of ex vivo tissue targets may provide additional information to non-invasively assess confined regions of diseased tissues from healthy areas.

  17. Controlled ultrasound tissue erosion: The role of dynamic interaction between insonation and microbubble activity

    PubMed Central

    Xu, Zhen; Fowlkes, J. Brian; Rothman, Edward D.; Levin, Albert M.; Cain, Charles A.

    2009-01-01

    Previous studies showed that ultrasound can mechanically remove tissue in a localized, controlled manner. Moreover, enhanced acoustic backscatter is highly correlated with the erosion process. “Initiation” and “extinction” of this highly backscattering environment were studied in this paper. The relationship between initiation and erosion, variability of initiation and extinction, and effects of pulse intensity and gas saturation on time to initiation (initiation delay time) were investigated. A 788-kHz single-element transducer was used. Multiple pulses at a 3-cycle pulse duration and a 20-kHz pulse repetition frequency were applied. ISPPA values between 1000 and 9000 W/cm2 and gas saturation ranges of 24%–28%, 39%–49%, and 77%–81% were tested. Results show the following: (1) without initiation, erosion was never observed; (2) initiation and extinction of the highly backscattering environment were stochastic in nature and dependent on acoustic parameters; (3) initiation delay times were shorter with higher intensity and higher gas saturation (e.g., the mean initiation delay time was 66.9 s at ISPPA of 4000 W/cm2 and 3.6 ms at ISPPA of 9000 W/cm2); and (4) once initiated by high-intensity pulses, the highly backscattering environment and erosion can be sustained using a significantly lower intensity than that required to initiate the process. PMID:15704435

  18. Experiences Using a Special Purpose Robot for Focal Ultrasound Based Tissue Ablation

    NASA Astrophysics Data System (ADS)

    Chauhan, S.; Li, J. R.; Mishral, R.; Lim, W. K.; Hacker, A.; Michel, M. S.; Alken, P.; Köhrmann, K. U.

    2005-03-01

    This paper describes implementation, empirical set-up and ex vivo trial results of a non-invasive robotic surgery system, called FUSBOT-BS, to treat tumours/cancers by the use of High Intensity Focused Ultrasound (HIFU). The desired surgical effects of ultrasonic irradiation are decided by a pre-planned delivered dosage and the temporal aspects of wave propagation. The temperature rise in the target site depends upon the exposure conditions. A multiple transducer approach is adopted in this research. Surgical planning and deployment of the probes in a given location and specified trajectory is accomplished using robotic techniques. The test results for ablation were conducted in biological phantoms and in various animal tissues, in vitro, such as fat, muscle, and kidney from lamb, beef and pork. The representative results obtained in these empirical studies are presented, which help to understand dependence of crucial HIFU parameters to decide the treatment planning and surgical protocols. The robotic system achieved an end-point accuracy of ±0.5mm. It is possible to precisely position target lesions and ablate remote target sites of varying shapes and sizes with flexible protocols.

  19. Contrast Enhanced Diagnostic Ultrasound Causes Renal Tissue Damage in a Porcine Model

    PubMed Central

    Miller, Douglas L.; Dou, Chunyan; Wiggins, Roger C.

    2010-01-01

    Objective Glomerular capillary hemorrhage (GCH) has been reported and confirmed as a consequence of contrast-enhanced diagnostic ultrasound (CEDUS) of rat kidney. This study assessed renal tissue injury in the larger porcine model. Methods The right kidneys of anesthetized pigs were imaged in 8 groups of 4 pigs. A Vingmed System Five (General Electric Co. Cincinnati OH) was used at 1.5 MHz in B-mode to intermittently scan the kidney at 4 s intervals. A Sequoia 512 (Acuson, Mountain View CA) was used in the 1.5 MHz Cadence CPS mode with intermittent agent-clearance bursts at 4 s intervals. Kidneys were scanned transabdominally, or after laparotomy through a saline standoff. The Sequoia 512 probe was placed in contact with the kidney for one group. Definity (Lantheus Medical Imaging, N. Billerica, MA) was infused at 4 ?l/kg/min (diluted 33:1 in saline) for 4 min during scanning. Results Blood-filled urinary tubules were evident on the kidney surface for all groups, except for the group with the probe in contact with the kidney. GCH was found by histology in 31.7 % ± 9.8 % of glomeruli in the center of the scan plane for 1.7 MPa transabdominal scanning and 1.5 % ± 2.9 % of glomeruli in sham samples (P<0.05). In addition, hematuria was detected after scanning, and tubular obstruction occurred in some nephrons. Conclusion Renal tissue damage was induced by CEDUS in the porcine model. This result, together with previous studies in rats, support an hypothesis that GCH would occur in humans from similar CEDUS. PMID:20876892

  20. Spatial and temporal-controlled tissue heating on a modified clinical ultrasound scanner for generating mild hyperthermia in tumors.

    PubMed

    Kruse, Dustin E; Lai, Chun-Yen; Stephens, Douglas N; Sutcliffe, Patrick; Paoli, Eric E; Barnes, Stephen H; Ferrara, Katherine W

    2010-01-01

    A new system is presented for generating controlled tissue heating with a clinical ultrasound scanner, and initial in vitro and in vivo results are presented that demonstrate both transient and sustained heating in the mild-hyperthermia range of 37 ( degrees )C-42 ( degrees )C. The system consists of a Siemens Antares ultrasound scanner, a custom dual-frequency three-row transducer array and an external temperature feedback control system. The transducer has two outer rows that operate at 1.5 MHz for tissue heating and a center row that operates at 5 MHz for B-mode imaging to guide the therapy. We compare the field maps obtained using a hydrophone against calculations of the ultrasound beam based on monochromatic and linear assumptions. Using the finite-difference time-domain (FDTD) method, we compare predicted time-dependent thermal profiles to measured profiles for soy tofu as a tissue-mimicking phantom. In vitro results show differential heating of 6 ( degrees )C for chicken breast and tofu. In vivo tests of the system were performed on three mice bearing Met-1 tumors, which is a model of aggressive, metastatic, and highly vascular breast cancer. In superficially implanted tumors, we demonstrate controlled heating to 42 ( degrees )C. We show that the system is able to maintain the temperature to within 0.1 ( degrees )C of the desired temperature both in vitro and in vivo. PMID:20064754

  1. A model for the propagation and scattering of ultrasound in tissue

    Microsoft Academic Search

    1991-01-01

    An inhomogeneous wave equation is derived describing propagation and scattering of ultrasound in an inhomogeneous medium. The scattering term is a function of density and propagation velocity perturbations. The integral solution to the wave equation is combined with a general description of the field from typical transducers used in clinical ultrasound to yield a model for the received pulse-echo pressure

  2. Visualization of multimodal polymer-shelled contrast agents using ultrasound contrast sequences: an experimental study in a tissue mimicking flow phantom

    PubMed Central

    2013-01-01

    Background A multimodal polymer-shelled contrast agent (CA) with target specific potential was recently developed and tested for its acoustic properties in a single element transducer setup. Since the developed polymeric CA has different chemical composition than the commercially available CAs, there is an interest to study its acoustic response when using clinical ultrasound systems. The aim of this study was therefore to investigate the acoustic response by studying the visualization capability and shadowing effect of three polymer-shelled CAs when using optimized sequences for contrast imaging. Methods The acoustic response of three types of the multimodal CA was evaluated in a tissue mimicking flow phantom setup by measuring contrast to tissue ratio (CTR) and acoustic shadowing using five image sequences optimized for contrast imaging. The measurements were performed over a mechanical index (MI) range of 0.2-1.2 at three CA concentrations (106, 105, 104 microbubbles/ml). Results The CTR-values were found to vary with the applied contrast sequence, MI and CA. The highest CTR-values were obtained when a contrast sequence optimized for higher MI imaging was used. At a CA concentration of 106 microbubbles/ml, acoustic shadowing was observed for all contrast sequences and CAs. Conclusions The CAs showed the potential to enhance ultrasound images generated by available contrast sequences. A CA concentration of 106 MBs/ml implies a non-linear relation between MB concentration and image intensity. PMID:23987142

  3. The effect of the shape and size of gold seeds irradiated with ultrasound on the bio-heat transfer in tissue.

    PubMed

    Gkigkitzis, Ioannis; Austerlitz, Carlos; Haranas, Ioannis; Campos, Diana

    2015-01-01

    The aim of this report is to propose a new methodology to treat prostate cancer with macro-rod-shaped gold seeds irradiated with ultrasound and develop a new computational method for temperature and thermal dose control of hyperthermia therapy induced by the proposed procedure. A computer code representation, based on the bio-heat diffusion equation, was developed to calculate the heat deposition and temperature elevation patterns in a gold rod and in the tissue surrounding it as a result of different therapy durations and ultrasound power simulations. The numerical results computed provide quantitative information on the interaction between high-energy ultrasound, gold seeds and biological tissues and can replicate the pattern observed in experimental studies. The effect of differences in shapes and sizes of gold rod targets irradiated with ultrasound is calculated and the heat enhancement and the bio-heat transfer in tissue are analyzed. PMID:25417020

  4. Data Analysis and Tissue Type Assignment for Glioblastoma Multiforme

    PubMed Central

    Li, Yuqian; Pi, Yiming; Liu, Xin; Liu, Yuhan; Van Cauter, Sofie

    2014-01-01

    Glioblastoma multiforme (GBM) is characterized by high infiltration. The interpretation of MRSI data, especially for GBMs, is still challenging. Unsupervised methods based on NMF by Li et al. (2013, NMR in Biomedicine) and Li et al. (2013, IEEE Transactions on Biomedical Engineering) have been proposed for glioma recognition, but the tissue types is still not well interpreted. As an extension of the previous work, a tissue type assignment method is proposed for GBMs based on the analysis of MRSI data and tissue distribution information. The tissue type assignment method uses the values from the distribution maps of all three tissue types to interpret all the information in one new map and color encodes each voxel to indicate the tissue type. Experiments carried out on in vivo MRSI data show the feasibility of the proposed method. This method provides an efficient way for GBM tissue type assignment and helps to display information of MRSI data in a way that is easy to interpret. PMID:24724098

  5. Monitoring tissue inflammation and responses to drug treatments in early stages of mice bone fracture using 50 MHz ultrasound

    PubMed Central

    Chen, Yen-Chu; Lin, Yi-Hsun; Wang, Shyh-Hau; Lin, Shih-Ping; Shung, K. Kirk; Wu, Chia-Ching

    2014-01-01

    Bone fracture induces moderate inflammatory responses that are regulated by cyclooxygenase-2 (COX-2) or 5-lipoxygenase (5-LO) for initiating tissue repair and bone formation. Only a handful of non-invasive techniques focus on monitoring acute inflammation of injured bone currently exists. In the current study, we monitored in vivo inflammation levels during the initial 2 weeks of the inflammatory stage after mouse bone fracture utilizing 50 MHz ultrasound. The acquired ultrasonic images were correlated well with histological examinations. After the bone fracture in the tibia, dynamic changes in the soft tissue at the medial-posterior compartment near the fracture site were monitored by ultrasound on the days of 0, 2, 4, 7, and 14. The corresponding echogenicity increased on the 2nd, 4th, and 7th day, and subsequently declined to basal levels after the 14th day. An increase of cell death was identified by the positive staining of deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) assay and was consistent with ultrasound measurements. The increases of both COX-2 and Leukotriene B4 receptor 1 (BLT1, 5- LO-relative receptor), which are regulators for tissue inflammation, in the immunohistochemistry staining revealed their involvement in bone fracture injury. Monitoring the inflammatory response to various non-steroidal anti-inflammatory drugs (NSAIDs) treatments was investigated by treating injured mice with a daily oral intake of aspirin (Asp), indomethacin (IND), and a selective COX-2 inhibitor (SC-236). The Asp treatment significantly reduced fracture-increased echogenicity (hyperechogenicity, p < 0.05) in ultrasound images as well as inhibited cell death, and expression of COX-2 and BLT1. In contrast, treatment with IND or SC-236 did not reduce the hyperechogenicity, as confirmed by cell death (TUNEL) and expression levels of COX-2 or BLT1. Taken together, the current study reports the feasibility of a noninvasive ultrasound method capable of monitoring post-fracture tissue inflammation that positively correlates with histological findings. Results of this study also suggest that this approach may be further applied to elucidate the underlying mechanisms of inflammatory processes and to develop therapeutic strategies for facilitating fracture healing. PMID:23871514

  6. Monitoring tissue inflammation and responses to drug treatments in early stages of mice bone fracture using 50 MHz ultrasound.

    PubMed

    Chen, Yen-Chu; Lin, Yi-Hsun; Wang, Shyh-Hau; Lin, Shih-Ping; Shung, K Kirk; Wu, Chia-Ching

    2014-01-01

    Bone fracture induces moderate inflammatory responses that are regulated by cyclooxygenase-2 (COX-2) or 5-lipoxygenase (5-LO) for initiating tissue repair and bone formation. Only a handful of non-invasive techniques focus on monitoring acute inflammation of injured bone currently exists. In the current study, we monitored in vivo inflammation levels during the initial 2 weeks of the inflammatory stage after mouse bone fracture utilizing 50 MHz ultrasound. The acquired ultrasonic images were correlated well with histological examinations. After the bone fracture in the tibia, dynamic changes in the soft tissue at the medial-posterior compartment near the fracture site were monitored by ultrasound on the days of 0, 2, 4, 7, and 14. The corresponding echogenicity increased on the 2nd, 4th, and 7th day, and subsequently declined to basal levels after the 14th day. An increase of cell death was identified by the positive staining of deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) assay and was consistent with ultrasound measurements. The increases of both COX-2 and Leukotriene B4 receptor 1 (BLT1, 5-LO-relative receptor), which are regulators for tissue inflammation, in the immunohistochemistry staining revealed their involvement in bone fracture injury. Monitoring the inflammatory response to various non-steroidal anti-inflammatory drugs (NSAIDs) treatments was investigated by treating injured mice with a daily oral intake of aspirin (Asp), indomethacin (IND), and a selective COX-2 inhibitor (SC-236). The Asp treatment significantly reduced fracture-increased echogenicity (hyperechogenicity, p<0.05) in ultrasound images as well as inhibited cell death, and expression of COX-2 and BLT1. In contrast, treatment with IND or SC-236 did not reduce the hyperechogenicity, as confirmed by cell death (TUNEL) and expression levels of COX-2 or BLT1. Taken together, the current study reports the feasibility of a non-invasive ultrasound method capable of monitoring post-fracture tissue inflammation that positively correlates with histological findings. Results of this study also suggest that this approach may be further applied to elucidate the underlying mechanisms of inflammatory processes and to develop therapeutic strategies for facilitating fracture healing. PMID:23871514

  7. Integrated photoacoustic, ultrasound and fluorescence platform for diagnostic medical imaging-proof of concept study with a tissue mimicking phantom

    PubMed Central

    James, Joseph; Murukeshan, Vadakke Matham; Woh, Lye Sun

    2014-01-01

    The structural and molecular heterogeneities of biological tissues demand the interrogation of the samples with multiple energy sources and provide visualization capabilities at varying spatial resolution and depth scales for obtaining complementary diagnostic information. A novel multi-modal imaging approach that uses optical and acoustic energies to perform photoacoustic, ultrasound and fluorescence imaging at multiple resolution scales from the tissue surface and depth is proposed in this paper. The system comprises of two distinct forms of hardware level integration so as to have an integrated imaging system under a single instrumentation set-up. The experimental studies show that the system is capable of mapping high resolution fluorescence signatures from the surface, optical absorption and acoustic heterogeneities along the depth (>2cm) of the tissue at multi-scale resolution (<1µm to <0.5mm). PMID:25071954

  8. Non-invasive Characterization of Polyurethane-based Tissue Constructs in a Rat Abdominal Repair Model Using High Frequency Ultrasound Elasticity Imaging

    PubMed Central

    Yu, Jiao; Takanari, Keisuke; Hong, Yi; Lee, Kee-Won; Amoroso, Nicholas J.; Wang, Yadong; Wagner, William R.; Kim, Kang

    2013-01-01

    The evaluation of candidate materials and designs for soft tissue scaffolds would benefit from the ability to monitor the mechanical remodeling of the implant site without the need for periodic animal sacrifice and explant analysis. Toward this end, the ability of non-invasive ultrasound elasticity imaging (UEI) to assess temporal mechanical property changes in three different types of porous, biodegradable polyurethane scaffolds was evaluated in a rat abdominal wall repair model. The polymers utilized were salt-leached scaffolds of poly(carbonate urethane) urea, poly(ester urethane) urea and poly(ether ester urethane) urea at 85% porosity. A total of 60 scaffolds (20 each type) were implanted in a full thickness muscle wall replacement in the abdomens of 30 rats. The constructs were ultrasonically scanned every 2 weeks and harvested at weeks 4, 8 and 12 for compression testing or histological analysis. UEI demonstrated different temporal stiffness trends among the different scaffold types, while the stiffness of the surrounding native tissue remained unchanged. The changes in average normalized strains developed in the constructs from UEI compared well with the changes of mean compliance from compression tests and histology. The average normalized strains and the compliance for the same sample exhibited a strong linear relationship. The ability of UEI to identify herniation and to characterize the distribution of local tissue in-growth with high resolution was also investigated. In summary, the reported data indicate that UEI may allow tissue engineers to sequentially evaluate the progress of tissue construct mechanical behavior in vivo and in some cases may reduce the need for interim time point animal sacrifice. PMID:23347836

  9. Non-contact, ultrasound-based indentation method for measuring elastic properties of biological tissues using Harmonic Motion Imaging (HMI)

    NASA Astrophysics Data System (ADS)

    Vappou, Jonathan; Hou, Gary Y.; Marquet, Fabrice; Shahmirzadi, Danial; Grondin, Julien; Konofagou, Elisa E.

    2015-04-01

    Noninvasive measurement of mechanical properties of biological tissues in vivo could play a significant role in improving the current understanding of tissue biomechanics. In this study, we propose a method for measuring elastic properties non-invasively by using internal indentation as generated by harmonic motion imaging (HMI). In HMI, an oscillating acoustic radiation force is produced by a focused ultrasound transducer at the focal region, and the resulting displacements are estimated by tracking radiofrequency signals acquired by an imaging transducer. In this study, the focal spot region was modeled as a rigid cylindrical piston that exerts an oscillatory, uniform internal force to the underlying tissue. The HMI elastic modulus EHMI was defined as the ratio of the applied force to the axial strain measured by 1D ultrasound imaging. The accuracy and the precision of the EHMI estimate were assessed both numerically and experimentally in polyacrylamide tissue-mimicking phantoms. Initial feasibility of this method in soft tissues was also shown in canine liver specimens in vitro. Very good correlation and agreement was found between the measured Young’s modulus and the HMI modulus in the numerical study (r2 > 0.99, relative error <10%) and on polyacrylamide gels (r2 = 0.95, relative error <24%). The average HMI modulus on five liver samples was found to EHMI = 2.62? ± ?0.41?kPa, compared to EMechTesting = 4.2? ± ?2.58?kPa measured by rheometry. This study has demonstrated for the first time the initial feasibility of a non-invasive, model-independent method to estimate local elastic properties of biological tissues at a submillimeter scale using an internal indentation-like approach. Ongoing studies include in vitro experiments in a larger number of samples and feasibility testing in in vivo models as well as pathological human specimens.

  10. Development of a Tissue-Mimicking Phantom for Evaluating the Focusing Performance of High Intensity Focused Ultrasound

    SciTech Connect

    Jing Zongyu; Li Faqi; Zou Jiangzhong; Wang Zhibiao [Institute of Ultrasound Engineering in Medicine, Biomedical Engineering Dept., Chongqing University of Medical Sciences, Chongqing 400016 (China)

    2006-05-08

    Objectives: To develop a tissue mimicking phantom which can be used to evaluate the focusing performance of the HIFU transducer, and the phantom should has the same acoustic characteristic and thermotics characteristic as the biological tissue. Materials and methods: The tissue mimicking phantom was made from water, gelatin, fresh biologic tissue Its ultrasonic parameters (attenuation coefficient) of the phantom was measured by the method of radiation pressure, and thermotics parameters of the phantom, including thermal conductivity, specific heat/fusion point et al were tested under the Measurement meter. The HIFU biological effect of the phantom was evaluated under the Model JC focused ultrasound tumor therapeutic system, developed and produced by Chongqing HIFU Technology Co. Ltd (working frequency: 0.7MHz; acoustic power: 200W; focal distance: 135mm; Acoustic focal region: 3x3x25 cubic mm). Results: The self-made phantom is sable, has smooth and glossy appearance, well-distributed construction, and good elasticity. We measured the followed values for acoustic and thermal properties: density 1049{+-}2 kg/m3; attenuation 0.532{+-}0.017 dB/cm (0.8 MHz), 0.612{+-}0.021 dB/cm (1.0 MHz); thermal conductivity 0.76{+-}0.08 W/m/- deg. C; specific heat 3653{+-}143 J/kg- deg. C; fusion point154{+-}8 deg. C. The BFR induced in the phantom after HIFU exposure was stable in its size and appearance. Conclusion: We produced and improved one tissue mimicking phantom successfully which had semblable ultrasound and thermphysical properties like the soft tissue, and can replace the bovine liver to investigate the HIFU biological effect and to detect the focusing performance of the HIFU energy transducer. The research was supported by Chongqing University of Medical Science (CX200320)

  11. Non-contact, ultrasound-based indentation method for measuring elastic properties of biological tissues using harmonic motion imaging (HMI).

    PubMed

    Vappou, Jonathan; Hou, Gary Y; Marquet, Fabrice; Shahmirzadi, Danial; Grondin, Julien; Konofagou, Elisa E

    2015-04-01

    Noninvasive measurement of mechanical properties of biological tissues in vivo could play a significant role in improving the current understanding of tissue biomechanics. In this study, we propose a method for measuring elastic properties non-invasively by using internal indentation as generated by harmonic motion imaging (HMI). In HMI, an oscillating acoustic radiation force is produced by a focused ultrasound transducer at the focal region, and the resulting displacements are estimated by tracking radiofrequency signals acquired by an imaging transducer. In this study, the focal spot region was modeled as a rigid cylindrical piston that exerts an oscillatory, uniform internal force to the underlying tissue. The HMI elastic modulus EHMI was defined as the ratio of the applied force to the axial strain measured by 1D ultrasound imaging. The accuracy and the precision of the EHMI estimate were assessed both numerically and experimentally in polyacrylamide tissue-mimicking phantoms. Initial feasibility of this method in soft tissues was also shown in canine liver specimens in vitro. Very good correlation and agreement was found between the measured Young's modulus and the HMI modulus in the numerical study (r(2) > 0.99, relative error <10%) and on polyacrylamide gels (r(2) = 0.95, relative error <24%). The average HMI modulus on five liver samples was found to EHMI = 2.62? ± ?0.41?kPa, compared to EMechTesting = 4.2? ± ?2.58?kPa measured by rheometry. This study has demonstrated for the first time the initial feasibility of a non-invasive, model-independent method to estimate local elastic properties of biological tissues at a submillimeter scale using an internal indentation-like approach. Ongoing studies include in vitro experiments in a larger number of samples and feasibility testing in in vivo models as well as pathological human specimens. PMID:25776065

  12. Real-Time Assessment of Tissue Hypoxia In Vivo with Combined Photoacoustics and High-Frequency Ultrasound

    PubMed Central

    Gerling, Marco; Zhao, Ying; Nania, Salvatore; Norberg, K. Jessica; Verbeke, Caroline S.; Englert, Benjamin; Kuiper, Raoul V.; Bergström, Åsa; Hassan, Moustapha; Neesse, Albrecht; Löhr, J. Matthias; Heuchel, Rainer L.

    2014-01-01

    Purpose: In preclinical cancer studies, non-invasive functional imaging has become an important tool to assess tumor development and therapeutic effects. Tumor hypoxia is closely associated with tumor aggressiveness and is therefore a key parameter to be monitored. Recently, photoacoustic (PA) imaging with inherently co-registered high-frequency ultrasound (US) has reached preclinical applicability, allowing parallel collection of anatomical and functional information. Dual-wavelength PA imaging can be used to quantify tissue oxygen saturation based on the absorbance spectrum differences between hemoglobin and deoxyhemoglobin. Experimental Design: A new bi-modal PA/US system for small animal imaging was employed to test feasibility and reliability of dual-wavelength PA for measuring relative tissue oxygenation. Murine models of pancreatic and colon cancer were imaged, and differences in tissue oxygenation were compared to immunohistochemistry for hypoxia in the corresponding tissue regions. Results: Functional studies proved feasibility and reliability of oxygenation detection in murine tissue in vivo. Tumor models exhibited different levels of hypoxia in localized regions, which positively correlated with immunohistochemical staining for hypoxia. Contrast-enhanced imaging yielded complementary information on tissue perfusion using the same system. Conclusion: Bimodal PA/US imaging can be utilized to reliably detect hypoxic tumor regions in murine tumor models, thus providing the possibility to collect anatomical and functional information on tumor growth and treatment response live in longitudinal preclinical studies. PMID:24723982

  13. Photoacoustic detection and optical spectroscopy of high-intensity focused ultrasound-induced thermal lesions in biologic tissue

    SciTech Connect

    Alhamami, Mosa; Kolios, Michael C.; Tavakkoli, Jahan, E-mail: jtavakkoli@ryerson.ca [Department of Physics, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3 (Canada)] [Department of Physics, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3 (Canada)

    2014-05-15

    Purpose: The aims of this study are: (a) to investigate the capability of photoacoustic (PA) method in detecting high-intensity focused ultrasound (HIFU) treatments in muscle tissuesin vitro; and (b) to determine the optical properties of HIFU-treated and native tissues in order to assist in the interpretation of the observed contrast in PA detection of HIFU treatments. Methods: A single-element, spherically concaved HIFU transducer with a centre frequency of 1 MHz was utilized to create thermal lesions in chicken breast tissuesin vitro. To investigate the detectability of HIFU treatments photoacoustically, PA detection was performed at 720 and 845 nm on seven HIFU-treated tissue samples. Within each tissue sample, PA signals were acquired from 22 locations equally divided between two regions of interest within two volumes in tissue – a HIFU-treated volume and an untreated volume. Optical spectroscopy was then carried out on 10 HIFU-treated chicken breast specimens in the wavelength range of 500–900 nm, in 1-nm increments, using a spectrophotometer with an integrating sphere attachment. The authors’ optical spectroscopy raw data (total transmittance and diffuse reflectance) were used to obtain the optical absorption and reduced scattering coefficients of HIFU-induced thermal lesions and native tissues by employing the inverse adding-doubling method. The aforementioned interaction coefficients were subsequently used to calculate the effective attenuation coefficient and light penetration depth of HIFU-treated and native tissues in the wavelength range of 500–900 nm. Results: HIFU-treated tissues produced greater PA signals than native tissues at 720 and 845 nm. At 720 nm, the averaged ratio of the peak-to-peak PA signal amplitude of HIFU-treated tissue to that of native tissue was 3.68 ± 0.25 (mean ± standard error of the mean). At 845 nm, the averaged ratio of the peak-to-peak PA signal amplitude of HIFU-treated tissue to that of native tissue was 3.75 ± 0.26 (mean ± standard error of the mean). The authors’ spectroscopic investigation has shown that HIFU-treated tissues have a greater optical absorption and reduced scattering coefficients than native tissues in the wavelength range of 500–900 nm. In fact, at 720 and 845 nm, the ratio of the optical absorption coefficient of HIFU-treated tissues to that of native tissues was 1.13 and 1.17, respectively; on the other hand, the ratio of the reduced scattering coefficient of HIFU-treated tissues to that of native tissues was 13.22 and 14.67 at 720 and 845 nm, respectively. Consequently, HIFU-treated tissues have a higher effective attenuation coefficient and a lower light penetration depth than native tissues in the wavelength range 500–900 nm. Conclusions: Using a PA approach, HIFU-treated tissues interrogated at 720 and 845 nm optical wavelengths can be differentiated from untreated tissues. Based on the authors’ spectroscopic investigation, the authors conclude that the observed PA contrast between HIFU-induced thermal lesions and untreated tissue is due, in part, to the increase in the optical absorption coefficient, the reduced scattering coefficient and, therefore, the deposited laser energy fluence in HIFU-treated tissues.

  14. Small Artery Remodeling Depends on Tissue-Type Transglutaminase

    Microsoft Academic Search

    Erik N. T. P. Bakker; Carsten L. Buus; Jos A. E. Spaan; Jop Perree; Anuradha Ganga; Titia M. Rolf; Oana Sorop; Linda H. Bramsen; Michael J. Mulvany; Ed VanBavel

    2010-01-01

    Remodeling of small arteries is essential in the long-term regulation of blood pressure and blood flow to specific organs or tissues. A large part of the change in vessel diameter may occur through non-growth-related reorganization of vessel wall components. The hypothesis was tested that tissue-type transglutaminase (tTG), a cross-linking enzyme, contributes to the inward remodeling of small arteries. The in

  15. Tissue-type plasminogen activator gene targets thrombolysis in atriums

    Microsoft Academic Search

    Yongsheng Gong; Fajiu Wang; Xia Li; Zhixin Gao; Kailun Zhang; Chen Fan; Xingen Liu

    2010-01-01

    Our previous investigations showed that retroviral gene transfer of tissue-type plasminogen activator (tPA) effectively targeted\\u000a thrombolysis in vitro and in the model of inferior caval veins of rabbits. This study is to identify the target thrombolysis\\u000a of retroviral vector recombinant pLEGFP-N1-tPA transferred into the tissue around the Dacron patch (the same materials making\\u000a of the ring of mechanical valve) in

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

    PubMed

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

    2014-01-01

    Non-destructive monitoring of engineered tissues is needed for translation of these products from the lab to the clinic. In this study, non-invasive, high resolution spectral ultrasound imaging (SUSI) was used to monitor the differentiation of MC3T3 pre-osteoblasts seeded within collagen hydrogels. SUSI was used to measure the diameter, concentration and acoustic attenuation of scatterers within such constructs cultured in either control or osteogenic medium over 21 days. Conventional biochemical assays were used on parallel samples to determine DNA content and calcium deposition. Construct volume and morphology were accurately imaged using ultrasound. Cell diameter was estimated to be approximately 12.5-15.5 µm using SUSI, which corresponded well to measurements of fluorescently stained cells. The total number of cells per construct assessed by quantitation of DNA content decreased from 5.6±2.4×10(4) at day 1 to 0.9±0.2×10(4) at day 21. SUSI estimation of the equivalent number of acoustic scatters showed a similar decreasing trend, except at day 21 in the osteogenic samples, which showed a marked increase in both scatterer number and acoustic impedance, suggestive of mineral deposition by the differentiating MC3T3 cells. Estimation of calcium content by SUSI was 41.7±11.4 µg/ml, which agreed well with the biochemical measurement of 38.7±16.7 µg/ml. Color coded maps of parameter values were overlaid on B-mode images to show spatiotemporal changes in cell diameter and calcium deposition. This study demonstrates the use of non-destructive ultrasound imaging to provide quantitative information on the number and differentiated state of cells embedded within 3D engineered constructs, and therefore presents a valuable tool for longitudinal monitoring of engineered tissue development. PMID:24465680

  17. TEMPORAL AND SPATIAL MONITORING OF TEMPERATURE-RELATED TISSUE CHANGES USING FOCUSED ULTRASOUND PHASED ARRAYS

    E-print Network

    Konofagou, Elisa E.

    Focused Ultrasound Laboratory, Department of Radiology ­ MR research, Brigham and Women's Hospital] to opening of the blood brain barrier [2] for drug delivery. However, in order for it to have the most frequencies with a kHz frequency difference, an oscillating radiation force can be generated at the focus

  18. Regularized autoregressive analysis of intravascular ultrasound backscatter: improvement in spatial accuracy of tissue maps

    Microsoft Academic Search

    Anuja Nair; Daniela Calvetti; D. Geoffrey Vince

    2004-01-01

    Autoregressive (AR) models are qualified for analysis of stochastic, short-time data, such as intravascular ultrasound (IVUS) backscatter. Regularization is required for AR analysis of short data lengths with an aim to increase spatial accuracy of predicted plaque composition and was achieved by determining suitable AR orders for short data records. Conventional methods of determining order were compared to the use

  19. DNA methylation age of human tissues and cell types

    PubMed Central

    2013-01-01

    Background It is not yet known whether DNA methylation levels can be used to accurately predict age across a broad spectrum of human tissues and cell types, nor whether the resulting age prediction is a biologically meaningful measure. Results I developed a multi-tissue predictor of age that allows one to estimate the DNA methylation age of most tissues and cell types. The predictor, which is freely available, was developed using 8,000 samples from 82 Illumina DNA methylation array datasets, encompassing 51 healthy tissues and cell types. I found that DNA methylation age has the following properties: first, it is close to zero for embryonic and induced pluripotent stem cells; second, it correlates with cell passage number; third, it gives rise to a highly heritable measure of age acceleration; and, fourth, it is applicable to chimpanzee tissues. Analysis of 6,000 cancer samples from 32 datasets showed that all of the considered 20 cancer types exhibit significant age acceleration, with an average of 36 years. Low age-acceleration of cancer tissue is associated with a high number of somatic mutations and TP53 mutations, while mutations in steroid receptors greatly accelerate DNA methylation age in breast cancer. Finally, I characterize the 353 CpG sites that together form an aging clock in terms of chromatin states and tissue variance. Conclusions I propose that DNA methylation age measures the cumulative effect of an epigenetic maintenance system. This novel epigenetic clock can be used to address a host of questions in developmental biology, cancer and aging research. PMID:24138928

  20. Stereotypic laryngeal and respiratory motor patterns generate different call types in rat ultrasound vocalization.

    PubMed

    Riede, Tobias

    2013-04-01

    Rodents produce highly variable ultrasound whistles as communication signals unlike many other mammals, who employ flow-induced vocal fold oscillations to produce sound. The role of larynx muscles in controlling sound features across different call types in ultrasound vocalization (USV) was investigated using laryngeal muscle electromyographic (EMG) activity, subglottal pressure measurements and vocal sound output in awake and spontaneously behaving Sprague-Dawley rats. Results support the hypothesis that glottal shape determines fundamental frequency. EMG activities of thyroarytenoid and cricothyroid muscles were aligned with call duration. EMG intensity increased with fundamental frequency. Phasic activities of both muscles were aligned with fast changing fundamental frequency contours, for example in trills. Activities of the sternothyroid and sternohyoid muscles, two muscles involved in vocal production in other mammals, are not critical for the production of rat USV. To test how stereotypic laryngeal and respiratory activity are across call types and individuals, sets of ten EMG and subglottal pressure parameters were measured in six different call types from six rats. Using discriminant function analysis, on average 80% of parameter sets were correctly assigned to their respective call type. This was significantly higher than the chance level. Since fundamental frequency features of USV are tightly associated with stereotypic activity of intrinsic laryngeal muscles and muscles contributing to build-up of subglottal pressure, USV provide insight into the neurophysiological control of peripheral vocal motor patterns. PMID:23423862

  1. Electromagnetically tracked ultrasound for small animal imaging

    Microsoft Academic Search

    Charles F. Caskey; Mario Hlawitschka; Shengping Qin; Katherine W. Ferrara

    2010-01-01

    The fusion of computed tomography (CT) and ultrasound (US) imaging has recently been examined for guiding interventional procedures such as biopsy, local drug delivery and radiofrequency ablation. During combined CT\\/US procedures, US facilitates real time visualization of blood flow and tissue structure, while CT provides a three-dimensional view of an extended region and is capable of differentiating tissue types based

  2. Ultrasonic tissue-type imaging (TTI) for planning treatment of prostate cancer

    NASA Astrophysics Data System (ADS)

    Feleppa, Ernest J.; Ketterling, Jeffrey A.; Porter, Christopher R.; Gillespie, John; Wuu, Cheng-Shie; Urban, Stella; Kalisz, Andrew; Ennis, Ronald D.; Schiff, Peter B.

    2004-04-01

    Our research is intended to develop ultrasonic methods for characterizing cancerous prostate tissue and thereby to improve the effectiveness of biopsy guidance, therapy targeting, and treatment monitoring. We acquired radio-frequency (RF) echo-signal data and clinical variables, e.g., PSA, during biopsy examinations. We computed spectra of the RF signals in each biopsied region, and trained neural network classifers with over 3,000 sets of data using biopsy data as the gold standard. For imaging, a lookup table returned scores for cancer likelihood on a pixel-by-pixel basis from spectral-parameter and PSA values. Using ROC analyses, we compared classification performance of artificial neural networks (ANNs) to conventional classification with a leave-one-patient-out approach intended to minimize the chance of bias. Tissue-type images (TTIs) were compared to prostatectomy histology to further assess classification performance. ROC-curve areas were greater for ANNs than for the B-mode-based classification by more than 20%, e.g., 0.75 +/- 0.03 for neural-networks vs. 0.64 +/- 0.03 for B-mode LOSs. ANN sensitivity was 17% better than the sensitivity range of ultrasound-guided biopsies. TTIs showed tumors that were entirely unrecognized in conventional images and undetected during surgery. We are investigating TTIs for guiding prostrate biopsies, and for planning radiation dose-escalation and tissue-sparing options, and monitoring prostrate cancer.

  3. Shock-induced heating and millisecond boiling in gels and tissue due to high intensity focused ultrasound.

    PubMed

    Canney, Michael S; Khokhlova, Vera A; Bessonova, Olga V; Bailey, Michael R; Crum, Lawrence A

    2010-02-01

    Nonlinear propagation causes high-intensity ultrasound waves to distort and generate higher harmonics, which are more readily absorbed and converted to heat than the fundamental frequency. Although such nonlinear effects have been investigated previously and found to not significantly alter high-intensity focused ultrasound (HIFU) treatments, two results reported here change this paradigm. One is that at clinically relevant intensity levels, HIFU waves not only become distorted but form shock waves in tissue. The other is that the generated shock waves heat the tissue to boiling in much less time than predicted for undistorted or weakly distorted waves. In this study, a 2-MHz HIFU source operating at peak intensities up to 25,000 W/cm(2) was used to heat transparent tissue-mimicking phantoms and ex vivo bovine liver samples. Initiation of boiling was detected using high-speed photography, a 20-MHz passive cavitation detector and fluctuation of the drive voltage at the HIFU source. The time to boil obtained experimentally was used to quantify heating rates and was compared with calculations using weak shock theory and the shock amplitudes obtained from nonlinear modeling and measurements with a fiber optic hydrophone. As observed experimentally and predicted by calculations, shocked focal waveforms produced boiling in as little as 3 ms and the time to initiate boiling was sensitive to small changes in HIFU output. Nonlinear heating as a result of shock waves is therefore important to HIFU, and clinicians should be aware of the potential for very rapid boiling because it alters treatments. PMID:20018433

  4. Shock-induced heating and millisecond boiling in gels and tissue due to high intensity focused ultrasound

    PubMed Central

    Canney, Michael S.; Khokhlova, Vera A.; Bessonova, Olga V.; Bailey, Michael R.; Crum, Lawrence A.

    2009-01-01

    Nonlinear propagation causes high intensity ultrasound waves to distort and generate higher harmonics, which are more readily absorbed and converted to heat than the fundamental frequency. Although such nonlinear effects have previously been investigated and found not to significantly alter high intensity focused ultrasound (HIFU) treatments, two results reported here change this paradigm. One is that at clinically relevant intensity levels, HIFU waves not only become distorted but form shock waves in tissue. The other is that the generated shock waves heat the tissue to boiling in much less time than predicted for undistorted or weakly distorted waves. In this study, a 2-MHz HIFU source operating at peak intensities up to 25,000 W/cm2 was used to heat transparent tissue-mimicking phantoms and ex vivo bovine liver samples. Initiation of boiling was detected using high-speed photography, a 20-MHz passive cavitation detector, and fluctuation of the drive voltage at the HIFU source. The time to boil obtained experimentally was used to quantify heating rates and was compared to calculations using weak shock theory and the shock amplitudes obtained from nonlinear modeling and from measurements with a fiber optic hydrophone. As observed experimentally and predicted by calculations, shocked focal waveforms produced boiling in as little as 3 ms and the time to initiate boiling was sensitive to small changes in HIFU output. Nonlinear heating due to shock waves is therefore important to HIFU and clinicians should be aware of the potential for very rapid boiling since it alters treatments. PMID:20018433

  5. Application of neural network in ultrasound tissue characterization using backscattered signal parameters

    Microsoft Academic Search

    Viren R. Amin; Vince J. Doerr; P. R. Arul; D. L. Carlson

    1992-01-01

    Ultrasonic techniques have shown good potential for estimating tissue composition for noninvasive imaging, diagnosis, and meat evaluation. Research carried out to define useful ultrasonic spectral parameters for tissue characterization, and to test multiparameter pattern recognition methods for tissue classification. The feasibility of two pattern recognition methods, linear discriminant analysis and artificial neural networks was studied for their applications to beef

  6. Method of and Apparatus for Histological Human Tissue Characterization Using Ultrasound

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, John H. (Inventor); Taler, George A. (Inventor)

    1998-01-01

    A method and apparatus for determining important histological characteristics of tissue, including a determination of the tissue's health is discussed. Electrical pulses are converted into meaningful numerical representations through the use of Fourier Transforms. These numerical representations are then used to determine important histological characteristics of tissue. This novel invention does not require rectification and thus provides for detailed information from the ultrasonic scan.

  7. Method of and Apparatus for Histological Human Tissue Characterization Using Ultrasound

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, John H. (Inventor); TalEr, George A. (Inventor)

    1999-01-01

    A method and apparatus for determining important histological characteristics of tissue, including a determination of the tissue's health. Electrical pulses are converted into meaningful numerical representations through the use of Fourier Transforms. These numerical representations are then used to determine important histological characteristics of tissue. This novel invention does not require rectification and thus provides for detailed information from the ultrasonic scan.

  8. SOUND-SPEED AND ATTENUATION IMAGING OF BREAST TISSUE USING WAVEFORM TOMOGRAPHY OF TRANSMISSION ULTRASOUND DATA

    SciTech Connect

    HUANG, LIANJIE [Los Alamos National Laboratory; PRATT, R. GERHARD [Los Alamos National Laboratory; DURIC, NEB [Los Alamos National Laboratory; LITTRUP, PETER [Los Alamos National Laboratory

    2007-01-25

    Waveform tomography results are presented from 800 kHz ultrasound transmission scans of a breast phantom, and from an in vivo ultrasound breast scan: significant improvements are demonstrated in resolution over time-of-flight reconstructions. Quantitative reconstructions of both sound-speed and inelastic attenuation are recovered. The data were acquired in the Computed Ultrasound Risk Evaluation (CURE) system, comprising a 20 cm diameter solid-state ultrasound ring array with 256 active, non-beamforming transducers. Waveform tomography is capable of resolving variations in acoustic properties at sub-wavelength scales. This was verified through comparison of the breast phantom reconstructions with x-ray CT results: the final images resolve variations in sound speed with a spatial resolution close to 2 mm. Waveform tomography overcomes the resolution limit of time-of-flight methods caused by finite frequency (diffraction) effects. The method is a combination of time-of-flight tomography, and 2-D acoustic waveform inversion of the transmission arrivals in ultrasonic data. For selected frequency components of the waveforms, a finite-difference simulation of the visco-acoustic wave equation is used to compute synthetic data in the current model, and the data residuals are formed by subtraction. The residuals are used in an iterative, gradient-based scheme to update the sound-speed and attenuation model to produce a reduced misfit to the data. Computational efficiency is achieved through the use of time-reversal of the data residuals to construct the model updates. Lower frequencies are used first, to establish the long wavelength components of the image, and higher frequencies are introduced later to provide increased resolution.

  9. Ultrasound produced homogenization and liquefaction of brain tissue in vivo at pressures beyond the cavitation threshold

    Microsoft Academic Search

    Natalia Vykhodtseva; Nathan McDannold; Kullervo Hynynen

    2001-01-01

    Histological effects of short-pulsed focused ultrasound at pressure amplitudes above the cavitation threshold were studied in the brain. Sixty locations in the brains of 13 rabbits were sonicated at a depth of 4-10 mm (1.5 MHz, burst lengths, 1-100 ms, PRF 1-100 Hz, acoustic power, up to 950 W). MRI was used to aim the beam, monitor the temperature, and

  10. High Frequency Ultrasound Tissue Characterization and Acoustic Microscopy of Intracellular Changes

    Microsoft Academic Search

    Sebastian Brand; Eike C. Weiss; Robert M. Lemor; Michael C. Kolios

    2008-01-01

    The objective of this work is to investigate changes in the acoustic properties of cells when exposed to chemotherapy for monitoring treatment response. High frequency ultrasound spectroscopy (10-60 MHz) and scanning acoustic microscopy (0.9 GHz) were performed on HeLa cells (Ackermann et al. 1954, Masters 2002) that were exposed to the chemotherapeutic agent cisplatin. Ultrasonic radio-frequency data were acquired from

  11. Ehlers-Danlos Syndrome Type VI: Collagen Type Specificity of Defective Lysyl Hydroxylation in Various Tissues

    Microsoft Academic Search

    Annegret Ihme; Thomas Krieg; Andreas Nerlich; Ursula Feldmann; Jürgen Rauterberg; Robert W. Glanville; Georg Edel; Peter K. Muller

    1984-01-01

    The Elhers-Danlos syndrome type VI is an inherited disorder of collagen metabolism characterized by a defective lysyl hydroxylase. The resulting lack of hydroxylysine has been found in several connective tissues, all of which show varying degrees of clinical symptoms. In the present study, collagen was isolated from different connective tissues and the degree of hydroxylation of lysyl residues was determined.

  12. Quantification of Frequency-Dependent Angular Scattering of Ultrasound by Tissue-Mimicking Materials and Excised Mammalian Tissues.

    NASA Astrophysics Data System (ADS)

    Davros, William John

    Scattering was measured using the differential scattering cross section per unit volume. A computer controlled apparatus was constructed for doing the measurements. An accuracy of 13% (+/- one standard deviation) was estimated using low attenuation targets consisting of small glass beads distributed in agar. Frequencies used were 2.0 MHz through 7.0 MHz. Accuracy was independent of scattering angle. Precision obtainable was +/-13% (+/- one standard deviation) for scattering angles between 45^circ and 170^circ at frequencies of 2.25 MHz, 3.5 MHz, 5.0 MHz, and 7.0 MHz. Precision was not a strong function of scattering angle. Attenuation, speed of sound, density, and scattering as a function of angle were measured from dog liver and human female breast tissue. The results showed that at frequencies of 2.0 MHz and 2.5 MHz forward scattering dominated. At 4.0 MHz the scattering was nearly isotropic. Near backscattering from breast tissue demonstrated a frequency dependence of f^{1.7}. Scattering measurements from dog liver tissue were measured from eleven donor livers at frequencies of 2.25 MHz, 3.5 MHz, 5.0 MHz, and 7.0 MHz. Some observations made concerning data from dog liver included, the dominance of forward scattering at 2.25 MHz, and the continual decrease in forward scattering as the frequency increased. Dog liver near backscattering data exhibited a frequency dependence of f^{0.6}. Ultrasonic scattering was modeled as a random walk process of vectors on the complex plane. The Rayleigh distribution function p(D) was used as the parent distribution. The signal-to-noise ratio, SNR_{rm o}, was found to be a constant 1.91 for the Rayleigh distribution. Data from a target consisting of glass beads in agar were found to conform very closely (SNR_{rm o} = 1.98) in a Rayleigh pdf. Scattering data from dog liver tissue and human breast tissue were tested for conformity to the Rayleigh pdf. Dog liver tissue had a SNR_ {rm o} = 2.06 and human breast tissue had a SNR_{rm o} = 2.08. This evidence supported the hypothesis that the scatterers within these two tissues were spatially and randomly distributed, that they were numerous, and that contributions to the total scattering due to coherent effects were small.

  13. Backward-mode multiwavelength photoacoustic scanner using a planar Fabry-Perot polymer film ultrasound sensor for high-resolution three-dimensional imaging of biological tissues

    Microsoft Academic Search

    Edward Zhang; Jan Laufer; Paul Beard

    2008-01-01

    A multiwavelength backward-mode planar photoacoustic scanner for 3D imaging of soft tissues to depths of several millimeters with a spatial resolution in the tens to hundreds of micrometers range is described. The system comprises a tunable optical parametric oscillator laser system that provides nanosecond laser pulses between 600 and 1200 nm for generating the photoacoustic signals and an optical ultrasound

  14. Transrectal Ablation Of Prostate Tissue Using Focused Ultrasound N.T. Sanghvil.2, R.S. Foster3, R. Bihrle3, F.J. Fry', M. Phillips' and

    E-print Network

    Illinois at Urbana-Champaign, University of

    not rise more than 5' C over the baseline. In 15 patients with benign prostatic hyperplasia (BPH), no majorTransrectal Ablation Of Prostate Tissue Using Focused Ultrasound N.T. Sanghvil.2, R.S. Foster3, RFocal Surgery Inc., Milpitas, CA ABSTRACT Canine and human prostates were treated with high intensity

  15. Listening to speech recruits specific tongue motor synergies as revealed by transcranial magnetic stimulation and tissue-Doppler ultrasound imaging

    PubMed Central

    D'Ausilio, A.; Maffongelli, L.; Bartoli, E.; Campanella, M.; Ferrari, E.; Berry, J.; Fadiga, L.

    2014-01-01

    The activation of listener's motor system during speech processing was first demonstrated by the enhancement of electromyographic tongue potentials as evoked by single-pulse transcranial magnetic stimulation (TMS) over tongue motor cortex. This technique is, however, technically challenging and enables only a rather coarse measurement of this motor mirroring. Here, we applied TMS to listeners’ tongue motor area in association with ultrasound tissue Doppler imaging to describe fine-grained tongue kinematic synergies evoked by passive listening to speech. Subjects listened to syllables requiring different patterns of dorso-ventral and antero-posterior movements (/ki/, /ko/, /ti/, /to/). Results show that passive listening to speech sounds evokes a pattern of motor synergies mirroring those occurring during speech production. Moreover, mirror motor synergies were more evident in those subjects showing good performances in discriminating speech in noise demonstrating a role of the speech-related mirror system in feed-forward processing the speaker's ongoing motor plan. PMID:24778384

  16. Feasibility of optoacoustic visualization of high-intensity focused ultrasound-induced thermal lesions in live tissue.

    PubMed

    Chitnis, Parag V; Brecht, Hans-Peter; Su, Richard; Oraevsky, Alexander A

    2010-01-01

    A 3-D optoacoustic imaging system was used to visualize thermal lesions produced in vivo using high-intensity focused ultrasound (HIFU). A 7.5-MHz, surgical, focused transducer with a radius of curvature of 35 mm and an aperture diameter of 23 mm was used to generate HIFU. A pulsed laser, which could operate at 755 nm and 1064 nm, was used to illuminate excised tissue and mice using a bifurcated fiber bundle resulting in two wide beams of light. Tomographic images were obtained while the specimens were rotated within a sphere outlined by a concave arc-shaped array of 64 piezo-composite transducers. These images were then combined to reconstruct 3-D volume images (voxel resolution 0.5 mm), which were acquired before and after HIFU exposure. In vivo optoacoustic images acquired at 1064 nm provided visualization of HIFU lesions. The lesion was indicated by a negative optoacoustic contrast. The molecular nature of such contrast may possibly be associated with reduction of the optical absorption due to reduced concentration of blood, tissue dehydration, denaturation of proteins and porphyrins, and reduction of thermoacoustic efficiency in the thermally treated tissue. These preliminary results demonstrate the potential of optoacoustic imaging to assess and monitor the progress of HIFU therapy. PMID:20459235

  17. Feasibility of optoacoustic visualization of high-intensity focused ultrasound-induced thermal lesions in live tissue

    PubMed Central

    Chitnis, Parag V.; Brecht, Hans-Peter; Su, Richard; Oraevsky, Alexander A.

    2010-01-01

    A 3-D optoacoustic imaging system was used to visualize thermal lesions produced in vivo using high-intensity focused ultrasound (HIFU). A 7.5-MHz, surgical, focused transducer with a radius of curvature of 35 mm and an aperture diameter of 23 mm was used to generate HIFU. A pulsed laser, which could operate at 755 nm and 1064 nm, was used to illuminate excised tissue and mice using a bifurcated fiber bundle resulting in two wide beams of light. Tomographic images were obtained while the specimens were rotated within a sphere outlined by a concave arc-shaped array of 64 piezo-composite transducers. These images were then combined to reconstruct 3-D volume images (voxel resolution 0.5 mm), which were acquired before and after HIFU exposure. In vivo optoacoustic images acquired at 1064 nm provided visualization of HIFU lesions. The lesion was indicated by a negative optoacoustic contrast. The molecular nature of such contrast may possibly be associated with reduction of the optical absorption due to reduced concentration of blood, tissue dehydration, denaturation of proteins and porphyrins, and reduction of thermoacoustic efficiency in the thermally treated tissue. These preliminary results demonstrate the potential of optoacoustic imaging to assess and monitor the progress of HIFU therapy. PMID:20459235

  18. Spatial-temporal ultrasound imaging of residual cavitation bubbles around a fluid-tissue interface in histotripsy.

    PubMed

    Hu, Hong; Xu, Shanshan; Yuan, Yuan; Liu, Runna; Wang, Supin; Wan, Mingxi

    2015-05-01

    Cavitation is considered as the primary mechanism of soft tissue fragmentation (histotripsy) by pulsed high-intensity focused ultrasound. The residual cavitation bubbles have a dual influence on the histotripsy pulses: these serve as nuclei for easy generation of new cavitation, and act as strong scatterers causing energy "shadowing." To monitor the residual cavitation bubbles in histotripsy, an ultrafast active cavitation imaging method with relatively high signal-to-noise ratio and good spatial-temporal resolution was proposed in this paper, which combined plane wave transmission, minimum variance beamforming, and coherence factor weighting. The spatial-temporal evolutions of residual cavitation bubbles around a fluid-tissue interface in histotripsy under pulse duration (PD) of 10-40??s and pulse repetition frequency (PRF) of 0.67-2?kHz were monitored by this method. The integrated bubble area curves inside the tissue interface were acquired from the bubble image sequence, and the formation process of histotripsy damage was estimated. It was observed that the histotripsy efficiency decreased with both longer PDs and higher PRFs. A direct relationship with a coefficient of 1.0365 between histotripsy lesion area and inner residual bubble area was found. These results can assist in monitoring and optimization of the histotripsy treatment further. PMID:25994689

  19. The role of acoustic nonlinearity in tissue heating behind the rib cage using high intensity focused ultrasound phased array

    PubMed Central

    Yuldashev, Petr V.; Shmeleva, Svetlana M.; Ilyin, Sergey A.; Sapozhnikov, Oleg A.; Gavrilov, Leonid R.; Khokhlova, Vera A.

    2013-01-01

    The goal of this study was to investigate theoretically the effects of nonlinear propagation in a high intensity focused ultrasound (HIFU) field produced by a therapeutic phased array and the resultant heating of tissue behind a rib cage. Three configurations of focusing were simulated: in water, in water with ribs in the beam path, and in water with ribs backed by a layer of soft tissue. The Westervelt equation was used to model the nonlinear HIFU field and a 1 MHz phased array consisting of 254 circular elements was used as a boundary condition to the model. The temperature rise in tissue was modelled using the bioheat equation, and thermally necrosed volumes were calculated using the thermal dose formulation. The shapes of lesions predicted by the modelling were compared with those previously obtained in in vitro experiments at low power sonications. Intensity levels at the face of the array elements that corresponded to formation of high amplitude shock fronts in the focal region were determined as 10 W·cm?2 in the free field in water and 40 W·cm?2 in the presence of ribs. It was shown that exposures with shocks provided a substantial increase in tissue heating, and its better spatial localization in the main focal region only. The relative effects of overheating ribs and splitting of the focus due to the periodic structure of the ribs were therefore reduced. These results suggest that utilizing nonlinear propagation and shock formation effects can be beneficial for inducing confined HIFU lesions when irradiating through obstructions such as ribs. Design of compact therapeutic arrays to provide maximum power outputs with lower intensity levels at the elements is necessary to achieve shock wave regimes for clinically relevant sonication depths in tissue. PMID:23528338

  20. Ultrasound signal wavelet analysis to quantify the microstructures of normal and frozen tissues in vitro.

    PubMed

    Sheng, Lei; Wang, Gubing; Li, Fubing; Luo, Jianwen; Liu, Jing

    2014-02-01

    Cryosurgery has a number of advantages that make it particularly appealing in the treatment of liver cancer. However, a major problem for the wide clinical adoption of hepatic cryosurgery is the lack of a cost effective high resolution imaging way which is capable of both performing precise monitoring of the freezing process in situ and evaluating the postoperative effects after surgery. The mean scatterer spacing has been found to be an important parameter for describing the ultrasonic scattering and characterization of biological tissues. However, its potential values in the evaluation of cryosurgical effects of tissues reserved unclear so far. Here, we investigated the wavelet analysis to estimate the mean scatterer spacing parameter in normal and freeze-thawed tissues on porcine livers in vitro. The experimental results carried out at 10 MHz using weakly focused pulse-echo signal element transducer indicated that the mean scatterer spacing in normal liver tissues is 1.12 ± 0.13 mm whereas it is 1.67 ± 0.25 mm in several pre-frozen and then thawed tissues. These results disclosed the good correlation between the wavelet data and microstructures of the normal or thawed tissues, and hence demonstrated that the wavelet analysis holds promise to be used as an effective method for the characterization of thawed tissues scatterer spacing. The present method offers a potential pragmatic strategy for monitoring the transition zone between frozen and unfrozen tissues during the surgical therapy, and evaluating postoperative effects. PMID:24269529

  1. TISSUE TYPE DIFFERENTIATION FOR BRAIN GLIOMA USING NON-NEGATIVE MATRIX FACTORIZATION

    E-print Network

    TISSUE TYPE DIFFERENTIATION FOR BRAIN GLIOMA USING NON-NEGATIVE MATRIX FACTORIZATION Yuqian Li1, customized for the problem of blindly separating brain glioma tumor tissue types using short-echo time proton detect the spectral profile corresponding to the most predominant tissue type, i.e., normal tissue, while

  2. Scale Space Texture Classification Using Combined Classifiers with Application to Ultrasound Tissue Characterization

    E-print Network

    Duin, Robert P.W.

    tissue characterization for discrimination of normal liver from cirrhosis yields prom- ising results or at least one lobe is completely affected. In diffused liver diseases like cirrhosis, the texture of liver

  3. Harmonic motion imaging for focused ultrasound (HMIFU): a fully integrated technique for sonication and monitoring of thermal ablation in tissues

    Microsoft Academic Search

    C Maleke; E E Konofagou

    2008-01-01

    FUS (focused ultrasound), or HIFU (high-intensity-focused ultrasound) therapy, a minimally or non-invasive procedure that uses ultrasound to generate thermal necrosis, has been proven successful in several clinical applications. This paper discusses a method for monitoring thermal treatment at different sonication durations (10 s, 20 s and 30 s) using the amplitude-modulated (AM) harmonic motion imaging for focused ultrasound (HMIFU) technique

  4. Assessment of the effects of ultrasound-mediated glucose on permeability of normal, benign, and cancerous human lung tissues with the Fourier-domain optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Wei, Huajiang; Wu, Guoyong; Guo, Zhouyi; Yang, Hongqin; He, Yonghong; Xie, Shusen; Guo, Xiao

    2012-11-01

    The objective of this study was to evaluate the effects of ultrasound-mediated analyte diffusion on permeability of normal, benign, and cancerous human lung tissue in vitro and to find more effective sonophoretic (SP) delivery in combination with the optical clearing agents (OCAs) method to distinguish normal and diseased lung tissues. The permeability coefficients of SP in combination with OCAs diffusion in lung tissue were measured with Fourier-domain optical coherence tomography (FD-OCT). 30% glucose and SP with a frequency of 1 MHz and an intensity of 0.80 W/cm2 over a 3 cm probe was simultaneously applied for 15 min. Experimental results show that the mean permeability coefficients of 30% glucose/SP were found to be (2.01±0.21)×10-5 cm/s from normal lung (NL) tissue, (2.75±0.28)×10-5 cm/s from lung benign granulomatosis (LBG) tissue, (4.53±0.49)×10-5 cm/s from lung adenocarcinoma tumor (LAT) tissue, and (5.81±0.62)×10-5 cm/s from lung squamous cell carcinoma (LSCC) tissue, respectively. The permeability coefficients of 30% glucose/SP increase approximately 36.8%, 125.4%, and 189.1% for the LBG, LAT, and LSCC tissue compared with that for the NL tissue, respectively. There were statistically significant differences in permeability coefficients of 30% glucose/SP between LBG and NL tissue (p<0.05), between LAT and NL tissue (p<0.05), and between LSCC and NL tissue (p<0.05). The results suggest that the OCT functional imaging technique to combine an ultrasound-OCAs combination method could become a powerful tool in early diagnosis and monitoring of changed microstructure of pathologic human lung tissue.

  5. Ultrasound assisted synthesis and characterization of M50 type nanostructured steel

    SciTech Connect

    Gonsalves, K.E.; Chen, X.; Rangarajan, S.P. [Univ. of Connecticut, Storrs, CT (United States)] [and others

    1995-12-31

    A nanophase multicomponent (Fe-Cr-Mo-V-C) type steel was prepared via the ultrasound decomposition of organometallic precursors. The synthesis involved the sonication of a mixture of iron pentacarbonyl, bis(ethylbenzene)chromium, bis(ethyl benzene)molybdenum and vanadium hexacarbonyl in decalin at 0{degrees}C. The as-synthesized powders are amorphous as determined by XRD. The nanopowders were compacted into a dense bulk sample which was then characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive analysis x-ray (EDAX). The major peaks in the X-ray spectra of the consolidated sample were assigned to {alpha}-Fe and the line broadening analysis revealed the crystallite size in the sample to be 27 nm. The hardness of the sample was estimated to be 66.3 Rockwell C.

  6. High frequency ultrasound measurements of the attenuation and backscatter from biological tissues

    Microsoft Academic Search

    Subha Maruvada

    2000-01-01

    There are now diagnostic ultrasonic imaging devices that operate at very high frequencies (VHF) of 20 MHz and beyond for clinical applications in ophthalmology, dermatology, and vascular surgery. To be able to better interpret these images and to further the development of these devices, knowledge of ultrasonic attenuation and scattering of biological tissues in this high frequency range is crucial.

  7. Miniaturized fiber-optic ultrasound probes for endoscopic tissue analysis by micro-opto-mechanical technology.

    PubMed

    Vannacci, E; Belsito, L; Mancarella, F; Ferri, M; Veronese, G P; Roncaglia, A; Biagi, E

    2014-06-01

    A new Micro-Opto-Mechanical System (MOMS) technology for the fabrication of optoacoustic probes on optical fiber is presented. The technology is based on the thermoelastic emission of ultrasonic waves from patterned carbon films for generation and on extrinsic polymer Fabry-Perot acousto-optical transducers for detection, both fabricated on miniaturized single-crystal silicon frames used to mount the ultrasonic transducers on the tip of an optical fiber. Thanks to the fabrication process adopted, high miniaturization levels are reached in the MOMS devices, demonstrating fiber-optic emitters and detectors with minimum diameter around 350 and 250 ?m respectively. A thorough functional testing of the ultrasound emitters mounted on 200 and 600 ?m diameter optical fibers is presented, in which the fiber-optic emitter with a diameter of 200 ?m shows generated acoustic pressures with peak-to-peak value up to 2.8 MPa with rather flat emission spectra extended beyond 150 MHz. The possibility to use the presented optoacoustic sources in conjunction with the fiber-optic acousto-optical detectors within a minimally invasive probe is also demonstrated by successfully measuring the ultrasonic echo reflected from a rigid surface immersed in water with various concentration of scatterers. The resulting spectra highlight the possibility to discriminate the effects due to frequency selective attenuation in a very wide range of frequencies within a biological medium using the presented fiber-optic probes. PMID:24573502

  8. Ultrasound-Enhanced Thrombolytic Effect of Tissue Plasminogen Activator–Loaded Echogenic Liposomes in an In Vivo Rabbit Aorta Thrombus Model—Brief Report

    PubMed Central

    Laing, Susan T.; Moody, Melanie; Smulevitz, Beverly; Kim, Hyunggun; Kee, Patrick; Huang, Shaoling; Holland, Christy K.; McPherson, David D.

    2012-01-01

    Objective Ultrasound enhances thrombolysis when combined with a thrombolytic and a contrast agent. This study aimed to evaluate the thrombolytic effect of our tissue plasminogen activator (tPA)–loaded echogenic liposomes (ELIP) in an in vivo clot model, with and without ultrasound treatment. Methods and Results The femoral arteries of New Zealand White rabbits (n=4 per group) were cannulated. The abdominal aortas were denuded, and thrombi were created using a solution of sodium ricinoleate plus thrombin. Rabbits were then randomly selected to receive tPA-loaded ELIP (200 ?g of tPA/5 mg of lipid) or empty ELIP with or without pulsed (color) Doppler ultrasound (5.7 MHz) for 2 minutes. Thrombus was imaged and echogenicity analyzed before and after ELIP injection. Blood flow velocities were measured at baseline, after clot formation, and serially after treatment up to 15 minutes. tPA-loaded ELIP highlighted thrombus in the abdominal aorta more effectively than empty ELIP (P<0.05). Ultrasound enhanced the thrombolytic effect of tPA-loaded ELIP, resulting in earlier and more complete recanalization rates (P<0.001). Conclusion This study demonstrates effective highlighting of clots and thrombolytic effect of tPA-loaded ELIP in an in vivo rabbit aorta clot model. Doppler ultrasound treatment enhances this thrombolytic effect, resulting in earlier and more complete recanalization rates. PMID:21441137

  9. Ultrasound skin tightening.

    PubMed

    Minkis, Kira; Alam, Murad

    2014-01-01

    Ultrasound skin tightening is a noninvasive, nonablative method that allows for energy deposition into the deep dermal and subcutaneous tissue while avoiding epidermal heating. Ultrasound coagulation is confined to arrays of 1-mm(3) zones that include the superficial musculoaponeurotic system and connective tissue. This technology gained approval from the Food and Drug Administration as the first energy-based skin "lifting" device, specifically for lifting lax tissue on the neck, submentum, and eyebrows. Ultrasound has the unique advantage of direct visualization of treated structures during treatment. Ultrasound is a safe and efficacious treatment for mild skin tightening and lifting. PMID:24267423

  10. Virtual Touch Tissue Quantification of Acoustic Radiation Force Impulse: A New Ultrasound Elastic Imaging in the Diagnosis of Thyroid Nodules

    PubMed Central

    Zhang, Yi-Feng; Xu, Hui-Xiong; He, Yong; Liu, Chang; Guo, Le-Hang; Liu, Lin-Na; Xu, Jun-Mei

    2012-01-01

    Objective Virtual touch tissue quantification (VTQ) of acoustic radiation force impulse (ARFI) is a new quantitative technique to measure tissue stiffness. The study was aimed to assess the usefulness of VTQ in the diagnosis of thyroid nodules. Methods 173 pathologically proven thyroid nodules in 142 patients were included and all were examined by conventional ultrasound (US), conventional elasticity imaging (EI) and VTQ of ARFI. The tissue stiffness for VTQ was expressed as shear wave velocity (SWV) (m/s). Receiver-operating characteristic curve (ROC) analyses were performed to assess the diagnostic performance. Intra- and inter-observer reproducibility of VTQ measurement was assessed. Results The SWVs of benign and malignant thyroid nodules were 2.34±1.17 m/s (range: 0.61–9.00 m/s) and 4.82±2.53 m/s (range: 2.32–9.00 m/s) respectively (P<0.001). The mean SWV ratios between each nodule and the adjacent thyroid tissue were 1.19±0.67 (range: 0.31–6.87) for benign and 2.50±1.54 (range: 0.85–6.69) for malignant nodules (P<0.001). ROC analyses indicated that the area under the curve was 0.861 (95% CI : 0.804, 0.918) (P<0.001) for SWV and 0.831(95% CI : 0.761, 0.900)(P<0.001) for the SWV ratio. The cutoff points for the differential diagnosis were 2.87 m/s for SWV and 1.59 for SWV ratio. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for EI were 65.9%, 66.7%, 66.5%, 40.3%, and 85.1%, respectively, and were 63.6%–75%, 82.2%–88.4%, 80.3%–82.1%, 58.9%–65.1%, and 87.7%–90.5%, respectively, for VTQ. The diagnostic value of VTQ is the highest for nodules >20 mm and lowest for those ?10 mm. The correlation coefficients were 0.904 for intraobserver measurement and 0.864 for interobserver measurement. Conclusions VTQ of ARFI provides quantitative and reproducible information about the tissue stiffness, which is useful for the differentiation between benign and malignant thyroid nodules. The diagnostic performance of VTQ is higher than that of conventional EI. PMID:23152855

  11. Ultrasound estimates of visceral and subcutaneous-abdominal adipose tissues in infancy.

    PubMed

    De Lucia Rolfe, Emanuella; Modi, Neena; Uthaya, Sabita; Hughes, Ieuan A; Dunger, David B; Acerini, Carlo; Stolk, Ronald P; Ong, Ken K

    2013-01-01

    Other imaging techniques to quantify internal-abdominal adiposity (IA-AT) and subcutaneous-abdominal adiposity (SCA-AT) are frequently impractical in infants. The aim of this study was twofold: (a) to validate ultrasound (US) visceral and subcutaneous-abdominal depths in assessing IA-AT and SCA-AT from MRI as the reference method in infants and (b) to analyze the association between US abdominal adiposity and anthropometric measures at ages 3 months and 12 months. Twenty-two infants underwent MRI and US measures of abdominal adiposity. Abdominal US parameters and anthropometric variables were assessed in the Cambridge Baby Growth Study (CBGS), n = 487 infants (23 girls) at age 3 months and n = 495 infants (237 girls) at 12 months. US visceral and subcutaneous-abdominal depths correlated with MRI quantified IA-AT (r = 0.48, P < 0.05) and SCA-AT (r = 0.71, P < 0.001) volumes, respectively. In CBGS, mean US-visceral depths increased by ~20 % between ages 3 and 12 months (P < 0.0001) and at both ages were lower in infants breast-fed at 3 months than in other infants. US-visceral depths at both 3 and 12 months were inversely related to skinfold thickness at birth (P = 0.03 and P = 0.009 at 3 and 12 months, resp.; adjusted for current skinfold thickness). In contrast, US-subcutaneous-abdominal depth at 3 months was positively related to skinfold thickness at birth (P = 0.004). US measures can rank infants with higher or lower IA-AT and SCA-AT. Contrasting patterns of association with visceral and subcutaneous-abdominal adiposities indicate that they may be differentially regulated in infancy. PMID:23710350

  12. Correlation of Femoral and Lumbar DXA and Calcaneal Ultrasound, Measured In Situ with Intact Soft Tissues, with the In Vitro Failure Loads of the Proximal Femur

    Microsoft Academic Search

    E.-M. Lochmüller; J.-B. Zeller; D. Kaiser; F. Eckstein; J. Landgraf; R. Putz; R. Steldinger

    1998-01-01

    :   The objective of this study was to determine experimentally the sex-specific correlation of femoral and lumbar DXA and calcaneal\\u000a ultrasound, measured in situ, with the in vitro failure loads of the proximal femur. Fifty-eight cadavers with intact skin\\u000a and soft tissues (34 male, aged 81.2 ± 8.7 years; 24 female, aged 83.7 ± 10.6 years) were examined. The bone

  13. Multimodal ultrasound-photoacoustic imaging of tissue engineering scaffolds and blood oxygen saturation in and around the scaffolds.

    PubMed

    Talukdar, Yahfi; Avti, Pramod; Sun, John; Sitharaman, Balaji

    2014-05-01

    Preclinical, noninvasive imaging of tissue engineering polymeric scaffold structure and/or the physiological processes such as blood oxygenation remains a challenge. In vitro or ex vivo, the widely used scaffold characterization modalities such as porosimetry, electron or optical microscopy, and X-ray microcomputed tomography have limitations or disadvantages-some are invasive or destructive, others have limited tissue penetration (few hundred micrometers) and/or show poor contrast under physiological conditions. Postmortem histological analysis, the most robust technique for the evaluation of neovascularization is obviously not appropriate for acquiring physiological or longitudinal data. In this study, we have explored the potential of ultrasound (US)-coregistered photoacoustic (PA) imaging as a noninvasive multimodal imaging modality to overcome some of the above challenges and/or provide complementary information. US-PA imaging was employed to characterize poly(lactic-co-glycolic acid) (PLGA) polymer scaffolds or single-walled carbon nanotube (SWCNT)-incorporated PLGA (SWCNT-PLGA) polymer scaffolds as well as blood oxygen saturation within and around the scaffolds. Ex vivo, PLGA and SWCNT-PLGA scaffolds were placed at 0.5, 2, and 6 mm depths in chicken breast tissues. PLGA scaffolds could be localized with US imaging, but generate no PA signal (excitation wavelengths 680 and 780 nm). SWCNT-PLGA scaffolds generated strong PA signals at both wavelengths due to the presence of the SWCNTs and could be localized with both US and PA imaging depths between 0.5-6 mm (lateral resolution = 90 ?m, axial resolution = 40 ?m). In vivo, PLGA and SWCNT-PLGA scaffolds were implanted in subcutaneous pockets at 2 mm depth in rats, and imaged at 7 and 14 days postsurgery. The anatomical position of both the scaffolds could be determined from the US images. Only SWCNT-PLGA scaffolds could be easily detected in the US-PA images. SWCNT-PLGA scaffolds had significant four times higher PA signal intensity compared with the surrounding tissue and PLGA scaffolds. In vivo blood oxygen saturation maps around and within the PLGA scaffolds could be obtained by PA imaging. There was no significant difference in oxygen saturation for the PLGA scaffolds at the two time points. The blood oxygen saturation maps complemented the histological analysis of neovascularization of the PLGA scaffolds. PMID:24107069

  14. Multimodal Ultrasound-Photoacoustic Imaging of Tissue Engineering Scaffolds and Blood Oxygen Saturation In and Around the Scaffolds

    PubMed Central

    Talukdar, Yahfi; Avti, Pramod; Sun, John

    2014-01-01

    Preclinical, noninvasive imaging of tissue engineering polymeric scaffold structure and/or the physiological processes such as blood oxygenation remains a challenge. In vitro or ex vivo, the widely used scaffold characterization modalities such as porosimetry, electron or optical microscopy, and X-ray microcomputed tomography have limitations or disadvantages—some are invasive or destructive, others have limited tissue penetration (few hundred micrometers) and/or show poor contrast under physiological conditions. Postmortem histological analysis, the most robust technique for the evaluation of neovascularization is obviously not appropriate for acquiring physiological or longitudinal data. In this study, we have explored the potential of ultrasound (US)-coregistered photoacoustic (PA) imaging as a noninvasive multimodal imaging modality to overcome some of the above challenges and/or provide complementary information. US-PA imaging was employed to characterize poly(lactic-co-glycolic acid) (PLGA) polymer scaffolds or single-walled carbon nanotube (SWCNT)-incorporated PLGA (SWCNT-PLGA) polymer scaffolds as well as blood oxygen saturation within and around the scaffolds. Ex vivo, PLGA and SWCNT-PLGA scaffolds were placed at 0.5, 2, and 6?mm depths in chicken breast tissues. PLGA scaffolds could be localized with US imaging, but generate no PA signal (excitation wavelengths 680 and 780?nm). SWCNT-PLGA scaffolds generated strong PA signals at both wavelengths due to the presence of the SWCNTs and could be localized with both US and PA imaging depths between 0.5–6?mm (lateral resolution=90??m, axial resolution=40??m). In vivo, PLGA and SWCNT-PLGA scaffolds were implanted in subcutaneous pockets at 2?mm depth in rats, and imaged at 7 and 14 days postsurgery. The anatomical position of both the scaffolds could be determined from the US images. Only SWCNT-PLGA scaffolds could be easily detected in the US-PA images. SWCNT-PLGA scaffolds had significant four times higher PA signal intensity compared with the surrounding tissue and PLGA scaffolds. In vivo blood oxygen saturation maps around and within the PLGA scaffolds could be obtained by PA imaging. There was no significant difference in oxygen saturation for the PLGA scaffolds at the two time points. The blood oxygen saturation maps complemented the histological analysis of neovascularization of the PLGA scaffolds. PMID:24107069

  15. Speckle Tracking Ultrasound for Assessment of the Relative Motion of Flexor Tendon and Subsynovial Connective Tissue in the Human Carpal Tunnel

    PubMed Central

    Yoshii, Yuichi; Villarraga, Hector R.; Henderson, Jacqueline; Zhao, Chunfeng; An, Kai-Nan; Amadio, Peter C.

    2009-01-01

    The objective of this study was to compare tissue Doppler imaging and speckle tracking ultrasound to assess the relative motion of flexor tendon and surrounding subsynovial connective tissue (SSCT). Twenty normal human wrists were imaged with an ultrasound scanner. The two ultrasound methods measured the excursion and maximum velocity of the tendon and SSCT while subjects gripped three different sized acrylic tubes, and these were correlated with tendon excursions estimated from finger joint angle changes. The maximum velocity ratio (=SSCT/tendon velocity) and the shear index (=[(Tendon excursion?SSCT excursion)/Tendon excursion]×100%) were calculated. The intraclass correlation coefficient was higher for joint angle/speckle tracking tendon excursion (0.642) than for joint angle/tissue Doppler excursion (0.377). The speckle tracking method could also discriminate differences in maximum velocity ratio and shear index for different tube sizes. We conclude that speckle tracking may be useful in assessing the relative motion of tendon and SSCT. PMID:19828231

  16. Study on the refractive index matching effect of ultrasound on optical clearing of bio-tissues based on the derivative total reflection method

    PubMed Central

    Zeng, Huanhuan; Wang, Jin; Ye, Qing; Deng, Zhichao; Mei, Jianchun; Zhou, Wenyuan; Zhang, Chunping; Tian, Jianguo

    2014-01-01

    In recent years, the tissue optical clearing (OC) technique in the biomedicine field has drawn lots of attention. Various physical and chemical methods have been introduced to improve the efficacy of OC. In this study, the effect of the combination of glycerol and ultrasound treatment on OC of in vitro porcine muscle tissues has been investigated. The refractive index (RI) matching mechanism of OC was directly observed based on the derivative total reflection method. A theoretical model was used to simulate the proportion of tissue fluid in the illuminated area. Moreover, the total transmittance spectra have been obtained by a spectrometer over the range from 450 nm to 700 nm. The administration of glycerol and ultrasound has led to an increase of the RI of background medium and a more RI matching environment was achieved. The experimental results support the validity of the ultrasound treatment for OC. The RI matching mechanism has been firstly quantitatively analyzed based on the derivative total reflection method. PMID:25360366

  17. Characterizing tissue microstructure using an ultrasound system-independent spatial autocorrelation function

    NASA Astrophysics Data System (ADS)

    Dong, Fang

    1999-09-01

    The research described in this dissertation is related to characterization of tissue microstructure using a system- independent spatial autocorrelation function (SAF). The function was determined using a reference phantom method, which employed a well-defined ``point- scatterer'' reference phantom to account for instrumental factors. The SAF's were estimated for several tissue-mimicking (TM) phantoms and fresh dog livers. Both phantom tests and in vitro dog liver measurements showed that the reference phantom method is relatively simple and fairly accurate, providing the bandwidth of the measurement system is sufficient for the size of the scatterer being involved in the scattering process. Implementation of this method in clinical scanner requires that distortions from patient's body wall be properly accounted for. The SAF's were estimated for two phantoms with body-wall-like distortions. The experimental results demonstrated that body wall distortions have little effect if echo data are acquired from a large scattering volume. One interesting application of the SAF is to form a ``scatterer size image''. The scatterer size image may help providing diagnostic tools for those diseases in which the tissue microstructure is different from the normal. Another method, the BSC method, utilizes information contained in the frequency dependence of the backscatter coefficient to estimate the scatterer size. The SAF technique produced accurate scatterer size images of homogeneous TM phantoms and the BSC method was capable of generating accurate size images for heterogeneous phantoms. In the scatterer size image of dog kidneys, the contrast-to-noise-ratio (CNR) between renal cortex and medulla was improved dramatically compared to the gray- scale image. The effect of nonlinear propagation was investigated by using a custom-designed phantom with overlaying TM fat layer. The results showed that the correlation length decreased when the transmitting power increased. The measurement results support the assumption that nonlinear propagation generates harmonic energies and causes underestimation of scatterer diameters. Nonlinear propagation can be further enhanced by those materials with high B/A value-a parameter which characterizes the degree of nonlinearity. Nine versions of TM fat and non-fat materials were measured for their B/A values using a new measurement technique, the ``simplified finite amplitude insertion substitution'' (SFAIS) method.

  18. Noninvasive pulsed focused ultrasound allows spatiotemporal control of targeted homing for multiple stem cell types in murine skeletal muscle and the magnitude of cell homing can be increased through repeated applications

    PubMed Central

    Burks, Scott R.; Ziadloo, Ali; Kim, Saejeong J.; Nguyen, Ben A.; Frank, Joseph A.

    2013-01-01

    Stem cells are promising therapeutics for cardiovascular diseases and intravenous injection is the most desirable route of administration clinically. Subsequent homing of exogenous stem cells to pathological loci is frequently required for therapeutic efficacy and is mediated by chemo attractants (cell adhesion molecules, cytokines, and growth factors). Homing processes are inefficient and depend on short-lived pathological inflammation that limits the window of opportunity for cell injections. Noninvasive pulsed focused ultrasound (plus), which emphasizes mechanical ultrasound-tissue interactions, can be precisely targeted in the body and is a promising approach to target and maximize stem cell delivery by stimulating chemo attractant expression in plus-treated tissue prior to cell infusions. We demonstrate that plus is nondestructive to marine skeletal muscle tissue (no necrosis, hemorrhage, or muscle stem cell activation) and initiates a largely M2-type macrophage response. We also demonstrate local up regulation of chemo attractants in plus-treated skeletal muscle leads to enhance homing, permeability, and retention of human mesenchymal stem cells (MSC) and human endothelial precursor cells (EPC). Furthermore, the magnitude of MSC or EPC homing was increased when plus treatments and cell infusions were repeated daily. This study demonstrates that plus defines transient “molecular zip codes” of elevated chemo attractants in targeted muscle tissue, which effectively provides spatiotemporal control and tenability of the homing process for multiple stem cell types. plus is a clinically-translatable modality that may ultimately improve homing efficiency and flexibility of cell therapies for cardiovascular diseases. PMID:23922277

  19. Finite element modeling of tissue for optimal ultrasonic transducer array design

    Microsoft Academic Search

    Clyde Clarke; D. Carl White; Ralph Etienne-cummings

    2008-01-01

    Tissue characterization using ultrasound scattering has been routinely used to extract the cellular properties of tissue. Ultrasonic backscattered radio frequency (RF) data is analyzed to provide estimates of the size, shape and concentration of a wide range of tissues. These tissue parameters form a feature space that can be used to discriminate between tissue types as well as indicate the

  20. Development of non-deterioration-type skin tissue phantom using silicone material

    NASA Astrophysics Data System (ADS)

    Iva, Saidatul; Tanabe, Akihiro; Maeda, Takaaki; Funamizu, Hideki; Aizu, Yoshihisa

    2014-05-01

    We developed a new type of three-layered skin tissue phantom using silicone material. This phantom maintains its optical properties in a certain period of time, typically about three months, which is much longer than about 30 min with our previous agar-type phantom. Experiments on spectral reflectance measurements and color analysis indicate the possibility of silicone-type skin tissue phantom.

  1. Influence of different sized nanoparticles combined with ultrasound on the optical properties of in vitro normal and cancerous human lung tissue studied with OCT and diffuse reflectance spectra

    NASA Astrophysics Data System (ADS)

    Zhou, L. P.; Wu, G. Y.; Wei, H. J.; Guo, Z. Y.; Yang, H. Q.; He, Y. H.; Xie, S. S.; Liu, Y.

    2014-11-01

    The present study is concerned with the in vitro study of different sized titanium dioxide (TiO2) nanoparticles’ (NPs) penetration and accumulation in human normal lung (NL) tissue and lung adenocarcinoma tumor (LAT) tissue by the methods of continuous optical coherence tomography (OCT) monitoring and diffuse reflectance (DR) spectra measurement, and their evaluating the effects of TiO2 NPs in two sizes (60?nm and 100?nm) and their combination with ultrasound (US) on the optical properties of human NL and LAT tissue. Spectral measurements indicate that TiO2 NPs penetrate and accumulate into the tissues and thus induce enhancement of DR. The averaged and normalized OCT signal intensity suggests that light penetration depth is significantly enlarged by ultrasound. The average attenuation coefficient of NL tissue changes from 5.10? ± ?0.26?mm?1 to 3.12? ± ?0.43?mm?1 and 2.15? ± ?0.54?mm?1 at 120?min for 60?nm TiO2 NPs and 60?nm TiO2NPs/US treatment, respectively, and from 5.54? ± ?0.46?mm?1 to 3.24? ± ?0.73?mm?1 and 2.69? ± ?0.34?mm?1 at 150?min for 100?nm TiO2 NPs and 100?nm TiO2NPs/US, respectively. The average attenuation coefficient of LAT tissue changes from 9.12? ± ?0.54?mm?1 to 4.54? ± ?0.39?mm?1 and 3.61? ± ?0.38?mm?1 at 120?min for 60?nm TiO2 NPs and 60?nm TiO2NPs/US treatment, respectively, and from 9.79? ± ?0.32?mm?1 to 5.12? ± ?0.47?mm?1 and 4.89? ± ?0.59?mm?1 at 150?min for 100?nm TiO2 NPs and 100?nm TiO2NPs/US, respectively. The results suggest that the optical properties of NL and LAT tissues are greatly influenced by TiO2 NPs and their combination with ultrasound.

  2. Tissue-type plasminogen activator gene is on chromosome 8

    Microsoft Academic Search

    P. Tripputi; F. Blasi; T. Ny; B. S. Emanuel; J. Letosfsky; C. M. Croce

    1986-01-01

    Tissue plasminogen activator is one of the two plasminogen activators, both serine proteases, that catalyze the conversion of inactive plasminogen to plasmin, which then degrades the fibrin network of blood clots. By combining somatic cell genetics, in situ hybridization, and Southern blot hybridization, we localized the human tissue plasminogen activator gene to the pericentromeric region of chromosome 8.Copyright © 1986

  3. High intensity focused ultrasound (HIFU) and ethanol induced tissue ablation: Thermal lesion volume and temperature ex vivo

    NASA Astrophysics Data System (ADS)

    Hoang, Nguyen Hai

    HIFU is the upcoming technology for noninvasive or minimally invasive tumor ablation via the localized acoustic energy deposition at the focal region within the tumor target. The presence of cavitation bubbles had been shown to improve the therapeutic effect of HIFU. In this study, we have investigated the effect of HIFU on temperature rise and cavitation bubble activity in ethanol-treated porcine liver and kidney tissues. We have also explored changes in the viability and proliferation rate of HepG2, SW1376, and FB1 cancer cells with their exposure to ethanol and HIFU. Tissues were submerged in 95% ethanol for five hours and then exposed to HIFU generated by a 1.1 MHz transducer or injected into focal spot before HIFU exposure. Cavitation events were measured by a passive cavitation detection technique for a range of acoustic power from 1.17 W to 20.52 W. The temperature around the focal zone was measured by type K or type E thermocouples embedded in the samples. In experiments with cancer cells, 2.7 millions cells were treated with concentration of ethanol at concentration 2%, 4%, 10%, 25%, and 50% and the cell were exposed to HIFU with power of 2.73 W, 8.72 W, and 12.0 W for 30 seconds. Our data show that the treatment of tissues with ethanol reduces the threshold power for inertial cavitation and increases the temperature rise. The exposure of cancer cells to various HIFU power only showed a higher number of viable cells 24 to 72 hours after HIFU exposure. On the other hand, both the viability and proliferation rate were significantly decreased in cells treated with ethanol and then HIFU at 8.7 W and 12.0 W even at ethanol concentration of 2 and 4 percent. In conclusion, the results of our study indicate that percutaneous ethanol injection (PEI) and HIFU have a synergistic effect on cancer cells ablation.

  4. Tissue type characterization using photoacoustic power spectrum, a feasibility study

    NASA Astrophysics Data System (ADS)

    Tavakoli, Behnoosh; Goldstein, Seth D.; Kang, Jin U.; Choti, Michaal; Boctor, Emad M.

    2015-03-01

    The development of technologies capable of non-invasive characterization of tissue has the potential to significantly improve diagnostic and therapeutic medical interventions. In this study we investigated the feasibility of a noninvasive photoacoustic (PA) approach for characterizing biological tissues. The measurement was performed in the transmission mode with a wideband hydrophone while a tunable Q-switched Nd:YAG pulsed laser was used for illumination. The power spectrum of photoacoustic signal induced by a pulsed laser light from tissue was analyzed and features were extracted to study their correlation with tissue biomechanical properties. For a controlled study, tissue mimicking gelatin phantoms with different densities and equivalent optical absorptions were used as targets. The correlation between gelatin concentration of such phantoms and their mechanical properties were validated independently with a dynamic mechanical analyzer capable of calculating complex loss and storage moduli between two compression plates. It was shown that PA spectrums were shifted towards higher frequencies by increasing gelatin concentration. In order to quantify this effect, signal energy in two intervals of low and high frequency ranges were calculated. Gelatin concentration was correlated with PA energy in high frequency range with R2=0.94. Subsequently, PA signals generated from freshly resected human thyroid specimens were measured and analyzed in a similar fashion. We found that in aggregate, malignant thyroid tissue contains approximately 1.6 times lower energy in the high frequency range in comparison to normal thyroid tissue (p<0.01). This ratio increased with increasing illumination wavelength from 700 nm to 900nm. In summary, this study demonstrated the feasibility of using photoacoustic technique for characterizing tissue on the basis of viscoelastic properties of the tissue.

  5. Duplex ultrasound

    MedlinePLUS

    ... and veins. Related topics include: Carotid duplex ultrasound Doppler ultrasound of the arms or the legs ... A duplex ultrasound combines traditional ultrasound with Doppler ... records sound waves reflecting off moving objects, such ...

  6. Time-domain simulation of ultrasound propagation in a tissue-like medium based on the resolution of the nonlinear acoustic constitutive relations

    E-print Network

    Jiménez, Noé; Redondo, Javier; Sánchez-Morcillo, Víctor; Hou, Yi; Konofagou, Elisa E

    2015-01-01

    A time-domain numerical code based on the constitutive relations of nonlinear acoustics for simulating ultrasound propagation is presented. To model frequency power law attenuation, such as observed in biological media, multiple relaxation processes are included and relaxation parameters are fitted to both exact frequency power law attenuation and empirically measured attenuation of a variety of tissues that does not fit an exact power law. A computational technique based on artificial relaxation is included to correct the non-negligible numerical dispersion of the numerical method and to improve stability when shock waves are present. This technique avoids the use of high order finite difference schemes, leading to fast calculations. The numerical code is especially suitable to study high intensity and focused axisymmetric acoustic beams in tissue-like medium, as it is based on the full constitutive relations that overcomes the limitations of the parabolic approximations, while some specific effects not cont...

  7. Adipose tissue distribution is different in type 2 diabetes123

    PubMed Central

    Kelley, David E; Yim, Jung-Eun; Spence, Natasha; Albu, Jeanine; Boxt, Lawrence; Pi-Sunyer, F Xavier; Heshka, Stanley

    2009-01-01

    Background: The extent to which adipose tissue (AT) distribution is different between persons with type 2 diabetes (T2DM) and nondiabetic control subjects remains unclear. Objective: The aim of this study was to establish whether total body adiposity and its distribution, quantified by using state-of-the-art whole-body magnetic resonance imaging, differs between these 2 groups. Design: This cross-sectional evaluation included 93 participants (n = 56 women and 37 men) in the Look AHEAD (Action for HEAlth in Diabetes) Trial with T2DM who had a mean (±SD) age of 58.3 ± 6.6 y and body mass index (in kg/m2) of 31.6 ± 3.1 and 93 healthy non-T2DM control subjects (n = 64 women and 29 men) who had a mean (±SD) age of 60.6 ± 17.1 y and body mass index of 29.6 ± 3.0. All participants self-reported being of African American or white ancestry. Magnetic resonance imaging–derived in vivo measures of total-body AT (TAT) and its distribution, subcutaneous AT (SAT), visceral AT (VAT), and intermuscular AT (IMAT) were acquired. Linear regression models were developed for each AT compartment to adjust for important covariates of race, sex, age, height, and weight and to examine potential interactions of covariates. Results: These models showed significantly less SAT (African American: ?1.2 kg; white: ?2.4 kg; both P = 0.001), including less femoral-gluteal SAT, more VAT (African American: 0.7 kg, P < 0.001; white: 1.8 kg, P = 0.007), and more IMAT (0.5 kg, P = 0.001) in the T2DM group. Conclusion: We concluded that AT distribution is significantly altered in T2DM, ie, more VAT and IMAT—2 depots known to exacerbate insulin resistance—and less SAT in persons with T2DM than in healthy control subjects, a novel finding that we posit may compound the risk of insulin resistance. PMID:19158213

  8. Temperature estimation with ultrasound

    NASA Astrophysics Data System (ADS)

    Daniels, Matthew

    Hepatocelluar carcinoma is the fastest growing type of cancer in the United States. In addition, the survival rate after one year is approximately zero without treatment. In many instances, patients with hepatocelluar carcinoma may not be suitable candidates for the primary treatment options, i.e. surgical resection or liver transplantation. This has led to the development of minimally invasive therapies focused on destroying hepatocelluar by thermal or chemical methods. The focus of this dissertation is on the development of ultrasound-based image-guided monitoring options for minimally invasive therapies such as radiofrequency ablation. Ultrasound-based temperature imaging relies on relating the gradient of locally estimated tissue displacements to a temperature change. First, a realistic Finite Element Analysis/ultrasound simulation of ablation was developed. This allowed evaluation of the ability of ultrasound-based temperature estimation algorithms to track temperatures for three different ablation scenarios in the liver. It was found that 2-Dimensional block matching and a 6 second time step was able to accurately track the temperature over a 12 minute ablation procedure. Next, a tissue-mimicking phantom was constructed to determine the accuracy of the temperature estimation method by comparing estimated temperatures to that measured using invasive fiber-optic temperature probes. The 2-Dimensional block matching was able to track the temperature accurately over the entire 8 minute heating procedure in the tissue-mimicking phantom. Finally, two separate in-vivo experiments were performed. The first experiment examined the ability of our algorithm to track frame-to-frame displacements when external motion due to respiration and the cardiac cycle were considered. It was determined that a frame rate between 13 frames per second and 33 frames per second was sufficient to track frame-to-frame displacements between respiratory cycles. The second experiment examined the ability of a novel dynamic frame selection based temperature algorithm to track temperatures during ablation of porcine kidney tissue. Here a novel multi-level 2-Dimensional cross-correlation algorithm was required to accurately track the temperature over an 8 minute ablation procedure.

  9. 3D conformal MRI-controlled transurethral ultrasound prostate therapy: validation of numerical simulations and demonstration in tissue-mimicking gel phantoms

    NASA Astrophysics Data System (ADS)

    Burtnyk, Mathieu; Apoutou N'Djin, William; Kobelevskiy, Ilya; Bronskill, Michael; Chopra, Rajiv

    2010-11-01

    MRI-controlled transurethral ultrasound therapy uses a linear array of transducer elements and active temperature feedback to create volumes of thermal coagulation shaped to predefined prostate geometries in 3D. The specific aims of this work were to demonstrate the accuracy and repeatability of producing large volumes of thermal coagulation (>10 cc) that conform to 3D human prostate shapes in a tissue-mimicking gel phantom, and to evaluate quantitatively the accuracy with which numerical simulations predict these 3D heating volumes under carefully controlled conditions. Eleven conformal 3D experiments were performed in a tissue-mimicking phantom within a 1.5T MR imager to obtain non-invasive temperature measurements during heating. Temperature feedback was used to control the rotation rate and ultrasound power of transurethral devices with up to five 3.5 × 5 mm active transducer elements. Heating patterns shaped to human prostate geometries were generated using devices operating at 4.7 or 8.0 MHz with surface acoustic intensities of up to 10 W cm-2. Simulations were informed by transducer surface velocity measurements acquired with a scanning laser vibrometer enabling improved calculations of the acoustic pressure distribution in a gel phantom. Temperature dynamics were determined according to a FDTD solution to Pennes' BHTE. The 3D heating patterns produced in vitro were shaped very accurately to the prostate target volumes, within the spatial resolution of the MRI thermometry images. The volume of the treatment difference falling outside ±1 mm of the target boundary was, on average, 0.21 cc or 1.5% of the prostate volume. The numerical simulations predicted the extent and shape of the coagulation boundary produced in gel to within (mean ± stdev [min, max]): 0.5 ± 0.4 [-1.0, 2.1] and -0.05 ± 0.4 [-1.2, 1.4] mm for the treatments at 4.7 and 8.0 MHz, respectively. The temperatures across all MRI thermometry images were predicted within -0.3 ± 1.6 °C and 0.1 ± 0.6 °C, inside and outside the prostate respectively, and the treatment time to within 6.8 min. The simulations also showed excellent agreement in regions of sharp temperature gradients near the transurethral and endorectal cooling devices. Conformal 3D volumes of thermal coagulation can be precisely matched to prostate shapes with transurethral ultrasound devices and active MRI temperature feedback. The accuracy of numerical simulations for MRI-controlled transurethral ultrasound prostate therapy was validated experimentally, reinforcing their utility as an effective treatment planning tool.

  10. Combined ultrasound, optoacoustic, and elasticity imaging

    Microsoft Academic Search

    Stanislav Y. Emelianov; Salavat R. Aglyamov; J. Shah; S. Sethuraman; W. G. Scott; R. Schmitt; Massoud Motamedi; A. Karpiouk; Alexander A. Oraevsky

    2004-01-01

    Combination of three complementary imaging technologies - ultrasound imaging, elastography, and optoacoustic imaging - is suggested for detection and diagnostics of tissue pathology including cancer. The fusion of these ultrasound-based techniques results in a novel imaging system capable of simultaneous imaging of the anatomy (ultrasound imaging), cancer-induced angiogenesis (optoacoustic imaging) and changes in mechanical properties (elasticity imaging) of tissue to

  11. Medical Imaging Techniques Combining Light and Ultrasound

    Microsoft Academic Search

    Charles A. DiMarzio; Todd W. Murray

    2003-01-01

    The combination of light and ultrasound can lead to new medical imaging techniques combining the spectroscopic capability of light with the spatial resolution of ultrasound. Spectroscopy can be used to measure blood volume and blood oxygen, but because most biological tissues are highly scattering at optical wavelengths, spatial resolution is poor. Ultrasound provides excellent resolution, but not good soft-tissue contrast.

  12. Feasibility of optoacoustic visualization of high-intensity focused ultrasound-induced thermal lesions in live tissue

    Microsoft Academic Search

    Parag V. Chitnis; Hans-Peter Brecht; Richard Su; Alexander A. Oraevsky

    2010-01-01

    A 3-D optoacoustic imaging system was used to visualize thermal lesions produced in vivo using high-intensity focused ultrasound (HIFU). A 7.5-MHz, surgical, focused transducer with a radius of curvature of 35 mm and an aperture diameter of 23 mm was used to generate HIFU. A pulsed laser, which could operate at 755 nm and 1064 nm, was used to illuminate

  13. Gold nanoparticle targeted photoacoustic cavitation for potential deep tissue imaging and therapy

    PubMed Central

    Ju, Hengyi; Roy, Ronald A.; Murray, Todd W.

    2012-01-01

    The laser generation of vapor bubbles around plasmonic nanoparticles can be enhanced through the application of an ultrasound field; a technique referred to as photoacoustic cavitation. The combination of light and ultrasound allows for bubble formation at lower laser fluence and peak negative ultrasound pressure than can be achieved using either modality alone. The growth and collapse of these bubbles leads to local mechanical disruption and acoustic emission, and can potentially be used to induce and monitor tissue therapy. Photoacoustic cavitation is investigated for a broad range of ultrasound pressures and nanoparticle concentrations for gold nanorods and nanospheres. The cavitation threshold fluences for both nanoparticle types are found to drastically reduce in the presence of an ultrasound field. The results indicate that photoacoustic cavitation can potentially be produced at depth in biological tissue without exceeding the safety limits for ultrasound or laser radiation at the tissue surface. PMID:23304648

  14. Course Outline Course Medical Physics /BME 575: Diagnostic Ultrasound Physics

    E-print Network

    Walker, Thad G.

    in Tissue 7 27th March Ultrasound Scattering in Tissue 1st April Doppler Ultrasound 7 3rd April Doppler aperture annular array, 1979. Evans D, McDicken W, Skidmore R, and Woodcock J, Doppler Ultrasound Physics1 Course Outline Course Medical Physics /BME 575: Diagnostic Ultrasound Physics Session Spring 2014

  15. The characteristic ultrasound features of specific types of ovarian pathology (review).

    PubMed

    Sayasneh, Ahmad; Ekechi, Christine; Ferrara, Laura; Kaijser, Jeroen; Stalder, Catriona; Sur, Shyamaly; Timmerman, Dirk; Bourne, Tom

    2015-02-01

    Characterizing ovarian masses enables patients with malignancy to be appropriately triaged for treatment by subspecialist gynecological oncologists, which has been shown to optimize care and improve survival. Furthermore, correctly classifying benign masses facilitates the selection of patients with ovarian pathology that may either not require intervention, or be suitable for minimal access surgery if intervention is required. However, predicting whether a mass is benign or malignant is not the only clinically relevant information that we need to know before deciding on appropriate treatment. Knowing the specific histology of a mass is becoming of increasing importance as management options become more tailored to the individual patient. For example predicting a mucinous borderline tumor gives the opportunity for fertility sparing surgery, and will highlight the need for further gastrointestinal assessment. For benign disease, predicting the presence of an endometrioma and possible deeply infiltrating endometriosis is important when considering both who should perform and the extent of surgery. An examiner's subjective assessment of the morphological and vascular features of a mass using ultrasonography has been shown to be highly effective for predicting whether a mass is benign or malignant. Many masses also have features that enable a reliable diagnosis of the specific pathology of a particular mass to be made. In this narrative review we aim to describe the typical morphological features seen on ultrasound of different adnexal masses and illustrate these by showing representative ultrasound images. PMID:25406094

  16. In-vivo synthetic aperture flow imaging in medical ultrasound

    Microsoft Academic Search

    Svetoslav Ivanov Nikolov; Jmgen Arendt Jensen

    2003-01-01

    A new method for acquiring flow images using synthetic aperture techniques in medical ultrasound is presented. The new approach makes it possible to have a continuous acquisition of flow data throughout the whole image simultaneously, and this can significantly improve blood velocity estimation. Any type of filter can be used for discrimination between tissue and blood flow without initialization, and

  17. Markov models of specular and diffuse scattering in restoration of medical ultrasound images

    Microsoft Academic Search

    J. H. Hokland; Patrick A. Kelly

    1996-01-01

    Observed medical ultrasound images are degraded representations of the true tissue reflectance. The specular reflections at boundaries between regions of different tissue types are blurred, and the diffuse scattering within such regions also contains speckle. This reduces the diagnostic value of such images. In order to remove both blur and speckle, the authors develop a maximum a posteriori deconvolution algorithm

  18. Tissue transglutaminase regulates chondrogenesis in mesenchymal stem cells on collagen type XI matrices

    Microsoft Academic Search

    Shobana Shanmugasundaram; Sheila Logan-Mauney; Kaitlin Burgos; Maria Nurminskaya

    Tissue transglutaminase (tTG) is a multifunctional enzyme with a plethora of potential applications in regenerative medicine\\u000a and tissue bioengineering. In this study, we examined the role of tTG as a regulator of chondrogenesis in human mesenchymal\\u000a stem cells (MSC) using nanofibrous scaffolds coated with collagen type XI. Transient treatment of collagen type XI films and\\u000a 3D scaffolds with tTG results

  19. Current time-domain methods for assessing tissue motion by analysis from reflected ultrasound echoes-a review

    Microsoft Academic Search

    I. A. Hein

    1993-01-01

    The Doppler technique has traditionally been the method used to extract motion information from ultrasonic echoes reflected by moving tissues. The Doppler technique has been around for a long time, and has been extensively reviewed and analyzed in the literature. Recently, time-domain methodologies for estimating tissue motion have gained in popularity. Time-domain methods have advantages over Doppler methods in many

  20. Tissue Fibrinolytic Activity in Different Types of Varicose Veins

    Microsoft Academic Search

    Viola Hach; Monika Fink; Norbert Blees; Inge Scharrer

    1986-01-01

    The fibrinolytic activity of the venous wall was investigated by using Todd's technique 1 in 92 patients with different types of varicosis.A control group consisted of 19 patients with apparently normal superficial veins who had had a saphenectomy prior to an aortocoronary bypass operation. Fibrinolytic activity was mainly localized in the adventitia of varicose and nor mal veins. It significantly

  1. Distribution of Basement Membrane Molecules, Laminin and Collagen Type IV, in Normal and Degenerated Cartilage Tissues

    PubMed Central

    Toh, Wei Seong; Gomoll, Andreas H.; Olsen, Bjørn Reino; Spector, Myron

    2014-01-01

    Objective: The objective of the present study was to investigate the presence and distribution of 2 basement membrane (BM) molecules, laminin and collagen type IV, in healthy and degenerative cartilage tissues. Design: Normal and degenerated tissues were obtained from goats and humans, including articular knee cartilage, the intervertebral disc, and meniscus. Normal tissue was also obtained from patella-tibial enthesis in goats. Immunohistochemical analysis was performed using anti-laminin and anti–collagen type IV antibodies. Human and goat skin were used as positive controls. The percentage of cells displaying the pericellular presence of the protein was graded semiquantitatively. Results: When present, laminin and collagen type IV were exclusively found in the pericellular matrix, and in a discrete layer on the articulating surface of normal articular cartilage. In normal articular (hyaline) cartilage in the human and goat, the proteins were found co-localized pericellularly. In contrast, in human osteoarthritic articular cartilage, collagen type IV but not laminin was found in the pericellular region. Nonpathological fibrocartilaginous tissues from the goat, including the menisci and the enthesis, were also positive for both laminin and collagen type IV pericellularly. In degenerated fibrocartilage, including intervertebral disc, as in degenerated hyaline cartilage only collagen type IV was found pericellularly around chondrocytes but with less intense staining than in non-degenerated tissue. In calcified cartilage, some cells were positive for laminin but not type IV collagen. Conclusions: We report differences in expression of the BM molecules, laminin and collagen type IV, in normal and degenerative cartilaginous tissues from adult humans and goats. In degenerative tissues laminin is depleted from the pericellular matrix before collagen type IV. The findings may inform future studies of the processes underlying cartilage degeneration and the functional roles of these 2 extracellular matrix proteins, normally associated with BM.

  2. Ultrasound—biophysics mechanisms†

    PubMed Central

    O'Brien, William D.

    2007-01-01

    Ultrasonic biophysics is the study of mechanisms responsible for how ultrasound and biological materials interact. Ultrasound-induced bioeffect or risk studies focus on issues related to the effects of ultrasound on biological materials. On the other hand, when biological materials affect the ultrasonic wave, this can be viewed as the basis for diagnostic ultrasound. Thus, an understanding of the interaction of ultrasound with tissue provides the scientific basis for image production and risk assessment. Relative to the bioeffect or risk studies, that is, the biophysical mechanisms by which ultrasound affects biological materials, ultrasound-induced bioeffects are generally separated into thermal and nonthermal mechanisms. Ultrasonic dosimetry is concerned with the quantitative determination of ultrasonic energy interaction with biological materials. Whenever ultrasonic energy is propagated into an attenuating material such as tissue, the amplitude of the wave decreases with distance. This attenuation is due to either absorption or scattering. Absorption is a mechanism that represents that portion of ultrasonic wave that is converted into heat, and scattering can be thought of as that portion of the wave, which changes direction. Because the medium can absorb energy to produce heat, a temperature rise may occur as long as the rate of heat production is greater than the rate of heat removal. Current interest with thermally mediated ultrasound-induced bioeffects has focused on the thermal isoeffect concept. The non-thermal mechanism that has received the most attention is acoustically generated cavitation wherein ultrasonic energy by cavitation bubbles is concentrated. Acoustic cavitation, in a broad sense, refers to ultrasonically induced bubble activity occurring in a biological material that contains pre-existing gaseous inclusions. Cavitation-related mechanisms include radiation force, microstreaming, shock waves, free radicals, microjets and strain. It is more challenging to deduce the causes of mechanical effects in tissues that do not contain gas bodies. These ultrasonic biophysics mechanisms will be discussed in the context of diagnostic ultrasound exposure risk concerns. PMID:16934858

  3. An In Vivo Study of the Effects on Serum Glucose, Amylase and Histopathology of the Feline Pancreatic Tissue Treated by Focused Ultrasound

    PubMed Central

    Li, Chongyan; Wang, Zhibiao; Wu, Junru; Bai, Jin; Li, Faqi

    2014-01-01

    Pancreatic cancer is one of the most malignant neoplasms originating in the digestive system. Focused ultrasound (FUS) treatment instead of the surgery operation has been used to treat Pancreatic cancer noninvasively in clinical trials. The endocrine and exocrine glands in pancreas provide the two unique functions for a person to be healthy. It is critically important to find out if the FUS treatment can still keep the normal functions of the two glands. The goal of this study is to examine and analyze changes in histopathology and serum glucose and amylase levels of the targeted in-vivo felines after the FUS treatment. Various percentage volumes of pancreas of felines were insonified. The FUS treatment (7.5 MHz of central frequency; 5 W of acoustical power; transducer f-number ?=?0.33; 6 s insonification time per point) effectively generated coagulative necrosis at the insonified site while leaving tissue outside the insonified site intact. It was also observed that all felines endured well with the FUS treatment; changes introduced to pancreatic tissue after up to 50% of a pancreas by volume was insonified by the FUS procedure did not affect its normal endocrine and exocrine functions. PMID:24558434

  4. Contrast-enhanced, real-time volumetric ultrasound imaging of tissue perfusion: preliminary results in a rabbit model of testicular torsion

    PubMed Central

    Paltiel, HJ; Padua, HM; Gargollo, PC; Cannon, GM; Alomari, AI; Yu, R; Clement, GT

    2011-01-01

    Contrast-enhanced ultrasound (US) imaging is potentially applicable to the clinical investigation of a wide variety of perfusion disorders. Quantitative analysis of perfusion is not widely performed, and is limited by the fact that data are acquired from a single tissue plane, a situation that is unlikely to accurately reflect global perfusion. Real-time perfusion information from a tissue volume in an experimental rabbit model of testicular torsion was obtained with a two-dimensional matrix phased array US transducer. Contrast-enhanced imaging was performed in 20 rabbits during intravenous infusion of the microbubble contrast agent Definity® before and after unilateral testicular torsion and contralateral orchiopexy. The degree of torsion was 0° in 4 (sham surgery), 180° in 4, 360° in 4, 540° in 4, and 720° in 4. An automated technique was developed to analyze the time history of US image intensity in experimental and control testes. Comparison of mean US intensity rate of change and of ratios between mean US intensity rate of change in experimental and control testes demonstrated good correlation with testicular perfusion and mean perfusion ratios obtained with radiolabeled microspheres, an accepted “gold standard”. This method is of potential utility in the clinical evaluation of testicular and other organ perfusion. PMID:21403185

  5. Immunohistochemical localization of short chain cartilage collagen (type X) in avian tissues

    Microsoft Academic Search

    THOMAS M. SCHMID; THOMAS F. LINSENMAYER

    1985-01-01

    Monoclonal antibodies were produced against the recently described short chain cartilage collagen (type X collagen), and one (AC9) was extensively characterized and used for immunohistochemical localization studies on chick tissues. By competition enzyme-linked immunosorbent assay, antibody AC9 was observed to bind to an epitope within the helical domain of type X collagen and did not react with the other collagen

  6. [Numerical modeling of ultrasound thermotherapy].

    PubMed

    Ginter, S; Liebler, M; Dreyer, T; Riedlinger, R E

    2002-01-01

    In ultrasound thermotherapy (USTT) high intensity focused ultrasound (HIFU) is used for noninvasive thermal treatment of human tissue deep inside the body. In this paper a FDTD-model is presented to simulate USTT. It combines nonlinear ultrasound propagation and broadband tissue attenuation together with the bio-heat transfer equation for calculation of temperature distribution in tissue. The temperature dependence of parameters is integrated in the complete model. Simulation results demonstrate the potentialities of this simulation tool to analyze and optimize thermotherapy. PMID:12451833

  7. 2-D PSTD Simulation of the time-reversed ultrasound-encoded deep-tissue imaging technique.

    PubMed

    Tseng, Snow H; Ting, Wei-Lun; Wang, Shiang-Jiu

    2014-03-01

    We present a robust simulation technique to model the time-reversed ultrasonically encoded (TRUE) technique for deep-tissue imaging. The pseudospectral time-domain (PSTD) algorithm is employed to rigorously model the electromagnetic wave interaction of light propagating through a macroscopic scattering medium. Based upon numerical solutions of Maxwell's equations, the amplitude and phase are accurately accounted for to analyze factors that affect the TRUE propagation of light through scattering media. More generally, we demonstrate the feasibility of modeling light propagation through a virtual tissue model of macroscopic dimensions with numerical solutions of Maxwell's equations. PMID:24688821

  8. Point-of-care musculoskeletal ultrasound is critical for the diagnosis of hemarthroses, inflammation and soft tissue abnormalities in adult patients with painful haemophilic arthropathy.

    PubMed

    Kidder, W; Nguyen, S; Larios, J; Bergstrom, J; Ceponis, A; von Drygalski, A

    2015-07-01

    We previously demonstrated in adult patients with haemophilia (PWH) that hemarthrosis is present in only ~1/3rd of acutely painful joints by using point-of-care-musculoskeletal ultrasound (MSKUS). Therefore, other unrecognized tissue abnormalities must contribute to pain. Using high resolution MSKUS, employing grey scale and power Doppler, we sought to retrospectively (i) investigate soft tissue abnormalities in painful haemophilic joints and (ii) to determine to what extent MSKUS findings, functional or radiographic joint scores correlate with biomarkers of inflammation in PWH. Findings were correlated with Hemophilia Joint Health Scores (HJHS), Pettersson scores, high sensitivity C-reactive protein and von Willebrand factor activity and antigen levels. A total of 65 MSKUS examinations for acute and chronic joint pains were performed for 34 adult haemophilia patients, mostly for chronic joint pains (72.3%). The most prominent findings (66.5%) pertained to inflammatory soft tissue changes including synovitis, tendinitis, enthesitis, bursitis and fat pad inflammation. Effusions were present in 55.5% and 46.8% of MSKUS performed for acute and chronic pain, respectively. Of those, 90.0% were bloody during acute and 47.6% during persistent pains. While inflammatory biomarkers correlated well with overall HJHS and total Pettersson scores (P < 0.05), they did not differ between those patients with synovitis and those without. MSKUS is emerging as an important modality to diagnose treatable musculoskeletal abnormalities contributing to pain in haemophilic arthropathy, and therefore seems critical for a personalized approach to haemophilia care. The role of biomarkers in this setting remains less clear and requires further investigation. PMID:25623830

  9. Imaging of high-intensity focused ultrasound-induced lesions in soft biological tissue using thermoacoustic tomography

    E-print Network

    Wang, Lihong

    thermoacoustic tomography Xing Jin, Yuan Xu, and Lihong V. Wanga) Optical Imaging Laboratory, Department December 2004) An imaging technology, thermoacoustic tomograpy (TAT), was applied to the visualization thermoacoustic sources in this tissue sample. The thermoacoustic signals were detected by an unfocused ultrasonic

  10. Despeckling of medical ultrasound images

    Microsoft Academic Search

    Oleg V. Michailovich; Allen Tannenbaum

    2006-01-01

    Speckle noise is an inherent property of medical ultrasound imaging, and it generally tends to reduce the image resolution and contrast, thereby reducing the diagnostic value of this imaging modality. As a result, speckle noise reduction is an important prerequisite, whenever ultrasound imaging is used for tissue characterization. Among the many methods that have been proposed to perform this task,

  11. Modelling tissue electrophysiology with multiple cell types: applications of the extended bidomain framework.

    PubMed

    Corrias, Alberto; Pathmanathan, Pras; Gavaghan, David J; Buist, Martin L

    2012-02-01

    The bidomain framework has been extensively used to model tissue electrophysiology in a variety of applications. One limitation of the bidomain model is that it describes the activity of only one cell type interacting with the extracellular space. If more than one cell type contributes to the tissue electrophysiology, then the bidomain model is not sufficient. Recently, evidence has suggested that this is the case for at least two important applications: cardiac and gastrointestinal tissue electrophysiology. In the heart, fibroblasts ubiquitously interact with myocytes and are believed to play an important role in the organ electrophysiology. Along the GI tract, interstitial cells of Cajal (ICC) generate electrical waves that are passed on to surrounding smooth muscle cells (SMC), which are interconnected with the ICC and with each other. Because of the contribution of more than one cell type to the overall organ electrophysiology, investigators in different fields have independently proposed similar extensions of the bidomain model to incorporate multiple cell types and tested it on simplified geometries. In this paper, we provide a general derivation of such an extended bidomain framework applicable to any tissue and provide a generic and efficient implementation applicable to any geometry. Proof-of-concept results of tissue electrophysiology on realistic 3D organ geometries using the extended bidomain framework are presented for the heart and the stomach. PMID:22222297

  12. Ultrasound Techniques for Space Applications

    NASA Technical Reports Server (NTRS)

    Rooney, James A.

    1985-01-01

    Ultrasound has proven to be a safe non-invasive technique for imaging organs and measuring cardiovascular function. It has unique advantages for application to problems with man in space including evaluation of cardiovascular function both in serial studies and during critical operations. In addition, specialized instrumentation may be capable of detecting the onset of decompression sickness during EVA activities. A spatial location and three-dimensional reconstruction system is being developed to improve the accuracy and reproducibility for serial comparative ultrasound studies of cardiovascular function. The three-dimensional method permits the acquisition of ultrasonic images from many views that can be recombined into a single reconstruction of the heart or vasculature. In addition to conventional imaging and monitoring systems, it is sometimes necessary or desirable to develop instrumentation for special purposes. One example of this type of development is the design of a pulsed-Doppler system to monitor cerebral blood flow during critical operations such as re-entry. A second example is the design of a swept-frequency ultrasound system for the detection of bubbles in the circulatory system and/or soft tissues as an early indication of the onset of decompression sickness during EVA activities. This system exploits the resonant properties of bubbles and can detect both fundamental and second harmonic emissions from the insonified region.

  13. Assessment of ultrasound-assisted extraction as sample pre-treatment for the measurement of lead isotope ratios in marine biological tissues by multicollector inductively coupled plasma-mass spectrometry

    NASA Astrophysics Data System (ADS)

    Costas-Rodríguez, M.; Lavilla, Isela; Bendicho, Carlos

    2011-06-01

    In this work, ultrasound-assisted extraction (UAE) was evaluated as a sample preparation procedure for lead isotope ratio measurements in marine biological tissues by multicollector inductively coupled plasma-mass spectrometry. 20 mg of marine biological tissue and 1 mL of acid extractant were sonicated for 3 min at 60% ultrasound amplitude. Matrix separation was performed in the supernatant using a chromatographic exchange resin (Sr-Spec™). Total elimination of organic matter was achieved during the separation step. Microwave-assisted digestion and dry-ashing were used for comparative purposes. No significant differences were found in lead isotope ratios at 95% of confidence level. UAE emerges as an advantageous alternative to classical methods for sample preparation owing to its simplicity and rapidity ( i.e. operation steps were reduced), low reagent consumption and low contamination risks.

  14. Classification of arterial plaque by spectral analysis of in vitro radio frequency intravascular ultrasound data

    Microsoft Academic Search

    Robin J. Watson; Calum C. McLean; M. Pauliina Moore; Timothy Spencer; Donald M. Salter; Tom Anderson; Keith A. A. Fox; W. Norman McDicken

    2000-01-01

    To test whether radio-frequency analysis of coronary plaques predicts the histological classification, r.f. data were collected using a 30 MHz intravascular ultrasound scanner. Two hundred ninety-nine regions-of-interest from eight postmortem coronary arteries were selected and identified by histology as falling into one of seven different tissue types. These are loose fibrous tissue (n = 78), moderate fibrous tissue (n =

  15. X-ray scattering for classifying tissue types associated with breast disease.

    PubMed

    Sidhua, Sabeena; Siu, Karen K W; Falzon, Gregory; Nazaretian, Simon; Harte, Stewart A; Fox, Jane G; Susil, Beatrice J; Lewis, Robert A

    2008-10-01

    Collagen types I and III can be characterized at the molecular level (at the tens to hundreds of nanometers scale) using small angle x-ray scattering (SAXS). Although collagen fibril structural parameters at this length scale have shown differences between diseased and nondiseased breast tissues, a comprehensive analysis involving a multitude of features with a large (>50) patient cohort has not previously been investigated. Breast tissue samples were excised from 80 patients presenting with either a breast lump or reduction mammoplasty. From these, invasive carcinoma, benign tissue, and normal parenchyma were analyzed. Parameters related to collagen structure, including longitudinal (axial) and lateral (equatorial) features, polar angle features, total scattering intensity, and tissue heterogeneity effects, were extracted from the SAXS patterns and examined. The amplitude of the third-order axial peak and the total scattering intensity (amorphous scatter) showed the most separation between tissue groups and a classification model using these two parameters demonstrated an accuracy of over 95% between invasive carcinoma and mammoplasty patients. Normal tissue taken from disease-free patients (mammoplasty) and normal tissue taken from patients with presence of disease showed significant differences, suggesting that SAXS may provide different diagnostic information from that of conventional histopathology. PMID:18975712

  16. X-ray scattering for classifying tissue types associated with breast disease

    SciTech Connect

    Sidhu, Sabeena; Siu, Karen K. W.; Falzon, Gregory; Nazaretian, Simon; Hart, Stewart A.; Fox, Jane G.; Susil, Beatrice J.; Lewis, Robert A. [Monash Centre for Synchrotron Science, and School of Physics, Monash University, Clayton, Victoria 3800 (Australia); School of Science and Technology, University of New England, Armidale, New South Wales 2351 (Australia); Department of Anatomical Pathology, The Royal Women's Hospital, Carlton, Victoria 3053, Australia, Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria 3800, Australia, and Department of Pathology, Monash Medical Centre, Clayton, Victoria 3168 (Australia); Department of Surgery, Monash Medical Centre, Clayton, Victoria 3168, Australia and Monash Breast Unit, Monash Medical Centre, Moorabin, Victoria 3165 (Australia); Department of Surgery, Monash Medical Centre, Clayton, Victoria 3168, Australia and Monash Breast Unit, Monash Medical Centre, Moorabin, Victoria 3165 (Australia); Department of Pathology, Monash Medical Centre, Clayton, Victoria 3168, Australia and Monash Breast Unit, Monash Medical Centre, Moorabin, Victoria 3165 (Australia); Monash Centre for Synchrotron Science, and School of Physics, Monash University, Clayton, Victoria 3800 (Australia)

    2008-10-15

    Collagen types I and III can be characterized at the molecular level (at the tens to hundreds of nanometers scale) using small angle x-ray scattering (SAXS). Although collagen fibril structural parameters at this length scale have shown differences between diseased and nondiseased breast tissues, a comprehensive analysis involving a multitude of features with a large (>50) patient cohort has not previously been investigated. Breast tissue samples were excised from 80 patients presenting with either a breast lump or reduction mammoplasty. From these, invasive carcinoma, benign tissue, and normal parenchyma were analyzed. Parameters related to collagen structure, including longitudinal (axial) and lateral (equatorial) features, polar angle features, total scattering intensity, and tissue heterogeneity effects, were extracted from the SAXS patterns and examined. The amplitude of the third-order axial peak and the total scattering intensity (amorphous scatter) showed the most separation between tissue groups and a classification model using these two parameters demonstrated an accuracy of over 95% between invasive carcinoma and mammoplasty patients. Normal tissue taken from disease-free patients (mammoplasty) and normal tissue taken from patients with presence of disease showed significant differences, suggesting that SAXS may provide different diagnostic information from that of conventional histopathology.

  17. Using Data Fusion to Characterize Breast Tissue

    SciTech Connect

    Littrup, P; Duric, N; Leach, R R; Azevedo, S G; Candy, J V; Moore, T; Chambers, D H; Mast, J E; Johnson, S A; Holsapple, E

    2002-01-23

    New ultrasound data, obtained with a circular experimental scanner, are compared with data obtained with standard X-ray CT. Ultrasound data obtained by scanning fixed breast tissue were used to generate images of sound speed and reflectivity. The ultrasound images exhibit approximately 1 mm resolution and about 20 dB of dynamic range. All data were obtained in a circular geometry. X-ray CT scans were used to generate X-ray images corresponding to the same 'slices' obtained with the ultrasound scanner. The good match of sensitivity, resolution and angular coverage between the ultrasound and X-ray data makes possible a direct comparison of the three types of images. We present the results of such a comparison for an excised breast fixed in formalin. The results are presented visually using various types of data fusion. A general correspondence between the sound speed, reflectivity and X-ray morphologies is found. The degree to which data fusion can help characterize tissue is assessed by examining the quantitative correlations between the ultrasound and X-ray images.

  18. Controlling collagen fiber microstructure in three-dimensional hydrogels using ultrasound

    PubMed Central

    Garvin, Kelley A.; VanderBurgh, Jacob; Hocking, Denise C.; Dalecki, Diane

    2013-01-01

    Type I collagen is the primary fibrillar component of the extracellular matrix, and functional properties of collagen arise from variations in fiber structure. This study investigated the ability of ultrasound to control collagen microstructure during hydrogel fabrication. Under appropriate conditions, ultrasound exposure of type I collagen during polymerization altered fiber microstructure. Scanning electron microscopy and second-harmonic generation microscopy revealed decreased collagen fiber diameters in response to ultrasound compared to sham-exposed samples. Results of mechanistic investigations were consistent with a thermal mechanism for the effects of ultrasound on collagen fiber structure. To control collagen microstructure site-specifically, a high frequency, 8.3-MHz, ultrasound beam was directed within the center of a large collagen sample producing dense networks of short, thin collagen fibrils within the central core of the gel and longer, thicker fibers outside the beam area. Fibroblasts seeded onto these gels migrated rapidly into small, circularly arranged aggregates only within the beam area, and clustered fibroblasts remodeled the central, ultrasound-exposed collagen fibrils into dense sheets. These investigations demonstrate the capability of ultrasound to spatially pattern various collagen microstructures within an engineered tissue noninvasively, thus enhancing the level of complexity of extracellular matrix microenvironments and cellular functions achievable within three-dimensional engineered tissues. PMID:23927189

  19. The future perspectives in transrectal prostate ultrasound guided biopsy

    PubMed Central

    Hwang, Sung II; Lee, Hak Jong

    2014-01-01

    Prostate cancer is one of the most common neoplasms in men. Transrectal ultrasound (TRUS)-guided systematic biopsy has a crucial role in the diagnosis of prostate cancer. However, it shows limited value with gray-scale ultrasound alone because only a small number of malignancies are visible on TRUS. Recently, new emerging technologies in TRUS-guided prostate biopsy were introduced and showed high potential in the diagnosis of prostate cancer. High echogenicity of ultrasound contrast agent reflect the increased status of angiogenesis in tumor. Molecular imaging for targeting specific biomarker can be also used using ultrasound contrast agent for detecting angiogenesis or surface biomarker of prostate cancer. The combination of TRUS-guided prostate biopsy and ultrasound contrast agents can increase the accuracy of prostate cancer diagnosis. Elastography is an emerging ultrasound technique that can provide the information regarding tissue elasticity and stiffness. Tumors are usually stiffer than the surrounding soft tissue. In two types of elastography techniques, shearwave elastography has many potential in that it can provide quantitative information on tissue elasticity. Multiparametric magnetic resonance imaging (MRI) from high resolution morphologic and functional magnetic resonance (MR) technique enables to detect more prostate cancers. The combination of functional techniques including apparent diffusion coefficient map from diffusion weighted imaging, dynamic contrast enhanced MR and MR spectroscopy are helpful in the localization of the prostate cancer. MR-ultrasound (US) fusion image can enhance the advantages of both two modalities. With MR-US fusion image, targeted biopsy of suspicious areas on MRI is possible and fusion image guided biopsy can provide improved detection rate. In conclusion, with recent advances in multiparametric-MRI, and introduction of new US techniques such as contrast-enhanced US and elastography, TRUS-guided biopsy may evolve toward targeted biopsies rather than systematic biopsy for getting information reflecting the exact status of the prostate. PMID:25599070

  20. Metabolic factors, adipose tissue, and plasminogen activator inhibitor-1 levels in Type 2 diabetes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plasminogen activator inhibitor-1 (PAI-1) production by adipose tissue is increased in obesity, and its circulating levels are high in type 2 diabetes. PAI-1 increases cardiovascular risk by favoring clot stability, interfering with vascular remodeling, or both. We investigated in obese diabetic per...

  1. Immunocytochemical Localization of Type 5 17 b -Hydroxysteroid Dehydrogenase in Human Reproductive Tissues

    Microsoft Academic Search

    Georges Pelletier; Bernard Têtu; Fernand Labrie

    SUMMARY 17 b -hydroxysteroid dehydrogenase (17 b -HSD) controls the last step in the for- mation of all androgens and all estrogens. At least six 17 b -HSD isoenzymes have been iden- tified. The recently cloned Type 5 17 b -HSD transforms 4-dione into testosterone. To gain a better understanding of the role of this enzyme in reproductive tissues, we

  2. The influence of gluten free diet on quantitative ultrasound of proximal phalanxes in children and adolescents with type 1 diabetes mellitus and celiac disease

    Microsoft Academic Search

    Giuliana Valerio; Raffaella Spadaro; Dario Iafusco; Francesca Lombardi; Antonio del Puente; Antonella Esposito; Francesca De Terlizzi; Francesco Prisco; Riccardo Troncone; Adriana Franzese

    2008-01-01

    A reduced bone mineral density has been reported in patients with untreated celiac disease (CD) as well as in patients with poorly controlled type 1 diabetes mellitus (T1DM). The aim of this study was to evaluate the bone mineral status by phalangeal quantitative ultrasound in 52 children and adolescents with both diseases (mean age 13.3±4.9 years). As a control group 50

  3. Laser-generated ultrasound in single-crystal Mindlin-type plates: theory and experiment

    Microsoft Academic Search

    D. H. Hurley; J. B. Spicer

    1998-01-01

    A Mindlin-type plate theory, appropriate for laser-line irradiation of a single-crystal plate with cubic symmetry, is developed to predict the temporal displacement profile in the far-field of the laser source. The [100] crystal axis coincides with the plate normal and the [010] crystal axis is inclined at an angle to the laser-line source. A formal solution for the out-of-plane displacements

  4. Analysis of type II diabetes mellitus adipose-derived stem cells for tissue engineering applications

    PubMed Central

    Minteer, Danielle Marie; Young, Matthew T; Lin, Yen-Chih; Over, Patrick J; Rubin, J Peter; Gerlach, Jorg C

    2015-01-01

    To address the functionality of diabetic adipose-derived stem cells in tissue engineering applications, adipose-derived stem cells isolated from patients with and without type II diabetes mellitus were cultured in bioreactor culture systems. The adipose-derived stem cells were differentiated into adipocytes and maintained as functional adipocytes. The bioreactor system utilizes a hollow fiber–based technology for three-dimensional perfusion of tissues in vitro, creating a model in which long-term culture of adipocytes is feasible, and providing a potential tool useful for drug discovery. Daily metabolic activity of the adipose-derived stem cells was analyzed within the medium recirculating throughout the bioreactor system. At experiment termination, tissues were extracted from bioreactors for immunohistological analyses in addition to gene and protein expression. Type II diabetic adipose-derived stem cells did not exhibit significantly different glucose consumption compared to adipose-derived stem cells from patients without type II diabetes (p?>?0.05, N?=?3). Expression of mature adipocyte genes was not significantly different between diabetic/non-diabetic groups (p?>?0.05, N?=?3). Protein expression of adipose tissue grown within all bioreactors was verified by Western blotting.The results from this small-scale study reveal adipose-derived stem cells from patients with type II diabetes when removed from diabetic environments behave metabolically similar to the same cells of non-diabetic patients when cultured in a three-dimensional perfusion bioreactor, suggesting that glucose transport across the adipocyte cell membrane, the hindrance of which being characteristic of type II diabetes, is dependent on environment. The presented observation describes a tissue-engineered tool for long-term cell culture and, following future adjustments to the culture environment and increased sample sizes, potentially for anti-diabetic drug testing.

  5. Medical ultrasound with microbubbles

    Microsoft Academic Search

    Yoichiro Matsumoto; John S. Allen; Shin Yoshizawa; Teiichiro Ikeda; Yukio Kaneko

    2005-01-01

    In the medical ultrasound applications, microbubbles are closely tied to the diagnostic\\/therapeutic uses. For diagnostic applications, their sound scattering properties yield improved imaging, when the microbubbles are used as contrast agents. The harmonics and subharmonics responses from the bubbles assist in distinguishing the acoustic scattering of blood from that of the surrounding tissue. The therapeutic use of microbubbles has recently

  6. L-Type calcium channel blockade reduces network activity in human epileptic hypothalamic hamartoma tissue

    PubMed Central

    Simeone, Kristina A; Sabesan, Shivkumar; Kim, Do Young; Kerrigan, John F; Rho, Jong M; Simeone, Timothy A

    2011-01-01

    Purpose Human hypothalamic hamartomas (HHs) are associated with gelastic seizures, intrinsically epileptogenic, and notoriously refractory to medical therapy. We previously reported that the L-type calcium channel antagonist nifedipine blocks spontaneous firing and ?-aminobutyric acid (GABA)A–induced depolarization of single cells in HH tissue slices. In this study, we examined whether blocking L-type calcium channels attenuates emergent activity of HH neuronal networks. Methods A high-density multielectrode array was used to record extracellular signals from surgically resected HH tissue slices. High-frequency oscillations (HFOs, ripples and fast ripples), field potentials, and multiunit activity (MUA) were studied (1) under normal and provoked [4-aminopyridine (4-AP)] conditions; and (2) following nifedipine treatment. Key Findings Spontaneous activity occurred during normal artificial cerebrospinal fluid (aCSF) conditions. Nifedipine reduced the total number and duration of HFOs, abolished the association of HFOs with field potentials, and increased the inter-HFO burst intervals. Notably, the number of active regions was decreased by 45 ± 9% (mean ± SEM) after nifedipine treatment. When considering electrodes that detected activity, nifedipine increased MUA in 58% of electrodes and reduced the number of field potentials in 67% of electrodes. Provocation with 4-AP increased the number of events and, as the number of electrodes that detected activity increased 248 ± 62%, promoted tissue-wide propagation of activity. During provocation with 4-AP, nifedipine effectively reduced HFOs, the association of HFOs with field potentials, field potentials, MUA, and the number of active regions, and limited propagation. Significance This is the first study to report (1) the presence of HFOs in human subcortical epileptic brain tissue in vitro; (2) the modulation of “pathologic” high-frequency oscillations (i.e., fast ripples) in human epileptic tissue by L-type calcium channel blockers; and (3) the modulation of network physiology and synchrony of emergent activity in human epileptic tissue following blockade of L-type calcium channels. Attenuation of activity in HH tissue during normal and provoked conditions supports a potential therapeutic usefulness of L-type calcium channel blockers in epileptic patients with HH. PMID:21269296

  7. Metformin Ameliorates Podocyte Damage by Restoring Renal Tissue Podocalyxin Expression in Type 2 Diabetic Rats

    PubMed Central

    Zhai, Limin; Gu, Junfei; Yang, Di; Wang, Wei; Ye, Shandong

    2015-01-01

    Podocalyxin (PCX) is a signature molecule of the glomerular podocyte and of maintaining integrity of filtration function of glomerulus. The aim of this study was to observe the effect of different doses of metformin on renal tissue PCX expression in type 2 diabetic rats and clarify its protection on glomerular podocytes. Type 2 diabetic Sprague-Dawley (SD) rats in which diabetes was induced by high-fat diet/streptozotocin (HFD-STZ) were treated with different doses of metformin (150, 300, and 500?mg/kg per day, resp.) for 8 weeks. Various biochemical parameters, kidney histopathology, and renal tissue PCX expression levels were examined. In type 2 diabetic rats, severe hyperglycemia and hyperlipidemia were developed. Urinary albumin and PCX were markedly increased. Diabetes induced significant alterations in renal glomerular structure. In addition, protein and mRNA expression of renal tissue PCX were highly decreased. However, treatment of rats with different doses of metformin restored all these changes to a varying degree. These results suggested that metformin can ameliorate glomerular podocyte damage in type 2 diabetic rats, which may be partly associated with its role in restoring PCX expression and inhibiting urinary excretion of PCX with dose dependence.

  8. Tissue-type specific systemin perception and the elusive systemin receptor.

    PubMed

    Hind, Sarah R; Malinowski, Robert; Yalamanchili, Roopa; Stratmann, Johannes W

    2010-01-01

    Systemin is a wound signaling peptide from tomato that is important for plant defenses against herbivory. The systemin receptor was initially identified as the tomato homolog of the brassinosteroid receptor BRI1, but genetic evidence argued against this finding. However, we found that BRI1 may function as an inappropriate systemin binding protein that does not activate the systemin signaling pathway. Here we provide evidence that systemin perception is localized in a tissue-type specific manner. Mesophyll protoplasts were not sensitive to systemin, while they responded to other elicitors. We hypothesize that the elusive systemin receptor is a protein with high similarity to BRI1 which is specifically localized in vascular tissue like the systemin precursor prosystemin. Binding of systemin to BRI1 may be an artifact of transgenic BRI1-overexpressing plants, but does not take place in wild type tomato cells. PMID:20592806

  9. Trajectory-based Deformation Correction in Ultrasound Images

    E-print Network

    Sun, Shih-Yu

    Tissue deformation in ultrasound imaging poses a challenge to the development of many image registration techniques, including multimodal image fusion, multi-angle compound image and freehand three-dimensional ultrasound. ...

  10. Tissue-type plasminogen activator modulates inflammatory responses and renal function in ischemia reperfusion injury

    Microsoft Academic Search

    Joris J. T. H. Roelofs; Kasper M. A. Rouschop; Jaklien C. Leemans; Nike Claessen; Boer de A. M; Wilma M. Frederiks; H. Roger Lijnen; Jan J. Weening; Sandrine Florquin

    2006-01-01

    Acute renal failure is often the result of ischemia-reperfusion (I\\/R) injury. Neutrophil influx is an important damaging event in I\\/R. Tissue-type plasminogen activator (tPA) not only is a major fibrinolytic agent but also is involved in inflammatory processes. A distinct upregulation of tPA after I\\/R, with de novo tPA production by proximal renal tubules, was found. For investigating the role

  11. Validation of four-dimensional ultrasound for targeting in minimally-invasive beating-heart surgery

    NASA Astrophysics Data System (ADS)

    Pace, Danielle F.; Wiles, Andrew D.; Moore, John; Wedlake, Chris; Gobbi, David G.; Peters, Terry M.

    2009-02-01

    Ultrasound is garnering significant interest as an imaging modality for surgical guidance, due to its affordability, real-time temporal resolution and ease of integration into the operating room. Minimally-invasive intracardiac surgery performed on the beating-heart prevents direct vision of the surgical target, and procedures such as mitral valve replacement and atrial septal defect closure would benefit from intraoperative ultrasound imaging. We propose that placing 4D ultrasound within an augmented reality environment, along with a patient-specific cardiac model and virtual representations of tracked surgical tools, will create a visually intuitive platform with sufficient image information to safely and accurately repair tissue within the beating heart. However, the quality of the imaging parameters, spatial calibration, temporal calibration and ECG-gating must be well characterized before any 4D ultrasound system can be used clinically to guide the treatment of moving structures. In this paper, we describe a comprehensive accuracy assessment framework that can be used to evaluate the performance of 4D ultrasound systems while imaging moving targets. We image a dynamic phantom that is comprised of a simple robot and a tracked phantom to which point-source, distance and spherical objects of known construction can be attached. We also follow our protocol to evaluate 4D ultrasound images generated in real-time by reconstructing ECG-gated 2D ultrasound images acquired from a tracked multiplanar transesophageal probe. Likewise, our evaluation framework allows any type of 4D ultrasound to be quantitatively assessed.

  12. Decreased type V collagen expression in human decidual tissues of spontaneous abortion during early pregnancy.

    PubMed Central

    Iwahashi, M; Nakano, R

    1998-01-01

    AIM: To provide some insight into the aetiology of spontaneous abortion, the contents of type V collagen was investigated in human decidual tissues in spontaneous abortion and normal pregnancy. METHODS: Collagens were extracted from decidual tissues in spontaneous abortion (n = 19) and normal pregnancy (n = 25). The different types of collagen alpha chains were separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), stained with Coomassie brilliant blue, and measured by densitometry. The relative amounts of the alpha 1 (III) and alpha 1 (V) chains were calculated by dividing the band intensities of the alpha 1 (III) and alpha 1 (V) chains by that of the alpha 1 (I) chain. RESULTS: The ratio of the alpha 1 (V) chain to that of the alpha 1 (I) chain in decidual tissues in spontaneous abortion was significantly lower than that found in normal pregnancy (p < 0.05). CONCLUSIONS: These results suggest that type V collagen might play an important role in the maintenance of pregnancy and that decreased expression of this collagen could be associated with spontaneous abortion. Images PMID:9577371

  13. Proteomic profiling of cardiac tissue by isolation of nuclei tagged in specific cell types (INTACT)

    PubMed Central

    Amin, Nirav M.; Greco, Todd M.; Kuchenbrod, Lauren M.; Rigney, Maggie M.; Chung, Mei-I; Wallingford, John B.; Cristea, Ileana M.; Conlon, Frank L.

    2014-01-01

    The proper dissection of the molecular mechanisms governing the specification and differentiation of specific cell types requires isolation of pure cell populations from heterogeneous tissues and whole organisms. Here, we describe a method for purification of nuclei from defined cell or tissue types in vertebrate embryos using INTACT (isolation of nuclei tagged in specific cell types). This method, previously developed in plants, flies and worms, utilizes in vivo tagging of the nuclear envelope with biotin and the subsequent affinity purification of the labeled nuclei. In this study we successfully purified nuclei of cardiac and skeletal muscle from Xenopus using this strategy. We went on to demonstrate the utility of this approach by coupling the INTACT approach with liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomic methodologies to profile proteins expressed in the nuclei of developing hearts. From these studies we have identified the Xenopus orthologs of 12 human proteins encoded by genes, which when mutated in human lead to congenital heart disease. Thus, by combining these technologies we are able to identify tissue-specific proteins that are expressed and required for normal vertebrate organ development. PMID:24496632

  14. Effect of ultrasound on the production of IL-8, basic FGF and VEGF.

    PubMed

    Reher, P; Doan, N; Bradnock, B; Meghji, S; Harris, M

    1999-06-01

    Therapeutic angiogenesis is the controlled induction or stimulation of new blood vessel formation to reduce unfavourable tissue effects caused by local hypoxia and to enhance tissue repair. The effects of ultrasound on wound healing, chronic ulcers, fracture healing and osteoradionecrosis may be explained by the enhancement of angiogenesis. The aim of this study was to identify which cytokines and angiogenesis factors are induced by ultrasound in vitro. Two ultrasound machines were evaluated, a "traditional" (1 MHz, pulsed 1:4, tested at four intensities), and a "long wave" machine (45 kHz, continuous, also tested at four intensities). The ultrasound was applied to human mandibular osteoblasts, gingival fibroblasts and peripheral blood mononuclear cells (monocytes). The following cytokines and angiogenesis factors were assayed by ELISA techniques: interleukin-1beta(IL-1beta), IL-6, tumour necrosis factor alpha (TNF-alpha), IL-8, fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF).A slight stimulation of IL-1beta was noted in all cell types. There was no difference in the IL-6 and TNF-alpha levels. The angiogenesis-related cytokines, IL-8 and bFGF, were significantly stimulated in osteoblasts, and VEGF was significantly stimulated in all cell types. Both ultrasound machines produced similar results, and the optimum intensities were 0.1 and 0. 4 W/cm2 (SATA) with 1 MHz ultrasound, and 15 and 30 mW/cm2 (SATA) with 45 kHz ultrasound.The results show that therapeutic ultrasound stimulates the production of angiogenic factors such as IL-8, bFGF and VEGF. This may be one of the mechanisms through which therapeutic ultrasound induces angiogenesis and healing. PMID:10346981

  15. Tissue Transglutaminase Regulates Chondrogenesis in Mesenchymal Stem Cells on Collagen Type XI Matrices

    PubMed Central

    Shanmugasundaram, Shobana; Logan-Mauney, Sheila; Burgos, Kaitlin

    2011-01-01

    Tissue transglutaminase (tTG) is a multifunctional enzyme with a plethora of potential applications in regenerative medicine and tissue bioengineering. In this study, we examined the role of tTG as a regulator of chondrogenesis in human mesenchymal stem cells (MSC) using nanofibrous scaffolds coated with collagen type XI. Transient treatment of collagen type XI films and 3D scaffolds with tTG results in enhanced attachment of MSC and supports rounded cell morphology compared to the untreated matrices or those incubated in the continuous presence of tTG. Accordingly, enhanced cell aggregation and augmented chondrogenic differentiation have been observed on the collagen type XI-coated poly (L-lactide) - nanofibrous scaffolds treated with tTG prior to cell seeding. Exogenous tTG increases resistance to collagenolysis in collagen type XI matrices by catalyzing intermolecular cross-linking, detected by a shift in the denaturation temperature. In addition, tTG auto-crosslinks to collagen type XI as detected by western blot and immunofluorescent analysis. This study identifies tTG as a novel regulator of MSC chondrogenesis further contributing to the expanding use of these cells in cartilage bioengineering. PMID:21830118

  16. Temporal Healing in Rat Achilles Tendon: Ultrasound Correlations

    PubMed Central

    Chamberlain, Connie S.; Duenwald-Kuehl, Sarah E.; Okotie, Gregory; Brounts, Sabrina H.; Baer, Geoffrey S.; Vanderby, Ray

    2012-01-01

    The purpose of this study was to explore whether a new ultrasound-based technique correlates with mechanical and biological metrics that describe the tendon healing. Achilles tendons in 32 rats were unilaterally transected and allowed to heal without repair. At 7, 9, 14, or 29 days post-injury, tendons were collected and examined for healing via ultrasound image analysis, mechanical testing, and immunohistochemistry. Consistent with previous studies, we observe that the healing tendons are mechanically inferior (ultimate stress, ultimate load, and normalized stiffness) and biologically altered (cellular and ECM factors) compared to contralateral controls with an incomplete recovery over healing time. Unique to this study, we report: 1) Echo intensity (defined by gray-scale brightness in the ultrasound image) in the healing tissue is related to stress and normalized stiffness. 2) Elongation to failure is relatively constant so that tissue normalized stiffness is linearly correlated with ultimate stress. Together, 1 and 2 suggest a method to quantify mechanical compromise in healing tendons. 3) The amount and type of collagen in healing tendons associates with their strength and normalized stiffness as well as their ultrasound echo intensity. 4) A significant increase of periostin in the healing tissues suggests an important but unexplored role for this ECM protein in tendon healing. PMID:23149902

  17. SPECIAL ISSUE DEVOTED TO MULTIPLE RADIATION SCATTERING IN RANDOM MEDIA: Opto-acoustic diagnostics of the thermal action of high-intensity focused ultrasound on biological tissues: the possibility of its applications and model experiments

    NASA Astrophysics Data System (ADS)

    Khokhlova, Tanya D.; Pelivanov, Ivan M.; Sapozhnikov, Oleg A.; Solomatin, Vladimir S.; Karabutov, Aleksander A.

    2006-12-01

    The possibility of using the opto-acoustic (OA) method for monitoring high-intensity ultrasonic therapy is studied. The optical properties of raw and boiled liver samples used as the undamaged model tissue and tissue destroyed by ultrasound, respectively, are measured. Experiments are performed with samples consisting of several alternating layers of raw and boiled liver of different thickness. The position and transverse size of the thermal lesion were determined from the temporal shape of the OA signals. The results of measurements are compared with the real size and position of the thermal lesion determined from the subsequent cuts of the sample. It is shown that the OA method permits the diagnostics of variations in biological tissues upon ultrasonic therapy.

  18. Interactions between Human Immunodeficiency Virus Type 1 and Vaccinia Virus in Human Lymphoid Tissue Ex Vivo?

    PubMed Central

    Vanpouille, Christophe; Biancotto, Angélique; Lisco, Andrea; Brichacek, Beda

    2007-01-01

    Vaccinia virus (VACV) has been attracting attention recently not only as a vector for various vaccines but also as an immunization tool against smallpox because of its potential use as a bioterrorism agent. It has become evident that in spite of a long history of studies of VACV, its tissue pathogenesis remains to be fully understood. Here, we investigated the pathogenesis of VACV and its interactions with human immunodeficiency virus type 1 (HIV-1) in the context of human lymphoid tissues. We found that ex vivo-cultured tonsillar tissue supports productive infection by the New York City Board of Health strain, the VACV strain of the Dryvax vaccine. VACV readily infected both T and non-T (B) lymphocytes and depleted cells of both of these subsets equally over a 12-day period postinfection. Among T lymphocytes, CD8+ cells are preferentially depleted in accordance with their preferential infection: the probability that a CD8+ T cell will be productively infected is almost six times higher than for a CD4+ T cell. T cells expressing CCR5 and the activation markers CD25, CD38, and HLA-DR are other major targets for infection by VACV in lymphoid tissue. As a consequence, VACV predominantly inhibits the replication of the R5SF162 phenotype of HIV-1 in coinfected tissues, as R5-tropic HIV-1 requires activated CCR5+ CD4+ cells for productive infection. Human lymphoid tissue infected ex vivo by VACV can be used to investigate interactions of VACV with other viruses, in particular HIV-1, and to evaluate various VACV vectors for the purpose of recombinant vaccine development. PMID:17804502

  19. Characterization of Human Papillomavirus Type 154 and Tissue Tropism of Gammapapillomaviruses

    PubMed Central

    Ure, Agustín Enrique; Forslund, Ola

    2014-01-01

    The novel human papillomavirus type 154 (HPV154) was characterized from a wart on the crena ani of a three-year-old boy. It was previously designated as the putative HPV type FADI3 by sequencing of a subgenomic FAP amplicon. We obtained the complete genome by combined methods including rolling circle amplification (RCA), genome walking through an adapted method for detection of integrated papillomavirus sequences by ligation-mediated PCR (DIPS-PCR), long-range PCR, and finally by cloning of four overlapping amplicons. Phylogenetically, the HPV154 genome clustered together with members of the proposed species Gammapapillomavirus 11, and demonstrated the highest identity in L1 to HPV136 (68.6%). The HPV154 was detected in 3% (2/62) of forehead skin swabs from healthy children. In addition, the different detection sites of 62 gammapapillomaviruses were summarized in order to analyze their tissue tropism. Several of these HPV types have been detected from multiple sources such as skin, oral, nasal, and genital sites, suggesting that the gammapapillomaviruses are generalists with a broader tissue tropism than previously appreciated. The study expands current knowledge concerning genetic diversity and tropism among HPV types in the rapidly growing gammapapillomavirus genus. PMID:24551244

  20. Long-Term Type VII Collagen Restoration to Human Epidermolysis Bullosa Skin Tissue

    PubMed Central

    Siprashvili, Zurab; Nguyen, Ngon T.; Bezchinsky, Maria Y.; Marinkovich, M. Peter; Lane, Alfred T.

    2010-01-01

    Abstract In spite of advances in the molecular diagnosis of recessive dystrophic epidermolysis bullosa (RDEB), an inherited blistering disease due to a deficiency of type VII collagen at the basement membrane zone (BMZ) of stratified epithelium, current therapy is limited to supportive palliation. Gene delivery has shown promise in short-term experiments; however, its long-term sustainability through multiple turnover cycles in human tissue has awaited confirmation. To characterize approaches for long-term genetic correction, retroviral vectors were constructed containing long terminal repeat-driven full-length and epitope-tagged COL7A1 cDNA and evaluated for durability of type VII collagen expression and function in RDEB skin tissue regenerated on immune-deficient mice. Type VII collagen expression was maintained for 1 year in vivo, or over 12 epidermal turnover cycles, with no abnormalities in skin morphology or self-renewal. Type VII collagen restoration led to correction of RDEB disease features, including reestablishment of anchoring fibrils at the BMZ. This approach confirms durably corrective and noninjurious gene delivery to long-lived epidermal progenitors and provides the foundation for a human clinical trial of ex vivo gene delivery in RDEB. PMID:20497034

  1. Characterization of human papillomavirus type 154 and tissue tropism of gammapapillomaviruses.

    PubMed

    Ure, Agustín Enrique; Forslund, Ola

    2014-01-01

    The novel human papillomavirus type 154 (HPV154) was characterized from a wart on the crena ani of a three-year-old boy. It was previously designated as the putative HPV type FADI3 by sequencing of a subgenomic FAP amplicon. We obtained the complete genome by combined methods including rolling circle amplification (RCA), genome walking through an adapted method for detection of integrated papillomavirus sequences by ligation-mediated PCR (DIPS-PCR), long-range PCR, and finally by cloning of four overlapping amplicons. Phylogenetically, the HPV154 genome clustered together with members of the proposed species Gammapapillomavirus 11, and demonstrated the highest identity in L1 to HPV136 (68.6%). The HPV154 was detected in 3% (2/62) of forehead skin swabs from healthy children. In addition, the different detection sites of 62 gammapapillomaviruses were summarized in order to analyze their tissue tropism. Several of these HPV types have been detected from multiple sources such as skin, oral, nasal, and genital sites, suggesting that the gammapapillomaviruses are generalists with a broader tissue tropism than previously appreciated. The study expands current knowledge concerning genetic diversity and tropism among HPV types in the rapidly growing gammapapillomavirus genus. PMID:24551244

  2. Optimizing ultrasound focus distributions for hyperthermia

    Microsoft Academic Search

    Ronald J. Lalonde; John W. Hunt

    1995-01-01

    A method is described for generating ultrasound focus patterns for ultrasound hyperthermia treatment planning for steady state and transient hyperthermia. The solution for placement and intensity of ultrasound focus points is based on two types of temperature constraints: 1) equality constraints on the tumor boundary (temperature is held at maximum safe level), and 2) inequality constraints in the tumor interior

  3. Ultrasound Imaging of Internal Corrosion Habib Ammari

    E-print Network

    Ammari, Habib

    Ultrasound Imaging of Internal Corrosion Habib Ammari Hyeonbae Kang Eunjoo Kim§ Mikyoung Lim ultrasound boundary measurements. The method is based on an asymp- totic expansion of the effect, reconstruction, ultrasound detection, high fre- quencies, MUSIC-type algorithm 1 Introduction Corrosion detection

  4. Protein dynamics in whole body and in splanchnic and leg tissues in type I diabetic patients.

    PubMed Central

    Nair, K S; Ford, G C; Ekberg, K; Fernqvist-Forbes, E; Wahren, J

    1995-01-01

    To elucidate the mechanism of insulin's anticatabolic effect in humans, protein dynamics were evaluated in the whole-body, splanchnic, and leg tissues in six C-peptide-negative type I diabetic male patients in the insulin-deprived and insulin-treated states using two separate amino acid models (leucine and phenylalanine). L-(1-13C,15N)leucine, L-(ring-2H5)phenylalanine, and L-(ring-2H2) tyrosine were infused intravenously, and isotopic enrichments of [1-13C,15N]-leucine, (13C)leucine, (13C)ketoisocaproate, (2H5)phenylalanine, [2H4]tyrosine, (2H2)tyrosine, and 13CO2 were measured in arterial, hepatic vein, and femoral vein samples. Whole-body leucine flux, phenylalanine flux, and tyrosine flux were decreased (< 0.01) by insulin treatment, indicating an inhibition of protein breakdown. Moreover, insulin decreased (< 0.05) the rates of leucine oxidation and leucine transamination (P < 0.01), but the percent rate of ketoisocaproate oxidation was increased by insulin (P < 0.01). Insulin also reduced (< 0.01) whole-body protein synthesis estimated from both the leucine model (nonoxidative leucine disposal) and the phenylalanine model (disposal of phenylalanine not accounted by its conversion to tyrosine). Regional studies demonstrated that changes in whole body protein breakdown are accounted for by changes in both splanchnic and leg tissues. The changes in whole-body protein synthesis were not associated with changes in skeletal muscle (leg) protein synthesis but could be accounted for by the splanchnic region. We conclude that though insulin decreases whole-body protein breakdown in patients with type I diabetes by inhibition of protein breakdown in splanchnic and leg tissues, it selectively decreases protein synthesis in splanchnic tissues, which accounted for the observed decrease in whole-body protein synthesis. Insulin also augmented anabolism by decreasing leucine transamination. Images PMID:7769135

  5. Focused Ultrasound and Microbubbles for Enhanced Extravasation

    PubMed Central

    Böhmer, M. R.; Chlon, C. H. T.; Raju, B. I.; Chin, C. T.; Shevchenko, T.; Klibanov, A. L.

    2010-01-01

    The permeability of blood vessels for albumin can be altered by using ultrasound and polymer or lipid-shelled microbubbles. The region in which the microbubbles were destroyed with focused ultrasound was quantified in gel phantoms as a function of pressure, number of cycles and type of microbubble. At 2 MPa the destruction took place in a fairly wide area for a lipid-shelled agent, while for polymer-shelled agents at this setting, distinct destruction spots with a radius of only 1 mm were obtained. When microbubbles with a thicker shell were used, the pressure above which the bubbles were destroyed shifts to higher values. In vivo both lipid and polymer microbubbles increased the extravasation of the albumin binding dye Evans Blue, especially in muscle leading to about 6–8% of the injected dose to extravasate per gram muscle tissue 30 minutes after start of the treatment, while no Evans Blue could be detected in muscle in the absence of microbubbles. Variation in the time between ultrasound treatment and Evans Blue injection, demonstrated that the time window for promoting extravasation is at least an hour at the settings used. In MC38 tumors, extravasation already occurred without ultrasound and only a trend towards enhancement with about a factor 2 could be established with a maximum percentage injected dose per gram of 3%. Ultrasound mediated microbubble destruction especially enhances the extravasation in the highly vascularized outer part of the MC38 tumor and adjacent muscle and would, therefore, be most useful for release of, for instance, anti-angiogenic drugs. PMID:20600402

  6. Tissue specific loss of A-type lamins in the gastrointestinal epithelium can enhance polyp size.

    PubMed

    Wang, Audrey S; Kozlov, Serguei V; Stewart, Colin L; Horn, Henning F

    2015-01-01

    The nuclear lamina, comprised of the A and B-type lamins, is important in maintaining nuclear shape and in regulating key nuclear functions such as chromatin organization and transcription. Deletion of the A-type lamins results in genome instability and many cancers show altered levels of A-type lamin expression. Loss of function mutations in the mouse Lmna gene result in early postnatal lethality, usually within 3-5 weeks of birth making an analysis of the role of lamins in carcinogenesis difficult. To circumvent early lethality, and determine the role of the A-type lamins in specific tissues in older mice we derived a conditional allele of Lmna(FL/FL) (floxed). Lmna(FL/FL) was specifically deleted in the gastrointestinal (GI) epithelium by crossing the Lmna(FL/FL) mice with Villin-Cre mice. Mice lacking Lmna in the GI are overtly normal with no effects on overall growth, longevity or GI morphology. On a GI specific sensitized (Apc(Min/+)) background, polyp numbers are unchanged, but polyp size is slightly increased, and only in the duodenum. Our findings reveal that although A-type lamins are dispensable in the postnatal GI epithelium, loss of Lmna under malignant conditions may, to a limited extent, enhance polyp size indicating that A-type lamins may regulate cell proliferation in the transformed GI epithelium. PMID:25578479

  7. The temperature dependence of ultrasound-stimulated acoustic emission

    Microsoft Academic Search

    Elisa E. Konofagou; Jonathan Thierman; Tero Karjalainen; Kullervo Hynynen

    2002-01-01

    Given the high variability of tissue properties during sonication, temperature monitoring is one of the most crucial components for accurate thermal treatment of tissues with focused ultrasound and other thermotherapy devices. Recently, the method of ultrasound-stimulated acoustic emission (USAE) has been introduced as a potential method for measurements of mechanical properties of tissues. In this paper, the dependence of USAE

  8. Insulin action in muscle and adipose tissue in type 2 diabetes: The significance of blood flow.

    PubMed

    Lambadiari, Vaia; Triantafyllou, Konstantinos; Dimitriadis, George D

    2015-05-15

    Under normal metabolic conditions insulin stimulates microvascular perfusion (capillary recruitment) of skeletal muscle and subcutaneous adipose tissue and thus increases blood flow mainly after meal ingestion or physical exercise. This helps the delivery of insulin itself but also that of substrates and of other signalling molecules to multiple tissues beds and facilitates glucose disposal and lipid kinetics. This effect is impaired in insulin resistance and type 2 diabetes early in the development of metabolic dysregulation and reflects early-onset endothelial dysfunction. Failure of insulin to increase muscle and adipose tissue blood flow results in decreased glucose handling. In fat depots, a blunted postprandial blood flow response will result in an insufficient suppression of lipolysis and an increased spill over of fatty acids in the circulation, leading to a more pronounced insulin resistant state in skeletal muscle. This defect in blood flow response is apparent even in the prediabetic state, implying that it is a facet of insulin resistance and exists long before overt hyperglycaemia develops. The following review intends to summarize the contribution of blood flow impairment to the development of the atherogenic dysglycemia and dyslipidaemia. PMID:25987960

  9. Combined ultrasound, optoacoustic, and elasticity imaging

    NASA Astrophysics Data System (ADS)

    Emelianov, Stanislav Y.; Aglyamov, Salavat R.; Shah, J.; Sethuraman, S.; Scott, W. G.; Schmitt, R.; Motamedi, Massoud; Karpiouk, A.; Oraevsky, Alexander A.

    2004-07-01

    Combination of three complementary imaging technologies - ultrasound imaging, elastography, and optoacoustic imaging - is suggested for detection and diagnostics of tissue pathology including cancer. The fusion of these ultrasound-based techniques results in a novel imaging system capable of simultaneous imaging of the anatomy (ultrasound imaging), cancer-induced angiogenesis (optoacoustic imaging) and changes in mechanical properties (elasticity imaging) of tissue to uniquely identify and differentiate pathology at various stages. To evaluate our approach, analytical and numerical studies were performed using heterogeneous phantoms where ultrasonic, optical and viscoelastic properties of the materials were chosen to closely mimic soft tissue. The results of this study suggest that combined ultrasound-based imaging is possible and can provide more accurate, reliable and earlier detection and diagnosis of tissue pathology. In addition, monitoring of cancer treatment and guidance of tissue biopsy are possible with a combined imaging system.

  10. Type and location of injection drug use-related soft tissue infections predict hospitalization.

    PubMed

    Takahashi, Traci A; Merrill, Joseph O; Boyko, Edward J; Bradley, Katharine A

    2003-03-01

    The prevalence of soft tissue infections (abscesses, cellulitides, infected ulcers) among injection drug users (IDUs) is estimated to be between 21% and 32%. Little is known regarding the health care utilization associated with these infections. This study describes IDUs seeking emergency department (ED) care for soft tissue infections, their inpatient health care utilization, including operating room procedures, and the types and locations of infections associated with increased inpatient health care utilization. This study used a medical record case series of all IDUs seeking initial care for soft tissue infections at an urban, public emergency department from November 1999 through April 2000. Initial care for IDU-related soft tissue infections was sought by 242 patients. Most were male (63.6%), Caucasian (69.4%) and without health insurance (52.0%), and most had abscesses (72.3%). All patients with only cellulitis had arm or leg infections, while most abscesses were arm, deltoid, or buttock infections (81.1%). Forty percent of the patients were hospitalized, and 44.3% of the hospitalizations were for 3 or more days. Patients with only cellulitis were more likely to be hospitalized compared to those with abscesses. Among those with abscesses, deltoid abscesses were 5.2 times more likely to receive an operating room procedure compared to other abscess locations. IDUs with cellulitis and deltoid abscesses commonly required inpatient care and operating room procedures. The morbidity associated with such infections and the intensive use of hospital services needed to treat these infections provide strong rationale for the development of preventive interventions and improved care for this neglected clinical problem. PMID:12612102

  11. Guided tissue regeneration following treatment of recession-type defects in the monkey.

    PubMed

    Gottlow, J; Karring, T; Nyman, S

    1990-11-01

    Recent studies have demonstrated extensive amounts of new attachment formation following reconstructive surgery based on the biological principle of guided tissue regeneration (GTR). The aim of the present investigation was to evaluate the effect of using a polytetrafluorethylene (PTFE) membrane in GTR-treatment of recession-type defects and to examine the interrelationship between the PTFE membrane and surrounding periodontal tissues. Full-thickness flaps were raised around 24 maxillary premolar and molar teeth in 6 monkeys. The buccal alveolar bone was surgically removed to a level corresponding to the apical third of the roots. The exposed root surfaces were scaled and planed. In 12 teeth, PTFE membranes were adjusted to cover the exposed root surfaces from a level 1 to 2 mm apical to the CEJ, to a level 3 to 4 mm apical to the alveolar crest. The coronal border of the membranes was tightly adapted to the root surfaces by sling sutures. Twelve teeth served as control teeth without placement of membranes. The flaps were placed with the margin coronal to the CEJ and sutured. The animals were sacrificed after 3 months of healing and all experimental teeth were subjected to histological analysis. The membranes were found to be incorporated with the surrounding connective tissue, and the apical extension of the junctional epithelium terminated at the coronal border of the membranes. The amount of new attachment formation was on the average 74.3% of the defect height in the test teeth, which corresponded to 100% of the membrane covered root portion. Newly formed connective tissue attachment in the controls amounted to an average of 36.9% of the defect height.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2254834

  12. Intravascular tissue reactions induced by various types of bioabsorbable polymeric materials: correlation between the degradation profiles and corresponding tissue reactions

    PubMed Central

    Uchiyama, Naoyuki; Murayama, Yuichi; Nien, Yih-Lin; Lee, Daniel; Ebara, Masaki; Ishii, Akira; Chiang, Alexander; Vinters, Harry V.; Nishimura, Ichiro; Wu, Benjamin M.; Vinuela, Fernando

    2010-01-01

    Introduction Several different bioabsorbable polymeric coil materials are currently used with the goal of improving treatment outcomes of endovascular embolization of intracranial aneurysms. However, little is known about the correlation between polymer degradation profiles and concomitant tissue responses in a blood vessel. The authors describe in vitro degradation characteristics of nine different polymeric materials and their corresponding tissue responses induced in rabbit carotid arteries. Methods Mass loss and molecular weight loss of nine commercially available bioabsorbable sutures were evaluated in vitro up to16 weeks. The same nine materials, as well as platinum coils, were implanted into blind-end carotid arteries (n?=?44) in rabbits, and their tissue reactions were evaluated histologically 14 days after the implantation. Results Five of the nine polymers elicited moderate to strong tissue reactions relative to the remaining materials. While polymer mass loss did not correlate with their histologic findings, polymers that showed a faster rate of molecular weight loss had a tendency to present more active tissue reactions such as strong fibrocellular response around the implanted material with a moderate inflammatory cell infiltration. Maxon exhibited the fastest rate of molecular weight loss and poly-l-lactic acid the slowest. Conclusions The rate of molecular weight loss may be an important factor that is associated with the degree of bioactivity when bioabsorbable polymers are implanted into blood vessels. For further quantitative analysis, additional experiments utilizing established aneurysm models need to be conducted. PMID:20145914

  13. Cryopreservation and in vitro culture of primary cell types from lung tissue of a stranded pygmy sperm whale (Kogia breviceps)?

    PubMed Central

    Mancia, Annalaura; Spyropoulos, Demetri D.; McFee, Wayne E.; Newton, Danforth A.; Baatz, John E.

    2011-01-01

    Current models for in vitro studies of tissue function and physiology, including responses to hypoxia or environmental toxins, are limited and rely heavily on standard 2-dimensional (2-D) cultures with immortalized murine or human cell lines. To develop a new more powerful model system, we have pursued methods to establish and expand cultures of primary lung cell types and reconstituted tissues from marine mammals. What little is known about the physiology of the deep-sea diving pygmy sperm whale (PSW), Kogia breviceps, comes primarily from stranding events that occur along the coast of the southeastern United States. Thus, development of a method for preserving live tissues and retrieving live cells from deceased stranded individuals was initiated. This report documents successful cryopreservation of PSW lung tissue. We established in vitro cultures of primary lung cell types from tissue fragments that had been cryopreserved several months earlier at the stranding event. Dissociation of cryopreserved lung tissues readily provides a variety of primary cell types that, to varying degrees, can be expanded and further studied/manipulated in cell culture. In addition, PSW-specific molecular markers have been developed that permitted the monitoring of fibroblast, alveolar type II, and vascular endothelial cell types. Reconstitution of 3-D cultures of lung tissues with these cell types is now underway. This novel system may facilitate the development of rare or disease-specific lung tissue models (e.g., to test causes of PSW stranding events and lead to improved treatments for pulmonary hypertension or reperfusion injury in humans). Also, the establishment of a “living” tissue bank biorepository for rare/endangered species could serve multiple purposes as surrogates for freshly isolated samples. PMID:21501697

  14. Adipocyte Hypertrophy, Inflammation and Fibrosis Characterize Subcutaneous Adipose Tissue of Healthy, Non-Obese Subjects Predisposed to Type 2 Diabetes

    PubMed Central

    Henninger, A. M. Josefin; Eliasson, Björn; Jenndahl, Lachmi E.; Hammarstedt, Ann

    2014-01-01

    Background The adipose tissue is important for development of insulin resistance and type 2 diabetes and adipose tissue dysfunction has been proposed as an underlying cause. In the present study we investigated presence of adipocyte hypertrophy, and gene expression pattern of adipose tissue dysfunction in the subcutaneous adipose tissue of healthy, non-obese subjects predisposed to type 2 diabetes compared to matched control subjects with no known genetic predisposition for type 2 diabetes. Method Seventeen healthy and non-obese subjects with known genetic predisposition for type 2 diabetes (first-degree relatives, FDRs) and 17 control subjects were recruited. The groups were matched for gender and BMI and had similar age. Glucose tolerance was determined by an oral glucose tolerance test and insulin sensitivity was calculated using HOMA-index. Blood samples were collected and subcutaneous abdominal adipose tissue biopsies obtained for gene expression analysis and adipocyte cell size measurement. Results Our findings show that, in spite of similar age, BMI and percent body fat, FDRs displayed adipocyte hypertrophy, as well as higher waist/hip ratio, fasting insulin levels, HOMA-IR and serum triglycerides. Adipocyte hypertrophy in the FDR group, but not among controls, was associated with measures of impaired insulin sensitivity. The adipocyte hypertrophy was accompanied by increased inflammation and Wnt-signal activation. In addition, signs of tissue remodeling and fibrosis were observed indicating presence of early alterations associated with adipose tissue dysfunction in the FDRs. Conclusion Genetic predisposition for type 2 diabetes is associated with impaired insulin sensitivity, adipocyte hypertrophy and other markers of adipose tissue dysfunction. A dysregulated subcutaneous adipose tissue may be a major susceptibility factor for later development of type 2 diabetes. PMID:25148116

  15. Ultrasound microscope: the new field in ultrasound diagnostics

    NASA Astrophysics Data System (ADS)

    Novyc'kyy, Victor V.; Lushchyk, Ulyana B.

    2001-06-01

    A device which is a new stage in the development of medical equipment has been developed. The device works as an ultrasound microscope in vivo and provides 4 up to 32 colored histological image. It gives possibility to estimate tissue acoustic density with the help of 4 up to 32 gradation coloring different tissues and enables tissue microcirculation visualization. With the help of the device a doctor can objectify fatty hepatitis and cirrhosis, edema of different organs and tissues as well as microcirculation in organs and tissues (e.g. muscles, myocard and bone system). New promising applications of ultrasound systems in diagnostics and for choosing individual treatment tactics, with pathogenesis being taken into account, may be developed with the help of the device.

  16. The molecular structure of human tissue type XV presents a unique conformation among the collagens.

    PubMed

    Myers, Jeanne C; Amenta, Peter S; Dion, Arnold S; Sciancalepore, Justin P; Nagaswami, Chandrasekaran; Weisel, John W; Yurchenco, Peter D

    2007-06-15

    Establishing the structure of the non-fibrillar collagens has provided a unique perspective to understanding their specialized functions in the extracellular matrix. These proteins exhibit very diverse conformations and supramolecular assemblies. Type XV collagen is a large macromolecule distinguished by a highly interrupted collagenous domain and many utilized sites of attachment for CS (chondroitin sulfate) and HS (heparan sulfate) glycosaminoglycan chains. It is present in most basement membrane zones of human tissues, where it is found closely associated with large collagen fibrils. To determine the molecular shape and organization of type XV, the protein was purified from human umbilical cords by salt extraction, and by ion-exchange and antibody-affinity chromatography. The representation of type XV in one of its most abundant tissue sources is estimated at only (1-2)x10(-4)% of dry weight. The molecules examined by transmission electron microscopy after rotary shadowing were visualized in multiple forms. Relatively few type XV monomers appeared elongated and kinked; most molecules were found in a knot/figure-of-eight/pretzel configuration not previously described for a collagen. Collective measurements of these populations revealed an average length of 193+/-16 nm. At the N-terminal end, identified by C-terminal antibody binding, were three 7.7 nm-diameter spheres, corresponding to TSPN-1 (N-terminal module of thrombospondin-1) modules, and attached to the collagen backbone by a short linker. The type XV monomers show the ability to self-assemble into higher-order structures. Some were arranged in complex clusters, but simpler oligomers, which may represent intermediates, were observed in a cruciform pattern with intermolecular binding sites that probably originate in the interruption sequences. The morphology of type XV is thus the antithesis of the fibrillar collagens, and the shape attains the required flexibility to form the spectrum of interconnecting links between banded fibrils at the basement membrane/interstitial border. These type XV structures may act as a biological 'spring' to stabilize and enhance resilience to compressive and expansive forces, and the multimers, in particular, with selective complements of many localized CS and HS chains, may be instrumental in spatial and temporal recruitment of modulators in growth, development and pathological processes. PMID:17355226

  17. Section-thickness profiling for brachytherapy ultrasound guidance

    NASA Astrophysics Data System (ADS)

    Peikari, Mohammad; Chen, Thomas K.; Burdette, Everette C.; Fichtinger, Gabor

    2011-03-01

    Purpose: Ultrasound (US) elevation beamwidth causes a certain type of image artifact around the anechoic areas of the tissue. It is generally assumed that the US image is of zero thickness, which contradicts the fact that the acoustic beam can only be mechanically focused at a depth resulting in a finite, non-uniformed elevation beamwidth. We suspect that elevation beamwidth artifacts contribute to target reconstruction error in computer-assisted interventions. This paper introduces a method for characterization of the beamwidth for transrectal ultrasound (TRUS) used in prostate brachythyerapy. In particular, we measure how the US sectionthickness varies along the beam's axial depth. Method: We developed a beam-profiling device (a TRUS-bridge phantom) specifically tailored for standard brachytherapy ultrasound imaging systems to generate a complete section-thickness profile of a given TRUS transducer. The device was designed in CAD software and prototyped by a 3D printer. Result: The experimental results demonstrated that the TRUS beam in the elevation direction is focused closely to the transducer and theoretically the transducer would provide a better elevational resolution within that range. Conclusion: We presented a beam profiling phantom to measure the section-thickness of a transrectal ultrasound transducer for operating room use. However, there are some limitations which need to be addressed, for example, phantom sterilization and the speed of sound in the current medium of experiment which is not the same as that of biological tissues.

  18. Ultrasound characterization of the infertile male testis with rf power spectrum analysis

    NASA Astrophysics Data System (ADS)

    Coleman, Jonathan A.; Silverman, Ronald H.; Rondeau, Mark; Coleman, D. J.; Schlegel, Peter

    2002-04-01

    Objective: To investigate and diagnose testicular pathology in patients with testicular dysfunction using the technique of ultrasound power spectrum analysis. Methods: Testicular ultrasound studies with power spectrum tissue characterization analysis were performed on men with testicular abnormalities as well as normal controls. Semen analysis, biopsy data, microscopic intra-operative findings and data pertaining to testicular function were collected for each surgically evaluated subject. Ultrasound data were analyzed for power spectrum characteristics of microscopic scatterer size and concentration within discrete areas of testicular tissue. Results: Patients with varicoceles and greater than 2x106 sperm/ml on semen analysis had larger average scatterer size (107.7 micrometers ) and lower scatterer concentration (-15.02 dB) than non-obstructed, azoospermic patients with varicoceles (92.4 micrometers and -11.41 dB, respectively). Subjects with obstructed azoospermia had slightly larger average tissue scatterer size (108.1 micrometers ) and lower concentration (-15.73 dB) while normal control data revealed intermediate values of size (102.3 micrometers ) and concentration (-13.1 dB) of scatterers. Spectral data from pure testicular seminoma lesions had the lowest average scatterer size (82.3 micrometers ) with low relative concentration (-14.7 dB). Summary: Ultrasound tissue characterization based on RF spectrum analysis may distinguish different types of testicular pathology including obstructed and non-obstructed azoospermia and tissue changes due to varicocele and tumor.

  19. An atlas of active enhancers across human cell types and tissues.

    PubMed

    Andersson, Robin; Gebhard, Claudia; Miguel-Escalada, Irene; Hoof, Ilka; Bornholdt, Jette; Boyd, Mette; Chen, Yun; Zhao, Xiaobei; Schmidl, Christian; Suzuki, Takahiro; Ntini, Evgenia; Arner, Erik; Valen, Eivind; Li, Kang; Schwarzfischer, Lucia; Glatz, Dagmar; Raithel, Johanna; Lilje, Berit; Rapin, Nicolas; Bagger, Frederik Otzen; Jørgensen, Mette; Andersen, Peter Refsing; Bertin, Nicolas; Rackham, Owen; Burroughs, A Maxwell; Baillie, J Kenneth; Ishizu, Yuri; Shimizu, Yuri; Furuhata, Erina; Maeda, Shiori; Negishi, Yutaka; Mungall, Christopher J; Meehan, Terrence F; Lassmann, Timo; Itoh, Masayoshi; Kawaji, Hideya; Kondo, Naoto; Kawai, Jun; Lennartsson, Andreas; Daub, Carsten O; Heutink, Peter; Hume, David A; Jensen, Torben Heick; Suzuki, Harukazu; Hayashizaki, Yoshihide; Müller, Ferenc; Forrest, Alistair R R; Carninci, Piero; Rehli, Michael; Sandelin, Albin

    2014-03-27

    Enhancers control the correct temporal and cell-type-specific activation of gene expression in multicellular eukaryotes. Knowing their properties, regulatory activity and targets is crucial to understand the regulation of differentiation and homeostasis. Here we use the FANTOM5 panel of samples, covering the majority of human tissues and cell types, to produce an atlas of active, in vivo-transcribed enhancers. We show that enhancers share properties with CpG-poor messenger RNA promoters but produce bidirectional, exosome-sensitive, relatively short unspliced RNAs, the generation of which is strongly related to enhancer activity. The atlas is used to compare regulatory programs between different cells at unprecedented depth, to identify disease-associated regulatory single nucleotide polymorphisms, and to classify cell-type-specific and ubiquitous enhancers. We further explore the utility of enhancer redundancy, which explains gene expression strength rather than expression patterns. The online FANTOM5 enhancer atlas represents a unique resource for studies on cell-type-specific enhancers and gene regulation. PMID:24670763

  20. An atlas of active enhancers across human cell types and tissues

    NASA Astrophysics Data System (ADS)

    Andersson, Robin; Gebhard, Claudia; Miguel-Escalada, Irene; Hoof, Ilka; Bornholdt, Jette; Boyd, Mette; Chen, Yun; Zhao, Xiaobei; Schmidl, Christian; Suzuki, Takahiro; Ntini, Evgenia; Arner, Erik; Valen, Eivind; Li, Kang; Schwarzfischer, Lucia; Glatz, Dagmar; Raithel, Johanna; Lilje, Berit; Rapin, Nicolas; Bagger, Frederik Otzen; Jørgensen, Mette; Andersen, Peter Refsing; Bertin, Nicolas; Rackham, Owen; Burroughs, A. Maxwell; Baillie, J. Kenneth; Ishizu, Yuri; Shimizu, Yuri; Furuhata, Erina; Maeda, Shiori; Negishi, Yutaka; Mungall, Christopher J.; Meehan, Terrence F.; Lassmann, Timo; Itoh, Masayoshi; Kawaji, Hideya; Kondo, Naoto; Kawai, Jun; Lennartsson, Andreas; Daub, Carsten O.; Heutink, Peter; Hume, David A.; Jensen, Torben Heick; Suzuki, Harukazu; Hayashizaki, Yoshihide; Müller, Ferenc; Consortium, The Fantom; Forrest, Alistair R. R.; Carninci, Piero; Rehli, Michael; Sandelin, Albin

    2014-03-01

    Enhancers control the correct temporal and cell-type-specific activation of gene expression in multicellular eukaryotes. Knowing their properties, regulatory activity and targets is crucial to understand the regulation of differentiation and homeostasis. Here we use the FANTOM5 panel of samples, covering the majority of human tissues and cell types, to produce an atlas of active, in vivo-transcribed enhancers. We show that enhancers share properties with CpG-poor messenger RNA promoters but produce bidirectional, exosome-sensitive, relatively short unspliced RNAs, the generation of which is strongly related to enhancer activity. The atlas is used to compare regulatory programs between different cells at unprecedented depth, to identify disease-associated regulatory single nucleotide polymorphisms, and to classify cell-type-specific and ubiquitous enhancers. We further explore the utility of enhancer redundancy, which explains gene expression strength rather than expression patterns. The online FANTOM5 enhancer atlas represents a unique resource for studies on cell-type-specific enhancers and gene regulation.

  1. Ultrasound medical image deconvolution using CLEAN L.-T. Chiraa

    E-print Network

    Boyer, Edmond

    Ultrasound medical image deconvolution using CLEAN algorithm L.-T. Chiraa , J.-M. Giraultb , T reconstruction problem of ultrasound medical images using blind deconvolution algorithm has been recognized tissues scatters number. 1 Introduction The medical diagnostic using ultrasounds has intensively used

  2. Doppler Ultrasound Driven Biomechanical Model of the Brain for

    E-print Network

    Paris-Sud XI, Université de

    Doppler Ultrasound Driven Biomechanical Model of the Brain for Intraoperative Brain features. This low-cost system relies on loca- lized 2D Doppler ultrasound imaging of the brain which makes, Doppler ultrasound. hal-00706803,version1-11Jun2012 Author manuscript, published in "Soft Tissue

  3. Human 72-Kilodalton Type IV Collagenase Forms a Complex with a Tissue Inhibitor of Metalloproteases Designated TIMP-2

    Microsoft Academic Search

    Gregory I. Goldberg; Barry L. Marmer; Gregory A. Grant; Arthur Z. Eisen; Scott Wilhelm; Chengshi He

    1989-01-01

    Simian virus 40 (SV40)-transformed human lung fibroblasts secrete both 72-kDa type IV collagenase and a closely related 92-kDa type IV collagenase that was not detected in the parental cell line. The 92-kDa type IV procollagenase purified from these cells exists in a noncovalent complex with the tissue inhibitor of metalloproteases, TIMP. Here we report that the 72-kDa type IV procollagenase

  4. A statistical modeling approach for tumor-type identification in surgical neuropathology using tissue mass spectrometry imaging.

    PubMed

    Gholami, Behnood; Norton, Isaiah; Eberlin, Livia S; Agar, Nathalie Y R

    2013-05-01

    Current clinical practice involves classification of biopsied or resected tumor tissue based on a histopathological evaluation by a neuropathologist. In this paper, we propose a method for computer-aided histopathological evaluation using mass spectrometry imaging. Specifically, mass spectrometry imaging can be used to acquire the chemical composition of a tissue section and, hence, provides a framework to study the molecular composition of the sample while preserving the morphological features in the tissue. The proposed classification framework uses statistical modeling to identify the tumor type associated with a given sample. In addition, if the tumor type for a given tissue sample is unknown or there is a great degree of uncertainty associated with assigning the tumor type to one of the known tumor models, then the algorithm rejects the given sample without classification. Due to the modular nature of the proposed framework, new tumor models can be added without the need to retrain the algorithm on all existing tumor models. PMID:24592474

  5. Study of factors affecting the magnitude and nature of ultrasound exposure with in vitro set-ups.

    PubMed

    Leskinen, Jarkko J; Hynynen, Kullervo

    2012-05-01

    Therapeutic ultrasound is a clinically applied method to improve fracture healing and holds great potential as a manipulator of biologic material relevant to tissue engineering approaches. Unfortunately, the cell stimulating property of ultrasound is not known, which inhibits the optimal use of this technique. Additionally, many in vitro studies in this field use ultrasound configurations that are vulnerable to errors during calibration and use. These errors arise from the structural simplicity and incomplete characterization of these configurations. In this study, pulse-echo ultrasound, laser Doppler vibrometry and Schlieren imaging were applied to noninvasively characterize common in vitro experimental configurations. Fine wire thermocouple measurements were conducted to characterize any possible temperature rise during the ultrasound exposures. The results quantified the frequency dependent sound transmission through culture wells and the standing wave effect within the cell volume. These effects can cause uncertainty of up to 700% in the actual ultrasound exposure experienced by the cell. A temperature rise of 2.7°C was measured from an ultrasound configuration commonly used in vitro ultrasound studies. Furthermore, wave mode conversion in culture wells was observed, emphasizing the complexity of these sonications. Similar type Lamb waves have been observed in bone in vivo. Thus, Lamb waves may be a mechanism for stimulating the cells. PMID:22425382

  6. Connective Tissue Reflex Massage for Type 2 Diabetic Patients with Peripheral Arterial Disease: Randomized Controlled Trial

    PubMed Central

    Castro-Sánchez, Adelaida María; Moreno-Lorenzo, Carmen; Matarán-Peñarrocha, Guillermo A.; Feriche-Fernández-Castanys, Belen; Granados-Gámez, Genoveva; Quesada-Rubio, José Manuel

    2011-01-01

    The objective of this study was to evaluate the efficacy of connective tissue massage to improve blood circulation and intermittent claudication symptoms in type 2 diabetic patients. A randomized, placebo-controlled trial was undertaken. Ninety-eight type 2 diabetes patients with stage I or II-a peripheral arterial disease (PAD) (Leriche-Fontaine classification) were randomly assigned to a massage group or to a placebo group treated using disconnected magnetotherapy equipment. Peripheral arterial circulation was determined by measuring differential segmental arterial pressure, heart rate, skin temperature, oxygen saturation and skin blood flow. Measurements were taken before and at 30?min, 6 months and 1 year after the 15-week treatment. After the 15-week program, the groups differed (P < .05) in differential segmental arterial pressure in right lower limb (lower one-third of thigh, upper and lower one-third of leg) and left lower limb (lower one-third of thigh and upper and lower one-third of leg). A significant difference (P < .05) was also observed in skin blood flow in digits 1 and 4 of right foot and digits 2, 4 and 5 of left foot. ANOVA results were significant (P < .05) for right and left foot oxygen saturation but not for heart rate and temperature. At 6 months and 1 year, the groups differed in differential segmental arterial pressure in upper third of left and right legs. Connective tissue massage improves blood circulation in the lower limbs of type 2 diabetic patients at stage I or II-a and may be useful to slow the progression of PAD. PMID:19933770

  7. Intravascular ultrasound and photoacoustic imaging.

    PubMed

    Emelianov, Stanislav; Wang, Bo; Su, Jimmy; Karpiouk, Andrei; Yantsen, Evgeniya; Sokolov, Konstantin; Amirian, James; Smalling, Richard; Sethuraman, Shriram

    2008-01-01

    There is a need for an imaging technique that can reliably identify and characterize the vulnerability of atherosclerotic plaques. Catheter-based intravascular ultrasound (IVUS) is one of the imaging tools of the clinical evaluation of atherosclerosis. However, histopathological information obtained with IVUS imaging is limited. We present and discuss the applicability of a combined intravascular photoacoustic (IVPA) and intravascular ultrasound (IVUS) imaging approach to assess both vessel structure and tissue composition thus identifying rupture-prone atherosclerotic plaques. Photoacoustic (or optoacoustic and, generally, thermoacoustic) imaging relies on the absorption of electromagnetic energy, such as light, and the subsequent emission of an acoustic wave. Therefore, the amplitude and temporal characteristics of the photoacoustic signal is primarily determined by optical absorption properties of different types of tissues and can be used to differentiate the lipid, fibrous and fibro-cellular components of an inflammatory lesion. Simultaneous IVUS and IVPA imaging studies were conducted using 40 MHz clinical IVUS imaging catheter interfaced with a pulsed laser system. The performance of the IVPA/IVUS imaging was assessed using phantoms with point targets and vessel-mimicking phantoms. To detect the lipids in the plaque, ex-vivo IVPA imaging studies of a normal and an atherosclerotic rabbit aorta were performed at a 532 nm wavelength. To assess plaque composition, multi-wavelength (680-950 nm) spectroscopic IVPA imaging studies were carried out. Finally, molecular and cellular IVPA imaging was demonstrated using plasmonic nanoparticles. Overall, our studies suggest that plaque detection and characterization can be improved using the combined IVPA/IVUS imaging. PMID:19162578

  8. Abdominal ultrasound

    MedlinePLUS

    An ultrasound machine makes images of organs and structures inside the body. The machine sends out high-frequency sound waves that reflect off body structures. A computer receives these waves and uses them ...

  9. Ultrasound -- Pelvis

    MedlinePLUS Videos and Cool Tools

    ... blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ... the standard speculum used when performing a Pap test . A protective cover is placed over the transducer, ...

  10. Two-dimensional acoustic attenuation mapping of high-temperature interstitial ultrasound lesions

    NASA Astrophysics Data System (ADS)

    Tyréus, Per Daniel; Diederich, Chris

    2004-02-01

    Acoustic attenuation change in biological tissues with temperature and time is a critical parameter for interstitial ultrasound thermal therapy treatment planning and applicator design. Earlier studies have not fully explored the effects on attenuation of temperatures (75-95 °C) and times (5-15 min) common in interstitial ultrasound treatments. A scanning transmission ultrasound attenuation measurement system was devised and used to measure attenuation changes due to these types of thermal exposures. To validate the approach and to loosely define expected values, attenuation changes in degassed ex vivo bovine liver, bovine brain and chicken muscle were measured after 10 min exposures in a water bath to temperatures up to 90 °C. Maximum attenuation increases of approximately seven, four and two times the values at 37 °C were measured for the three tissue models at 5 MHz. By using the system to scan over lesions produced using interstitial ultrasound applicators, 2D contour maps of attenuation were produced. Attenuation profiles measured through the centrelines of lesions showed that attenuation was highest close to the applicator and decreased with radial distance, as expected with decreasing thermal exposure. Attenuation values measured in profiles through lesions were also shown to decrease with reduced power to the applicator. Attenuation increases in 2D maps of interstitial ultrasound lesions in ex vivo chicken breast, bovine liver and bovine brain were correlated with visible tissue coagulation. While regions of visible coagulation corresponded well to contours of attenuation increase in liver and chicken, no lesion was visible under the same experimental conditions in brain, due primarily to the heterogeneity of the tissue. Acoustic and biothermal simulations were employed to show that attenuation models taking into account these attenuation changes at higher temperatures and longer times were better able to fit experimental data than previous models. These simulations also indicated that the characterization of tissue acoustic and thermal properties over a large range of temperatures is critical for accurate treatment planning or design studies involving high-temperature interstitial ultrasound.

  11. Simulation of ultrasound backscatter images from fish

    NASA Astrophysics Data System (ADS)

    Pham, An Hoai; Stage, Bjarne; Hemmsen, Martin Christian; Lundgren, Bo; Pedersen, Mads Møller; Pedersen, Tina Bock; Jensen, Jørgen Arendt

    2011-03-01

    The objective of this work is to investigate ultrasound (US) backscatter in the MHz range from fish to develop a realistic and reliable simulation model. The long term objective of the work is to develop the needed signal processing for fish species differentiation using US. In in-vitro experiments, a cod (Gadus morhua) was scanned with both a BK Medical ProFocus 2202 ultrasound scanner and a Toshiba Aquilion ONE computed tomography (CT) scanner. The US images of the fish were compared with US images created using the ultrasound simulation program Field II. The center frequency of the transducer is 10 MHz and the Full Width at Half Maximum (FWHM) at the focus point is 0.54 mm in the lateral direction. The transducer model in Field II was calibrated using a wire phantom to validate the simulated point spread function. The inputs to the simulation were the CT image data of the fish converted to simulated scatter maps. The positions of the point scatterers were assumed to be uniformly distributed. The scatter amplitudes were generated with a new method based on the segmented CT data in Hounsfield Units and backscatter data for the different types of tissues from the literature. The simulated US images reproduce most of the important characteristics of the measured US image.

  12. Distribution of a macaque immunosuppressive type D retrovirus in neural, lymphoid, and salivary tissues

    SciTech Connect

    Lackner, A.A.; Rodriguez, M.H.; Bush, C.E.; Munn, R.J.; Kwang, Hweising; Moore, P.F.; Osborn, K.G.; Marx, P.A.; Gardner, M.B.; Lowenstine, L.J. (Univ. of California, Davis (USA))

    1988-06-01

    Simian acquired immune deficiency syndrome (SAIDS) in rhesus macaques (Macaca mulatta) at the California Primate Research Center is caused by a type D retrovirus designated SAIDS retrovirus serotype 1 (SRV-1). This syndrome is characterized by profound immunosuppression and death associated with opportunistic infections. Neurologic signs and lesions have not been described as part of this syndrome. The distribution of SRV-1 in the salivary glands, lymph nodes, spleens, thymuses, and brains of eight virus-infected rhesus macaques was examined by immunohistochemistry. Electron microscopy, in situ RNA hybridization, and Southern blot hybridization were also performed on selected tissues to detect viral particles, RNA, and DNA, respectively. In seven of eight SRV-1-infected animals, the transmembrane envelope glycoprotein (gp20) of SRV-1 was present in three or more tissues, but never in the brain. In the remaining animal, no viral antigen was detected in any tissue. In this same group of animals, viral nucleic acid was detected in the lymph nodes of six of six animals by Southern blot hybridization, in the salivary glands of two of five animals by both Southern blot and in situ hybridizations, and, surprisingly, in the brains of three of three animals by Southern blot and of three of five animals by in situ hybridization, including the one animal in which viral gp20 was undetectable. None of these animals had neurologic signs or lesions. The detection of viral nucleic acid in the absence of viral antigen in the brain suggests latent SRV-1 infection of the central nervous system.

  13. Quantitative multispectral analysis following fluorescent tissue transplant for visualization of cell origins, types, and interactions.

    PubMed

    Spaeth, Erika L; Booth, Christopher M; Marini, Frank C

    2013-01-01

    With the desire to understand the contributions of multiple cellular elements to the development of a complex tissue; such as the numerous cell types that participate in regenerating tissue, tumor formation, or vasculogenesis, we devised a multi-colored cellular transplant model of tumor development in which cell populations originate from different fluorescently colored reporter gene mice and are transplanted, engrafted or injected in and around a developing tumor. These colored cells are then recruited and incorporated into the tumor stroma. In order to quantitatively assess bone marrow derived tumor stromal cells, we transplanted GFP expressing transgenic whole bone marrow into lethally irradiated RFP expressing mice as approved by IACUC. 0ovarian tumors that were orthotopically injected into the transplanted mice were excised 6-8 weeks post engraftment and analyzed for bone marrow marker of origin (GFP) as well as antibody markers to detect tumor associated stroma using multispectral imaging techniques. We then adapted a methodology we call MIMicc- Multispectral Interrogation of Multiplexed cellular compositions, using multispectral unmixing of fluoroprobes to quantitatively assess which labeled cell came from which starting populations (based on original reporter gene labels), and as our ability to unmix 4, 5, 6 or more spectra per slide increases, we've added additional immunohistochemistry associated with cell lineages or differentiation to increase precision. Utilizing software to detect co-localized multiplexed-fluorescent signals, tumor stromal populations can be traced, enumerated and characterized based on marker staining. PMID:24084599

  14. Athlete's nodules: sports-related connective tissue nevi of the collagen type (collagenomas).

    PubMed

    Cohen, P R; Eliezri, Y D; Silvers, D N

    1992-08-01

    Sports-related connective tissue nevi of the collagen type (collagenomas) have been referred to as athlete's nodules. Surfers, boxers, marbles players, and football players are some of the athletes in whom these lesions have been observed. The nodules can be found on the dorsal aspect of the feet, knees, or knuckles and can readily be differentiated from other conditions by either clinical history or microscopic features or both. Treatment options include conservative measures or surgical intervention. Recurrent trauma and friction to the involved location are likely causative factors. Although the ultrastructural pathogenesis remains to be established, changes in the molecular metabolism of collagen resulting in enhanced synthesis and/or accumulation of collagen may have a contributory role. PMID:1511619

  15. Tissue-type plasminogen activator in the ischemic brain: more than a thrombolytic.

    PubMed

    Yepes, Manuel; Roussel, Benoit D; Ali, Carine; Vivien, Denis

    2009-01-01

    Thrombolysis with tissue-type plasminogen activator (tPA) is used for the treatment of patients with acute ischemic stroke. However, a growing body of evidence indicates that, besides the unquestionable benefit from its thrombolytic activity, tPA also has a deleterious effect on the ischemic brain including cytotoxicity and increased permeability of the neurovascular unit with the development of cerebral edema. Because an increasing number of acute stroke patients are treated with tPA, it is important to know the mechanisms of harmful effects of tPA on the ischemic brain. Here, the best studied pathways of tPA neurotoxicity are discussed along with future directions for a safer use of tPA as a thrombolytic agent in the setting of acute ischemic stroke. PMID:18963068

  16. Balloon Type Elasticity Sensing of Left Ventricular Tissue for Small Experimental Animals

    NASA Astrophysics Data System (ADS)

    Higashimori, Mitsuru; Ishii, Ryohei; Tadakuma, Kenjiro; Kaneko, Makoto; Tamaki, Syunsuke; Sakata, Yasushi; Yamamoto, Kazuhiro

    This paper describes an elasticity sensing system for a left ventricular tissue of small experimental animal. We first show the basic concept of the proposed method, where a ring shaped specimen is dilated by a balloon type probe with pressure based control and the elasticity is estimated by using the stress and strain information. We introduce the dual cylinder model for approximating the strengths of material of the specimen and the balloon. Based on this model, we can derive the Young's modulus of the specimen. After showing the developed experimental system, we show basic experiments using silicone specimens. We finally show a couple of experimental results using rat and mouse, where specimens with HFPEF (Heart Failure with Preserved Ejection Fraction) can be separated from normal specimens.

  17. Distribution and characterization of rhogocyte cell types in the mantle tissue of Haliotis laevigata.

    PubMed

    Sairi, Fareed; Valtchev, Peter; Gomes, Vincent G; Dehghani, Fariba

    2015-04-01

    Molluscan rhogocytes are known to be the only cells able to synthesize hemocyanin that is one of the largest respiratory proteins in nature. However, investigation of rhogocyte cells in vitro is limited due to difficulty in isolating and establishing marine cell culture. The aim of this study was to investigate the nature and distribution of rhogocyte cells of Haliotis laevigata in the mantle tissue with respect to the expression of the two known isoforms of hemocyanin. Rhogocyte cells were identified using immunofluorescence-fluorescence in situ hybridization (IF-FISH) that involved simultaneous staining of localized hemocyanin by a polyclonal antibody while the mRNA was hybridized with FISH probes. The distribution of rhogocyte cells was demonstrated using flow cytometry, followed by cell sorting with fluorescence-activated cell sorter (FACS) and confocal microscope imaging for further characterization. Our results suggested that the mantle tissue is dominated by two distinct populations of rhogocyte cells that synthesize hemocyanin type 1. Observation with confocal microscopy of both populations revealed hemocyanin localization in the periphery of the cell membrane. Cell population with higher antibody signal had irregular and elongated cell morphology with punctate mRNA probe signals. The second population with lower antibody signal had ovoid morphology and wide distribution of mRNA probe signals. We suggest that these populations represent two distinct phases of hemocyanin biosynthesis of a single isoform, which is closely related to Haliotis tuberculata type 1 hemocyanin (HtH1). The knowledge acquired in this study enhances the understanding of the biology of rhogocyte cells and biosynthesis of hemocyanin. PMID:25382219

  18. New method of ultrasound-modulated optical tomography

    Microsoft Academic Search

    Yong Yao; Da Xing; Yonghong He; Kenichi Ueda

    2000-01-01

    A new method of ultrasound-modulated optical tomography is reported, which ultrasound wave is amplitude modulated to increase detection sensitivity and signal-to-noise rate. Near-infrared laser is incident to tissue simulating medium and modulated by focused ultrasound. A buried object in simulating medium mis imaged with modulated multi-diffuse light that pass through ultrasound focal zone. The light signal is demodulated by real-time

  19. Differential modulation of the functionality of white adipose tissue of obese Zucker (fa/fa) rats by the type of protein and the amount and type of fat.

    PubMed

    Díaz-Villaseñor, Andrea; Granados, Omar; González-Palacios, Berenice; Tovar-Palacio, Claudia; Torre-Villalvazo, Ivan; Olivares-García, Verónica; Torres, Nimbe; Tovar, Armando R

    2013-11-01

    Recent evidence indicates that several metabolic abnormalities developed during obesity are associated with the presence of dysfunctional adipose tissue. Diet is a key factor that modulates several functions of adipose tissue; however, each nutrient in the diet produces specific changes. Thus, the aim of this work was to study the effect of the interaction of the type (coconut or soybean oil) and amount (5% or 10%) of fat with the type of dietary protein (casein or soy protein) on the functionality of white adipose tissue of Zucker (fa/fa) rats. The results showed that soybean oil reduced adipocyte size and decreased esterified saturated fatty acids in white adipose tissue. Excess dietary fat also modified the composition of esterified fatty acids in white adipose tissue, increased the secretion of saturated fatty acids to serum from white adipose tissue and reduced the process of fatty acids re-esterification. On the other hand, soy protein sensitized the activation of the hormone-sensitive lipase by increasing the phosphorylation of this enzyme (Ser 563) despite rats fed soy protein were normoglucagonemic, in contrast with rats fed casein that showed hyperglucagonemia but reduced hormone-sensitive lipase phosphorylation. Finally, in white adipose tissue, the interaction between the tested dietary components modulated the transcription/translation process of lipid and carbohydrate metabolism genes via the activity of the PERK-endoplasmic reticulum stress response. Therefore, our results showed that the type of protein and the type and amount of dietary fat selectively modify the activity of white adipose tissue, even in a genetic model of obesity. PMID:23773624

  20. Selenium and Vitamin E: Cell Type– and Intervention-Specific Tissue Effects in Prostate Cancer

    PubMed Central

    Tsavachidou, Dimitra; McDonnell, Timothy J.; Wen, Sijin; Wang, Xuemei; Vakar-Lopez, Funda; Pisters, Louis L.; Pettaway, Curtis A.; Wood, Christopher G.; Do, Kim-Anh; Thall, Peter F.; Stephens, Clifton; Efstathiou, Eleni; Taylor, Robert; Menter, David G.; Troncoso, Patricia; Lippman, Scott M.; Logothetis, Christopher J.

    2009-01-01

    Background Secondary analyses of two randomized, controlled phase III trials demonstrated that selenium and vitamin E could reduce prostate cancer incidence. To characterize pharmacodynamic and gene expression effects associated with use of selenium and vitamin E, we undertook a randomized, placebo-controlled phase IIA study of prostate cancer patients before prostatectomy and created a preoperative model for prostatectomy tissue interrogation. Methods Thirty-nine men with prostate cancer were randomly assigned to treatment with 200 ?g of selenium, 400 IU of vitamin E, both, or placebo. Laser capture microdissection of prostatectomy biopsy specimens was used to isolate normal, stromal, and tumor cells. Gene expression in each cell type was studied with microarray analysis and validated with a real-time polymerase chain reaction (PCR) and immunohistochemistry. An analysis of variance model was fit to identify genes differentially expressed between treatments and cell types. A beta-uniform mixture model was used to analyze differential expression of genes and to assess the false discovery rate. All statistical tests were two-sided. Results The highest numbers of differentially expressed genes by treatment were 1329 (63%) of 2109 genes in normal epithelial cells after selenium treatment, 1354 (66%) of 2051 genes in stromal cells after vitamin E treatment, and 329 (56%) of 587 genes in tumor cells after combination treatment (false discovery rate = 2%). Validation of 21 representative genes across all treatments and all cell types yielded Spearman correlation coefficients between the microarray analysis and the PCR validation ranging from 0.64 (95% confidence interval [CI] = 0.31 to 0.79) for the vitamin E group to 0.87 (95% CI = 0.53 to 0.99) for the selenium group. The increase in the mean percentage of p53-positive tumor cells in the selenium-treated group (26.3%), compared with that in the placebo-treated group (5%), showed borderline statistical significance (difference = 21.3%; 95% CI = 0.7 to 41.8; P = .051). Conclusions We have demonstrated the feasibility and efficiency of the preoperative model and its power as a hypothesis-generating engine. We have also identified cell type– and zone-specific tissue effects of interventions with selenium and vitamin E that may have clinical implications. PMID:19244175

  1. Ontology-aware classification of tissue and cell-type signals in gene expression profiles across platforms and technologies

    PubMed Central

    Lee, Young-suk; Krishnan, Arjun; Zhu, Qian; Troyanskaya, Olga G.

    2013-01-01

    Motivation: Leveraging gene expression data through large-scale integrative analyses for multicellular organisms is challenging because most samples are not fully annotated to their tissue/cell-type of origin. A computational method to classify samples using their entire gene expression profiles is needed. Such a method must be applicable across thousands of independent studies, hundreds of gene expression technologies and hundreds of diverse human tissues and cell-types. Results: We present Unveiling RNA Sample Annotation (URSA) that leverages the complex tissue/cell-type relationships and simultaneously estimates the probabilities associated with hundreds of tissues/cell-types for any given gene expression profile. URSA provides accurate and intuitive probability values for expression profiles across independent studies and outperforms other methods, irrespective of data preprocessing techniques. Moreover, without re-training, URSA can be used to classify samples from diverse microarray platforms and even from next-generation sequencing technology. Finally, we provide a molecular interpretation for the tissue and cell-type models as the biological basis for URSA’s classifications. Availability and implementation: An interactive web interface for using URSA for gene expression analysis is available at: ursa.princeton.edu. The source code is available at https://bitbucket.org/youngl/ursa_backend. Contact: ogt@cs.princeton.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24037214

  2. Low-frequency quantitative ultrasound imaging of cell death in vivo

    SciTech Connect

    Sadeghi-Naini, Ali; Falou, Omar; Czarnota, Gregory J. [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada) [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Department of Radiation Oncology, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Papanicolau, Naum; Tadayyon, Hadi [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada)] [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Lee, Justin [Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada)] [Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Zubovits, Judit [Department of Pathology, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada)] [Department of Pathology, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Sadeghian, Alireza [Department of Computer Science, Ryerson University, Toronto, Ontario M5B 2K3 (Canada)] [Department of Computer Science, Ryerson University, Toronto, Ontario M5B 2K3 (Canada); Karshafian, Raffi [Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3 (Canada)] [Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3 (Canada); Al-Mahrouki, Azza; Giles, Anoja [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada)] [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Kolios, Michael C. [Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5, Canada and Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3 (Canada)] [Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5, Canada and Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3 (Canada)

    2013-08-15

    Purpose: Currently, no clinical imaging modality is used routinely to assess tumor response to cancer therapies within hours to days of the delivery of treatment. Here, the authors demonstrate the efficacy of ultrasound at a clinically relevant frequency to quantitatively detect changes in tumors in response to cancer therapies using preclinical mouse models.Methods: Conventional low-frequency and corresponding high-frequency ultrasound (ranging from 4 to 28 MHz) were used along with quantitative spectroscopic and signal envelope statistical analyses on data obtained from xenograft tumors treated with chemotherapy, x-ray radiation, as well as a novel vascular targeting microbubble therapy.Results: Ultrasound-based spectroscopic biomarkers indicated significant changes in cell-death associated parameters in responsive tumors. Specifically changes in the midband fit, spectral slope, and 0-MHz intercept biomarkers were investigated for different types of treatment and demonstrated cell-death related changes. The midband fit and 0-MHz intercept biomarker derived from low-frequency data demonstrated increases ranging approximately from 0 to 6 dBr and 0 to 8 dBr, respectively, depending on treatments administrated. These data paralleled results observed for high-frequency ultrasound data. Statistical analysis of ultrasound signal envelope was performed as an alternative method to obtain histogram-based biomarkers and provided confirmatory results. Histological analysis of tumor specimens indicated up to 61% cell death present in the tumors depending on treatments administered, consistent with quantitative ultrasound findings indicating cell death. Ultrasound-based spectroscopic biomarkers demonstrated a good correlation with histological morphological findings indicative of cell death (r{sup 2}= 0.71, 0.82; p < 0.001).Conclusions: In summary, the results provide preclinical evidence, for the first time, that quantitative ultrasound used at a clinically relevant frequency, in addition to high-frequency ultrasound, can detect tissue changes associated with cell death in vivo in response to cancer treatments.

  3. Breast ultrasound elastography.

    PubMed

    Baldwin, Pat

    2011-01-01

    Elastography is a newly emerging study of interest that can be especially helpful when used as an adjunct to conventional B-mode ultrasound in evaluating breast lesions. It is estimated that 80% of breast lesions currently biopsied prove to be benign. Reducing that percentage is advantageous to both patients and the imaging community. The specificity of conventional ultrasound when added to a mammography work-up needs improvement. Adding elastography may improve specificity. This Directed Reading describes different acoustic techniques used to obtain an elastogram and evaluation of scoring procedures. Major technique differences exist in imaging the elastic properties of tissue. This article is a Directed Reading. Your access to Directed Reading quizzes for continuing education credit is determined by your continuing education preference. For access to other quizzes, go to www.asrt.org/store. PMID:21406711

  4. [High frequency ultrasound].

    PubMed

    Sattler, E

    2015-07-01

    Diagnostic ultrasound has become a standard procedure in clinical dermatology. Devices with intermediate high frequencies of 7.5-15 MHz are used in dermato-oncology for the staging and postoperative care of skin tumor patients and in angiology for improved vessel diagnostics. In contrast, the high frequency ultrasound systems with 20-100 MHz probes offer a much higher resolution, yet with a lower penetration depth of about 1 cm. The main indications are the preoperative measurements of tumor thickness in malignant melanoma and other skin tumors and the assessment of inflammatory and soft tissue diseases, offering information on the course of these dermatoses and allowing therapy monitoring. This article gives an overview on technical principles, devices, mode of examination, influencing factors, interpretation of the images, indications but also limitations of this technique. PMID:25636803

  5. Cell type specific gene expression analysis of prostate needle biopsies resolves tumor tissue heterogeneity

    PubMed Central

    Krönig, Malte; Walter, Max; Drendel, Vanessa; Werner, Martin; Jilg, Cordula A.; Richter, Andreas S.; Backofen, Rolf; McGarry, David; Follo, Marie; Schultze-Seemann, Wolfgang; Schüle, Roland

    2015-01-01

    A lack of cell surface markers for the specific identification, isolation and subsequent analysis of living prostate tumor cells hampers progress in the field. Specific characterization of tumor cells and their microenvironment in a multi-parameter molecular assay could significantly improve prognostic accuracy for the heterogeneous prostate tumor tissue. Novel functionalized gold-nano particles allow fluorescence-based detection of absolute mRNA expression levels in living cells by fluorescent activated flow cytometry (FACS). We use of this technique to separate prostate tumor and benign cells in human prostate needle biopsies based on the expression levels of the tumor marker alpha-methylacyl-CoA racemase (AMACR). We combined RNA and protein detection of living cells by FACS to gate for epithelial cell adhesion molecule (EPCAM) positive tumor and benign cells, EPCAM/CD45 double negative mesenchymal cells and CD45 positive infiltrating lymphocytes. EPCAM positive epithelial cells were further sub-gated into AMACR high and low expressing cells. Two hundred cells from each population and several biopsies from the same patient were analyzed using a multiplexed gene expression profile to generate a cell type resolved profile of the specimen. This technique provides the basis for the clinical evaluation of cell type resolved gene expression profiles as pre-therapeutic prognostic markers for prostate cancer. PMID:25514598

  6. The Magnitude of Tissue Cooling During Cryotherapy With Varied Types of Compression

    PubMed Central

    Tomchuk, David; Rubley, Mack D.; Holcomb, William R.; Guadagnoli, Mark; Tarno, Jason M.

    2010-01-01

    Abstract Context: Certified athletic trainers can choose different types of external compression (none, Flex-i-Wrap, and elastic wrap) when applying an ice bag to the body. However, which type facilitates the greatest magnitude of tissue cooling is unclear. Objective: To compare the effects of 2 common types of external compression on the magnitude of surface and intramuscular cooling during an ice-bag treatment. Design: Randomized controlled trial. Setting: University research laboratory. Patients or Other Participants: Fourteen college students (10 women, 4 men; age ?=? 22.4 ± 1.8 years, height ?=? 169.1 ± 8.2 cm, mass ?=? 73.3 ± 18.5 kg, skinfold ?=? 13.14 ± 1.61 mm) with previous cryotherapy experience and a posterior lower leg skinfold equal to or less than 15 mm. Intervention(s): On 3 different days separated by 24 to 48 hours, an ice bag was applied to the posterior lower leg surface of each participant for 30 minutes with no compression, with elastic wrap, or with Flex-i-Wrap. Main Outcome Measure(s): Posterior lower leg surface and intramuscular (2 cm) temperatures were recorded for 95 minutes. Results: At 15 minutes, the elastic wrap produced greater surface temperature reduction than no compression (P ?=? .03); this difference remained throughout the protocol (P range, .03 to .04). At 30 minutes, surface temperatures were 14.95°C, 11.55°C, and 9.49°C when an ice bag was applied with no external compression, Flex-i-Wrap, and elastic wrap, respectively. Surface temperatures between Flex-i-Wrap and elastic wrap and between Flex-i-Wrap and no compression were never different. At 10 minutes, Flex-i-Wrap (P ?=? .006) and elastic wrap (P < .001) produced greater intramuscular temperature reduction than no compression produced; these differences remained throughout the protocol. At 10 minutes, no compression, Flex-i-Wrap, and elastic wrap decreased intramuscular temperature by 1.34°C, 2.46°C, and 2.73°C, respectively. At 25 minutes, elastic wrap (8.03°C) produced greater temperature reduction than Flex-i-Wrap (6.65°C) (P ?=? .03) or no compression (4.63°C) (P < .001 ). These differences remained throughout ice application and until 50 minutes after ice-bag removal. Conclusions: During an ice-bag application, external compression with elastic wrap was more effective than Flex-i-Wrap at reducing intramuscular tissue temperature. Elastic wraps should be used for acute injury care. PMID:20446835

  7. Angle-dependent ultrasonic detection and imaging of two types of brachytherapy seeds using singular spectrum analysis

    PubMed Central

    Mamou, Jonathan; Ramachandran, Sarayu; Feleppa, Ernest J.

    2008-01-01

    Brachytherapy to treat prostate cancer uses transrectal ultrasound to guide implantation of titanium-shelled radioactive seeds. Transperitoneal implantation allows errors in placement that cause suboptimal dosimetry. Conventional ultrasound cannot reliably image implanted seeds; therefore, seed misplacements cannot be corrected in the operating room. Previously, an algorithm based on singular spectrum analysis was shown to image palladium seeds better than B-mode ultrasound could. The algorithm is now applied to imaging an iodine seed in gel and in beef tissue as a function of seed angle relative to the incident ultrasound. Results indicate that both seed types are imaged reliably by the algorithm. PMID:19206692

  8. Analyzing Gene Expression from Whole Tissue vs. Different Cell Types Reveals the Central Role of Neurons

    E-print Network

    Ruppin, Eytan

    separately in whole brain tissue, in astrocytes and in neurons, a rigorous comparative study quantifying. Here we analyze gene expression from neurons, astrocytes and whole tissues across different brain based on astrocyte or whole tissue expression. The findings explicate the central role of neurons

  9. Different Types of Scaffolds for Reconstruction of the Urinary Tract by Tissue Engineering

    Microsoft Academic Search

    Bernhard Brehmer; Dorothea Rohrmann; Christoph Becker; Günther Rau; Gerhard Jakse

    2007-01-01

    Introduction: Tissue engineering is an important and expanding field in reconstructive surgery. The ideal biomaterial for urologic tissue engineering should be biodegradable and support autologous cell growth. We examined different scaffolds to select the ideal material for the reconstruction of the bladder wall by tissue engineering. Materials and Methods: We seeded mouse fibroblasts and human keratinocytes in a co-culture model

  10. ULTRASOUND INTRACAVITY SYSTEM FOR IMAGING, THERAPY PLANNING AND TREATMENT OF FOCAL DISEASE

    E-print Network

    Illinois at Urbana-Champaign, University of

    The transrectal approach to treatment of benign prostate disease such as Benign Prostatic Hyperplasia (BPH intensity focused ultrasound for tissue ablation. This intracavity device is presently used for prostate tissue ablation. Ultrasound visualization of the prostate guides the probe placing the ultrasound beam

  11. Tongue movement and syllable onset complexity: ultrasound study 

    E-print Network

    Kocjancic, Tanja

    2008-01-01

    In this study ultrasound was used to investigate tongue movements in syllables with different number and type of onset consonants. Ultrasound recordings provided the information of the distance the tongue travels over a target, and audio recordings...

  12. Host protective roles of type 2 immunity: Parasite killing and tissue repair, flip sides of the same coin

    PubMed Central

    Allen, Judith E.; Sutherland, Tara E.

    2014-01-01

    Metazoan parasites typically induce a type 2 immune response, characterized by T helper 2 (Th2) cells that produce the cytokines IL-4, IL-5 and IL-13 among others. The type 2 response is host protective, reducing the number of parasites either through direct killing in the tissues, or expulsion from the intestine. Type 2 immunity also protects the host against damage mediated by these large extracellular parasites as they migrate through the body. At the center of both the innate and adaptive type 2 immune response, is the IL-4R? that mediates many of the key effector functions. Here we highlight the striking overlap between the molecules, cells and pathways that mediate both parasite control and tissue repair. We have proposed that adaptive Th2 immunity evolved out of our innate repair pathways to mediate both accelerated repair and parasite control in the face of continual assault from multicellular pathogens. Type 2 cytokines are involved in many aspects of mammalian physiology independent of helminth infection. Therefore understanding the evolutionary relationship between helminth killing and tissue repair should provide new insight into immune mechanisms of tissue protection in the face of physical injury. PMID:25028340

  13. The Interaction of Plasminogen Activator Inhibitor 1 With Plasminogen Activators (Tissue-Type and Urokinase-Type) and Fibrin: Localization of Interaction Sites and Physiologic Relevance

    Microsoft Academic Search

    Jaap Keijer; Marijke Linders; Anton-Jan van Zonneveld; Hartmut J. Ehrlich; Jan-Paul de Boer; Hans Pannekoek

    1991-01-01

    tory protein of the fibrinolytic system, harbors interaction sitesfor plasminogen activators (tissue-type (t-PA) and uroki- nase-type (u-PA)) and for fibrin. In this study, anti-PAl-1 monocional antibodies (MoAbs) were used to identify interac- tion sites of PAI-1 with these components. The binding sites of 18 different MoAbs were established and are located on five distinct \\

  14. Doppler ultrasound

    Microsoft Academic Search

    H. F. Routh

    1996-01-01

    The use of Doppler today ranges from assessing blood flow in the fetus and umbilical cord, to flow patterns through valves in the heart or monitoring of blood flow to the brain. This article looks at how the Doppler effect is applied in commercial systems, its clinical uses, and research developments. It is concluded that Doppler ultrasound has progressed over

  15. The type 2 iodothyronine deiodinase is essential for adaptive thermogenesis in brown adipose tissue

    PubMed Central

    de Jesus, Lucia A.; Carvalho, Suzy D.; Ribeiro, Mirian O.; Schneider, Mark; Kim, Sung-Woo; Harney, John W.; Larsen, P. Reed; Bianco, Antonio C.

    2001-01-01

    Type 2 iodothyronine deiodinase (D2) is a selenoenzyme, the product of the recently cloned cAMP-dependent Dio2 gene, which increases 10- to 50-fold during cold stress only in brown adipose tissue (BAT). Here we report that despite a normal plasma 3,5,3?-triiodothyronine (T3) concentration, cold-exposed mice with targeted disruption of the Dio2 gene (Dio2–/–) become hypothermic due to impaired BAT thermogenesis and survive by compensatory shivering with consequent acute weight loss. This occurs despite normal basal mitochondrial uncoupling protein 1 (UCP1) concentration. In Dio2–/– brown adipocytes, the acute norepinephrine-, CL316,243-, or forskolin-induced increases in lipolysis, UCP1 mRNA, and O2 consumption are all reduced due to impaired cAMP generation. These hypothyroid-like abnormalities are completely reversed by a single injection of T3 14 hours earlier. Recent studies suggest that UCP1 is primarily dependent on thyroid hormone receptor ? (TR?) while the normal sympathetic response of brown adipocytes requires TR?. Intracellularly generated T3 may be required to saturate the TR?, which has an approximately fourfold lower T3-binding affinity than does TR?. Thus, D2 is an essential component in the thyroid-sympathetic synergism required for thermal homeostasis in small mammals. PMID:11696583

  16. Experience-dependent regulation of tissue-type plasminogen activator in the mouse barrel cortex.

    PubMed

    Chen, Chia-Chien; Chu, Philip; Brumberg, Joshua C

    2015-07-10

    It has been suggested that tissue-type plasminogen activator (tPA), a serine protease, plays a key role in regulating the extracellular matrix core proteins, thereby impacting the structural plasticity in the cerebral cortex. Much is known about its role in regulating plasticity in the visual cortex. However, its permissive role has not been demonstrated to generalize to other cerebral cortical areas. By utilizing a combination of immunofluorescent histochemistry and confocal microscopy, we demonstrate that endogenous tPA is indeed present in the somatosensory cortex, and its expression is experience-dependent. Chronic sensory deprivation induced by whisker trimming from birth for one month leads to increased tPA immunoreactivity in all layers of the barrel cortex. Furthermore, tPA immunoreactivity remains high even after sensation has been restored to the mystacial pad (by allowing whiskers to grow back to full length for one month). Our results suggest that tPA levels in the cerebral cortex are regulated by sensory experience, and play a key role in regulating structural remodeling in the cerebral cortex. PMID:26021877

  17. Aprotinin: an antidote for recombinant tissue-type plasminogen activator (rt-PA) active in vivo.

    PubMed

    Clozel, J P; Banken, L; Roux, S

    1990-08-01

    The goal of the study was to assess if aprotinin, a protease inhibitor, could be used to antagonize in vivo the effects of recombinant tissue-type plasminogen activator (rt-PA). The time course of the lysis of a radioactive jugular vein thrombus was monitored continuously with an external gamma counter in anesthetized rabbits. Recombinant t-PA (0.25 mg) was given intravenously as a bolus injection (10% of the dose), followed by a 4 h infusion (90% of the dose). Rabbits received aprotinin 20 min after the start of the infusion as an intravenous bolus injection at a dose of 60,000 IU/kg (n = 4) or 20,000 IU/kg (n = 4). The rate of lysis in the different groups was compared 2, 60 and 180 min after aprotinin administration. Both doses of aprotinin immediately stopped thrombolysis. Thrombolysis was still blocked at 180 min with the highest dose but not with the lowest dose. Moreover, aprotinin could prevent the increase in bleeding time secondary to the injection of rt-PA. These results suggest that aprotinin might be used in vivo as an antidote for rt-PA. PMID:1695642

  18. Location of type XV collagen in human tissues and its accumulation in the interstitial matrix of the fibrotic kidney.

    PubMed Central

    Hägg, P. M.; Hägg, P. O.; Peltonen, S.; Autio-Harmainen, H.; Pihlajaniemi, T.

    1997-01-01

    An antipeptide antibody was produced against the carboxyl-terminal noncollagenous domain of human type XV collagen and used to localize this recently described collagen in a number of human tissues. The most conspicuous findings were powerful staining of most of the capillaries and staining of the basement membrane (BM) zones of muscle cells. Not all of the BM zones were positive, however, as shown by the lack of staining in the developing fetal alveoli and some of the tubules in developing kidney. Nor was type XV collagen staining restricted to the BM zones, as some could be observed in the fibrillar collagen matrix of the papillary dermis and placental villi, for example. Interestingly, differences in the expression of type XV collagen could be observed during kidney development, and staining of fetal lung tissue suggested that changes in its expression may also occur during the formation of vascular structures. Another intriguing finding was pronounced renal interstitial type XV collagen staining in patients with kidney fibrosis due to different pathological processes. This suggests that the accumulation of type XV collagen may accompany fibrotic processes. Full-length human type XV collagen chains with an apparent molecular mass of approximately 200 kd were produced in insect cells using a baculovirus expression system. The fact that these had a markedly higher molecular mass than the 100- to 110-kd type XV collagen chains found in homogenates of heart and kidney tissue suggests either proteolytic processing during the synthesis of type XV collagen or an inability to solubilize complete molecules from tissues. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:9176399

  19. Mechanical and histological characterization of trachea tissue subjected to blast-type pressures

    NASA Astrophysics Data System (ADS)

    Butler, B. J.; Bo, C.; Tucker, A. W.; Jardine, A. P.; Proud, W. G.; Williams, A.; Brown, K. A.

    2014-05-01

    Injuries to the respiratory system can be a component of polytrauma in blast-loading injuries. Tissues located at air-liquid interfaces, including such tissues in the respiratory system, are particularly vulnerable to damage by blast overpressures. There is a lack of information about the mechanical and cellular responses that contribute to the damage of this class of tissues subjected to the high strain rates associated with blast loading. Here, we describe the results of dynamic blast-like pressure loading tests at high strain rates on freshly harvested ex vivo trachea tissue specimens.

  20. d Technical Note THREE-DIMENSIONAL ULTRASOUND GUIDANCE OF AUTONOMOUS ROBOTIC

    E-print Network

    Smith, Stephen

    -dimensional (3-D) ultrasound, Surgical robotics, Computer aided diagnosis. INTRODUCTION The combinationd Technical Note THREE-DIMENSIONAL ULTRASOUND GUIDANCE OF AUTONOMOUS ROBOTIC BREAST BIOPSY form 28 August 2009) Abstract--Feasibility studies of autonomous robot biopsies in tissue have been

  1. Ultrasound Annual, 1984

    SciTech Connect

    Sanders, R.C.; Hill, M.C.

    1984-01-01

    The 1984 edition of Ultrasound Annual explores new applications of ultrasound in speech and swallowing and offers guidelines on the use of ultrasound and nuclear medicine in thyroid and biliary tract disease. Other areas covered include Doppler sonography of the abdomen, intraoperative abdominal ultrasound, sonography of the placenta, ultrasound of the neonatal head and abdomen, and sonographic echo patterns created by fat.

  2. A novel approach in personal identification from tissue samples undergone different processes through STR typing

    Microsoft Academic Search

    N. Staiti; D. Di Martino; L. Saravo

    2004-01-01

    Short tandem repeats (STRs) or microsatellites have been recognized worldwide as a powerful tool for human identification. They have become widely used in human identification especially in criminal cases and mass disasters. Police departments are often interested in cases where tissues are already decomposed and only do bones remain to let them perform laboratory analyses.Bone is the most resistant tissue

  3. High definition ultrasound imaging for battlefield medical applications

    SciTech Connect

    Kwok, K.S.; Morimoto, A.K.; Kozlowski, D.M.; Krumm, J.C.; Dickey, F.M. [Sandia National Labs., Albuquerque, NM (United States); Rogers, B; Walsh, N. [Texas Univ. Health Science Center, San Antonio, TX (United States)

    1996-06-23

    A team has developed an improved resolution ultrasound system for low cost diagnostics. This paper describes the development of an ultrasound based imaging system capable of generating 3D images showing surface and subsurface tissue and bone structures. We include results of a comparative study between images obtained from X-Ray Computed Tomography (CT) and ultrasound. We found that the quality of ultrasound images compares favorably with those from CT. Volumetric and surface data extracted from these images were within 7% of the range between ultrasound and CT scans. We also include images of porcine abdominal scans from two different sets of animal trials.

  4. Emerging non-cancer applications of therapeutic ultrasound.

    PubMed

    O'Reilly, Meaghan A; Hynynen, Kullervo

    2015-05-01

    Ultrasound therapy has been investigated for over half a century. Ultrasound can act on tissue through a variety of mechanisms, including thermal, shockwave and cavitation mechanisms, and through these can elicit different responses. Ultrasound therapy can provide a non-invasive or minimally invasive treatment option, and ultrasound technology has advanced to the point where devices can be developed to investigate a wide range of applications. This review focuses on non-cancer clinical applications of therapeutic ultrasound, with an emphasis on treatments that have recently reached clinical investigations, and preclinical research programmes that have great potential to impact patient care. PMID:25792225

  5. Molecular Ultrasound Imaging: Current Status and Future Directions

    PubMed Central

    Deshpande, Nirupama; Needles, Andrew; Willmann, Jürgen K.

    2011-01-01

    Targeted contrast-enhanced ultrasound (molecular ultrasound) is an emerging imaging strategy that combines ultrasound technology with novel molecularly-targeted ultrasound contrast agents for assessing biological processes at the molecular level. Molecular ultrasound contrast agents are nano- or micro-sized particles that are targeted to specific molecular markers by adding high-affinity binding ligands onto the surface of the particles. Following intravenous administration, these targeted ultrasound contrast agents accumulate at tissue sites overexpressing specific molecular markers, thereby enhancing the ultrasound imaging signal. High spatial and temporal resolution, real-time imaging, non-invasiveness, relatively low costs, lack of ionizing irradiation and wide availability of ultrasound systems are advantages compared to other molecular imaging modalities. In this article we review current concepts and future directions of molecular ultrasound imaging, including different classes of molecular ultrasound contrast agents, ongoing technical developments of preclinical and clinical ultrasound systems , the potential of molecular ultrasound for imaging different diseases at the molecular level, and the translation of molecular ultrasound into the clinic. PMID:20541656

  6. Breast biopsy - ultrasound

    MedlinePLUS

    Biopsy - breast - ultrasound; Ultrasound-guided breast biopsy; Core needle breast biopsy - ultrasound ... following: Fine needle aspiration Hollow needle (called a core needle) Vacuum-powered device Both a hollow needle ...

  7. Eye and orbit ultrasound

    MedlinePLUS

    Echography - eye orbit; Ultrasound - eye orbit; Ocular ultrasonography; Orbital ultrasonography ... ophthalmology department of a hospital or clinic. Your eye is numbed with medicine (anesthetic drops). The ultrasound ...

  8. Low dose high frequency ultrasound therapy for stellate ganglion blockade in complex regional pain syndrome type I: a randomised placebo controlled trial

    PubMed Central

    Askin, Ayhan; Savas, Serpil; Koyuncuoglu, Hasan Rifat; Baloglu, Hale Hekim; Inci, Mehmet Fatih

    2014-01-01

    Background: We aimed to determine the sympatholytic and clinical effects of low dose high frequency ultrasound (US) applied on stellate ganglion in Complex Regional Pain Syndrome (CRPS) type I patients. Material and method: Fourty-five patients with CRPS type I were randomly allocated into three groups. Pharmacological treatment, transcutaneous electrical nerve stimulation (TENS), contrast bath and exercise were applied to all groups for 20 sessions. In addition to this treatment protocol, low dose high frequency US was applied on stellate ganglion as 0.5 watts/cm2 in group I; 3 watts/cm2 in group II and as placebo in group III. Forty age and sex matched healthy controls were served as controls. Sympathetic skin response (SSR) was used for determining the sympatholytic effects of US. Pain was assessed with visual analog scale (VAS), limitation of total finger flexion was assessed with finger pulp-distal crease distance, muscle strength was assessed with measuring the grip strength, upper extremity disability was assessed with Disability of the Arm, Shoulder and Hand (DASH) scale before and after the treatment. Results: All groups evalueted in terms of VAS score, finger pulp-distal crease distance, grip strength and DASH score after the treatment. The improvements in those parameters were not statistically significant between the groups (P > 0.05). SSR latency was significantly shorter in CRPS patients than controls (P < 0.05). Pre- and post-treatment SSR amplitude and latency values were not different within patient groups (P > 0.05). The differences in pre- and post-treatment SSR amplitude and latency values were not statistically different between patient groups (P > 0.05). Conclusion: Low dose high frequency US applied on stellate ganglion did not make a sympathetic blockade and was not of further benefit for pain, range of motion, grip strength and upper extremity disability in CRPS type I patients. PMID:25664079

  9. Soft tissue response to different types of sintered metal fibre-web materials.

    PubMed

    Jansen, J A; von Recum, A F; van der Waerden, J P; de Groot, K

    1992-01-01

    Recently, it has been demonstrated that the soft tissue response to polymeric filter implants was predominantly dependent on the implant surface topography and that variation in the implant material had little effect. The purpose of this study, therefore, was to compare histologically the soft tissue response to sintered fibre-web implants made from different materials and with varying web porosity. Three different fibre-web materials with two different weights and two different porosities were used. The implants were inserted subcutaneously in the dorsum of rabbits. The implants were left in situ for 4 and 12 wk. Histological and tissue compatibility evaluations were performed. It is found that all the tested fibre-web materials show a good biocompatible behaviour. In addition, the results appear to indicate a relation between flexibility of an implant material and tissue behaviour. PMID:1477267

  10. STR typing of formalin-fixed paraffin embedded (FFPE) aborted foetal tissue in criminal paternity cases.

    PubMed

    Reshef, Ayeleth; Barash, Mark; Voskoboinik, Lev; Brauner, Paul; Gafny, Roni

    2011-03-01

    Sexual assault or rape cases occasionally result in unwanted pregnancies. In almost all such cases the foetus is aborted. A forensic laboratory may receive the foetus, the placenta, or paraffin embedded abortion material for paternity testing. Obtaining a foetal profile DNA from a foetus or placenta may not be successful due to the age or condition of the tissue. Moreover, maternal contamination of placental material will invariably result in a mixed DNA profile. However, the use of properly screened abortion material from paraffin blocks will almost always result in obtaining a foetal DNA profile. Furthermore, foetal tissue fixed in paraffin blocks does not require special conditions for submission and storage as required to preserve fresh foetal or placental tissue. As hospitals routinely prepare foetal tissue in paraffin blocks, which should be readily obtainable by forensic laboratories, these samples would appear to be the preferred choice for paternity testing. PMID:21334577

  11. Wavelet Lifting for Speckle Noise Reduction in Ultrasound Images

    E-print Network

    Raheja, Amar

    . The efficacy of this filter is demonstrated on both simulated and real medical ultrasound images. The result of research has been done for medical ultrasound speckle de-noising [2][8][10] using different typesWavelet Lifting for Speckle Noise Reduction in Ultrasound Images Yuan Chen, and Amar Raheja

  12. Tongue movements and syllable onset complex-ity: Ultrasound study

    E-print Network

    Edinburgh, University of

    Tongue movements and syllable onset complex- ity: Ultrasound study Tanja Kocjancic1 1 Speech of Edinburgh, UK Abstract In this study ultrasound was used to investigate tongue movements in syllables with different number and type of onset consonants. Ultrasound recordings provided the information

  13. siRNA-targeting transforming growth factor-? type I receptor reduces wound scarring and extracellular matrix deposition of scar tissue.

    PubMed

    Wang, Yi-Wen; Liou, Nien-Hsien; Cherng, Juin-Hong; Chang, Shu-Jen; Ma, Kuo-Hsing; Fu, Earl; Liu, Jiang-Chuan; Dai, Niann-Tzyy

    2014-07-01

    Hypertrophic scarring is related to persistent activation of transforming growth factor-? (TGF-?)/Smad signaling. In the TGF-?/Smad signaling cascade, the TGF-? type I receptor (TGFBRI) phosphorylates Smad proteins to induce fibroblast proliferation and extracellular matrix deposition. In this study, we inhibited TGFBRI gene expression via TGFBRI small interfering RNA (siRNA) to reduce fibroblast proliferation and extracellular matrix deposition. Our results demonstrate that downregulating TGFBRI expression in cultured human hypertrophic scar fibroblasts significantly suppressed cell proliferation and reduced type I collagen, type III collagen, fibronectin, and connective tissue growth factor (CTGF) mRNA, and type I collagen and fibronectin protein expression. In addition, we applied TGFBRI siRNA to wound granulation tissue in a rabbit model of hypertrophic scarring. Downregulating TGFBRI expression reduced wound scarring, the extracellular matrix deposition of scar tissue, and decreased CTGF and ?-smooth muscle actin mRNA expression in vivo. These results suggest that TGFBRI siRNA could be applied clinically to prevent hypertrophic scarring. PMID:24670383

  14. Ultrasound Echoes as Biometric Navigators

    PubMed Central

    Schwartz, Benjamin M.; McDannold, Nathan J.

    2014-01-01

    We demonstrate a new method of using ultrasound data to achieve prospective motion compensation in MRI, especially for respiratory motion during interventional MRI procedures in moving organs such as the liver. The method relies on fingerprint-like biometrically distinct ultra-sound echo patterns produced by different locations in tissue, which are collated with geometrical information from MRI during a training stage to form a mapping table that relates ultrasound measurements to positions. During prospective correction, the system makes frequent ultrasound measurements and uses the map to determine the corresponding position. Results in motorized linear motion phantoms and freely breathing animals indicate that the system performs well. Apparent motion is reduced by up to 97.8%, and motion artifacts are reduced or eliminated in 2D Spoiled Gradient-Echo images. The motion compensation is sufficient to permit MRI thermometry of focused ultrasound heating during respiratory-like motion, with results similar to those obtained in the absence of motion. This new technique may have applications for MRI thermometry and other dynamic imaging in the abdomen during free breathing. PMID:22648783

  15. A Multiresolution Technique to Despeckle Ultrasound Images

    Microsoft Academic Search

    Parvinder Kaur; Baljit Singh

    \\u000a Ultrasonography is a very prevailing technique for imaging soft tissue structures and organs of human body. But when an Ultrasound\\u000a image is captured it gets noisy and this added noise is known as speckle noise which hinders the diagnostic process of the\\u000a radiocologists and doctors. In this paper a method to remove speckle noise from ultrasound images is proposed. So

  16. Role of structural anisotropy of biological tissues in poroelastic wave propagation

    PubMed Central

    Cardoso, Luis; Cowin, Stephen C.

    2011-01-01

    Ultrasound waves have a broad range of clinical applications as a non-destructive testing approach in imaging and in the diagnoses of medical conditions. Generally, biological tissues are modeled as an homogenized equivalent medium with an apparent density through which a single wave propagates. Only the first wave arriving at the ultrasound probe is used for the measurement of the speed of sound. However, the existence of a second wave in tissues such as cancellous bone has been reported and its existence is an unequivocal signature of Biot type poroelastic media. To account for the fact that ultrasound is sensitive to microarchitecture as well as density, a fabric-dependent anisotropic poroelastic ultrasound (PEU) propagation theory was recently developed. Key to this development was the inclusion of the fabric tensor - a quantitative stereological measure of the degree of structural anisotropy of bone - into the linear poroelasticity theory. In the present study, this framework is extended to the propagation of waves in several soft and hard tissues. It was found that collagen fibers in soft tissues and the mineralized matrix in hard tissues are responsible for the anisotropy of the solid tissue constituent through the fabric tensor in the model. PMID:22162897

  17. [Renal ultrasound. Urologic and nephrologic viewpoint].

    PubMed

    Heynemann, H; Tuma, J

    2006-05-01

    Renal ultrasound examination is an integral part of urologic and nephrologic clinical examination. It brings very useful information about kidney morphology (B-mode) and haemoperfusion (renal color coded duplex ultrasonography). Standard examination technique is required for recognition of normal findings, urinary transport disturbances of diverse causes (stones, intrinsic or extrinsic compression), kidney tumours and kidney injury. Typical ultrasound findings of these abnormalities were demonstrated. Renal ultrasound with new techniques (sono-CT, harmonic tissue imaging, power mode etc.) is for urology and nephrology an indispensable diagnostic method. In combination with patient history, clinical and laboratory examination takes important part in accomplishing the diagnosis. PMID:16722403

  18. Patterns of regulatory activity across diverse human cell types predict tissue identity, transcription factor binding, and long-range interactions

    PubMed Central

    Sheffield, Nathan C.; Thurman, Robert E.; Song, Lingyun; Safi, Alexias; Stamatoyannopoulos, John A.; Lenhard, Boris; Crawford, Gregory E.; Furey, Terrence S.

    2013-01-01

    Regulatory elements recruit transcription factors that modulate gene expression distinctly across cell types, but the relationships among these remains elusive. To address this, we analyzed matched DNase-seq and gene expression data for 112 human samples representing 72 cell types. We first defined more than 1800 clusters of DNase I hypersensitive sites (DHSs) with similar tissue specificity of DNase-seq signal patterns. We then used these to uncover distinct associations between DHSs and promoters, CpG islands, conserved elements, and transcription factor motif enrichment. Motif analysis within clusters identified known and novel motifs in cell-type-specific and ubiquitous regulatory elements and supports a role for AP-1 regulating open chromatin. We developed a classifier that accurately predicts cell-type lineage based on only 43 DHSs and evaluated the tissue of origin for cancer cell types. A similar classifier identified three sex-specific loci on the X chromosome, including the XIST lincRNA locus. By correlating DNase I signal and gene expression, we predicted regulated genes for more than 500K DHSs. Finally, we introduce a web resource to enable researchers to use these results to explore these regulatory patterns and better understand how expression is modulated within and across human cell types. PMID:23482648

  19. Ultrasound therapy in musculoskeletal disorders: a meta-analysis

    Microsoft Academic Search

    Arne Nyholm Gam; Finn Johannsen

    1995-01-01

    We have reviewed 293 papers published since 1950 to assess the evidence of effect of ultrasound in the treatment of musculoskeletal disorders. Twenty-two clinical papers describing trials comparing ultrasound treatment with sham-ultrasound treated, non-ultrasound treatment and untreated groups were found. These papers were evaluated with respect to a list of criteria which should be met in this type of trial.

  20. Use of Discriminatory Probes for Strain Typing of Formalin-Fixed, Rabies Virus-Infected Tissues by In Situ Hybridization

    Microsoft Academic Search

    Susan A. Nadin-Davis; Mary Sheen; Alexander I. Wandeler

    2003-01-01

    An in situ hybridization (ISH) method has been developed to overcome difficulties encountered in the viral typing of formalin-fixed rabies virus-infected brain tissue. Rabies viruses representative of all strains normally encountered in diagnostic submissions throughout Canada, including 3 strains of terrestrial hosts (arctic fox, western skunk, mid-Atlantic raccoon), 10 strains circulating in several bat reservoirs (BBCAN1 to BBCAN7, LACAN, SHCAN,

  1. EXPRESSION ANALYSIS AND PURIFICATION OF HUMAN RECOMBINANT TISSUE TYPE PLASMINOGEN ACTIVATOR (rt-PA) FROM TRANSGENIC TOBACCO PLANTS

    Microsoft Academic Search

    Haidar Saify Nabiabad; Mohammad Mehdi Yaghoobi; Mokhtar Jalali Javaran; Saman Hosseinkhani

    2011-01-01

    Recombinant tissue-type plasminogen activator (rt-PA) has been produced in different hosts. In this research, transgenic tobacco was selected for production of human rt-PA. Transgenic plants were analyzed by polymerase chain reaction (PCR) and reverse-transcription (RT)-PCR. The protein was extracted by Lysine Sepharose chromatography column and was further purified by HiTrap desalting column. The function of eluted protein was analyzed on

  2. Association of plasminogen activator inhibitor-1 and tissue plasminogen activator with type 2 diabetes and metabolic syndrome in Malaysian subjects

    Microsoft Academic Search

    Zaid Al-Hamodi; Ikram S Ismail; Khaled A Ahmed; Sekaran Muniandy

    2011-01-01

    Background: Increased plasma plasminogen activator inhibitor-1 (PAI-1) activity and decreased tissue plasminogen activator (tPA) activity could be considered a true component of the metabolic syndrome (MetS) associated with an increased risk of developing cardiovascular diseases (CVD) and fibrinolytic abnormalities. The aim of this study was to investigate the association of tPA and its inhibitor PAI-1 with type 2 diabetes (T2D)

  3. Regression of primary gastric lymphoma of mucosa-associated lymphoid tissue type after cure of Helicobacter pylori infection

    Microsoft Academic Search

    E. Bayerdörffer; B. Rudolph; A. Neubauer; C. Thiede; N. Lehn; S. Eidt; M. Stolte

    1995-01-01

    Lymphoma of gastric-mucosa-associated lymphatic tissue (MALT) type has been linked to infection with Helicobacter pylori. We investigated the effect on MALT lymphoma of eradicating H pylori infection. 33 patients with primary gastric low-grade MALT lymphoma associated with H pylori gastritis were treated with omeprazole (120 mg daily) and amoxycillin (2·25 g daily) for 14 days to eradicate H pylori. In

  4. Cross-linking of galectin 3, a galactose-binding protein of mammalian cells, by tissue-type transglutaminase

    Microsoft Academic Search

    Bruno Mehul; Sulemana Bawumia; R Colin Hughes

    1995-01-01

    The 30 kDa ?-galactoside-binding protein of baby hamster kidney (BHK) cells [Mehul et al. (1994), J. Biol. Chem. 269, 18250–18258] homologous to galectin 3, a widely distributed mammlian lectin, has been found to be a substrate for tissue type transglutaminase, as shown by the incorporation in a calcium- and time-dependent manner of 5-(biotinamido) pentylamine in the presence of guinea pig

  5. Human Immunodeficiency Virus Type 1 Infection of Cells and Tissues from the Upper and Lower Human Female Reproductive Tract

    Microsoft Academic Search

    ALEXANDRA L. HOWELL; ROBERT D. EDKINS; SHERRY E. RIER; GRANT R. YEAMAN; JUDY E. STERN; MICHAEL W. FANGER; ANDCHARLES R. WIRA

    Viable tissue sections and isolated cell cultures from the human fallopian tube, uterus, cervix, and vaginal mucosa were examined for susceptibility to infection with human immunodeficiency virus type 1 (HIV-1). We examined infectivity by using the monocytotropic strain HIV-1JR-FL and several primary isolates of HIV-1 obtained from infected neonates. HIV-1 infection was measured by p24 production in short-term culture and

  6. Surface modification of nanofibrous polycaprolactone/gelatin composite scaffold by collagen type I grafting for skin tissue engineering.

    PubMed

    Gautam, Sneh; Chou, Chia-Fu; Dinda, Amit K; Potdar, Pravin D; Mishra, Narayan C

    2014-01-01

    In the present study, a tri-polymer polycaprolactone (PCL)/gelatin/collagen type I composite nanofibrous scaffold has been fabricated by electrospinning for skin tissue engineering and wound healing applications. Firstly, PCL/gelatin nanofibrous scaffold was fabricated by electrospinning using a low cost solvent mixture [chloroform/methanol for PCL and acetic acid (80% v/v) for gelatin], and then the nanofibrous PCL/gelatin scaffold was modified by collagen type I (0.2-1.5wt.%) grafting. Morphology of the collagen type I-modified PCL/gelatin composite scaffold that was analyzed by field emission scanning electron microscopy (FE-SEM), showed that the fiber diameter was increased and pore size was decreased by increasing the concentration of collagen type I. Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric (TG) analysis indicated the surface modification of PCL/gelatin scaffold by collagen type I immobilization on the surface of the scaffold. MTT assay demonstrated the viability and high proliferation rate of L929 mouse fibroblast cells on the collagen type I-modified composite scaffold. FE-SEM analysis of cell-scaffold construct illustrated the cell adhesion of L929 mouse fibroblasts on the surface of scaffold. Characteristic cell morphology of L929 was also observed on the nanofiber mesh of the collagen type I-modified scaffold. Above results suggest that the collagen type I-modified PCL/gelatin scaffold was successful in maintaining characteristic shape of fibroblasts, besides good cell proliferation. Therefore, the fibroblast seeded PCL/gelatin/collagen type I composite nanofibrous scaffold might be a potential candidate for wound healing and skin tissue engineering applications. PMID:24268275

  7. ABCB- and ABCC-type transporters confer multixenobiotic resistance and form an environment-tissue barrier in bivalve gills.

    PubMed

    Luckenbach, Till; Epel, David

    2008-06-01

    Aquatic organisms and, in particular, filter feeders, such as mussels, are continuously exposed to toxicants dissolved in the water and, presumably, require adaptations to avoid the detrimental effects from such chemicals. Previous work indicates that activity of ATP-binding cassette (ABC) transporters protects mussels against toxicants, but the nature of these transporters and the structural basis of protection are not known. Here we meld studies on transporter function, gene expression, and localization of transporter protein in mussel gill tissue and show activity and expression of two xenobiotic transporter types in the gills, where they provide an effective structural barrier against chemicals. Activity of ABCB/MDR/P-glycoprotein and ABCC/MRP-type transporters was indicated by sensitivity of efflux of the test substrate calcein-AM to the ABCB inhibitor PSC-833 and the ABCC inhibitor MK-571. This activity profile is supported by our cloning of the complete sequence of two ABC transporter types from RNA in mussel tissue with a high degree of identity to transporters from the ABCB and ABCC subfamilies. Overall identity of the amino acid sequences with corresponding homologs from other organisms was 38-50% (ABCB) and 27-44% (ABCC). C219 antibody staining specific for ABCB revealed that this transporter was restricted to cells in the gill filaments with direct exposure to water flow. Taken together, our data demonstrate that ABC transporters form an active, physiological barrier at the tissue-environment interface in mussel gills, providing protection against environmental xenotoxicants. PMID:18401003

  8. of Ultrasound to Materials

    E-print Network

    Suslick, Kenneth S.

    plications of Ultrasound to Materials Chemistry Kenneth S. Suslick This article willbegin of ultrasound. Some re- cent applications of sonochemistry to the synthesis of nanophase and amorphous metals of ultrasound on metal polvders in liquid-solid slurries. Cavitation The chemical effects of ultrasound do

  9. An augmented reality simulator for ultrasound guided needle placement training

    Microsoft Academic Search

    Derek R. Magee; Y. Zhu; Rish Ratnalingam; P. Gardner; David Kessel

    2007-01-01

    Details are presented of a low cost augmented-reality system for the simulation of ultrasound guided needle insertion procedures\\u000a (tissue biopsy, abscess drainage, nephrostomy etc.) for interventional radiology education and training. The system comprises physical elements; a mannequin, a mock ultrasound probe and a needle, and software elements; generating virtual ultrasound anatomy and allowing data collection. These two elements are linked

  10. Strain imaging using conventional and ultrafast ultrasound imaging: numerical analysis

    Microsoft Academic Search

    S. R. Aglyamov; W. G. Scott; Stanislav Emelianov

    2007-01-01

    In elasticity imaging, the ultrasound frames acquired during tissue deformation are analyzed to estimate the internal displacements and strains. If the deformation rate is high, high-frame-rate imaging techniques are required to avoid the severe decorrelation between the neighboring ultrasound images. In these high-frame-rate techniques, however, the broader and less focused ultrasound beam is transmitted and, hence, the image quality is

  11. Recent Experiences and Advances in Contrast-Enhanced Subharmonic Ultrasound

    PubMed Central

    Eisenbrey, John R.; Liu, Ji-Bin; Forsberg, Flemming

    2015-01-01

    Nonlinear contrast-enhanced ultrasound imaging schemes strive to suppress tissue signals in order to better visualize nonlinear signals from blood-pooling ultrasound contrast agents. Because tissue does not generate a subharmonic response (i.e., signal at half the transmit frequency), subharmonic imaging has been proposed as a method for isolating ultrasound microbubble signals while suppressing surrounding tissue signals. In this paper, we summarize recent advances in the use of subharmonic imaging in vivo. These advances include the implementation of subharmonic imaging on linear and curvilinear arrays, intravascular probes, and three-dimensional probes for breast, renal, liver, plaque, and tumor imaging.

  12. Human adipose tissue stromal vascular fraction cells differentiate depending on distinct types of media

    Microsoft Academic Search

    A. Balwierz; U. Czech; A. Polus; R. K. Filipkowski; B. Mioduszewska; T. Proszynski; P. Kolodziejczyk; J. Skrzeczynska-Moncznik; W. Dudek; L. Kaczmarek; J. Kulig; J. Pryjma; A. Dembinska-Kiec

    2008-01-01

    Objectives : Angiogenesis, the process of formation of blood vessels, is essential for many physiological as well as pathological processes. It has been shown that human adipose tissue contains a population of non-characterized cells, called stromal-vascular fraction (SVF) cells, which are able to differentiate into several lineages. The aim of this study was to determine conditions for promoting differentiation of

  13. Evaluation of ultrasound-assisted extraction as sample pre-treatment for quantitative determination of rare earth elements in marine biological tissues by inductively coupled plasma-mass spectrometry.

    PubMed

    Costas, M; Lavilla, I; Gil, S; Pena, F; de la Calle, I; Cabaleiro, N; Bendicho, C

    2010-10-29

    In this work, the determination of rare earth elements (REEs), i.e. Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu in marine biological tissues by inductively coupled-mass spectrometry (ICP-MS) after a sample preparation method based on ultrasound-assisted extraction (UAE) is described. The suitability of the extracts for ICP-MS measurements was evaluated. For that, studies were focused on the following issues: (i) use of clean up of extracts with a C18 cartridge for non-polar solid phase extraction; (ii) use of different internal standards; (iii) signal drift caused by changes in the nebulization efficiency and salt deposition on the cones during the analysis. The signal drift produced by direct introduction of biological extracts in the instrument was evaluated using a calibration verification standard for bracketing (standard-sample bracketing, SSB) and cumulative sum (CUSUM) control charts. Parameters influencing extraction such as extractant composition, mass-to-volume ratio, particle size, sonication time and sonication amplitude were optimized. Diluted single acids (HNO(3) and HCl) and mixtures (HNO(3)+HCl) were evaluated for improving the extraction efficiency. Quantitative recoveries for REEs were achieved using 5 mL of 3% (v/v) HNO(3)+2% (v/v) HCl, particle size <200 ?m, 3 min of sonication time and 50% of sonication amplitude. Precision, expressed as relative standard deviation from three independent extractions, ranged from 0.1 to 8%. In general, LODs were improved by a factor of 5 in comparison with those obtained after microwave-assisted digestion (MAD). The accuracy of the method was evaluated using the CRM BCR-668 (mussel tissue). Different seafood samples of common consumption were analyzed by ICP-MS after UAE and MAD. PMID:20951856

  14. Effects of various laser types and beam transmission methods on female organ tissue in the pig: an in vitro study.

    PubMed

    Spörri, S; Frenz, M; Altermatt, H J; Bratschi, H U; Romano, V; Forrer, M; Dreher, E; Weber, H P

    1994-01-01

    The purpose of this in vitro study was to investigate and compare effects of various laser types (CO2, Argon, Erbium:YAG, Erbium:YSGG, and Holmium:YAG) and laser beam transmission methods (optical lens and flexible fiber) on ovarian and uterine tissue of the pig. The Erbium laser radiation was transmitted through Zirconium fluoride fibers (ZrF4). To circumvent the low mechanical stability of these fibers, we developed a special microlens system, which refocuses the radiation and protects the distal end from damage. Tissue lesions were performed with 1 and 5 joule. Histologic analysis of acute Er:YAG laser lesions reveal precise cutting effects with a minimal thermal damage zone of 40 microns and a high damage resistance of the fiber microlens systems. The extent of thermal damage caused by the Erbium:YSGG and CO2 laser is about two times larger, whereas the Argon and Holmium laser tissue lesions show a damage of the surrounding tissue of 200-300 microns. This study suggests that for precise cutting and coagulation, Erbium and Holmium lasers transmitted via our modified fiber tip may render the use of these lasers possible in a wide range of laparoscopic surgery applications. PMID:8208053

  15. Effect of the type of dietary triacylglycerol fatty acids on ?-tocopherol concentration in plasma and tissues of growing pigs.

    PubMed

    Prévéraud, D P; Devillard, E; Rouffineau, F; Borel, P

    2014-11-01

    A study was performed in growing pigs to evaluate the efficacy of ?-tocopherol (Tol) concentration in plasma, muscle, liver, and adipose tissue following dietary supplementation with vitamin E (VE) and various sources of fat. The trial involved 96 piglets weaned at an average of 28 d of age. Piglets were fed for 2 wk a semipurified diet not supplemented with VE. Piglets were then randomly assigned to 5 isoenergetic semipurified diets with 100 IU/kg VE as dl-?-tocopheryl acetate: a control (CTRL) diet (with no added fat) and 4 other diets containing either 3% linseed oil (LIN), 3% hydrogenated coconut oil (COC), 3% olive oil (OLI), or 3% safflower oil (SAF) representing diets rich in n-3 PUFA, SFA, MUFA, and n-6 PUFA, respectively. After 49 d of treatment, pigs were killed and blood, muscle (longissimus dorsi), adipose tissue, and whole liver (without gallbladder) were collected and analyzed for their Tol concentrations. For all tissues, LIN and SAF diets led to lower (P < 0.02) Tol concentrations as compared to the CTRL diet: -63 and -67%, respectively. ?-Tocopherol concentrations in plasma, liver, and adipose tissue were greater (P < 0.001) in the COC group as compared to the CTRL group. The OLI diet led to greater (P < 0.01) liver Tol concentration (+92%) as compared to the CTRL diet but had no significant effect on plasma, muscle, and adipose tissue Tol concentrations. There were significant correlations (P < 0.001) between plasma, muscle, and liver Tol concentrations (r > 0.78). These results show that supplementation with PUFA markedly decreases Tol concentration in blood and tissues of growing pigs, whereas SFA increase Tol content in blood, liver, and adipose tissue. Monounsaturated fatty acids only increase liver Tol concentrations. Therefore, increasing the amount of fat in the diet (from <0.1 to approximately 3.5%) and the type of dietary fatty acids supplemented with VE are key factors with regards to VE concentration in plasma and tissue. The Tol:PUFA needs to be carefully considered to meet the VE pigs requirement and to ensure an optimal Tol meat enrichment. PMID:25349346

  16. Accelerated Focused Ultrasound Imaging

    PubMed Central

    White, P. Jason; Thomenius, Kai; Clement, Gregory T.

    2010-01-01

    One of the most, basic trade-offs in ultrasound imaging involves frame rate, depth, and number of lines. Achieving good spatial resolution and coverage requires a large number of lines, leading to decreases in frame rate. An even more serious imaging challenge occurs with imaging modes involving spatial compounding and 3-D/4-D imaging, which are severely limited by the slow speed of sound in tissue. The present work can overcome these traditional limitations, making ultrasound imaging many-fold faster. By emitting several beams at once, and by separating the resulting overlapped signals through spatial and temporal processing, spatial resolution and/or coverage can be increased by many-fold while leaving frame rates unaffected. The proposed approach can also be extended to imaging strategies that do not involve transmit beamforming, such as synthetic aperture imaging. Simulated and experimental results are presented where imaging speed is improved by up to 32-fold, with little impact on image quality. Object complexity has little impact on the method’s performance, and data from biological systems can readily be handled. The present work may open the door to novel multiplexed and/or multidimensional protocols considered impractical today. PMID:20040398

  17. Ultrasonic tissue-type imaging (TTI) for planning treatment of prostate cancer

    Microsoft Academic Search

    Ernest J. Feleppa; Jeffrey A. Ketterling; Christopher R. Porter; John Gillespie; Cheng-Shie Wuu; Stella Urban; Andrew Kalisz; Ronald D. Ennis; Peter B. Schiff

    2004-01-01

    Our research is intended to develop ultrasonic methods for characterizing cancerous prostate tissue and thereby to improve the effectiveness of biopsy guidance, therapy targeting, and treatment monitoring. We acquired radio-frequency (RF) echo-signal data and clinical variables, e.g., PSA, during biopsy examinations. We computed spectra of the RF signals in each biopsied region, and trained neural network classifers with over 3,000

  18. Analysis of tall fescue ESTs representing different abiotic stresses, tissue types and developmental stages

    PubMed Central

    Mian, MA Rouf; Zhang, Yan; Wang, Zeng-Yu; Zhang, Ji-Yi; Cheng, Xiaofei; Chen, Lei; Chekhovskiy, Konstantin; Dai, Xinbin; Mao, Chunhong; Cheung, Foo; Zhao, Xuechun; He, Ji; Scott, Angela D; Town, Christopher D; May, Gregory D

    2008-01-01

    Background Tall fescue (Festuca arundinacea Schreb) is a major cool season forage and turf grass species grown in the temperate regions of the world. In this paper we report the generation of a tall fescue expressed sequence tag (EST) database developed from nine cDNA libraries representing tissues from different plant organs, developmental stages, and abiotic stress factors. The results of inter-library and library-specific in silico expression analyses of these ESTs are also reported. Results A total of 41,516 ESTs were generated from nine cDNA libraries of tall fescue representing tissues from different plant organs, developmental stages, and abiotic stress conditions. The Festuca Gene Index (FaGI) has been established. To date, this represents the first publicly available tall fescue EST database. In silico gene expression studies using these ESTs were performed to understand stress responses in tall fescue. A large number of ESTs of known stress response gene were identified from stressed tissue libraries. These ESTs represent gene homologues of heat-shock and oxidative stress proteins, and various transcription factor protein families. Highly expressed ESTs representing genes of unknown functions were also identified in the stressed tissue libraries. Conclusion FaGI provides a useful resource for genomics studies of tall fescue and other closely related forage and turf grass species. Comparative genomic analyses between tall fescue and other grass species, including ryegrasses (Lolium sp.), meadow fescue (F. pratensis) and tetraploid fescue (F. arundinacea var glaucescens) will benefit from this database. These ESTs are an excellent resource for the development of simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) PCR-based molecular markers. PMID:18318913

  19. A constrained adaptive beamformer for medical ultrasound: initial results

    Microsoft Academic Search

    J. A. Mann; W. F. Walker

    2002-01-01

    Adaptive beamforming has been widely used as a way to improve image quality in medical ultrasound applications by correcting phase and amplitude aberration errors resulting from tissue inhomogeneity. A less-studied concern in ultrasound beamforming is the deleterious contribution of bright off-axis targets. This paper describes a new approach, the constrained adaptive beamformer (CAB), which builds on classic array processing methods

  20. Flux analysis of cholesterol biosynthesis in vivo reveals multiple tissue and cell-type specific pathways

    PubMed Central

    Mitsche, Matthew A; McDonald, Jeffrey G; Hobbs, Helen H; Cohen, Jonathan C

    2015-01-01

    Two parallel pathways produce cholesterol: the Bloch and Kandutsch-Russell pathways. Here we used stable isotope labeling and isotopomer analysis to trace sterol flux through the two pathways in mice. Surprisingly, no tissue used the canonical K–R pathway. Rather, a hybrid pathway was identified that we call the modified K–R (MK–R) pathway. Proportional flux through the Bloch pathway varied from 8% in preputial gland to 97% in testes, and the tissue-specificity observed in vivo was retained in cultured cells. The distribution of sterol isotopomers in plasma mirrored that of liver. Sterol depletion in cultured cells increased flux through the Bloch pathway, whereas overexpression of 24-dehydrocholesterol reductase (DHCR24) enhanced usage of the MK–R pathway. Thus, relative use of the Bloch and MK–R pathways is highly variable, tissue-specific, flux dependent, and epigenetically fixed. Maintenance of two interdigitated pathways permits production of diverse bioactive sterols that can be regulated independently of cholesterol. DOI: http://dx.doi.org/10.7554/eLife.07999.001 PMID:26114596

  1. Tissue specific regulation of peripheral-type benzodiazepine receptor density after chemical sympathectomy

    SciTech Connect

    Basile, A.S.; Skolnick, P.

    1988-01-01

    The characteristics of (/sup 3/H)Ro 5-4864 binding to peripheral benzodiazepine receptors (PBR) in the central nervous system and peripheral tissues were examined after chemical sympathectomy with 6-hydroxydopamine (6-OHDA). One week after the intracisternal administration of 6-OHDA, the number of (/sup 3/H)Ro 5-4864 binding sites (Bmax) in the hypothalamus and striatum increased 41 and 50% respectively, concurrent with significant reductions in catecholamine content. An increase (34%) in the Bmax of (/sup 3/H)Ro 5-4864 to cardiac ventricle was observed one week after parenteral 6-OHDA administration. In contrast, the B/sub max/ of (/sup 3/H)Ro 5-4684 to pineal gland decreased 48% after 6-OHDA induced reduction in norepinephrine content. The Bmax values for (/sup 3/H)Ro 5-4864 binding to other tissues (including lung, kidney, spleen, cerebral cortex, cerebellum, hippocampus and olfactory bulbs) were unaffected by 6-OHDA administration. The density of pineal, but not cardiac PBR was also reduced after reserpine treatment, an effect reversed by isoproterenol administration. These findings demonstrate that alterations in sympathetic input may regulate the density of PBR in both the central nervous system and periphery in a tissue specific fashion. 33 references, 4 tables.

  2. ULTRASOUND IMAGE DENOISING VIA MAXIMUM A POSTERIORI ESTIMATION OF WAVELET COEFFICIENTS

    E-print Network

    Tsakalides, Panagiotis

    removal by means of digital image processors could improve the diagnostic potential of medical ultrasound the tissue being imaged. Speckle filtering is thus a criti- cal pre-processing step in medical ultrasound1 ULTRASOUND IMAGE DENOISING VIA MAXIMUM A POSTERIORI ESTIMATION OF WAVELET COEFFICIENTS A. Achim1

  3. IEEE Trans Ultrason Ferroelectr Freq Control . Author manuscript MR-guided adaptive focusing of ultrasound

    E-print Network

    Paris-Sud XI, Université de

    focusing of ultrasound Beno t Larratî * , Mathieu Pernot , Gabriel Montaldo , Mathias Fink , Micka l potential in the field of MR-Guided Ultrasound Therapy in particular for transcranial brain HIFU. Author of medical ultrasound. The heterogeneities of biological tissues in terms of speed of sound, density

  4. Convex Ultrasound Image Reconstruction with Log-Euclidean Priors Jos Seabra, Joo Xavier and Joo Sanches

    E-print Network

    Instituto de Sistemas e Robotica

    Convex Ultrasound Image Reconstruction with Log-Euclidean Priors José Seabra, João Xavier and João regularizes the solution. A Bayesian algorithm for ultrasound image reconstruction and de-noising is proposed and tissue transitions) are preserved. I. INTRODUCTION Ultrasound imaging is widely used in clinical practice

  5. Tubular Structure Enhancement for Surgical Instrument Detection in 3D Ultrasound

    E-print Network

    Dupont, Pierre

    Tubular Structure Enhancement for Surgical Instrument Detection in 3D Ultrasound Hongliang Ren and Pierre E. Dupont, Fellow, IEEE Abstract--Three-dimensional ultrasound has been an effective imaging since it enables visualization of both instruments and tissue. Challenges to ultrasound

  6. Estimation of Speed of Sound in Dual-Layered Media using Medical Ultrasound Image

    E-print Network

    Kingsbury, Nick

    Estimation of Speed of Sound in Dual-Layered Media using Medical Ultrasound Image Deconvolution Ho The speed of sound in soft tissues is assumed as 1540 m/s in medical pulse-echo ultrasound imaging systems of image deconvolution. This enables the use of unmodified ultrasound machines and a normal scanning

  7. Enhancement of fibrinolysis in vitro by ultrasound.

    PubMed Central

    Francis, C W; Onundarson, P T; Carstensen, E L; Blinc, A; Meltzer, R S; Schwarz, K; Marder, V J

    1992-01-01

    The effect of ultrasound on the rate of fibrinolysis has been investigated using an in vitro system. Plasma or blood clots containing a trace label of 125I fibrin were suspended in plasma containing plasminogen activator and intermittently exposed to continuous wave 1-MHz ultrasound at intensities up to 8 W/cm2. Plasma clot lysis at 1 h with 1 microgram/ml recombinant tissue plasminogen activator (rt-PA) was 12.8 +/- 1.2% without ultrasound and was significantly (P = 0.0001) increased by exposure to ultrasound with greater lysis at 1 W/cm2 (18.0 +/- 1.4%), 2 W/cm2 (19.3 +/- 0.7%), 4 W/cm2 (22.8 +/- 1.8%), and 8 W/cm2 (58.7 +/- 7.1%). Significant increases in lysis were also seen with urokinase at ultrasound intensities of 2 W/cm2 and above. Exposure of clots to ultrasound in the absence of plasminogen activator did not increase lysis. Ultrasound exposure resulted in a marked reduction in the rt-PA concentration required to achieve an equivalent degree of lysis to that seen without ultrasound. For example, 15% lysis occurred in 1 h at 1 microgram/ml rt-PA without ultrasound or with 0.2 microgram/ml with ultrasound, a five-fold reduction in concentration. Ultrasound at 1 W/cm2 and above also potentiated lysis of retracted whole blood clots mediated by rt-PA or urokinase. The maximum temperature increase of plasma clots exposed to 4 W/cm2 ultrasound was only 1.7 degrees C, which could not explain the enhancement of fibrinolysis. Ultrasound exposure did not cause mechanical fragmentation of the clot into sedimentable fragments, nor did it alter the sizes of plasmic derivatives as demonstrated by SDS polyacrylamide gel electrophoresis. We conclude that ultrasound at 1 MHz potentiates enzymatic fibrinolysis by a nonthermal mechanism at energies that can potentially be applied and tolerated in vivo to accelerate therapeutic fibrinolysis. Images PMID:1430229

  8. Development of Ultrasound Tomography for Breast Imaging: Technical Assessment

    SciTech Connect

    Duric, N; Littrup, P; Babkin, A; Chambers, D; Azevedo, S; Arkady, K; Pevzner, R; Tokarev, M; Holsapple, E

    2004-09-30

    Ultrasound imaging is widely used in medicine because of its benign characteristics and real-time capabilities. Physics theory suggests that the application of tomographic techniques may allow ultrasound imaging to reach its full potential as a diagnostic tool allowing it to compete with other tomographic modalities such as X-ray CT and MRI. This paper describes the construction and use of a prototype tomographic scanner and reports on the feasibility of implementing tomographic theory in practice and the potential of US tomography in diagnostic imaging. Data were collected with the prototype by scanning two types of phantoms and a cadaveric breast. A specialized suite of algorithms was developed and utilized to construct images of reflectivity and sound speed from the phantom data. The basic results can be summarized as follows: (1) A fast, clinically relevant US tomography scanner can be built using existing technology. (2) The spatial resolution, deduced from images of reflectivity, is 0.4 mm. The demonstrated 10 cm depth-of-field is superior to that of conventional ultrasound and the image contrast is improved through the reduction of speckle noise and overall lowering of the noise floor. (3) Images of acoustic properties such as sound speed suggest that it is possible to measure variations in the sound speed of 5 m/s. An apparent correlation with X-ray attenuation suggests that the sound speed can be used to discriminate between various types of soft tissue. (4) Ultrasound tomography has the potential to improve diagnostic imaging in relation to breast cancer detection.

  9. Microbubble-mediated ultrasound therapy: a review of its potential in cancer treatment

    PubMed Central

    Ibsen, Stuart; Schutt, Carolyn E; Esener, Sadik

    2013-01-01

    The inherently toxic nature of chemotherapy drugs is essential for them to kill cancer cells but is also the source of the detrimental side effects experienced by patients. One strategy to reduce these side effects is to limit the healthy tissue exposure by encapsulating the drugs in a vehicle that demonstrates a very low leak rate in circulation while simultaneously having the potential for rapid release once inside the tumor. Designing a vehicle with these two opposing properties is the major challenge in the field of drug delivery. A triggering event is required to change the vehicle from its stable circulating state to its unstable release state. A unique mechanical actuation type trigger is possible by harnessing the size changes that occur when microbubbles interact with ultrasound. These mechanical actuations can burst liposomes and cell membranes alike allowing for rapid drug release and facilitating delivery into nearby cells. The tight focusing ability of the ultrasound to just a few cubic millimeters allows for precise control over the tissue location where the microbubbles destabilize the vehicles. This allows the ultrasound to highlight the tumor tissue and cause rapid drug release from any carrier present. Different vehicle designs have been demonstrated from carrying drug on just the surface of the microbubble itself to encapsulating the microbubble along with the drug within a liposome. In the future, nanoparticles may extend the circulation half-life of these ultrasound triggerable drug-delivery vehicles by acting as nucleation sites of ultrasound-induced mechanical actuation. In addition to the drug delivery capability, the microbubble size changes can also be used to create imaging contrast agents that could allow the internal chemical environment of a tumor to be studied to help improve the diagnosis and detection of cancer. The ability to attain truly tumor-specific release from circulating drug-delivery vehicles is an exciting future prospect to reduce chemotherapy side effects while increasing drug effectiveness. PMID:23667309

  10. Framework of Collagen Type I – Vasoactive Vessels Structuring Invariant Geometric Attractor in Cancer Tissues: Insight into Biological Magnetic Field

    PubMed Central

    Díaz, Jairo A.; Murillo, Mauricio F.; Jaramillo, Natalia A.

    2009-01-01

    In a previous research, we have described and documented self-assembly of geometric triangular chiral hexagon crystal-like complex organizations (GTCHC) in human pathological tissues. This article documents and gathers insights into the magnetic field in cancer tissues and also how it generates an invariant functional geometric attractor constituted for collider partners in their entangled environment. The need to identify this hierarquic attractor was born out of the concern to understand how the vascular net of these complexes are organized, and to determine if the spiral vascular subpatterns observed adjacent to GTCHC complexes and their assembly are interrelational. The study focuses on cancer tissues and all the macroscopic and microscopic material in which GTCHC complexes are identified, which have been overlooked so far, and are rigorously revised. This revision follows the same parameters that were established in the initial phase of the investigation, but with a new item: the visualization and documentation of external dorsal serous vascular bed areas in spatial correlation with the localization of GTCHC complexes inside the tumors. Following the standard of the electro-optical collision model, we were able to reproduce and replicate collider patterns, that is, pairs of left and right hand spin-spiraled subpatterns, associated with the orientation of the spinning process that can be an expansion or contraction disposition of light particles. Agreement between this model and tumor data is surprisingly close; electromagnetic spiral patterns generated were identical at the spiral vascular arrangement in connection with GTCHC complexes in malignant tumors. These findings suggest that the framework of collagen type 1 – vasoactive vessels that structure geometric attractors in cancer tissues with invariant morphology sets generate collider partners in their magnetic domain with opposite biological behavior. If these principles are incorporated into nanomaterial, biomedical devices, and engineered tissues, new therapeutic strategies could be developed for cancer treatment. PMID:19223987

  11. Functional DNA methylation differences between tissues, cell types, and across individuals discovered using the M&M algorithm

    PubMed Central

    Zhang, Bo; Zhou, Yan; Lin, Nan; Lowdon, Rebecca F.; Hong, Chibo; Nagarajan, Raman P.; Cheng, Jeffrey B.; Li, Daofeng; Stevens, Michael; Lee, Hyung Joo; Xing, Xiaoyun; Zhou, Jia; Sundaram, Vasavi; Elliott, GiNell; Gu, Junchen; Shi, Taoping; Gascard, Philippe; Sigaroudinia, Mahvash; Tlsty, Thea D.; Kadlecek, Theresa; Weiss, Arthur; O’Geen, Henriette; Farnham, Peggy J.; Maire, Cécile L.; Ligon, Keith L.; Madden, Pamela A.F.; Tam, Angela; Moore, Richard; Hirst, Martin; Marra, Marco A.; Zhang, Baoxue; Costello, Joseph F.; Wang, Ting

    2013-01-01

    DNA methylation plays key roles in diverse biological processes such as X chromosome inactivation, transposable element repression, genomic imprinting, and tissue-specific gene expression. Sequencing-based DNA methylation profiling provides an unprecedented opportunity to map and compare complete DNA methylomes. This includes one of the most widely applied technologies for measuring DNA methylation: methylated DNA immunoprecipitation followed by sequencing (MeDIP-seq), coupled with a complementary method, methylation-sensitive restriction enzyme sequencing (MRE-seq). A computational approach that integrates data from these two different but complementary assays and predicts methylation differences between samples has been unavailable. Here, we present a novel integrative statistical framework M&M (for integration of MeDIP-seq and MRE-seq) that dynamically scales, normalizes, and combines MeDIP-seq and MRE-seq data to detect differentially methylated regions. Using sample-matched whole-genome bisulfite sequencing (WGBS) as a gold standard, we demonstrate superior accuracy and reproducibility of M&M compared to existing analytical methods for MeDIP-seq data alone. M&M leverages the complementary nature of MeDIP-seq and MRE-seq data to allow rapid comparative analysis between whole methylomes at a fraction of the cost of WGBS. Comprehensive analysis of nineteen human DNA methylomes with M&M reveals distinct DNA methylation patterns among different tissue types, cell types, and individuals, potentially underscoring divergent epigenetic regulation at different scales of phenotypic diversity. We find that differential DNA methylation at enhancer elements, with concurrent changes in histone modifications and transcription factor binding, is common at the cell, tissue, and individual levels, whereas promoter methylation is more prominent in reinforcing fundamental tissue identities. PMID:23804400

  12. Critical roles of specimen type and temperature before and during fixation in the detection of phosphoproteins in breast cancer tissues

    PubMed Central

    Gündisch, Sibylle; Annaratone, Laura; Beese, Christian; Drecol, Enken; Marchiò, Caterina; Quaglino, Elena; Sapino, Anna; Becker, Karl-Friedrich; Bussolati, Gianni

    2015-01-01

    The most efficient approach for therapy selection to inhibit the deregulated kinases in cancer tissues is to measure their phosphorylation status prior to the treatment. The aim of our study was to evaluate the influence of pre-analytical parameters (cold ischemia time, temperature before and during tissue fixation, and sample type) on the levels of proteins and phosphoproteins in breast cancer tissues, focusing on the PI3 kinase/AKT pathway. The BALB-neuT mouse breast cancer model expressing HER2 and pAKT proteins and human biopsy and resection specimens were analyzed. By using quantitative reverse phase protein arrays (RPPA), 9 proteins and 16 phosphoproteins relevant to breast cancer biology were assessed. Cold temperatures before and during fixation resulted in a marked improvement in the preservation of the reactivity of biological markers (eg, ER, HER2) in general and, specifically, pHER2 and pAKT. Some phosphoproteins, eg, pHER2 and pAKT, were more sensitive to prolonged cold ischemia times than others (eg, pS6RP and pSTAT5). By comparing the phosphoprotein levels in core needle biopsies with those in resection specimens, we found a marked decrease in many phosphoproteins in the latter. Cold conditions can improve the preservation of proteins and phosphoproteins in breast cancer tissues. Biopsies?1 mm in size are the preferred sample type for assessing the activity of deregulated kinases for personalized cancer treatments because the phosphoprotein levels are better preserved compared with resection specimens. Each potential new (phospho)protein biomarker should be tested for its sensitivity to pre-analytical processing prior to the development of a diagnostic assay. PMID:25730369

  13. Ultrasound-enhanced intrascleral delivery of protein.

    PubMed

    Cheung, Alex Chi Yeung; Yu, Yu; Tay, David; Wong, Hoi Sang; Ellis-Behnke, Rutledge; Chau, Ying

    2010-11-30

    We aim to investigate ultrasound on enhancing protein penetration into the sclera, a non-invasive method to overcome the first barrier in taking the transscleral route for delivering therapeutics. Rabbit eyes were immersed in a fluorescein isothiocyanate conjugated bovine serum albumin solution. The distances of protein penetration, with and without ultrasound (30s continuous wave, 1MHz, 0.05W/cm(2)) applied on the sclera, and at different immersion time intervals (0, 5, 15, 30 and 60min), were measured by examining the cryo-sectioned tissues under fluorescence microscope (?60 measurements from 3 eyes for each condition). Retina was examined for structural damage by histology. It was found that ultrasound enhances the intrascleral penetration of protein, increasing the diffusivity by 1.6-folds while causing no damage to the retinal tissues. This physical modulation of the sclera is temporary, as evident by the restoration of the diffusional resistance at 15min after ultrasound treatment. The negligible effect of ultrasound-induced convection and the minimal temperature rise (<0.5°C), together with cavitation detected by acoustic emission and a decreased penetration distance at higher ultrasound frequency (30s continuous wave, 3MHz, 0.05W/cm(2)), suggest that cavitation is a possible mechanism for increasing the permeability of the sclera for diffusive transport. PMID:20868732

  14. Effects of temperature and tissue type on Chrysomya rufifacies (Diptera: Calliphoridae) (Macquart) development

    E-print Network

    Tomberlin, Jeff

    under controlled laboratory conditions on three muscle types (i.e., porcine, equine and canine) at three temperatures (i.e., 20.8, 24.8 and 28.3 8C). Rate of larval weight gain across time was statistically significant between muscle types (P 0.0001) and approaching significance across time between temperatures (P

  15. Ultrasound triggered, image guided, local drug delivery.

    PubMed

    Deckers, Roel; Moonen, Chrit T W

    2010-11-20

    Ultrasound allows the deposition of thermal and mechanical energies deep inside the human body in a non-invasive way. Ultrasound can be focused within a region with a diameter of about 1mm. The bio-effects of ultrasound can lead to local tissue heating, cavitation, and radiation force, which can be used for 1) local drug release from nanocarriers circulating in the blood, 2) increased extravasation of drugs and/or carriers, and 3) enhanced diffusivity of drugs. When using nanocarriers sensitive to mechanical forces (the oscillating ultrasound pressure waves) and/or sensitive to temperature, the content of the nanocarriers can be released locally. Thermo-sensitive liposomes have been suggested for local drug release in combination with local hyperthermia more than 25 years ago. Microbubbles may be designed specifically to enhance cavitation effects. Real-time imaging methods, such as magnetic resonance, optical and ultrasound imaging have led to novel insights and methods for ultrasound triggered drug delivery. Image guidance of ultrasound can be used for: 1) target identification and characterization; 2) spatio-temporal guidance of actions to release or activate the drugs and/or permeabilize membranes; 3) evaluation of bio-distribution, pharmacokinetics and pharmacodynamics; and 4) physiological read-outs to evaluate the therapeutic efficacy. PMID:20709123

  16. Markers of tissue-specific insulin resistance predict the worsening of hyperglycemia, incident type 2 diabetes and cardiovascular disease.

    PubMed

    FízeI'ová, Mária; Cederberg, Henna; Stan?áková, Alena; Jauhiainen, Raimo; Vangipurapu, Jagadish; Kuusisto, Johanna; Laakso, Markku

    2014-01-01

    We investigated the ability of surrogate markers of tissue-specific insulin resistance (IR, Matsuda IR, Adipocyte IR, Liver IR) to predict deterioration of hyperglycemia, incident type 2 diabetes and cardiovascular events in the Metabolic Syndrome in Men (METSIM) Study. The METSIM Study includes 10,197 Finnish men, aged 45-73 years, and examined in 2005-2010. A total of 558 of 8,749 non-diabetic participants at baseline were diagnosed with new-onset diabetes and 239 with a new CVD event during a 5.9-year follow-up of this cohort (2010-2013). Compared to fasting plasma insulin level, Matsuda IR (IR in skeletal muscle) and Adipocyte IR were significantly better predictors of 2-hour plasma glucose and glucose area under the curve after adjustment for confounding factors. Liver IR was the strongest predictor of both incident type 2 diabetes (hazard ratio?=?1.83, 95% confidence interval: 1.68-1.98) and cardiovascular events (hazard ratio?=?1.31, 95% confidence interval: 1.15-1.48). Hazard ratios for fasting insulin were 1.37 (95% confidence interval: 1.32-1.42) and 1.11 (95% confidence interval: 1.00-1.24), respectively. Tissue-specific markers of IR, Matsuda IR and Adipocyte IR, were superior to fasting plasma insulin level in predicting worsening of hyperglycemia, and Liver IR was superior to fasting insulin level in predicting incident type 2 diabetes and cardiovascular events. PMID:25310839

  17. Markers of Tissue-Specific Insulin Resistance Predict the Worsening of Hyperglycemia, Incident Type 2 Diabetes and Cardiovascular Disease

    PubMed Central

    FízeI'ová, Mária; Cederberg, Henna; Stan?áková, Alena; Jauhiainen, Raimo; Vangipurapu, Jagadish; Kuusisto, Johanna; Laakso, Markku

    2014-01-01

    We investigated the ability of surrogate markers of tissue-specific insulin resistance (IR, Matsuda IR, Adipocyte IR, Liver IR) to predict deterioration of hyperglycemia, incident type 2 diabetes and cardiovascular events in the Metabolic Syndrome in Men (METSIM) Study. The METSIM Study includes 10,197 Finnish men, aged 45–73 years, and examined in 2005–2010. A total of 558 of 8,749 non-diabetic participants at baseline were diagnosed with new-onset diabetes and 239 with a new CVD event during a 5.9-year follow-up of this cohort (2010–2013). Compared to fasting plasma insulin level, Matsuda IR (IR in skeletal muscle) and Adipocyte IR were significantly better predictors of 2-hour plasma glucose and glucose area under the curve after adjustment for confounding factors. Liver IR was the strongest predictor of both incident type 2 diabetes (hazard ratio?=?1.83, 95% confidence interval: 1.68–1.98) and cardiovascular events (hazard ratio?=?1.31, 95% confidence interval: 1.15–1.48). Hazard ratios for fasting insulin were 1.37 (95% confidence interval: 1.32–1.42) and 1.11 (95% confidence interval: 1.00–1.24), respectively. Tissue-specific markers of IR, Matsuda IR and Adipocyte IR, were superior to fasting plasma insulin level in predicting worsening of hyperglycemia, and Liver IR was superior to fasting insulin level in predicting incident type 2 diabetes and cardiovascular events. PMID:25310839

  18. Variogram methods for texture classification of atherosclerotic plaque ultrasound images

    NASA Astrophysics Data System (ADS)

    Jeromin, Oliver M.; Pattichis, Marios S.; Pattichis, Constantinos; Kyriacou, Efthyvoulos; Nicolaides, Andrew

    2006-03-01

    Stroke is the third leading cause of death in the western world and the major cause of disability in adults. The type and stenosis of extracranial carotid artery disease is often responsible for ischemic strokes, transient ischemic attacks (TIAs) or amaurosis fugax (AF). The identification and grading of stenosis can be done using gray scale ultrasound scans. The appearance of B-scan pictures containing various granular structures makes the use of texture analysis techniques suitable for computer assisted tissue characterization purposes. The objective of this study is to investigate the usefulness of variogram analysis in the assessment of ultrasound plague morphology. The variogram estimates the variance of random fields, from arbitrary samples in space. We explore stationary random field models based on the variogram, which can be applied in ultrasound plaque imaging leading to a Computer Aided Diagnosis (CAD) system for the early detection of symptomatic atherosclerotic plaques. Non-parametric tests on the variogram coefficients show that the cofficients coming from symptomatic versus asymptomatic plaques come from distinct distributions. Furthermore, we show significant improvement in class separation, when a log point-transformation is applied to the images, prior to variogram estimation. Model fitting using least squares is explored for anisotropic variograms along specific directions. Comparative classification results, show that variogram coefficients can be used for the early detection of symptomatic cases, and also exhibit the largest class distances between symptomatic and asymptomatic plaque images, as compared to over 60 other texture features, used in the literature.

  19. Measuring cell-type specific differential methylation in human brain tissue.

    PubMed

    Montaño, Carolina M; Irizarry, Rafael A; Kaufmann, Walter E; Talbot, Konrad; Gur, Raquel E; Feinberg, Andrew P; Taub, Margaret A

    2013-01-01

    The behavior of epigenetic mechanisms in the brain is obscured by tissue heterogeneity and disease-related histological changes. Not accounting for these confounders leads to biased results. We develop a statistical methodology that estimates and adjusts for celltype composition by decomposing neuronal and non-neuronal differential signal. This method provides a conceptual framework for deconvolving heterogeneous epigenetic data from postmortem brain studies. We apply it to find cell-specific differentially methylated regions between prefrontal cortex and hippocampus. We demonstrate the utility of the method on both Infinium 450k and CHARM data. PMID:24000956

  20. Extraction and characterization of the tissue forms of collagen types II and IX from bovine vitreous.

    PubMed Central

    Bishop, P N; Crossman, M V; McLeod, D; Ayad, S

    1994-01-01

    We report for the first time that, after centrifugation of adult bovine vitreous, the hyaluronan-rich supernatant contains collagens which can be isolated in their intact forms by precipitation with 4.5 M NaCl. This precipitate constituted approx. 4% of the total vitreous collagen and comprised collagen types IX and II (in the approximate ratio of 4:1) with negligible amounts of type-V/XI collagen. Type-II collagen was present partly in a pro-alpha 1(II) form, suggesting that there is active synthesis of type-II collagen into the matrix of adult bovine vitreous. Type-IX collagen was purified (2-2.5 mg/l of vitreous) and its glycosaminoglycan chain composition was analysed. Bovine vitreous type-IX collagen always possessed a glycosaminoglycan chain of comparatively low M(r) that was predominantly 4-sulphated, with chondroitin 6-sulphate representing a more minor component. By contrast, chick vitreous has been shown to contain type-IX collagen which always possesses a high-M(r) chondroitin sulphate chain that is predominantly 6-sulphated. The functional significance of these different glycosaminoglycan chain lengths and sulphation patterns is discussed. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:8172611

  1. A Review of Shearwave Dispersion Ultrasound Vibrometry (SDUV) and its Applications

    PubMed Central

    Urban, Matthew W.; Chen, Shigao; Fatemi, Mostafa

    2011-01-01

    Measurement of tissue elasticity has emerged as an important advance in medical imaging and tissue characterization. However, soft tissue is inherently a viscoelastic material. One way to characterize the viscoelastic material properties of a material is to measure shear wave propagation velocities within the material at different frequencies and use the dispersion of the velocities, or variation with frequency, to solve for the material properties. Shearwave Dispersion Ultrasound Vibrometry (SDUV) is an ultrasound-based technique that uses this feature to characterize the viscoelastic nature of soft tissue. This method has been used to measure the shear elasticity and viscosity in various types of soft tissues including skeletal muscle, cardiac muscle, liver, kidney, prostate, and arterial vessels. This versatile technique provides measurements of viscoelastic material properties with high spatial and temporal resolution, which can be used for assessing these properties in normal and pathologic tissues. The goals of this paper are to 1) give an overview of viscoelasticity and shear wave velocity dispersion, 2) provide a history of the development of the SDUV method, and 3) survey applications for SDUV that have been previously reported. PMID:22866026

  2. Nucleic acid delivery with microbubbles and ultrasound

    PubMed Central

    Rychak, Joshua J.; Klibanov, Alexander L.

    2014-01-01

    Nucleic acid-based therapy is a growing field of drug delivery research. Although ultrasound has been suggested to enhance transfection decades ago, it took a combination of ultrasound with nucleic acid carrier systems (microbubbles, liposomes, polyplexes, viral carriers) to achieve reasonable nucleic acid delivery efficacy. Microbubbles serve as foci for local deposition of ultrasound energy near the target cell, and greatly enhance sonoporation. Major advantage of this approach is in the minimal transfection in the non-insonated non-target tissues. Microbubbles can be simply co-administered with the nucleic acid carrier or can be modified to carry nucleic acid themselves. Liposomes with embedded gas or gas precursor particles can also be used to carry nucleic acid, release and deliver it by the ultrasound trigger. Successful testing in a wide variety of animal models (myocardium, solid tumors, skeletal muscle, pancreas) proves the potential usefulness of this technique for nucleic acid drug delivery. PMID:24486388

  3. Monitoring Radiofrequency Ablation Using Real-Time Ultrasound Nakagami Imaging Combined with Frequency and Temporal Compounding Techniques

    PubMed Central

    Zhou, Zhuhuang; Wu, Shuicai; Wang, Chiao-Yin; Ma, Hsiang-Yang; Lin, Chung-Chih; Tsui, Po-Hsiang

    2015-01-01

    Gas bubbles induced during the radiofrequency ablation (RFA) of tissues can affect the detection of ablation zones (necrosis zone or thermal lesion) during ultrasound elastography. To resolve this problem, our previous study proposed ultrasound Nakagami imaging for detecting thermal-induced bubble formation to evaluate ablation zones. To prepare for future applications, this study (i) created a novel algorithmic scheme based on the frequency and temporal compounding of Nakagami imaging for enhanced ablation zone visualization, (ii) integrated the proposed algorithm into a clinical scanner to develop a real-time Nakagami imaging system for monitoring RFA, and (iii) investigated the applicability of Nakagami imaging to various types of tissues. The performance of the real-time Nakagami imaging system in visualizing RFA-induced ablation zones was validated by measuring porcine liver (n = 18) and muscle tissues (n = 6). The experimental results showed that the proposed algorithm can operate on a standard clinical ultrasound scanner to monitor RFA in real time. The Nakagami imaging system effectively monitors RFA-induced ablation zones in liver tissues. However, because tissue properties differ, the system cannot visualize ablation zones in muscle fibers. In the future, real-time Nakagami imaging should be focused on the RFA of the liver and is suggested as an alternative monitoring tool when advanced elastography is unavailable or substantial bubbles exist in the ablation zone. PMID:25658424

  4. Progression from High Insulin Resistance to Type 2 Diabetes Does Not Entail Additional Visceral Adipose Tissue Inflammation

    PubMed Central

    Barbarroja, Nuria; Lopez-Pedrera, Chary; Garrido-Sanchez, Lourdes; Mayas, Maria Dolores; Oliva-Olivera, Wilfredo; Bernal-Lopez, Maria Rosa; El Bekay, Rajaa; Tinahones, Francisco Jose

    2012-01-01

    Obesity is associated with a low-grade chronic inflammation state. As a consequence, adipose tissue expresses pro-inflammatory cytokines that propagate inflammatory responses systemically elsewhere, promoting whole-body insulin resistance and consequential islet ?-cell exhaustation. Thus, insulin resistance is considered the early stage of type 2 diabetes. However, there is evidence of obese individuals that never develop diabetes indicating that the mechanisms governing the association between the increase of inflammatory factors and type 2 diabetes are much more complex and deserve further investigation. We studied for the first time the differences in insulin signalling and inflammatory pathways in blood and visceral adipose tissue (VAT) of 20 lean healthy donors and 40 equal morbidly obese (MO) patients classified in high insulin resistance (high IR) degree and diabetes state. We studied the changes in proinflammatory markers and lipid content from serum; macrophage infiltration, mRNA expression of inflammatory cytokines and transcription factors, activation of kinases involved in inflammation and expression of insulin signalling molecules in VAT. VAT comparison of these experimental groups revealed that type 2 diabetic-MO subjects exhibit the same pro-inflammatory profile than the high IR-MO patients, characterized by elevated levels of IL-1?, IL-6, TNF?, JNK1/2, ERK1/2, STAT3 and NF?B. Our work rules out the assumption that the inflammation should be increased in obese people with type 2 diabetes compared to high IR obese. These findings indicate that some mechanisms, other than systemic and VAT inflammation must be involved in the development of type 2 diabetes in obesity. PMID:23110196

  5. Practice guideline for the performance of breast ultrasound elastography.

    PubMed

    Lee, Su Hyun; Chang, Jung Min; Cho, Nariya; Koo, Hye Ryoung; Yi, Ann; Kim, Seung Ja; Youk, Ji Hyun; Son, Eun Ju; Choi, Seon Hyeong; Kook, Shin Ho; Chung, Jin; Cha, Eun Suk; Park, Jeong Seon; Jung, Hae Kyoung; Ko, Kyung Hee; Choi, Hye Young; Ryu, Eun Bi; Moon, Woo Kyung

    2014-01-01

    Ultrasound (US) elastography is a valuable imaging technique for tissue characterization. Two main types of elastography, strain and shear-wave, are commonly used to image breast tissue. The use of elastography is expected to increase, particularly with the increased use of US for breast screening. Recently, the US elastographic features of breast masses have been incorporated into the 2nd edition of the Breast Imaging Reporting and Data System (BI-RADS) US lexicon as associated findings. This review suggests practical guidelines for breast US elastography in consensus with the Korean Breast Elastography Study Group, which was formed in August 2013 to perform a multicenter prospective study on the use of elastography for US breast screening. This article is focused on the role of elastography in combination with B-mode US for the evaluation of breast masses. Practical tips for adequate data acquisition and the interpretation of elastography results are also presented. PMID:24936489

  6. Dietary fatty acid composition alters 11?-hydroxysteroid dehydrogenase type 1 gene expression in rat retroperitoneal white adipose tissue.

    PubMed

    Vara Prasad, Sakamuri S S; Jeya Kumar, Shanmugam S; Kumar, Putcha Uday; Qadri, Syed S Y H; Vajreswari, Ayyalasomayajula

    2010-01-01

    The enzyme 11?-hydroxysteroid dehydrogenase type 1 (11?-HSD1) amplifies intracellular glucocorticoid action by converting inactive glucocorticoids to their active forms in vivo. Adipose-specific overexpression of 11?-HSD1 induces metabolic syndrome in mice, whereas 11?-HSD1 null mice are resistant to it. Dietary trans and saturated fatty acids (TFAs and SFAs) are involved in the development of metabolic syndrome, whereas polyunsaturated fatty acids (PUFA) offer protection against this. Here, we report the effects of chronic feeding of different diets containing vanaspati (TFA rich), palm oil (SFA rich) and sunflower oil (PUFA rich) at 10%level on 11?-HSD1 gene expression in rat retroperitoneal adipose tissue. 11?-HSD1 gene expression was significantly higher in TFA rich diet-fed rats compared to SFA rich diet-fed rats, which in turn was significantly higher than PUFA rich diet-fed rats. Similar trend was observed in the expression of CCAAT-enhancer binding protein-? (C/EBP-?), the main transcription factor required for the expression of 11?-HSD1. We propose that TFAs and SFAs increase local amplification of glucocorticoid action in adipose tissue by upregulating 11?-HSD1 by altering C/EBP-?-gene expression. The increased levels of glucocorticoids in adipose tissue may lead to development of obesity and insulin resistance, thereby increasing the risk of developing metabolic syndrome. PMID:20932307

  7. Urokinase-type plasminogen activator is effective in fibrin clearance in the absence of its receptor or tissue-type plasminogen activator.

    PubMed Central

    Bugge, T H; Flick, M J; Danton, M J; Daugherty, C C; Romer, J; Dano, K; Carmeliet, P; Collen, D; Degen, J L

    1996-01-01

    The availability of gene-targeted mice deficient in the urokinase-type plasminogen activator (uPA), urokinase receptor (uPAR), tissue-type plasminogen activator (tPA), and plasminogen permits a critical, genetic-based analysis of the physiological and pathological roles of the two mammalian plasminogen activators. We report a comparative study of animals with individual and combined deficits in uPAR and tPA and show that these proteins are complementary fibrinolytic factors in mice. Sinusoidal fibrin deposits are found within the livers of nearly all adult mice examined with a dual deficiency in uPAR and tPA, whereas fibrin deposits are never found in livers collected from animals lacking uPAR and rarely detected in animals lacking tPA alone. This is the first demonstration that uPAR has a physiological role in fibrinolysis. However, uPAR-/-/tPA-/- mice do not develop the pervasive, multi-organ fibrin deposits, severe tissue damage, reduced fertility, and high morbidity and mortality observed in mice with a combined deficiency in tPA and the uPAR ligand, uPA. Furthermore, uPAR-/-/tPA-/- mice do not exhibit the profound impairment in wound repair seen in uPA-/-/tPA-/- mice when they are challenged with a full-thickness skin incision. These results indicate that plasminogen activation focused at the cell surface by uPAR is important in fibrin surveillance in the liver, but that uPA supplies sufficient fibrinolytic potential to clear fibrin deposits from most tissues and support wound healing without the benefit of either uPAR or tPA. Images Fig. 1 Fig. 2 Fig. 3 PMID:8650190

  8. Use of Discriminatory Probes for Strain Typing of Formalin-Fixed, Rabies Virus-Infected Tissues by In Situ Hybridization

    PubMed Central

    Nadin-Davis, Susan A.; Sheen, Mary; Wandeler, Alexander I.

    2003-01-01

    An in situ hybridization (ISH) method has been developed to overcome difficulties encountered in the viral typing of formalin-fixed rabies virus-infected brain tissue. Rabies viruses representative of all strains normally encountered in diagnostic submissions throughout Canada, including 3 strains of terrestrial hosts (arctic fox, western skunk, mid-Atlantic raccoon), 10 strains circulating in several bat reservoirs (BBCAN1 to BBCAN7, LACAN, SHCAN, and MYCAN), and the Evelyn-Rokitniki-Abelseth (ERA) strain, used as an oral vaccine for fox rabies control in Ontario, were targeted. Partial phosphoprotein gene fragments generated from reverse transcription (RT)-PCR products of specimens of each viral type were molecularly cloned and used to produce negative-sense digoxigenin-labeled RNA transcripts. Conditions permitting the use of these transcripts as strain-specific probes were optimized by blotting analyses with RT-PCR amplicons generated with representative rabies viruses and by ISH applied to mouse brains inoculated with these strains. The successful application of this methodology to two rabies virus-positive specimens that were also identified by traditional methods and the retrospective typing of two archival rabies virus-positive equine specimens is described. This technique provides a typing regimen for rabies virus isolates submitted in a form that is normally recalcitrant to alternate typing strategies. PMID:12958267

  9. Acute and chronic effects of oestrogen on endothelial tissue-type plasminogen activator release in postmenopausal women

    PubMed Central

    Hoetzer, Greta L; Stauffer, Brian L; Irmiger, Heather M; Ng, Marilyn; Smith, Derek T; DeSouza, Christopher A

    2003-01-01

    The capacity of vascular endothelium to locally release tissue-type plasminogen activator (t-PA) represents an important endogenous defence mechanism against intravascular fibrin deposition and thrombosis. We determined the influence of chronic and acute oestrogen administration on endothelial t-PA release in postmenopausal women. Sixty-three healthy postmenopausal women were studied: 31 non-users (age 58 ± 1 years) and 32 users of hormone replacement therapy, including oestrogen alone (ORT: 62 ± 2 years; n = 15) and in combination with progesterone (HRT: 57 ± 1 years; n = 17). Net endothelial t-PA release was determined in vivo, in response to intrabrachial infusions of bradykinin and sodium nitroprusside. To examine the acute effects of oestrogen on endothelial t-PA release, bradykinin and sodium nitroprusside dose-response curves were repeated in the presence of 17 ?-oestradiol in 20 of the 31 non-users. Net endothelial release of t-PA was ?30 % higher (P < 0.01) in women taking ORT (from 2.0 ± 1.0 to 83.6 ± 9.2 ng (100 ml tissue)?1 min?1) compared with those taking HRT (from 1.4 ± 0.4 to 63.5 ± 5.6 ng (100 ml tissue)?1 min?1) and those not taking supplementation (1.0 ± 0.7 to 63.0 ± 4.7 ng (100 ml tissue)?1 min?1). Intra-arterial infusion of 17 ?-oestradiol significantly potentiated bradykinin-induced t-PA release. Net endothelial release of t-PA was ?45 % higher (P < 0.01) after (from 1.0 ± 0.8 to 87.4 ± 9.9 ng (100 ml tissue)?1 min?1) versus before (1.2 ± 0.6 to 60.8 ± 5.6 ng (100 ml tissue)?1 min?1) acute 17 ?-oestradiol administration. Our results suggest that oestrogen has a direct modulatory effect on the capacity of the endothelium to release t-PA in healthy postmenopausal women. However, progesterone appears to oppose the favourable influence of oestrogen on endothelial fibrinolytic capacity. PMID:12815179

  10. ?-type Ti-10Mo-1.25Si-xZr biomaterials for applications in hard tissue replacements.

    PubMed

    Zhan, Yongzhong; Li, Chunliu; Jiang, Wenping

    2012-08-01

    In order to develop new ?-type Ti-based biochemical materials, a series of Ti-10Mo-1.25Si-xZr (x=4-13) alloys were designed and prepared using vacuum arc melting method. Phase analysis and microstructural observation showed that all the as cast samples consisted of equiaxed ?-Ti phase. With the increase of Zr content, the structure of grain boundary changed from semi-continuous network to denser granular, and the microstructure was refined. The solid solution effect of the ?-phase stabilization elements (i.e. Mo, Zr and Si) predominantly determined the mechanical properties. These ?-type Ti-10Mo-1.25Si-xZr biomaterials exhibited a good combination of high compressive strength, high yield stress, good plasticity, as well as rather low Young's modulus (in the range of 23.086 GPa-32.623 GPa), which may offer potential advantages in the applications in hard tissue replacements (HTRs). PMID:24364974

  11. Characterization of vascular strain during in-vitro angioplasty with high-resolution ultrasound speckle tracking

    PubMed Central

    2010-01-01

    Background Ultrasound elasticity imaging provides biomechanical and elastic properties of vascular tissue, with the potential to distinguish between tissue motion and tissue strain. To validate the ability of ultrasound elasticity imaging to predict structurally defined physical changes in tissue, strain measurement patterns during angioplasty in four bovine carotid artery pathology samples were compared to the measured physical characteristics of the tissue specimens. Methods Using computational image-processing techniques, the circumferences of each bovine artery specimen were obtained from ultrasound and pathologic data. Results Ultrasound-strain-based and pathology-based arterial circumference measurements were correlated with an R2 value of 0.94 (p = 0.03). The experimental elasticity imaging results confirmed the onset of deformation of an angioplasty procedure by indicating a consistent inflection point where vessel fibers were fully unfolded and vessel wall strain initiated. Conclusion These results validate the ability of ultrasound elasticity imaging to measure localized mechanical changes in vascular tissue. PMID:20727172

  12. Validation of potential reference genes for qPCR in maize across abiotic stresses, hormone treatments, and tissue types.

    PubMed

    Lin, Yueai; Zhang, Chenlu; Lan, Hai; Gao, Shibin; Liu, Hailan; Liu, Jian; Cao, Moju; Pan, Guangtang; Rong, Tingzhao; Zhang, Suzhi

    2014-01-01

    The reverse transcription quantitative polymerase chain reaction (RT-qPCR) is a powerful and widely used technique for the measurement of gene expression. Reference genes, which serve as endogenous controls ensure that the results are accurate and reproducible, are vital for data normalization. To bolster the literature on reference gene selection in maize, ten candidate reference genes, including eight traditionally used internal control genes and two potential candidate genes from our microarray datasets, were evaluated for expression level in maize across abiotic stresses (cold, heat, salinity, and PEG), phytohormone treatments (abscisic acid, salicylic acid, jasmonic acid, ethylene, and gibberellins), and different tissue types. Three analytical software packages, geNorm, NormFinder, and Bestkeeper, were used to assess the stability of reference gene expression. The results revealed that elongation factor 1 alpha (EF1?), tubulin beta (?-TUB), cyclophilin (CYP), and eukaryotic initiation factor 4A (EIF4A) were the most reliable reference genes for overall gene expression normalization in maize, while GRP (Glycine-rich RNA-binding protein), GLU1(beta-glucosidase), and UBQ9 (ubiquitin 9) were the least stable and most unsuitable genes. In addition, the suitability of EF1?, ?-TUB, and their combination as reference genes was confirmed by validating the expression of WRKY50 in various samples. The current study indicates the appropriate reference genes for the urgent requirement of gene expression normalization in maize across certain abiotic stresses, hormones, and tissue types. PMID:24810581

  13. Medical Ultrasound Imaging.

    ERIC Educational Resources Information Center

    Hughes, Stephen

    2001-01-01

    Explains the basic principles of ultrasound using everyday physics. Topics include the generation of ultrasound, basic interactions with material, and the measurement of blood flow using the Doppler effect. (Author/MM)

  14. Adaptive Real-Time Closed-Loop Temperature Control for Ultrasound Hyperthermia Using Magnetic Resonance Thermometry

    PubMed Central

    Sun, L.; Collins, C.M.; Schiano, J.L.; Smith, M.B.; Smith, N.B.

    2012-01-01

    Previous researchers have successfully demonstrated the application of temperature feedback control for thermal treatment of disease using MR thermometry. Using the temperature-dependent proton resonance frequency (PRF) shift, ultrasound heating for hyperthermia to a target organ (such as the prostate) can be tightly controlled. However, using fixed gain controllers, the response of the target to ultrasound heating varies with type, size, location, shape, stage of growth, and proximity to other vulnerable organs. To adjust for clinical variables, feedback self-tuning regulator (STR) and model reference adaptive control (MRAC) methods have been designed and implemented using real-time, online MR thermometry by adjusting the output power to an ultrasound array to quickly reach the hyperthermia target temperatures. The use of fast adaptive controllers in this application is advantageous because adaptive controllers do not require a priori knowledge of the initial tissue properties and blood perfusion and can quickly reach the steady-state target temperature in the presence of dynamic tissue properties (e.g., thermal conductivity, blood perfusion). This research was conducted to rapidly achieve and manage therapeutic temperatures from an ultrasound array using novel MRI-guided adaptive closed-loop controllers both in ex vivo and in vivo experiments. The ex vivo phantom experiments with bovine muscle (n = 5) show that within 6 ± 0.2 minutes, the tissue temperature increased by 8 ± 1.37°C. Using rabbits’ (n = 5) thigh muscle, the in vivo experiments demonstrated the target temperature reached 44.5°C ± 1.2°C in 8.0 ± 0.5 minutes. The preliminary in vivo experiment with canine prostate hyperthermia achieved 43 ± 2°C in 6.5 ± 0.5 minutes. These results demonstrate that the adaptive controllers with MR thermometry are able to effectively track the target temperature with dynamic tissue properties. PMID:22723751

  15. Ultrasound fiber guides and sensor applications

    NASA Astrophysics Data System (ADS)

    Safaai-Jazi, A.

    2007-09-01

    An overview of ultrasound fiber guides, their transmission properties, and their applications in sensing is presented. Ultrasound fiber guides are structures similar to optical fibers that are used for transmission of acoustic waves. They consist of a core region surrounded by a cladding layer to help confine the wave to the core. Ultrasound fiber guides may be fabricated with glass materials such as pure and doped fused silica, using fiber optics manufacturing technology. The underlying principles of fiber optic sensing in many cases are also applicable to ultrasound fiber guides, hence the potential applications of these waveguides in sensing and health monitoring of infrastructures. Propagation properties of ultrasound fiber guides are reviewed. Attention is focused on guides with small differences between the parameters of the core and cladding, often a necessary requirement for single-mode operation. Various types of guided modes including flexural, torsional, and radial modes are discussed. These modes are predominantly shear type. Ultrasound fiber guides also support another group of modes with complex propagation constants, which are referred to as leaky longitudinal modes. These modes lose power as propagate along the guide through radiation. Similarities and differences between optical and ultrasound modes in fiber guides are addressed.

  16. Ultrasound Imaging System Video

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In this video, astronaut Peggy Whitson uses the Human Research Facility (HRF) Ultrasound Imaging System in the Destiny Laboratory of the International Space Station (ISS) to image her own heart. The Ultrasound Imaging System provides three-dimension image enlargement of the heart and other organs, muscles, and blood vessels. It is capable of high resolution imaging in a wide range of applications, both research and diagnostic, such as Echocardiography (ultrasound of the heart), abdominal, vascular, gynecological, muscle, tendon, and transcranial ultrasound.

  17. Noninvasive measurement of local thermal diffusivity using backscattered ultrasound and focused ultrasound heating.

    PubMed

    Anand, Ajay; Kaczkowski, Peter J

    2008-09-01

    Previously, noninvasive methods of estimating local tissue thermal and acoustic properties using backscattered ultrasound have been proposed in the literature. In this article, a noninvasive method of estimating local thermal diffusivity in situ during focused ultrasound heating using beamformed acoustic backscatter data and applying novel signal processing techniques is developed. A high intensity focused ultrasound (HIFU) transducer operating at subablative intensities is employed to create a brief local temperature rise of no more than 10 degrees C. Beamformed radio-frequency (RF) data are collected during heating and cooling using a clinical ultrasound scanner. Measurements of the time-varying "acoustic strain", that is, spatiotemporal variations in the RF echo shifts induced by the temperature related sound speed changes, are related to a solution of the heat transfer equation to estimate the thermal diffusivity in the heated zone. Numerical simulations and experiments performed in vitro in tissue mimicking phantoms and excised turkey breast muscle tissue demonstrate agreement between the ultrasound derived thermal diffusivity estimates and independent estimates made by a traditional hot-wire technique. The new noninvasive ultrasonic method has potential applications in thermal therapy planning and monitoring, physiological monitoring and as a means of noninvasive tissue characterization. PMID:18450361

  18. Mesoporous silica nanoparticles as a breast cancer targeting contrast agent for ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Milgroom, Andrew Carson

    Current clinical use of ultrasound for breast cancer diagnostics is strictly limited to a role as a supplementary detection method to other modalities, such as mammography or MRI. A major reason for ultrasound’s role as a secondary method is its inability to discern between cancerous and non-cancerous bodies of similar density, like dense calcifications or benign fibroadenomas. Its detection capabilities are further diminished by the variable density of the surrounding breast tissue with the progression of age. Preliminary studies suggest that mesoporous silica nanoparticles (MSNs) are a good candidate as an in situ contrast agent for ultrasound. By tagging the silica particle surface with the cancer-targeting antibody trastuzumab (Herceptin), suspect regions of interest can be better identified in real time with standard ultrasound equipment. Once the silica-antibody conjugate is injected into the bloodstream and enters the cancerous growth’s vasculature, the antibody arm will bind to HER2, a cell surface receptor known to be dysfunctional or overexpressed in certain types of breast cancer. As more particles aggregate at the cell surface, backscatter of the ultrasonic waves increases as a result of the higher porous silica concentration. This translates to an increased contrast around the lesion boundary. Tumor detection through ultrasound contrast enhancement provides a tremendous advantage over current cancer diagnostics because is it significantly cheaper and can be monitored in real time. Characterization of MCM-41 type MSNs suggests that these particles have sufficient stability and particle size distribution to penetrate through fenestrated tumor vasculature and accumulate in HER2+ breast cancer cells through the enhanced permeation and retention (EPR) effect. A study of acoustic properties showed that particle concentration is linearly correlated to image contrast in clinical frequency-range ultrasound, although less pronounced than typical microbubble-type contrast agents. In vitro studies using cells with varied levels of HER2 expression demonstrated the selectivity of the MSN-Herceptin conjugate to cells with HER2 overexpression. Fluorescence imaging suggest these images remain surface-bound and are not incorporated into the cell body. This study demonstrates the potential of MSNs as a stable, safe, and effective imaging contrast agent for ultrasound-based cancer diagnostics. Ultimately this work will contribute towards the improvement of diagnostic alternatives to conventional ionizing radiation-intensive imaging—such as MRI or X-ray—without compromising the specificity of the test.

  19. Ultrasound Strain Imaging Towards Verification and Guidance of Prostate Thermal Therapy with Catheter-Based Ultrasound Applicators

    NASA Astrophysics Data System (ADS)

    Sridhar-Keralapura, Mallika; Chubb, Nicole; Scott, Serena; Phipps, Natalie; Burdette, Clif; Diederich, Chris

    2010-03-01

    Ultrasound based transurethral and interstitial catheters have been developed and tested in vivo to thermally ablate prostate cancers. Treatment validation and accurate control of therapy is currently done using MR thermal imaging (±1° C, update: 5-15 s). MRTI is effective for real-time monitoring and guidance, but, cost, setup time, and accessibility can be limiting. Ultrasound imaging methods could be a practicable approach to monitoring. We investigated Ultrasound Strain Imaging (USI) as a tool towards verifying and controlling prostate treatments by developing a novel methodology for tissue compression using ultrasound phantoms and ex vivo tissue models. We estimate strain using quasi real-time estimation algorithms and added automatic segmentation features. The methodology involved inserting an ultrasound applicator into ex vivo liver or porcine muscle tissue, ablating it for 10 min at 15 W to create a well defined thermal lesion. After treatment, the tissue was compressed either externally (3-5%) using the probe or by deflating/inflating the applicator's coupling balloon internally. Ultrasound RF data was recorded during the compression and USI was computed within 20 seconds and compared with photographs of corresponding excised tissue sections. USI estimated post ablation using balloon and external methods yielded significant contrast that correlated well with measurements of excised tissue sections. From these preliminary studies, USI can become an effective feasible tool for verification and guidance of ablation regions with these devices. Balloon compressions could potentially allow computation USI in clinical treatments for confirmation and boundary control.

  20. Retina Is Protected by Neuroserpin from Ischemic/Reperfusion-Induced Injury Independent of Tissue-Type Plasminogen Activator

    PubMed Central

    Gu, R. P.; Fu, L. L.; Jiang, C. H.; Xu, Y. F.; Wang, X.; Yu, J.

    2015-01-01

    The purpose of the present study was to investigate the potential neuroprotective effect of neuroserpin (NSP) on acute retinal ischemic/reperfusion-induced (IR) injury. An IR injury model was established by elevating intraocular pressure (IOP) for 60 minutes in wild type and tPA-deficient (tPA-/-) mice. Prior to IR injury, 1 ?L of 20 ?mol/L NSP or an equal volume of bovine serum albumin (BSA) was intravitreally administered. Retinal function was evaluated by electroretinograph (ERG) and the number of apoptotic neurons was determined via TUNEL labeling. Caspase-3, -8, -9,poly (ADP-ribose) polymerase (PARP)and their cleaved forms were subsequently analyzed. It was found that IR injury significantly damaged retinal function, inducing apoptosis in the retina, while NSP attenuated the loss of retinal function and significantly reduced the number of apoptotic neurons in both wild type and tPA-/- mice. The levels of cleaved caspase-3, cleaved PARP (the substrate of caspase-3) and caspase-9 (the modulator of the caspase-3), which had increased following IR injury, were significantly inhibited by NSP in both wild type and tPA-/- mice. NSP increased ischemic tolerance in the retina at least partially by inhibiting the intrinsic cell death signaling pathway of caspase-3. It was therefore concluded that the protective effect of neuroserpin maybe independent from its canonical interaction with a tissue-type plasminogen activator. PMID:26176694

  1. Ultrasound of the ankle and foot

    Microsoft Academic Search

    Nandkumar M Rawool; Levon N Nazarian

    2000-01-01

    Ultrasound is an excellent tool for evaluating common ankle problems. it is more economical than MRI and its real-time nature helps in correlating the study with the symptomatic area. US can be used in ankle to evaluate tendons (including tears, tendinits and tenosynovitis), joints, plantar fascia, ligaments, soft tissue masses, ganglion cysts, Morton's neuroma, and to look for foreign bodies.

  2. Extended focal depth imaging for medical ultrasound

    Microsoft Academic Search

    J. A. Hossack

    1996-01-01

    A new method for achieving extended depth of focus is presented which is shown to possess desirable characteristics in terms of ease of implementation, performance and stability in the presence of tissue related phase aberration and attenuation. Simple coded waveforms are used on individual elements. The performance is analyzed using a simple model for a generic ultrasound system. A major

  3. Medical ultrasound imaging

    Microsoft Academic Search

    Jørgen Arendt Jensen

    2007-01-01

    The paper gives an introduction to current medical ultrasound imaging systems. The basics of anatomic and blood flow imaging are described. The properties of medical ultrasound and its focusing are described, and the various methods for two- and three-dimensional imaging of the human anatomy are shown. Systems using both linear and non-linear propagation of ultrasound are described. The blood velocity

  4. Ultrasound mediated nanoparticle drug delivery

    NASA Astrophysics Data System (ADS)

    Mullin, Lee B.

    Ultrasound is not only a powerful diagnostic tool, but also a promising therapeutic technology that can be used to improve localized drug delivery. Microbubble contrast agents are micron sized encapsulated gas filled bubbles that are administered intravenously. Originally developed to enhance ultrasound images, microbubbles are highly echogenic due to the gas core that provides a detectable impedance difference from the surrounding medium. The core also allows for controlled response of the microbubbles to ultrasound pulses. Microbubbles can be pushed using acoustic radiation force and ruptured using high pressures. Destruction of microbubbles can increase permeability at the cellular and vascular level, which can be advantageous for drug delivery. Advances in drug delivery methods have been seen with the introduction of nanoparticles, nanometer sized objects often carrying a drug payload. In chemotherapy, nanoparticles can deliver drugs to tumors while limiting systemic exposure due to abnormalities in tumor vasculature such large gaps between endothelial cells that allow nanoparticles to enter into the interstitial space; this is referred to as the enhanced permeability and retention (EPR) effect. However, this effect may be overestimated in many tumors. Additionally, only a small percentage of the injected dose accumulates in the tumor, which most the nanoparticles accumulating in the liver and spleen. It is hypothesized that combining the acoustic activity of an ultrasound contrast agent with the high payload and extravasation ability of a nanoparticle, localized delivery to the tumor with reduced systemic toxicity can be achieved. This method can be accomplished by either loading nanoparticles onto the shell of the microbubble or through a coadministration method of both nanoparticles and microbubbles. The work presented in this dissertation utilizes novel and commercial nanoparticle formulations, combined with microbubbles and a variety of ultrasound systems. Ultrasound parameters are optimized to achieve maximum cell internalization of molecules and increased nanoparticle delivery to a cell layer on a coverslip. In-vivo studies demonstrate the possibility of using a lower dose of paclitaxel to slow tumor growth rates, increase doxorubicin concentration in tumor tissue, and enhance tumor delivery of fluorescent molecules through treatments that combine nanoparticles with ultrasound and microbubbles.

  5. Effects of dressing type on 3D tissue microdeformations during negative pressure wound therapy: a computational study.

    PubMed

    Wilkes, R; Zhao, Y; Kieswetter, K; Haridas, B

    2009-03-01

    Vacuum-assisted closure (VAC) therapy, also referred to as vacuum-assisted closure negative pressure wound therapy (VAC NPWT), delivered to various dermal wounds is believed to influence the formation of granulation tissue via the mechanism of microdeformational signals. In recent years, numerous experimental investigations have been initiated to study the cause-effect relationships between the mechanical signals and the transduction pathways that result in improved granulation response. To accurately quantify the tissue microdeformations during therapy, a new three-dimensional finite element model has been developed and is described in this paper. This model is used to study the effect of dressing type and subatmospheric pressure level on the variations in the microdeformational strain fields in a model dermal wound bed. Three-dimensional geometric models representing typical control volumes of NPWT dressings were generated using micro-CT scanning of VAC GranuFoam, a reticulated open-cell polyurethane foam (ROCF), and a gauze dressing (constructed from USP Class VII gauze). Using a nonlinear hyperfoam constitutive model for the wound bed, simulated tissue microdeformations were generated using the foam and gauze dressing models at equivalent negative pressures. The model results showed that foam produces significantly greater strain than gauze in the tissue model at all pressures and in all metrics (p<0.0001 for all but epsilon(vol) at -50 mm Hg and -100 mm Hg where p<0.05). Specifically, it was demonstrated in this current work that the ROCF dressing produces higher levels of tissue microdeformation than gauze at all levels of subatmospheric pressure. This observation is consistent across all of the strain invariants assessed, i.e., epsilon(vol), epsilon(dist), the minimum and maximum principal strains, and the maximum shear strain. The distribution of the microdeformations and strain appears as a repeating mosaic beneath the foam dressing, whereas the gauze dressings appear to produce an irregular distribution of strains in the wound surface. Strain predictions from the developed computational model results agree well with those predicted from prior two-dimensional experimental and computational studies of foam-based NPWT (Saxena, V., et al., 2004, "Vacuum-assisted closure: Microdeformations of Wounds and Cell Proliferation," Plast. Reconstr. Surg., 114(5), pp. 1086-1096). In conjunction with experimental in vitro and in vivo studies, the developed model can now be extended into more detailed investigations into the mechanobiological underpinnings of VAC NPWT and can help to further develop and optimize this treatment modality for the treatment of challenging patient wounds. PMID:19154071

  6. FFT-based computation of the bioheat transfer equation for the HCC ultrasound surgery therapy modeling

    E-print Network

    Boyer, Edmond

    the hepatocellular carcinoma curative treatment by a percutaneous high intensity ultrasound surgery. The tissue ; interstitial therapy ; ultrasound therapy ; modeling Introduction At an early stage, the hepatocellular equation (BHTE)T ' [ :5] where: and refer to tissue density and specific heat; models the thermal diffusion

  7. Breast cancer diagnosis based on ultrasound RF echo modeling and physician's level of confidence

    Microsoft Academic Search

    B. Alacam; B. Yazici; N. Bilgutay

    2003-01-01

    A number of researchers have shown that the ultrasound RF echo from tissue exhibits (1\\/f ) ? characteristics and developed tissue characterization methods based on the fractal parameter of the received signal. In this paper a new model for the received ultrasound RF data has been proposed, namely the fractional differencing auto regressive moving-average (FARMA) model, whose parameters were investigated

  8. Ultrafast imaging of in vivo muscle contraction using ultrasound Thomas Deffieux,a

    E-print Network

    Paris 7 - Denis Diderot, Université

    Ultrafast imaging of in vivo muscle contraction using ultrasound Thomas Deffieux,a Jean of an in vivo contracting muscle is proposed. The principle is to use an ultrafast ultrasound scanner up to 5000 these images local strains are calculated.3 Doppler tissue imaging gives the tissues' velocity distribution

  9. Insulin-independent reversal of type 1 diabetes in nonobese diabetic mice with brown adipose tissue transplant.

    PubMed

    Gunawardana, Subhadra C; Piston, David W

    2015-06-15

    Traditional therapies for type 1 diabetes (T1D) involve insulin replacement or islet/pancreas transplantation and have numerous limitations. Our previous work demonstrated the ability of embryonic brown adipose tissue (BAT) transplants to establish normoglycemia without insulin in chemically induced models of insulin-deficient diabetes. The current study sought to extend the technique to an autoimmune-mediated T1D model and document the underlying mechanisms. In nonobese diabetic (NOD) mice, BAT transplants result in complete reversal of T1D associated with rapid and long-lasting euglycemia. In addition, BAT transplants placed prior to the onset of diabetes on NOD mice can prevent or significantly delay the onset of diabetes. As with streptozotocin (STZ)-diabetic models, euglycemia is independent of insulin and strongly correlates with decrease of inflammation and increase of adipokines. Plasma insulin-like growth factor-I (IGF-I) is the first hormone to increase following BAT transplants. Adipose tissue of transplant recipients consistently express IGF-I compared with little or no expression in controls, and plasma IGF-I levels show a direct negative correlation with glucose, glucagon, and inflammatory cytokines. Adipogenic and anti-inflammatory properties of IGF-I may stimulate regeneration of new healthy white adipose tissue, which in turn secretes hypoglycemic adipokines that substitute for insulin. IGF-I can also directly decrease blood glucose through activating insulin receptor. These data demonstrate the potential for insulin-independent reversal of autoimmune-induced T1D with BAT transplants and implicate IGF-I as a likely mediator in the resulting equilibrium. PMID:25898954

  10. Isolation, in vitro culture and identification of a new type of mesenchymal stem cell derived from fetal bovine lung tissues.

    PubMed

    Hu, Pengfei; Pu, Yabin; Li, Xiayun; Zhu, Zhiqiang; Zhao, Yuhua; Guan, Weijun; Ma, Yuehui

    2015-09-01

    Lung?derived mesenchymal stem cells (LMSCs) are considered to be important in lung tissue repair and regenerative processes. However, the biological characteristics and differentiation potential of LMSCs remain to be elucidated. In the present study, fetal lung?derived mesenchymal stem cells (FLMSCs) were isolated from fetal bovine lung tissues by collagenase digestion. The in vitro culture conditions were optimized and stabilized and the self?renewal ability and differentiation potential were evaluated. The results demonstrated that the FLMSCs were morphologically consistent with fibroblasts, were able to be cultured and passaged for at least 33 passages and the cell morphology and proliferative ability were stable during the first 10 passages. In addition, FLMSCs were found to express CD29, CD44, CD73 and CD166, however, they did not express hematopoietic cell specific markers, including CD34, CD45 and BOLA?DR?. The growth kinetics of FLMSCs consisted of a lag phase, a logarithmic phase and a plateau phase, and as the passages increased, the proliferative ability of cells gradually decreased. The majority of FLMSCs were in G0/G1 phase. Following osteogenic induction, FLMSCs were positive for the expression of osteopontin and collagen type I ?2. Following neurogenic differentiation, the cells were morphologically consistent with neuronal cells and positive for microtubule?associated protein 2 and nestin expression. It was concluded that the isolated FLMSCs exhibited typical characteristics of mesenchymal stem cells and that the culture conditions were suitable for their proliferation and the maintenance of stemness. The present study illustrated the potential application of lung tissue as an adult stem cell source for regenerative therapies. PMID:26016556

  11. Novel fusion algorithms for medical ultrasound tomography

    NASA Astrophysics Data System (ADS)

    Bashford, Gregory R.; Morse, Jonathan L.; Melander, Jennifer R.

    2004-10-01

    Ultrasound tomography is a bioimaging method that combines the geometry of X-ray computed tomography with the non-ionizing energy of ultrasound. This modality has potential clinical utility in breast cancer screening and diagnosis. In conventional ultrasound tomography, data sets from different interrogation angles are used to reconstruct an estimate of a biomechanical property of the tissue, such as sound velocity, in the form of an image. Here we describe an alternative method of reconstruction using novel algorithms which weight the data based on a "quality" score. The quality score is derived from beamforming characteristics, for example, the weighting of angle-dependent data by its distance from the transmit focal zones. The new approach is that for each data set (taken at a different view angle), the reliability of the data (in the range dimension) is assumed to vary. By fusing (combining) the data based on the quality score, a complete image is formed. In this paper, we describe the construction of a rotational translation stage and tissue-mimicking phantoms that are used in conjunction with a commercial medical ultrasound machine to test our reconstruction algorithms. The new algorithms were found to increase the contrast-to-speckle ratio of simulated cysts by 114% from raw data over a 77% improvement by spatial compounding (averaging), and to decrease wire target width by 54% over a 39% reduction by spatial compounding alone. The new method shows promise as a computationally efficient method of improving contrast and resolution in ultrasound images.

  12. Visualizing tissue molecular structure of a black type of canola (Brassica) seed with a thick seed coat after heat-related processing in a chemical way.

    PubMed

    Yu, Peiqiang

    2013-02-20

    Heat-related processing of cereal grains, legume seeds, and oil seeds could be used to improve nutrient availability in ruminants. However, different types of processing may have a different impact on intrinsic structure of tissues. To date, there is little research on structure changes after processing within intact tissues. The synchrotron-based molecular imaging technique enables us to detect inherent structure change on a molecular level. The objective of this study was to visualize tissue of black-type canola (Brassica) seed with a thick seed coat after heat-related processing in a chemical way using the synchrotron imaging technique. The results showed that the chemical images of protein amides were obtained through the imaging technique for the raw, wet, and dry heated black type of canola seed tissues. It seems that different types of processing have a different impact on the protein spectral profile in the black type of canola tissues. Wet heating had a greater impact on the protein ?-helix to ?-sheet ratio than dry heating. Both dry and wet heating resulted in different patterns in amide I, the second derivative, and FSD spectra. However, the exact differences in the tissue images are relatively difficult to be obtained through visual comparison. Future studies should focus on (1) comparing the response and sensitivity of canola seeds to various processing methods between the yellow-type and black-type of canola seeds; (2) developing a sensitive method to compare the image difference between tissues and between treatments; (3) developing a method to link images to nutrient digestion, and (4) revealing how structure changes affect nutrient absorption in humans and animals. PMID:23350902

  13. Management of type 1 diabetes mellitus using in vitro autologous adipose tissue trans-differentiated insulin-making cells

    PubMed Central

    Dave, Shruti D; Trivedi, Hargovind L; Chooramani, Saroj G; Chandra, Tulika

    2013-01-01

    Type 1 diabetes mellitus (T1DM) is a result of autoimmune destruction of insulin-producing ? cells of pancreas. Insulin is a widely used therapeutic modality. Nearing a complete century since the discovery of insulin, it is time to expect change in management strategies of T1DM. We report two men aged 22 and 15?years, respectively, with T1DM since 6 and 11?years, on exogenous insulin therapy of 64 and 56 International units (IU)/day respectively. We infused in vitro generated insulin-making cells trans-differentiated from donor adipose tissue derived mesenchymal stem cells and bone marrow-derived haematopoietic stem cells in their abdominal subcutaneous tissue, portal and thymic circulation under non-myeloablative conditioning. Over follow-up of 22.93 and 13.8?months they have stable blood sugar levels with glycosylated haemoglobin level of 6.3% and 6.8% with present insulin requirement of 18? and 22?IU/day, respectively. PMID:23893283

  14. Ehlers-Danlos Syndrome, Hypermobility Type: An Underdiagnosed Hereditary Connective Tissue Disorder with Mucocutaneous, Articular, and Systemic Manifestations

    PubMed Central

    Castori, Marco

    2012-01-01

    Ehlers-Danlos syndrome, hypermobility type, constituting a phenotypic continuum with or, perhaps, corresponding to the joint hypermobility syndrome (JHS/EDS-HT), is likely the most common, though the least recognized, heritable connective tissue disorder. Known for decades as a hereditary condition with predominant rheumatologic manifestations, it is now emerging as a multisystemic disorder with widespread manifestations. Nevertheless, the practitioners' awareness of this condition is generally poor and most patients await years or, perhaps, decades before reaching the correct diagnosis. Among the various sites of disease manifestations, skin and mucosae represent a neglected organ where the dermatologist can easily spot diagnostic clues, which consistently integrate joint hypermobility and other orthopedic/neurologic manifestations at physical examination. In this paper, actual knowledge on JHS/EDS-HT is summarized in various sections. Particular attention has been posed on overlooked manifestations, including cutaneous, mucosal, and oropharyngeal features, and early diagnosis techniques, as a major point of interest for the practicing dermatologist. Actual research progresses on JH/EDS-HT envisage an unexpected link between heritable dysfunctions of the connective tissue and a wide range of functional somatic syndromes, most of them commonly diagnosed in the office of various specialists, comprising dermatologists. PMID:23227356

  15. The Relationship between Intramuscular Adipose Tissue, Functional Mobility, and Strength in Postmenopausal Women with and without Type 2 Diabetes.

    PubMed

    Pritchard, Janet M; Karampatos, Sarah; Beattie, Karen A; Giangregorio, Lora M; Ioannidis, George; Atkinson, Stephanie A; Thabane, Lehana; Gerstein, Hertzel; Punthakee, Zubin; Adachi, Jonathan D; Papaioannou, Alexandra

    2015-01-01

    Objectives. To determine (1) whether intramuscular adipose tissue (IntraMAT) differs between women with and without type 2 diabetes and (2) the association between IntraMAT and mobility and strength. Methods. 59 women ? 65 years with and without type 2 diabetes were included. A 1-Tesla MRI was used to acquire images of the leg. Timed-up-and-go (TUG) and grip strength were measured. Regression was used to determine associations between the following: (1) type 2 diabetes and IntraMAT (covariates: age, ethnicity, BMI, waist?:?hip ratio, and energy expenditure), (2) IntraMAT and TUG (covariates: diabetes, age, BMI, and energy expenditure), and (3) IntraMAT and grip strength (covariates: diabetes, age, height, and lean mass). Results. Women with diabetes had more IntraMAT. After adjustment, IntraMAT was similar between groups (diabetes mean [SD] = 13.2 [1.4]%, controls 11.8 [1.3]%, P = 0.515). IntraMAT was related to TUG and grip strength, but the relationships became nonsignificant after adjustment for covariates (difference/percent IntraMAT [95% CI]: TUG = 0.041 seconds [-0.079-0.161], P = 0.498, grip strength = -0.144?kg [-0.335-0.066], P = 0.175). Conclusions. IntraMAT alone may not be a clinically important predictor of functional mobility and strength; however, whether losses in functional mobility and strength are promoted by IntraMAT accumulation should be explored. PMID:25692042

  16. Microfocused ultrasound for skin tightening.

    PubMed

    MacGregor, Jennifer L; Tanzi, Elizabeth L

    2013-03-01

    The demand for noninvasive skin tightening procedures is increasing as patients seek safe and effective alternatives to aesthetic surgical procedures of the face, neck, and body. Over the past decade, radiofrequency and infrared laser devices have been popularized owing to their ability to deliver controlled heat to the dermis, stimulate neocollagenesis, and effect modest tissue tightening with minimal recovery. However, these less invasive approaches are historically associated with inferior efficacy so that surgery still remains the treatment of choice to address moderate to severe tissue laxity. Microfocused ultrasound was recently introduced as a novel energy modality for transcutaneous heat delivery that reaches the deeper subdermal connective tissue in tightly focused zones at consistent programmed depths. The goal is to produce a deeper wound healing response at multiple levels with robust collagen remodeling and a more durable clinical response. The Ulthera device (Ulthera, Inc, Meza, AZ), with refined microfocused ultrasound technology, has been adapted specifically for skin tightening and lifting with little recovery or risk of complications since its introduction in 2009. As clinical parameters are studied and optimized, enhanced efficacy and consistency of clinical improvement is expected. PMID:24049925

  17. Endoscopic ultrasound guided fine needle aspiration and useful ancillary methods

    PubMed Central

    Tadic, Mario; Stoos-Veic, Tajana; Kusec, Rajko

    2014-01-01

    The role of endoscopic ultrasound (EUS) in evaluating pancreatic pathology has been well documented from the beginning of its clinical use. High spatial resolution and the close proximity to the evaluated organs within the mediastinum and abdominal cavity allow detection of small focal lesions and precise tissue acquisition from suspected lesions within the reach of this method. Fine needle aspiration (FNA) is considered of additional value to EUS and is performed to obtain tissue diagnosis. Tissue acquisition from suspected lesions for cytological or histological analysis allows, not only the differentiation between malignant and non-malignant lesions, but, in most cases, also the accurate distinction between the various types of malignant lesions. It is well documented that the best results are achieved only if an adequate sample is obtained for further analysis, if the material is processed in an appropriate way, and if adequate ancillary methods are performed. This is a multi-step process and could be quite a challenge in some cases. In this article, we discuss the technical aspects of tissue acquisition by EUS-guided-FNA (EUS-FNA), as well as the role of an on-site cytopathologist, various means of specimen processing, and the selection of the appropriate ancillary method for providing an accurate tissue diagnosis and maximizing the yield of this method. The main goal of this review is to alert endosonographers, not only to the different possibilities of tissue acquisition, namely EUS-FNA, but also to bring to their attention the importance of proper sample processing in the evaluation of various lesions in the gastrointestinal tract and other accessible organs. All aspects of tissue acquisition (needles, suction, use of stylet, complications, etc.) have been well discussed lately. Adequate tissue samples enable comprehensive diagnoses, which answer the main clinical questions, thus enabling targeted therapy. PMID:25339816

  18. [Amyloid typing from formalin-fixed paraffin-embedded tissues using LMD-LC-MS/MS system].

    PubMed

    Tasaki, Masayoshi; Obayashi, Konen; Ueda, Mitsuharu; Ando, Yukio

    2014-03-01

    Amyloidosis is one of the protein conformational disorders in which normally soluble proteins accumulate insoluble amyloid fibrils, leading to severe organ dysfunction. To date, 30 different amyloidogenic proteins have been reported. Immunohistochemistry (IHC) is usually used to identify the amyloid precursor protein, but the results may be inconclusive owing to a loss of epitopes or small amounts of amyloid deposits, comprising unknown amyloidogenic protein. Recently, laser microdissection (LMD)-liquid chromatography tandem mass spectrometry (LC-MS/MS) has been used in a novel method to identify amyloid precursor protein from amyloid-laden formalin-fixed paraffin embedded (FFPE) tissues. We describe the usefulness of the system for amyloid typing in this report. PMID:24800507

  19. Similarities and differences in 13C and 15N stable isotope ratios in two non-lethal tissue types from shovelnose sturgeon Scaphirhynchus platorynchus (Rafinesque, 1820)

    USGS Publications Warehouse

    DeVries, R. J.; Schramm, Harold L., Jr.

    2015-01-01

    We tested the hypothesis that ?13C and ?15N signatures of pectoral spines would provide measures of ?13C and ?15N similar to those obtained from fin clips for adult shovelnose sturgeon Scaphirhynchus platorynchus. Thirty-two shovelnose sturgeon (fork length [FL] = 500–724 mm) were sampled from the lower Mississippi River, USA on 23 February 2013. Isotopic relationships between the two tissue types were analyzed using mixed model analysis of covariance. Tissue types differed significantly for both ?13C (P < 0.01; spine: mean = ?23.83, SD = 0.62; fin clip: mean = ?25.74, SD = 0.97) and ?15N (P = 0.01; spine: mean = 17.01, SD = 0.51; fin clip: mean = 17.19, SD = 0.62). Neither FL nor the FL × tissue type interaction had significant (P > 0.05) effects on ?13C. Fin clip ?13C values were highly variable and weakly correlated (r = 0.16, P = 0.40) with those from pectoral spines. We found a significant FL-tissue type interaction for ?15N, reflecting increasing ?15N with FL for spines and decreasing ?15N with FL for fin clips. These results indicate that spines are not a substitute for fin clip tissue for measuring ?13C and ?15N for shovelnose sturgeon in the lower Mississippi River, but the two tissues have different turnover rates they may provide complementary information for assessing trophic position at different time scales.

  20. Tissue-type plasminogen activator-binding RNA aptamers inhibiting low-density lipoprotein receptor family-mediated internalisation.

    PubMed

    Bjerregaard, N; Bøtkjær, K A; Helsen, N; Andreasen, P A; Dupont, D M

    2015-06-30

    Recombinant tissue-type plasminogen activator (tPA, trade name Alteplase), currently the only drug approved by the US Food and Drug Administration and the European Medicines Agency for the treatment of cerebral ischaemic stroke, has been implicated in a number of adverse effects reportedly mediated by interactions with the low-density lipoprotein (LDL) family receptors, including neuronal cell death and an increased risk of cerebral haemorrhage. The tissue-type plasminogen activator is the principal initiator of thrombolysis in human physiology, an effect that is mediated directly via localised activation of the plasmin zymogen plasminogen at the surface of fibrin clots in the vascular lumen. Here, we sought to identify a ligand to tPA capable of inhibiting the relevant LDL family receptors without interfering with the fibrinolytic activity of tPA. Systematic evolution of ligands by exponential enrichment (SELEX) was employed to isolate tPA-binding RNA aptamers, which were characterised in biochemical assays of tPA association to low density lipoprotein receptor-related protein-1 (LRP-1, an LDL receptor family member); tPA-mediated in vitro and ex vivo clot lysis; and tPA-mediated plasminogen activation in the absence and presence of a stimulating soluble fibrin fragment. Two aptamers, K18 and K32, had minimal effects on clot lysis, but were able to efficiently inhibit tPA-LRP-1 association and LDL receptor family-mediated endocytosis in human vascular endothelial cells and astrocytes. These observations suggest that coadministration alongside tPA may be a viable strategy to improve the safety of thrombolytic treatment of cerebral ischaemic stroke by restricting tPA activity to the vascular lumen. PMID:25855589

  1. Fast and Automatic Ultrasound Simulation from CT Images

    PubMed Central

    Yang, Jian; Liu, Yue; Wang, Yongtian

    2013-01-01

    Ultrasound is currently widely used in clinical diagnosis because of its fast and safe imaging principles. As the anatomical structures present in an ultrasound image are not as clear as CT or MRI. Physicians usually need advance clinical knowledge and experience to distinguish diseased tissues. Fast simulation of ultrasound provides a cost-effective way for the training and correlation of ultrasound and the anatomic structures. In this paper, a novel method is proposed for fast simulation of ultrasound from a CT image. A multiscale method is developed to enhance tubular structures so as to simulate the blood flow. The acoustic response of common tissues is generated by weighted integration of adjacent regions on the ultrasound propagation path in the CT image, from which parameters, including attenuation, reflection, scattering, and noise, are estimated simultaneously. The thin-plate spline interpolation method is employed to transform the simulation image between polar and rectangular coordinate systems. The Kaiser window function is utilized to produce integration and radial blurring effects of multiple transducer elements. Experimental results show that the developed method is very fast and effective, allowing realistic ultrasound to be fast generated. Given that the developed method is fully automatic, it can be utilized for ultrasound guided navigation in clinical practice and for training purpose. PMID:24348736

  2. Necrotizing soft tissue infection

    MedlinePLUS

    Necrotizing fasciitis; Fasciitis - necrotizing; Flesh-eating bacteria; Soft tissue gangrene; Gangrene - soft tissue ... Many different types of bacteria can cause this infection. A very ... of necrotizing soft tissue infection is due to Streptococcus ...

  3. Ultrasound findings in cutaneous sarcoidosis.

    PubMed

    Dybiec, Ewa; Pietrzak, Aldona; Bartosi?ska, Joanna; Kieszko, Robert; Kanitakis, Jean

    2015-02-01

    The diagnosis of cutaneous sarcoidosis relies mainly on the patient's history, presence of characteristic skin lesions and histological examination that shows a granulomatous, non-necrotizing dermal infiltration. The aim of the study was to assess the ultrasonographic features of cutaneous lesions of sarcoidosis before and after treatment. A 38-year-old woman with systemic sarcoidosis and specific cutaneous lesions was treated with systemic steroids followed by hydroxychloroquine. Ultrasonographic examination of the cutaneous sarcoidosis lesions was performed with a Philips iU 22 and Siemens Acuson S 2000 device, with the use of linear 15 MHz and 17 MHz transducers. Histological examination of skin lesions showed characteristic, naked, non-necrotizing granulomas in the upper dermis. Ultrasound examination revealed well-demarcated, hypoechogenic changes. Power-Doppler scan revealed increased vascularity within the lesions and the surrounding tissue. Clinical improvement of the skin lesions was confirmed by ultrasound examination, which showed a decrease in their size and normalization of dermal echogenicity and vascularity. Ultrasound examination can show cutaneous sarcoidosis lesions and their regression after appropriate treatment. PMID:25821428

  4. Ultrasound findings in cutaneous sarcoidosis

    PubMed Central

    Dybiec, Ewa; Pietrzak, Aldona; Kieszko, Robert; Kanitakis, Jean

    2015-01-01

    The diagnosis of cutaneous sarcoidosis relies mainly on the patient's history, presence of characteristic skin lesions and histological examination that shows a granulomatous, non-necrotizing dermal infiltration. The aim of the study was to assess the ultrasonographic features of cutaneous lesions of sarcoidosis before and after treatment. A 38-year-old woman with systemic sarcoidosis and specific cutaneous lesions was treated with systemic steroids followed by hydroxychloroquine. Ultrasonographic examination of the cutaneous sarcoidosis lesions was performed with a Philips iU 22 and Siemens Acuson S 2000 device, with the use of linear 15 MHz and 17 MHz transducers. Histological examination of skin lesions showed characteristic, naked, non-necrotizing granulomas in the upper dermis. Ultrasound examination revealed well-demarcated, hypoechogenic changes. Power-Doppler scan revealed increased vascularity within the lesions and the surrounding tissue. Clinical improvement of the skin lesions was confirmed by ultrasound examination, which showed a decrease in their size and normalization of dermal echogenicity and vascularity. Ultrasound examination can show cutaneous sarcoidosis lesions and their regression after appropriate treatment. PMID:25821428

  5. Abstract--Conventional ultrasound B-mode imaging is mainly qualitative in nature. While conventional imaging techniques,

    E-print Network

    Illinois at Urbana-Champaign, University of

    in their capabilities and have grown in their importance to medical practice. X-ray, X-ray CT, MRI, ultrasound, nuclearAbstract-- Conventional ultrasound B-mode imaging is mainly qualitative in nature. While conventional imaging techniques, including ultrasound, may be sensitive to the detection of anomalous tissue

  6. Isolation of Mitochondria from Leaf Tissue of Panicum miliaceum, a NAD-Malic Enzyme Type C(4) Plant.

    PubMed

    Gardeström, P; Edwards, G E

    1983-01-01

    A mechanical isolation procedure was developed to study the respiratory properties of mitochondria from the mesophyll and bundle sheath tissue of Panicum miliaceum, a NAD-malic enzyme C(4) plant. A mesophyll fraction and a bundle sheath fraction were obtained from young leaves by differential mechanical treatment. The purity of both fractions was about 80%, based on analysis of the cross-contamination of ribulose bisphosphate carboxylase activity and phosphoenolpyruvate carboxylase activity.Mitochondria were isolated from the two fractions by differential centrifugation and Percoll density gradient centrifugation. The enrichment of mitochondria relative to chloroplast material was about 75-fold in both preparations.Both types of mitochondria oxidized NADH and succinate with respiratory control. Malate oxidation in mesophyll mitochondria was sensitive to KCN and showed good respiratory control. In bundle sheath mitochondria, malate oxidation was largely insensitive to KCN and showed no respiratory control. The oxidation was strongly inhibited by salicylhydroxamic acid, showing that the alternative oxidase was involved. The bundle sheath mitochondria of this type of C(4) species contribute to C(4) photosynthesis through decarboxylation of malate. Malate oxidation linked to an uncoupled, alternative pathway may allow decarboxylation to proceed without the restraints which might occur via coupled electron flow through the cytochrome chain. PMID:16662792

  7. Muscle Tissue Overview

    NSDL National Science Digital Library

    Ms. Wendy M Rappazzo (Harford Community College Science, Technology, Engineering & Math)

    2007-08-15

    This is a short overview of the three types of muscle tissue. Each type of muscle tissue is briefly described with a histology view of the tissue. This presentation also incorporates information regarding each muscle tissue and its role in attaining VO2 max.

  8. Ultrasound and photoacoustic imaging to monitor mesenchymal stem cells labeled with gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Nam, Seung Yun; Ricles, Laura M.; Sokolov, Konstantin; Suggs, Laura J.; Emelianov, Stanislav Y.

    2011-03-01

    Mesenchymal stem cells (MSCs) are versatile in many tissue engineering applications and have the potential to be used for cellular therapies because they can differentiate into many cell types. Specifically, the use of MSCs for the treatment of ischemic disease is promising because MSCs can express characteristics of vascular cells. MSCs can promote vascular growth at the site of injury after delivery using a PEGylated fibrin gel. In order to quantitatively assess in vivo delivery and differentiation of MSCs, a non-invasive and high-resolution imaging technique is required. In this study, the combined ultrasound and photoacoustic imaging was demonstrated to monitor MSCs labeled with citrate-stabilized gold nanoparticles (Au NPs). It was observed that uptake of nanoparticles did not have a significant effect on cell viability and proliferation over a two-week period. Four different cell concentrations of either the non-labeled MSCs or the Au NP labeled MSCs were embedded in the tissue mimicking gelatin phantom. The ultrasound and photoacoustic signals were acquired and quantitatively analyzed to assess sensitivity and accuracy of the developed imaging approach. Furthermore, based on the results, the feasibility of in vivo ultrasound and photoacoustic imaging of MSCs was discussed.

  9. Fatty acid profile of plasma, muscle and adipose tissues in Chilota lambs grazing on two different low quality pasture types in Chiloé Archipelago (Chile).

    PubMed

    Gallardo, Maria A; Dannenberger, Dirk; Rivero, Jordana; Pulido, Ruben; Nuernberg, Karin

    2014-11-01

    There is no information about the effect of different pasture types on tissue fatty acid profiles of a native rustic lamb breed of the Chiloe Archipelago, the Chilota. Eight Chilota lambs were grazed on a 'Calafatal' pasture (CP), a typical secondary succession of Chiloé Archipelago (Chile) and eight Chilota lambs were located to graze on naturalized pasture (NP) of Chiloé. Botanical, chemical and lipid composition of the two types of pastures and of different lamb tissues (muscle, subcutaneous - and tail adipose tissues) and plasma were performed. Both pasture types induced high n-3 polyunsaturated fatty acids (PUFA) and CLAcis-9,trans-11 proportions in Chilota meat. Thus, in muscle, Chilota lambs grazing CP showed higher sum PUFA, sum n-6 PUFA proportion and n-6/n-3 PUFA ratio compared with Chilota lambs grazing NP. In tail fats of Chilota lambs grazing CP significantly higher proportions of 18:3n-3, sum saturated fatty acids, sum PUFA, n-3 and n-6 PUFA were detected compared with Chilota lambs grazing NP. Feeding of different pasture types (CP?vs.?NP) caused significant differences in fatty acid composition of muscle and the two fat depots in Chilota lambs, but also point to tissue-specific responses of de novo synthesized fatty acid deposition in the tissues. PMID:24964067

  10. Sound Speed Measurement in Prostatic Cancer by Ultrasound Speed Microscope

    NASA Astrophysics Data System (ADS)

    Tanoue, Hideki; Urata, Youji; Hagiwara, Yoshihiro; Saijo, Yoshifumi

    The diagnostic sensitivity of transrectal ultrasonography (TRUS) of the prostate is not sufficient for definitive diagnosis of prostatic cancer. Prostatic cancer sometimes appears as low intensity echo but it sometimes appears as isointensity echo as normal prostate. Thus, precise ultrasonic information rather than ultrasonic intensity is needed for further diagnosis. In the present study, ultrasonic properties of prostatic tissue are measured by ultrasound speed microscope (USM) and malignancy of the tissue is discussed. The sample obtained by radical prostatectomy was fixed by formalin and sliced as approximately 5 ?m in thickness. One slice without staining was used for USM observation and the neighboring slice with Elastica-Masson staining was used for optical microscopic observation for comparison. In the prostatic cancer tissue, the sound speed of the poorly differentiated adenocarcinoma was 1,570 ± 8 m/s whereas as that of the well-differentiated adenocarcinoma was 1,660 ± 30 m/s. The sound speed measurement clearly classified the tissue type of prostatic cancer. As the imaging resolution is anti-proportional to the ultrasonic frequency, USM provides ten times higher resolution compared with TRUS. The basic acoustic information obtained by USM is useful for understanding clinical echo findings by TRUS.

  11. Differentially Methylated Loci Distinguish Ovarian Carcinoma Histological Types: Evaluation of a DNA Methylation Assay in FFPE Tissue

    PubMed Central

    Kelemen, Linda E.; Köbel, Martin; Chan, Angela; Taghaddos, Soreh; Dinu, Irina

    2013-01-01

    Epigenomic markers can identify tumor subtypes, but few platforms can accommodate formalin-fixed paraffin-embedded (FFPE) tumor tissue. We tested different amounts of bisulfite-converted (bs) DNA from six FFPE ovarian carcinomas (OC) of serous, endometrioid, and clear cell histologies and two HapMap constitutional genomes to evaluate the performance of the GoldenGate methylation assay. Methylation status at each 1,505 CpG site was expressed as ?-values. Comparing 400?ng versus 250?ng bsDNA, reproducibility of the assay ranged from Spearman r2 = 0.41 to 0.90, indicating that ?-values obtained with a lower DNA amount did not always correlate well with the higher amount. Average methylation for the six samples was higher using 250?ng (?-value = 0.45, SD = 0.29) than with 400?ng (?-value = 0.36, SD = 0.32). Reproducibility between duplicate HapMap samples (r2 = 0.76 to 0.92) was also variable. Using 400?ng input bsDNA, THBS2 and ERG were differentially methylated across all histologic types and between endometrioid and clear cell types at <0.1% false discovery rate. Methylation did not always correlate with gene expression (r2 = ?0.70 to 0.15). We found that lower bsDNA overestimates methylation, and, using higher bsDNA amounts, we confirmed a previous report of higher methylation of THBS2 in clear cell OC, which could provide new insight into biological pathways that distinguish OC histological types. PMID:24175302

  12. Alteration of the bone tissue material properties in type 1 diabetes mellitus: A Fourier transform infrared microspectroscopy study.

    PubMed

    Mieczkowska, Aleksandra; Mansur, Sity Aishah; Irwin, Nigel; Flatt, Peter R; Chappard, Daniel; Mabilleau, Guillaume

    2015-07-01

    Type 1 diabetes mellitus (T1DM) is a severe disorder characterized by hyperglycemia and hypoinsulinemia. A higher occurrence of bone fractures has been reported in T1DM, and although bone mineral density is reduced in this disorder, it is also thought that bone quality may be altered in this chronic pathology. Vibrational microscopies such as Fourier transform infrared microspectroscopy (FTIRM) represent an interesting approach to study bone quality as they allow investigation of the collagen and mineral compartment of the extracellular matrix in a specific bone location. However, as spectral feature arising from the mineral may overlap with those of the organic component, the demineralization of bone sections should be performed for a full investigation of the organic matrix. The aims of the present study were to (i) develop a new approach, based on the demineralization of thin bone tissue section to allow a better characterization of the bone organic component by FTIRM, (ii) to validate collagen glycation and collagen integrity in bone tissue and (iii) to better understand what alterations of tissue material properties in newly forming bone occur in T1DM. The streptozotocin-injected mouse (150mg/kg body weight, injected at 8weeks old) was used as T1DM model. Animals were randomly allocated to control (n=8) or diabetic (n=10) groups and were sacrificed 4weeks post-STZ injection. Bones were collected at necropsy, embedded in polymethylmethacrylate and sectioned prior to examination by FTIRM. FTIRM collagen parameters were collagen maturity (area ratio between 1660 and 1690cm(-1) subbands), collagen glycation (area ratio between the 1032cm(-1) subband and amide I) and collagen integrity (area ratio between the 1338cm(-1) subband and amide II). No significant differences in the mineral compartment of the bone matrix could be observed between controls and STZ-injected animals. On the other hand, as compared with controls, STZ-injected animals presented with significant higher value for collagen maturity (17%, p=0.0048) and collagen glycation (99%, p=0.0121), while collagen integrity was significantly lower by 170% (p=0.0121). This study demonstrated the profound effect of early T1DM on the organic compartment of the bone matrix in newly forming bone. Further studies in humans are required to ascertain whether T1DM also lead to similar effect on the quality of the bone matrix. PMID:25813583

  13. Glucose transporter Glut1 is detectable in peri-necrotic regions in many human tumor types but not normal tissues: Study using tissue microarrays

    Microsoft Academic Search

    Rachel Airley; Andrew Evans; Ali Mobasheri; Stephen M. Hewitt

    2010-01-01

    The hypoxic tumor microenvironment is associated with malignant progression and poor treatment response. The glucose transporter Glut-1 is a prognostic factor and putative hypoxia marker. So far, studies of Glut-1 in cancer have utilized conventional immunohistochemical analysis in a series of individual biopsy or surgical specimens. Tissue microarrays, however, provide a rapid, inexpensive means of profiling biomarker expression. To evaluate

  14. Ultrasound Microscope: Quantative Backscatter Imaging

    E-print Network

    Greenaway, Alan

    Ultrasound Microscope: Quantative Backscatter Imaging Srikanta Sharma Academic supervisor: Sandy Cochran Industrial supervisor: Jim McAneny #12;Hypothesis of Intra-membrane Cavitation: Ultrasound Induced and cellular membranes that could explain cavitational and non- cavitational ultrasound induced bio

  15. Geometric reconstruction using tracked ultrasound strain imaging Thomas S. Pheiffera

    E-print Network

    Miga, Michael I.

    Geometric reconstruction using tracked ultrasound strain imaging Thomas S. Pheiffera , Amber L stiffness which can be used in real-time. The information offered by strain imaging can be placed within properties than the surrounding soft tissue. The biological basis for this effect is due to changes in tissue

  16. Finding the dispersion relations for lamb-type waves in a concave piezoelectric plate by optical visualization of the ultrasound field radiated into a fluid

    NASA Astrophysics Data System (ADS)

    Sapozhnikov, O. A.; Smagin, M. A.

    2015-03-01

    We propose and experimentally demonstrate a method for measuring the phase velocities of Lamb waves in concave piezoelectric plates submerged in a fluid. The method is based on the optical shadowgraphy method of visualizing the ultrasound field that occurs in a fluid when Lamb modes are excited in the plate under study. According to the condition of wave resonance, the propagation direction of the waves radiated into the fluid is determined by the phase velocity of a Lamb wave in the plate, which makes it possible to measure the indicated velocity. Proceeding from this, we demonstrate that when spherical concave piezoelectric plates are used, the phase velocities of Lamb waves can be determined by the position of the caustics—areas of acoustic wave focusing in the fluid. We have experimentally measured the dispersion curves of several Lamb modes for a concave piezoelectric plate with a diameter of 100 mm and thickness of around 2 mm, which was submerged in water. Ultrasound waves were optically visualized in the fluid by the schlieren method on a specially designed setup, in which off-axis parabolic mirrors were used to implement the dark-field method. We demonstrated that the measured dispersion curves for low-order Lamb modes are well described by the theoretical dependences calculated using the Rayleigh-Lamb equation.

  17. Ultrasound-heated photoacoustic flowmetry

    PubMed Central

    Wang, Lidai; Yao, Junjie; Maslov, Konstantin I.; Xing, Wenxin; Wang, Lihong V.

    2013-01-01

    Abstract. We report the development of photoacoustic flowmetry assisted by high-intensity focused ultrasound (HIFU). This novel method employs HIFU to generate a heating impulse in the flow medium, followed by photoacoustic monitoring of the thermal decay process. Photoacoustic flowmetry in a continuous medium remains a challenge in the optical diffusive regime. Here, both the HIFU heating and photoacoustic detection can focus at depths beyond the optical diffusion limit (?1??mm in soft tissue). This method can be applied to a continuous medium, i.e., a medium without discrete scatterers or absorbers resolvable by photoacoustic imaging. Flow speeds up to 41??mm·s?1 have been experimentally measured in a blood phantom covered by 1.5-mm-thick tissue. PMID:24194064

  18. Acoustic imaging of thick biological tissue

    Microsoft Academic Search

    Elena Maeva; Fedar Severin; Chiaki Miyasaka; Bernhard Tittmann; Roman Maev

    2009-01-01

    Up to now, biomedical imaging with ultrasound for observing a cellular tissue structure has been limited to very thinly sliced tissue at very high ultrasonic frequencies, i.e., 1 GHz. In this paper, we present the results of a systematic study to use a 150 to 200 MHz frequency range for thickly sliced biological tissue. A mechanical scanning reflection acoustic microscope

  19. A Targeting Microbubble for Ultrasound Molecular Imaging

    PubMed Central

    Yeh, James Shue-Min; Sennoga, Charles A.; McConnell, Ellen; Eckersley, Robert; Tang, Meng-Xing; Nourshargh, Sussan; Seddon, John M.; Haskard, Dorian O.; Nihoyannopoulos, Petros

    2015-01-01

    Rationale Microbubbles conjugated with targeting ligands are used as contrast agents for ultrasound molecular imaging. However, they often contain immunogenic (strept)avidin, which impedes application in humans. Although targeting bubbles not employing the biotin-(strept)avidin conjugation chemistry have been explored, only a few reached the stage of ultrasound imaging in vivo, none were reported/evaluated to show all three of the following properties desired for clinical applications: (i) low degree of non-specific bubble retention in more than one non-reticuloendothelial tissue; (ii) effective for real-time imaging; and (iii) effective for acoustic quantification of molecular targets to a high degree of quantification. Furthermore, disclosures of the compositions and methodologies enabling reproduction of the bubbles are often withheld. Objective To develop and evaluate a targeting microbubble based on maleimide-thiol conjugation chemistry for ultrasound molecular imaging. Methods and Results Microbubbles with a previously unreported generic (non-targeting components) composition were grafted with anti-E-selectin F(ab’)2 using maleimide-thiol conjugation, to produce E-selectin targeting microbubbles. The resulting targeting bubbles showed high specificity to E-selectin in vitro and in vivo. Non-specific bubble retention was minimal in at least three non-reticuloendothelial tissues with inflammation (mouse heart, kidneys, cremaster). The bubbles were effective for real-time ultrasound imaging of E-selectin expression in the inflamed mouse heart and kidneys, using a clinical ultrasound scanner. The acoustic signal intensity of the targeted bubbles retained in the heart correlated strongly with the level of E-selectin expression (|r|?0.8), demonstrating a high degree of non-invasive molecular quantification. Conclusions Targeting microbubbles for ultrasound molecular imaging, based on maleimide-thiol conjugation chemistry and the generic composition described, may possess properties (i)–(iii) desired for clinical applications. PMID:26161541

  20. Differentiating fatty and non-fatty tissue using photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Pan, Leo; Rohling, Robert; Abolmaesumi, Purang; Salcudean, Septimiu; Tang, Shuo

    2014-03-01

    In this paper, we demonstrate a temporal-domain intensity-based photoacoustic imaging method that can differentiate between fatty and non-fatty tissues. PA pressure intensity is partly dependent on the tissue's speed of sound, which increases as temperature increases in non-fatty tissue and decreases in fatty tissue. Therefore, by introducing a temperature change in the tissue and subsequently monitoring the change of the PA intensity, it is possible to distinguish between the two types of tissue. A commercial ultrasound system with a 128-element 5-14 MHz linear array transducer and a tunable ND:YAG laser were used to produce PA images. Ex-vivo bovine fat and porcine liver tissues were precooled to below 10°C and then warmed to room-temperature over ~1 hour period. A thermocouple monitored the temperature rise while PA images were acquired at 0.5°C intervals. The averaged intensity of the illuminated tissue region at each temperature interval was plotted and linearly fitted. Liver samples showed a mean increase of 2.82 %/°C, whereas bovine fat had a mean decrease of 6.24 %/°C. These results demonstrate that this method has the potential to perform tissue differentiation in the temporal-domain.

  1. A Guide to Analysing Tongue Motion from Ultrasound Images

    ERIC Educational Resources Information Center

    Stone, Maureen

    2005-01-01

    This paper is meant to be an introduction to and general reference for ultrasound imaging for new and moderately experienced users of the instrument. The paper consists of eight sections. The first explains how ultrasound works, including beam properties, scan types and machine features. The second section discusses image quality, including the…

  2. Disease Markers 19 (2003,2004) 123138 123 Ultrasound-mediated biophotonic imaging: A

    E-print Network

    Wang, Lihong

    Disease Markers 19 (2003,2004) 123­138 123 IOS Press Ultrasound-mediated biophotonic imaging-3120, USA Abstract. This article reviews two types of ultrasound-mediated biophotonic imaging­acousto-optical tomography (AOT, also called ultrasound-modulated optical tomography) and photo-acoustic tomography (PAT

  3. Hepatic acetyl CoA links adipose tissue inflammation to hepatic insulin resistance and type 2 diabetes.

    PubMed

    Perry, Rachel J; Camporez, João-Paulo G; Kursawe, Romy; Titchenell, Paul M; Zhang, Dongyan; Perry, Curtis J; Jurczak, Michael J; Abudukadier, Abulizi; Han, Myoung Sook; Zhang, Xian-Man; Ruan, Hai-Bin; Yang, Xiaoyong; Caprio, Sonia; Kaech, Susan M; Sul, Hei Sook; Birnbaum, Morris J; Davis, Roger J; Cline, Gary W; Petersen, Kitt Falk; Shulman, Gerald I

    2015-02-12

    Impaired insulin-mediated suppression of hepatic glucose production (HGP) plays a major role in the pathogenesis of type 2 diabetes (T2D), yet the molecular mechanism by which this occurs remains unknown. Using a novel in vivo metabolomics approach, we show that the major mechanism by which insulin suppresses HGP is through reductions in hepatic acetyl CoA by suppression of lipolysis in white adipose tissue (WAT) leading to reductions in pyruvate carboxylase flux. This mechanism was confirmed in mice and rats with genetic ablation of insulin signaling and mice lacking adipose triglyceride lipase. Insulin's ability to suppress hepatic acetyl CoA, PC activity, and lipolysis was lost in high-fat-fed rats, a phenomenon reversible by IL-6 neutralization and inducible by IL-6 infusion. Taken together, these data identify WAT-derived hepatic acetyl CoA as the main regulator of HGP by insulin and link it to inflammation-induced hepatic insulin resistance associated with obesity and T2D. PMID:25662011

  4. Type I interferon receptors in goose: molecular cloning, structural identification, evolutionary analysis and age-related tissue expression profile.

    PubMed

    Zhou, Hao; Chen, Shun; Qi, Yulin; Zhou, Qin; Wang, Mingshu; Jia, Renyong; Zhu, Dekang; Liu, Mafeng; Sun, Kunfeng; Liu, Fei; Chen, Xiaoyue; Cheng, Anchun

    2015-04-25

    The cDNAs encoding two distinct type I interferon receptors were firstly cloned from the spleen of white goose (the Chinese goose, Anser cygnoides). The cDNA of goose IFNAR1 consisted of 1616 bp and encoded 406 amino acids with a predicted molecular weight of 46.4 kDa, while the cDNA of goose IFNAR2 consisted of 1525 bp and encoded 294 amino acids with a predicted molecular weight of 32.6 kDa. The IFNAR1 shared 85.4% identity in deduced amino acid sequence with duck IFNAR1, while IFNAR2 amino acid sequence showed 86% identity with that of duck IFNAR2. The age-related analysis of gene expression revealed that goose IFN? and IFNARs were all highly transcribed in pancreas, which may due to a reasonable amount of dendritic cells aggregated in pancreas. And goose IFN? and its cognate receptors had different structural features and tissue expression patterns during the period from embryonic goose to adult goose, suggesting that IFN? and IFNARs may maintain a developmental dynamic immune competence in unstimulated states. The data provided in this study may contribute to future understanding of the interaction between interferon and interferon receptors in immune mechanism. And it also helps us to understand the age-related susceptibility to pathogens in birds better. PMID:25617523

  5. Improvements in optical generation of high-frequency ultrasound

    Microsoft Academic Search

    Yang Hou; Shai Ashkenazi; Sheng-Wen Huang; Matthew O'Donnell

    2007-01-01

    The thermoelastic effect in a black poly-dimethylsiloxane (PDMS) film is used to produce high-frequency, high-intensity ultrasound for applications in water and soft tissue. We show that the optoacoustic transduction efficiency is improved by about 10 dB by decreasing the thickness of the black PDMS film from 25 mum to 11 mum. The center frequency of the generated ultrasound is 60

  6. Ultrasound as a Tool to Assess Body Fat

    PubMed Central

    Wagner, Dale R.

    2013-01-01

    Ultrasound has been used effectively to assess body fat for nearly 5 decades, yet this method is not known as well as many other body composition techniques. The purpose of this review is to explain the technical principles of the ultrasound method, explain the procedures for taking a measurement and interpreting the results, evaluate the reliability and validity of this method for measuring subcutaneous and visceral adipose tissue, highlight the advantages and limitations of ultrasound relative to other body composition methods, consider its utility to clinical populations, and introduce new body composition-specific ultrasound technology. The focus of this review is adipose, although various tissue thicknesses (e.g., muscle and bone) can be measured with ultrasound. Being a portable imaging device that is capable of making fast regional estimates of body composition, ultrasound is an attractive assessment tool in instances when other methods are limited. Furthermore, much of the research suggests that it is reliable, reproducible, and accurate. The biggest limitations appear to be a lack of standardization for the measurement technique and results that are highly dependent on operator proficiency. New ultrasound devices and accompanying software designed specifically for the purpose of body composition assessment might help to minimize these limitations. PMID:24062944

  7. Detection and characterisation of an overmodified type III collagen by analysis of non-cutaneous connective tissues in a patient with Ehlers-Danlos syndrome IV

    Microsoft Academic Search

    L Nuytinck; P Narcisi; A Nicholls; J P Renard; F M Pope; A De Paepe

    1992-01-01

    The clinical and biochemical observations in a patient with a mild form of Ehlers-Danlos syndrome (EDS) type IV are described. The patient's skin fibroblasts produced markedly diminished amounts of type III collagen. SDS-polyacrylamide gel electrophoresis of collagens produced by cells obtained from other, non-cutaneous tissues showed two forms of collagen alpha 1(III) chains, a normal and a slow migrating, mutant

  8. Treatment of Type 1 Diabetes Mellitus in Non-Obese Diabetic Mice by Transplantation of Allogeneic Bone Marrow and Pancreatic Tissue

    Microsoft Academic Search

    Ryoji Yasumizu; Kikuya Sugiura; Hiroshi Iwai; Muneo Inaba; Susumu Makino; Tatuya Ida; Hiroshi Imura; Yoshihiro Hamashima; Robert A. Good; Susumu Ikehara

    1987-01-01

    Non-obese diabetic (NOD) mice provide a model for type 1 diabetes mellitus. We previously showed that allogeneic bone marrow transplantation (ABMT) can prevent and treat insulitis and overt diabetes in NOD mice. However, ABMT alone could not be used to treat overt diabetes in NOD mice whose islets had been completely destroyed. To provide insulin-producing cells, pancreatic tissue from newborn

  9. Exploiting Ultrasound Harmonics

    Microsoft Academic Search

    G. M. Matte

    2010-01-01

    Ultrasound imaging is an inexpensive method which provides an accurate diagnosis tool. \\u000aThis thesis provides elements to characterise the acoustic pressure generated by ultrasound transducers as well as signal processing method that could improve modern echography. The first measurement method to assess transducers characteristics consists in deducing the absolute amplitude of the acoustic pressure from a distortion measurement. Using this

  10. Ultrasound-modulated fluorescence based on fluorescent microbubbles.

    PubMed

    Liu, Yuan; Feshitan, Jameel A; Wei, Ming-Yuan; Borden, Mark A; Yuan, Baohong

    2014-08-01

    Ultrasound-modulated fluorescence (UMF) imaging has been proposed to provide fluorescent contrast while maintaining ultrasound resolution in an optical-scattering medium (such as biological tissue). The major challenge is to extract the weakly modulated fluorescent signal from a bright and unmodulated background. UMF was experimentally demonstrated based on fluorophore-labeled microbubble contrast agents. These contrast agents were produced by conjugating N-hydroxysuccinimide (NHS)-ester-attached fluorophores on the surface of amine-functionalized microbubbles. The fluorophore surface concentration was controlled so that a significant self-quenching effect occurred when no ultrasound was applied. The intensity of the fluorescent emission was modulated when microbubbles were oscillated by ultrasound pulses, presented as UMF signal. Our results demonstrated that the UMF signals were highly dependent on the microbubbles' oscillation amplitude and the initial surface fluorophore-quenching status. A maximum of ?42% UMF modulation depth was achieved with a single microbubble under an ultrasound peak-to-peak pressure of 675 kPa. Further, UMF was detected from a 500-?m tube filled with contrast agents in water and scattering media with ultrasound resolution. These results indicate that ultrasound-modulated fluorescent microbubble contrast agents can potentially be used for fluorescence-based molecular imaging with ultrasound resolution in the future. PMID:25104407

  11. Nonlinear propagation of ultrasound through microbubble contrast agents and implications for imaging.

    PubMed

    Tang, Meng-Xing; Eckersley, Robert J

    2006-12-01

    Microbubble contrast agents produce nonlinear echoes under ultrasound insonation, and current imaging techniques detect these nonlinear echoes to generate contrast agent images accordingly. For these techniques, there is a potential problem in that bubbles along the ultrasound transmission path between transducer and target can alter the ultrasound transmission nonlinearly and contribute to the nonlinear echoes. This can lead to imaging artefacts, especially in regions at depth. In this paper we provide insight, through both simulation and experimental measurement, into the nonlinear propagation caused by microbubbles and the implications for current imaging techniques. A series of investigations at frequencies below, at, and above the resonance frequency of microbubbles were performed. Three specific effects on the pulse propagation (i.e., amplitude attenuation, phase changes, and harmonic generation) were studied. It was found that all these effects are dependent on the initial pulse amplitude, and their dependence on the initial phase of the pulse is shown to be insignificant. Two types of imaging errors are shown to result from this nonlinear propagation: first, that tissue can be misclassified as microbubbles; second, the concentration of microbubbles in the image can be misrepresented. It is found that these imaging errors are significant for all three pulse frequencies when the pulses transmit through a microbubble suspension of 6 cm in path length. It also is found that the first type of error is larger at the bubble resonance frequency. PMID:17186923

  12. Ultrasound in critical care.

    PubMed

    Andruszkiewicz, Pawe?; Sobczyk, Dorota

    2013-01-01

    Ultrasound has been revolutionising our specialty. The introduction of new, portable machines and goal-directed protocols has led many anaesthetists to use this diagnostic tool in their daily practice. Immediate, bedside ultrasound diagnosis of many life-threatening emergencies (pneumothorax, cardiac tamponade, or internal haemorrhage) enables not only the institution of proper treatment, but also the monitoring of its effectiveness. Ultrasound guided invasive procedures (such as vascular cannulations, toraco- and pericardiocentesis) have superseded the old anatomical landmarks-based techniques due to a greater safety margin. In order to perform a credible ultrasound examination, a proper level of competence is required. In this review article, the authors present various critical ultrasound applications. PMID:24092516

  13. Ultrasound in vasculitis.

    PubMed

    Schmidt, Wolfgang A

    2014-01-01

    Colour Doppler ultrasound displays a pathognomonic circumferential wall thickening in large-vessel vasculitis. Even rather small arteries like the temporal arteries can be easily examined with modern ultrasound equipment. In addition, ultrasound can detect stenoses and acute arterial occlusions. In large-vessel giant cell arteritis, the axillary arteries are most commonly involved. Takayasu arteritis affects particularly the left subclavian and the left common carotid arteries. As ultrasound diagnosis at the temporal arteries becomes more difficult already after a few days of glucocorticoid treatment in some patients, institutions are implementing fast-track clinics for which patients receive an appointment within 24 hours. An experienced rheumatologist is able to establish a definite diagnosis in most cases with standardised history, clinical examination and ultrasound of temporal and axillary arteries. Furthermore, early diagnosis and treatment may prevent blindness. PMID:24529335

  14. Ultrasound imaging during pregnancy.

    PubMed

    Gold, R B

    1984-01-01

    Review by a panel of experts convened by the National Institute of Health (NIH) and the Federal Food and Drug Administration (FDA) resulted in a recommendation for diagnostic ultrasound imaging in about 1/3 of pregnancies only when medically indicated but not routinely. Ultrasound technology, 1st developed for use in submarine warfare sonar devices, is widely used by physicians because of its clinical significance and because it allows seeing intrauterine structures without exposing the fetus to dangerous radiation. Its most important uses include estimating the gestational age for patients with uncertain clinical dates, evaluating fetal growth, determining the cause of vaginal bleeding, determining fetal presentation, identifying multiple gestation, supplementing amniocentesis or other special procedures, diagnosing, confirming fetal death and locating intrauterine devices. Recently, many physicians have been advocating routine ultrasound screening of all pregnancies but this is an issue of concern among leading physicians and the NIH. The panel stressed the urgent need for additional research on the safety and efficacy of the procedure. Many studies that found adverse reactions associated with ultrasound use in humans suffer from sever methodological flaws. The panel recommended ultrasound not to be used for routine screening. Some studies indicate that no clear benefit from routine screening results. The panel's recommendations were criticized for unnecessarily restricting ultrasound use and for inappropriately sanctioning widespread use of the technology. Human Life International, an anti-abortion organization, opposed using ultrasound to detect fetal abnormalities, contending that this would promote abortion. Some abortion opponents, however, believe ultrasound would cause bonding between the mother and the fetus and discourage abortion. The panel underscored the importance of the skill and training of ultrasound examiners. In regard to informed consent, the panel recommended that it be obtained. Further intensive research on the use of ultrasound was highly recommended. PMID:6389174

  15. Visualization and GPU-accelerated simulation of medical ultrasound from CT images

    Microsoft Academic Search

    Oliver Kutter; Ramtin Shams; Nassir Navab

    2009-01-01

    We present a fast GPU-based method for simulation of ultrasound images from volumetric CT scans and their visualization. The method uses a ray-based model of the ultrasound to generate view-dependent ultrasonic effects such as occlusions, large-scale reflections and attenuation combined with speckle patterns derived from pre-processing the CT image using a wave-based model of ultrasound propagation in soft tissue. The

  16. Nerve growth factor induces development of connective tissue-type mast cells in vitro from murine bone marrow cells

    PubMed Central

    1991-01-01

    The effect of nerve growth factor (NGF) on proliferation/differentiation of mast cells was investigated in vitro. Although NGF alone neither supported colony formation of bone marrow- derived cultured mast cells (BMCMC) nor induced development of mast cell colonies from nonadherent bone marrow cells (NBMC), addition of NGF to the suboptimal dose of interleukin 3 (IL-3) significantly increased the numbers of mast cell colonies produced by BMCMC or NBMC in methylcellulose. When stimulated by IL-3 alone, cells in mast cell colonies were not stained by berberine sulfate, a fluorescent dye. In contrast, mast cells developing in methylcellulose cultures obtaining both IL-3 and NGF were stained by berberine sulfate. The fluorescence was abolished by the treatment of heparinase but not of chondroitinase ABC, suggesting that mast cells stimulated by IL-3 and NGF produced and stored heparin proteoglycan. The histamine content of BMCMC maintained by IL-3 was also increased by addition of NGF. Since BMCMC showed mucosal mast cell-like phenotype, NGF appeared to induce the phenotypic change to connective tissue-type mast cells (CTMC). In the culture containing BMCMC, 3T3 fibroblasts, and IL-3, the phenotypic change of BMCMC to CTMC was observed as well. Since NGF was detected in this coculture and since addition of anti-NGF monoclonal antibody suppressed the phenotypic change, NGF produced by fibroblasts appeared to induce the phenotypic change. Neither BMCMC alone nor IL-3 alone increased the concentration of NGF. Therefore, there is a possibility that BMCMC stimulated by IL-3 may induce the production and/or release of NGF by fibroblasts. PMID:1711569

  17. Disrupted G{sub 1} to S phase clearance via cyclin signaling impairs liver tissue repair in thioacetamide-treated type 1 diabetic rats

    SciTech Connect

    Devi, Sachin S. [Department of Toxicology, School of Pharmacy, College of Health Sciences, University of Louisiana at Monroe, 700 University Avenue, Sugar Hall no. 306, Monroe, LA 71209-0470 (United States); Mehendale, Harihara M. [Department of Toxicology, School of Pharmacy, College of Health Sciences, University of Louisiana at Monroe, 700 University Avenue, Sugar Hall no. 306, Monroe, LA 71209-0470 (United States)]. E-mail: mehendale@ulm.edu

    2005-09-01

    Previously we reported that a nonlethal dose of thioacetamide (TA, 300 mg/kg) causes 90% mortality in type 1 diabetic (DB) rats because of irreversible acute liver injury owing to inhibited hepatic tissue repair, primarily due to blockage of G{sub 0} to S phase progression of cell division cycle. On the other hand, DB rats receiving 30 mg TA/kg exhibited equal initial liver injury and delayed tissue repair compared to nondiabetic (NDB) rats receiving 300 mg TA/kg, resulting in a delay in recovery from liver injury and survival. The objective of the present study was to test the hypothesis that impaired cyclin-regulated progression of G{sub 1} to S phase of the cell cycle may explain inhibited liver tissue repair, hepatic failure, and death, contrasted with delayed liver tissue repair but survival observed in the DB rats receiving 300 in contrast to 30 mg TA/kg. In the TA-treated NDB rats sustained MAPKs and cyclin expression resulted in higher phosphorylation of retinoblastoma (pRb), explaining prompt tissue repair and survival. In contrast, DB rats receiving the same dose of TA (300 mg/kg) exhibited suppressed MAPKs and cyclin expression that led to inhibition of pRb, inhibited tissue repair, and death. On the other hand, DB rats receiving 30 mg TA/kg exhibited delayed up regulation of MAPK signaling that delayed the expression of CD1 and pRb, explaining delayed stimulation of tissue repair observed in this group. In conclusion, the hepatotoxicant TA has a dose-dependent adverse effect on cyclin-regulated pRb signaling: the lower dose causes a recoverable delay, whereas the higher dose inhibits it with corresponding effect on the ultimate outcomes on hepatic tissue repair; this dose-dependent adverse effect is substantially shifted to the left of the dose response curve in diabetes.

  18. Ultrasound induced improvement in optical coherence tomography (OCT) resolution

    PubMed Central

    Schenk, John O.; Brezinski, Mark E.

    2002-01-01

    Optical coherence tomography (OCT) is a rapidly emerging technology for high-resolution biomedical imaging. The axial resolution of this technology is determined by the bandwidth of the source. Commercial sources generally provide resolutions of 10–20 ?m whereas laboratory-based solid state lasers have resolutions of ?4 ?m. The resolution in tissue depends almost exclusively on detecting single scattered events. However, the phenomenon known as multiple scattering results in a deterioration of resolution as a function of depth. In this study, OCT was combined with ultrasound in an attempt to reduce the effect of multiple scattering. The theory is that, with parallel ultrasound and OCT beams, multiply scattered light with a momentum component significantly perpendicular to the OCT beam will be reduced because the light is Doppler shifted outside the bandpass filter of the OCT detection electronics. A 7.5-MHz ultrasound transducer was used to introduce the photon/phonon interaction. A reflecting metal plate was placed within biological tissue, and the point spread function (PSF) was assessed off the reflector. The PSF was determined in the presence of no ultrasound, pulsed ultrasound, and continuous-wave (CW) ultrasound. CW ultrasound resulted in a 17% improvement (P < 0.001) in resolution and pulsed ultrasound resulted in 8% (P < 0.01). Image noise reduction could also be noted. Combining OCT with a parallel ultrasound beam results in an improvement in resolution through a reduced effect of multiple scattering due to photon/phonon interaction. With higher frequencies, better control of the acoustical beam, and tests in media with higher rates of multiple scattering, improved results are anticipated. PMID:12119391

  19. Ultrasound induced improvement in optical coherence tomography (OCT) resolution.

    PubMed

    Schenk, John O; Brezinski, Mark E

    2002-07-23

    Optical coherence tomography (OCT) is a rapidly emerging technology for high-resolution biomedical imaging. The axial resolution of this technology is determined by the bandwidth of the source. Commercial sources generally provide resolutions of 10-20 microm whereas laboratory-based solid state lasers have resolutions of approximately 4 microm. The resolution in tissue depends almost exclusively on detecting single scattered events. However, the phenomenon known as multiple scattering results in a deterioration of resolution as a function of depth. In this study, OCT was combined with ultrasound in an attempt to reduce the effect of multiple scattering. The theory is that, with parallel ultrasound and OCT beams, multiply scattered light with a momentum component significantly perpendicular to the OCT beam will be reduced because the light is Doppler shifted outside the bandpass filter of the OCT detection electronics. A 7.5-MHz ultrasound transducer was used to introduce the photon/phonon interaction. A reflecting metal plate was placed within biological tissue, and the point spread function (PSF) was assessed off the reflector. The PSF was determined in the presence of no ultrasound, pulsed ultrasound, and continuous-wave (CW) ultrasound. CW ultrasound resulted in a 17% improvement (P < 0.001) in resolution and pulsed ultrasound resulted in 8% (P < 0.01). Image noise reduction could also be noted. Combining OCT with a parallel ultrasound beam results in an improvement in resolution through a reduced effect of multiple scattering due to photon/phonon interaction. With higher frequencies, better control of the acoustical beam, and tests in media with higher rates of multiple scattering, improved results are anticipated. PMID:12119391

  20. Tissue Issue Adekunle Raji

    E-print Network

    Contractor, Anis

    Tissue Issue Adekunle Raji Director of Cooperative Group Studies & BIOREPOSITORY Pathology Core Facility - RHLCCC Northwestern University ACCR July 20, 2012 #12;Tissue Issues Tissue for research, banking and clinical trials Tissue types Human subject research Non-human subject research Acquiring

  1. [System design of small intellectualized ultrasound hyperthermia instrument in the LabVIEW environment].

    PubMed

    Jiang, Feng; Bai, Jingfeng; Chen, Yazhu

    2005-08-01

    Small-scale intellectualized medical instrument has attracted great attention in the field of biomedical engineering, and LabVIEW (Laboratory Virtual Instrument Engineering Workbench) provides a convenient environment for this application due to its inherent advantages. The principle and system structure of the hyperthermia instrument are presented. Type T thermocouples are employed as thermotransducers, whose amplifier consists of two stages, providing built-in ice point compensation and thus improving work stability over temperature. Control signals produced by specially designed circuit drive the programmable counter/timer 8254 chip to generate PWM (Pulse width modulation) wave, which is used as ultrasound radiation energy control signal. Subroutine design topics such as inner-tissue real time feedback temperature control algorithm, water temperature control in the ultrasound applicator are also described. In the cancer tissue temperature control subroutine, the authors exert new improvments to PID (Proportional Integral Differential) algorithm according to the specific demands of the system and achieve strict temperature control to the target tissue region. The system design and PID algorithm improvement have experimentally proved to be reliable and excellent, meeting the requirements of the hyperthermia system. PMID:16156285

  2. Automated hierarchical time gain compensation for in-vivo ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Moshavegh, Ramin; Hemmsen, Martin C.; Martins, Bo; Brandt, Andreas H.; Hansen, Kristoffer L.; Nielsen, Michael B.; Jensen, Jørgen A.

    2015-03-01

    Time gain compensation (TGC) is essential to ensure the optimal image quality of the clinical ultrasound scans. When large fluid collections are present within the scan plane, the attenuation distribution is changed drastically and TGC compensation becomes challenging. This paper presents an automated hierarchical TGC (AHTGC) algorithm that accurately adapts to the large attenuation variation between different types of tissues and structures. The algorithm relies on estimates of tissue attenuation, scattering strength, and noise level to gain a more quantitative understanding of the underlying tissue and the ultrasound signal strength. The proposed algorithm was applied to a set of 44 in vivo abdominal movie sequences each containing 15 frames. Matching pairs of in vivo sequences, unprocessed and processed with the proposed AHTGC were visualized side by side and evaluated by two radiologists in terms of image quality. Wilcoxon signed-rank test was used to evaluate whether radiologists preferred the processed sequences or the unprocessed data. The results indicate that the average visual analogue scale (VAS) is positive ( p-value: 2.34 × 10-13) and estimated to be 1.01 (95% CI: 0.85; 1.16) favoring the processed data with the proposed AHTGC algorithm.

  3. Ethics of prenatal ultrasound.

    PubMed

    Howe, David

    2014-04-01

    Prenatal ultrasound has opened new opportunities to examine, diagnose and treat the fetus, but these advances bring with them ethical dilemmas. In this chapter, I address the ethical principles that need to be considered when treating both mother and fetus as patients, and how these can be applied in practice. In particular, ultrasound practitioners have an ethical duty to maintain their theoretical knowledge and practical skills to ensure they advise parents correctly. I also discuss the ethical issues in carrying out intrauterine therapy, ultrasound-related research, and termination of pregnancy for fetal abnormality. PMID:24374013

  4. [Abdominal vascular structural and functional features in patients with connective tissue dysplasia].

    PubMed

    Lialiukova, E A; Orlova, N I; Aksenov, S I

    2012-01-01

    Doppler ultrasound study records decreased volume blood flow in patients with connective tissue dysplasia. Their hemodynamic features are more marked during food testing. Dysplasia-dependent structural changes in the vascular system, such as vascular hypoplasia, wall-occluding lesions, different types of deformities, are one of the causes of lower volumetric blood flow in the abdominal vessels. The found abdominal vascular structural and functional features in patients with connective tissue dysplasia can serve as the basis for blood flow disproportion in different stages of digestion. PMID:23214026

  5. Ultrasound enhanced thrombolysis: Clinical evidence

    NASA Astrophysics Data System (ADS)

    Alexandrov, Andrei V.

    2005-04-01

    Phase II CLOTBUST randomized clinical trial (Houston, Barcelona, Edmonton, Calgary) evaluated patients with acute ischemic stroke due to intracranial occlusion and treated with intravenous tissue plasminogen activator (TPA) within 3 h of symptom onset. Randomization: monitoring with pulsed wave 2 MHz transcranial Doppler (TCD) (Target) or placebo monitoring (Control). Safety: symptomatic bleeding to the brain (sICH). Primary end-point: complete recanalization on TCD or dramatic clinical recovery by the total NIHSS score <3, or improvement by >10 NIHSS points within 2 hours after TPA bolus. All projected 126 patients were randomized 1:1 to target (median NIHSS 16) or control (NIHSS 17). sICH: 4.8% Target, 4.8% Controls. Primary end-point was achieved by 31 (49%, Target) versus 19 (30%, Control), p<0.03. At 3 months, 22 (42% Target) and 14 (29% Control) patients achieved favorable outcomes. Continuous TCD monitoring of intracranial occlusion safely augments TPA-induced arterial recanalization, and 2 MHz diagnostic ultrasound has a positive biological activity that aids systemic thrombolytic therapy. For the first time in clinical medicine, the CLOTBUST trial provides the evidence that ultrasound enhances thrombolytic activity of a drug in humans thereby confirming intense multi-disciplinary experimental research conducted worldwide for the past 30 years.

  6. Combined ultrasound and optoacoustic system for real-time high-contrast vascular imaging in vivo

    Microsoft Academic Search

    Joel J. Niederhauser; Michael Jaeger; Robert Lemor; Peter Weber; Martin Frenz

    2005-01-01

    In optoacoustic imaging, short laser pulses irradiate highly scattering human tissue and adiabatically heat embedded absorbing structures, such as blood vessels, to generate ultrasound transients by means of the thermoelastic effect. We present an op- toacoustic vascular imaging system that records these transients on the skin surface with an ultrasound transducer array and displays the images online. With a single

  7. Ultrasound characterization of the infertile male testis with rf power spectrum analysis

    Microsoft Academic Search

    Jonathan A. Coleman; Ronald H. Silverman; Mark Rondeau; D. J. Coleman; Peter Schlegel

    2002-01-01

    Objective: To investigate and diagnose testicular pathology in patients with testicular dysfunction using the technique of ultrasound power spectrum analysis. Methods: Testicular ultrasound studies with power spectrum tissue characterization analysis were performed on men with testicular abnormalities as well as normal controls. Semen analysis, biopsy data, microscopic intra-operative findings and data pertaining to testicular function were collected for each surgically

  8. Interstitial ultrasound ablation of tumors within or adjacent to bone: Contributions of preferential heating at the bone surface

    NASA Astrophysics Data System (ADS)

    Scott, Serena J.; Prakash, Punit; Salgaonkar, Vasant; Jones, Peter D.; Cam, Richard N.; Han, Misung; Rieke, Viola; Burdette, E. Clif; Diederich, Chris J.

    2013-02-01

    Preferential heating of bone due to high ultrasound attenuation may enhance thermal ablation performed with cathetercooled interstitial ultrasound applicators in or near bone. At the same time, thermally and acoustically insulating cortical bone may protect sensitive structures nearby. 3D acoustic and biothermal transient finite element models were developed to simulate temperature and thermal dose distributions during catheter-cooled interstitial ultrasound ablation near bone. Experiments in ex vivo tissues and tissue-mimicking phantoms were performed to validate the models and to quantify the temperature profiles and ablated volumes for various distances between the interstitial applicator and the bone surface. 3D patient-specific models selected to bracket the range of clinical usage were developed to investigate what types of tumors could be treated, applicator configurations, insertion paths, safety margins, and other parameters. Experiments show that preferential heating at the bone surface decreases treatment times compared to when bone is absent and that all tissue between an applicator and bone can be ablated when they are up to 2 cm apart. Simulations indicate that a 5-7 mm safety margin of normal bone is needed to protect (thermal dose < 6 CEM43°C and T < 45°C) sensitive structures behind ablated bone. In 3D patient-specific simulations, tumors 1.0-3.8 cm (L) and 1.3-3.0 cm (D) near or within bone were ablated (thermal dose > 240 CEM43°C) within 10 min without damaging the nearby spinal cord, lungs, esophagus, trachea, or major vasculature. Preferential absorption of ultrasound by bone may provide improved localization, faster treatment times, and larger treatment zones in tumors in and near bone compared to other heating modalities.

  9. Genetic analysis of hydatidiform moles in paraffin wax embedded tissue using rapid, sequence specific PCR-based HLA class II typing.

    PubMed Central

    Bateman, A C; Hemmatpour, S K; Theaker, J M; Howell, W M

    1997-01-01

    AIMS: To determine the applicability of rapid, sequence specific polymerase chain reaction (PCR)-based HLA class II genotyping for the distinction of complete from partial hydatidiform moles (HM) using DNA extracted from formalin fixed and paraffin wax embedded tissue. METHODS: Nine HM were studied. DNA was extracted from formalin fixed and paraffin wax embedded tissue after mechanical separation of decidual and molar components. HLA class II DRB (DRB1, -3, -4, and -5) and DQB1 genotyping was performed using a parallel series of PCR reactions, each of which contained sequence specific primers designed to amplify different HLA DRB and DQB1 alleles or allele groups (PCR-SSP analysis). In each case the HLA DRB and DQB1 genotypes identified within the decidua and HM were compared. RESULTS: Within the decidual tissue, HLA DRB genotypes were assignable in all nine cases, and HLA DQB1 genotypes were identified in seven cases. Within the molar tissue, HLA DRB genotypes were assignable in seven cases, and at least one HLA DQB1 allele was identified in seven cases. Interpretation based on HLA class II genotyping was therefore possible in two cases classified on histological appearances as complete HM, in four classified as partial HM, and in one HM of uncertain type. Different HLA DRB and DQB1 haplotypes were identified within the decidual and molar tissue from both complete HM, consistent with a solely paternal origin and supporting the histological diagnosis. HLA DRB and DQB1 alleles common to the decidual and molar tissue were present within the four partial HM and the HM of histologically uncertain type, consistent with combined maternal and paternal genetic input to these HM, supporting the histological diagnosis in four cases and suggesting that the histologically equivocal case was also a partial HM. CONCLUSION: PCR-SSP HLA class II DRB and DQB1 typing is reliably applicable to DNA extracted from formalin fixed and paraffin wax embedded tissue. Therefore, in a suitably equipped HLA typing laboratory, this technique provides a useful adjunct to histological examination for differentiation of complete from partial HM. Images PMID:9215143

  10. Ultrasound: Pelvis (For Parents)

    MedlinePLUS

    ... pelvic area and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  11. Ultrasound: Head (For Parents)

    MedlinePLUS

    ... the head and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  12. Ultrasound comparison (image)

    MedlinePLUS

    ... inside. Solid structures, such as bones and muscles, reflect sound waves from the ultrasound transducer and show ... areas, like chambers of the heart, do not reflect sound waves and appear as black. The white ...

  13. Implementing volume ultrasound workflow.

    PubMed

    Sanguinetti, Kathy

    2008-01-01

    Ultrasound departments are consistently challenged with increasing patient loads, backlog/access, repetitive stress injuries, operator dependent technology, and the recruitment and retention of qualified sonographers. The value of the volume ultrasound workflow will dramatically enhance the operations of any ultrasound department. Although change is always a stressful transition for everyone involved, perserverance will lead to great rewards and will benefit all personnel involved. Sonographers currently using this new workflow model state they will never turn back to the traditional 2D stillframe repetitive imaging from the ability to reconstruct volumes and visualize in the 3 orthogonal planes. Together, volume imaging workflow and structured reporting will shift work from the scan rooms and radiologist reading rooms to a central workstation. This technology is truly changing the traditional and less efficient workflow of the ultrasound department to a more consistent and easier way of working. PMID:19115713

  14. Ultrasound Modulated Bioluminescence Tomography

    E-print Network

    Bal, Guillaume

    2013-01-01

    We propose a method to reconstruct the density of a luminescent source in a highly-scattering medium from ultrasound modulated optical measurements. Our approach is based on the solution to a hybrid inverse source problem for the diffusion equation.

  15. Measurements in ultrasound

    SciTech Connect

    Goldberg, B.B.; Kurtz, A.B.; Goldberg, P.

    1988-01-01

    This book gathers all published and original data pertaining to anatomical measurements as projected on ultrasound scans. It covers all major anatomic regions and organ systems, including abdomen, pelvic, obstetrical, head and neck, and heart.

  16. [Ultrasound diagnosis of the shoulder].

    PubMed

    Helweg, G; Moriggl, B; Sperner, G; Golser, K; Frauscher, F; Sögner, P; Frede, T; zur Nedden, D

    1996-12-01

    Sonography of the shoulder joint is a well-established technique in the hands of the experienced examiner, when using a standardized protocol. It has proved invaluable in assessing pathological soft tissue changes, especially after trauma. The static evaluation of anatomy and dynamic assessment of function are especially helpful in both preoperative staging and postoperative follow-up. The normal anatomy, examination techniques, including our own variations, and pathological conditions are discussed. The findings and various classifications of impingement syndrome, rotator cuff injuries, biceps tendon lesions and inflammatory changes are examined. Review of the major articles in the literature shows excellent correlation with our results, the overall sensitivity in the case of rotator cuff lesions being over 90%. A well-performed ultrasound examination in most cases obviates the need for the more invasive arthroscopy and the more cumbersome and expensive MRI examinations. PMID:9082479

  17. Physical mechanisms of the therapeutic effect of ultrasound (a review)

    NASA Astrophysics Data System (ADS)

    Bailey, M. R.; Khokhlova, V. A.; Sapozhnikov, O. A.; Kargl, S. G.; Crum, L. A.

    2003-07-01

    Therapeutic ultrasound is an emerging field with many medical applications. High intensity focused ultrasound (HIFU) provides the ability to localize the deposition of acoustic energy within the body, which can cause tissue necrosis and hemostasis. Similarly, shock waves from a lithotripter penetrate the body to comminute kidney stones, and transcutaneous ultrasound enhances the transport of chemotherapy agents. New medical applications have required advances in transducer design and advances in numerical and experimental studies of the interaction of sound with biological tissues and fluids. The primary physical mechanism in HIFU is the conversion of acoustic energy into heat, which is often enhanced by nonlinear acoustic propagation and nonlinear scattering from bubbles. Other mechanical effects from ultrasound appear to stimulate an immune response, and bubble dynamics play an important role in lithotripsy and ultrasound-enhanced drug delivery. A dramatic shift to understand and exploit these nonlinear and mechanical mechanisms has occurred over the last few years. Specific challenges remain, such as treatment protocol planning and real-time treatment monitoring. An improved understanding of the physical mechanisms is essential to meet these challenges and to further advance therapeutic ultrasound.

  18. Advances in Molecular Imaging with Ultrasound

    PubMed Central

    Gessner, Ryan; Dayton, Paul A.

    2010-01-01

    Ultrasound imaging has long demonstrated utility in the study and measurement of anatomic features and noninvasive observation of blood flow. Within the last decade, advances in molecular biology and contrast agents have allowed researchers to use ultrasound to detect changes in the expression of molecular markers on the vascular endothelium and other intravascular targets. This new technology, referred to as ultrasonic molecular imaging, is still in its infancy. However, in preclinical studies, ultrasonic molecular imaging has shown promise in assessing angiogenesis, inflammation, and thrombus. In this review, we discuss recent advances in microbubble-type contrast agent development, ultrasound technology, and signal processing strategies that have the potential to substantially improve the capabilities and utility of ultrasonic molecular imaging. PMID:20487678

  19. Ultrasound in perinatology

    SciTech Connect

    Maklad, N.F.

    1986-01-01

    This 19th volume in the series Clinics in Diagnostic Ultrasound provides an overview and update of some of the recent applications of ultrasound (US) in the pernatal period. Prenatal topics include estimation of gestational age; evaluation of intrauterine growth retardation, non-immune hydrops, and fetal urinary abnormalities; fetal echocardiography; and biophysical scoring. The discussion of postnatal topics includes US studies of the head and abdomen, echocardiography, and interventional procedures.

  20. Theranostic Oxygen Delivery Using Ultrasound and Microbubbles

    PubMed Central

    Kwan, James J.; Kaya, Mehmet; Borden, Mark A.; Dayton, Paul A.

    2012-01-01

    Means to overcome tumor hypoxia have been the subject of clinical investigations since the 1960's; however these studies have yet to find a treatment which is widely accepted. It has been known for nearly a century that hypoxic cells are more resistant to radiotherapy than aerobic cells, and tumor hypoxia is a major factor leading to the resistance of tumors to radiation treatment as well as several cytotoxic agents. In this manuscript, the application of ultrasound combined with oxygen-carrier microbubbles is demonstrated as a method to locally increase dissolved oxygen. Microbubbles can also be imaged by ultrasound, thus providing the opportunity for image-guided oxygen delivery. Simulations of gas diffusion and microbubble gas exchange show that small amounts (down to 5 vol%) of a low-solubility osmotic gas can substantially increase microbubble persistence and therefore production rates and stability of oxygen-carrier microbubbles. Simulations also indicate that the lipid shell can be engineered with long-chain lipids to increase oxygen payload during in vivo transit. Experimental results demonstrate that the application of ultrasound to destroy the microbubbles significantly enhances the local oxygen release. We propose this technology as an application for ultrasound image-guided release of oxygen directly to hypoxic tissue, such as tumor sites to enhance radiotherapy. PMID:23382774

  1. Rapid repair and regeneration of damaged rabbit sciatic nerves by tissue-engineered scaffold made from nano-silver and collagen type I

    Microsoft Academic Search

    Tan Ding; Zhuo-Jing Luo; Yan Zheng; Xue-Yu Hu; Zheng-Xu Ye

    2010-01-01

    A tissue-engineered scaffold with nano-silver and collagen type I was constructed and investigated for its ability to adsorb laminin and the usefulness in the repair and regeneration of damaged peripheral nerves in animals. The nano-silver scaffold displayed ideal microtubule structure under electronic microscope; even distribution of the nano-silver particles was also seen with energy spectrometry. After immersion in a laminin

  2. 2G-2 Tissue-Type Imaging (TTI) of Prostate Cancer Based on Ultrasonic and Magnetic-Resonance Methods: Latest Developments

    Microsoft Academic Search

    Ernest J. Feleppa; Shreedevi Dasgupta; Sarayu Ramachandran; Jeffrey A. Ketterling; Christopher R. Porter; Marc LaCrampe; David Dail

    2006-01-01

    Our prostate tissue-typing studies seek to develop imaging methods that have high sensitivity and specificity for visualizing cancerous regions of the prostate to improve the effectiveness of biopsy guidance, therapy targeting, and treatment monitoring. Spectral parameters obtained from radio-frequency (RF) ultrasonic (US) echo signals acquired from biopsy regions, along with the PSA are used to train a neural-network classifier. This

  3. Adipose tissue-derived stem cells rescue Purkinje neurons and alleviate inflammatory responses in Niemann-Pick disease type C mice

    Microsoft Academic Search

    Jae-sung Bae; Janet E. Carter; Hee Kyung Jin

    2010-01-01

    Adult stem cells offer special therapeutic prospects because they can be isolated for autologous transplantation, expanded\\u000a ex vivo, and differentiated into various cell types. We previously reported that bone marrow-derived mesenchymal stem cells\\u000a improve neurological deficits in neurodegenerative disease animal models. However, the efficacy of adipose tissue-derived\\u000a stem cells (ADSCs) transplantation in similar models remains unknown. Herein, we demonstrate that

  4. Rates of development of immatures of three species of Chrysomya (Diptera: Calliphoridae) reared in different types of animal tissues: implications for estimating the postmortem interval.

    PubMed

    Thyssen, Patricia Jacqueline; de Souza, Carina Mara; Shimamoto, Paula Midori; Salewski, Thais de Britto; Moretti, Thiago Carvalho

    2014-09-01

    Blowflies have major medical and sanitary importance because they can be vectors of viruses, bacteria, and helminths and are also causative agents of myiasis. Also, these flies, especially those belonging to the genus Chrysomya, are among the first insects to arrive at carcasses and are therefore valuable in providing data for the estimation of the minimum postmortem interval (PMImin). The PMImin can be calculated by assessing the weight, length, or development stage of blowfly larvae. Lack of information on the variables that might affect these parameters in different fly species can generate inaccuracies in estimating the PMImin. This study evaluated the effects of different types of bovine tissues (the liver, muscle, tongue, and stomach) and chicken heart on the development rates of larvae of Chrysomya albiceps Wiedemann, Chrysomya megacephala Fabricius, and Chrysomya putoria Wiedemann (Diptera: Calliphoridae). The efficiency of each rearing substrate was assessed by maggot weight gain (mg), larval development time (h), larval and pupal survival (%), and emergence interval (h). The development rates of larvae of all blowfly species studied here were directly influenced by the type of food substrate. Tissues that have high contents of protein and fat (muscle and heart) allowed the highest larval weight gain. For bovine liver, all Chrysomya species showed slower growth, by as much as 48 h, compared to the other tissues. Different rates of development are probably associated with specific energy requirements of calliphorids and the nutritional composition of each type of food. PMID:25082014

  5. Immunohistochemical Characterisation of Cell-Type Specific Expression of CK1? in Various Tissues of Young Adult BALB/c Mice

    PubMed Central

    Löhler, Jürgen; Hirner, Heidrun; Schmidt, Bernhard; Kramer, Klaus; Fischer, Dietmar; Thal, Dietmar R.; Leithäuser, Frank; Knippschild, Uwe

    2009-01-01

    Background Casein kinase 1 delta (CK1?) phosphorylates many key proteins playing important roles in such biological processes as cell growth, differentiation, apoptosis, circadian rhythm and vesicle transport. Furthermore, deregulation of CK1? has been linked to neurodegenerative diseases and cancer. In this study, the cell specific distribution of CK1? in various tissues and organs of young adult BALB/c mice was analysed by immunohistochemistry. Methodology/Principal Findings Immunohistochemical staining of CK1? was performed using three different antibodies against CK1?. A high expression of CK1? was found in a variety of tissues and organ systems and in several cell types of endodermal, mesodermal and ectodermal origin. Conclusions These results give an overview of the cell-type specific expression of CK1? in different organs under normal conditions. Thus, they provide evidence for possible cell-type specific functions of CK1?, where CK1? can interact with and modulate the activity of key regulator proteins by site directed phosphorylation. Furthermore, they provide the basis for future analyses of CK1? in these tissues. PMID:19137063

  6. Treatment of tension-type headache with articulatory and suboccipital soft tissue therapy: A double-blind, randomized, placebo-controlled clinical trial.

    PubMed

    Espí-López, Gemma V; Gómez-Conesa, Antonia; Gómez, Anna Arnal; Martínez, Josep Benítez; Pascual-Vaca, Angel Oliva; Blanco, Cleofás Rodríguez

    2014-10-01

    This study researches the effectiveness of two manual therapy treatments focused on the suboccipital region for tension-type headache. A randomized double-blind clinical trial was conducted over a period of four weeks with a follow-up at one month. Eighty-four patients with a mean age of 39.7 years (SD 11.4) with tension-type headache were assigned to 4 groups which included the following manual therapy treatment: suboccipital soft tissue inhibition; occiput-atlas-axis global manipulation; combination of both techniques; and a control group. The primary assessment consisted of collecting socio-demographic data and headache characteristics in a one-month base period, data such as age, gender, severity of pain, intensity and frequency of headache, among other. Outcome secondary assessment were: impact of headache, disability, ranges of motion of the craniocervical junction, frequency and intensity of headache, and pericranial tenderness. In the month prior to the study, average pain intensity, was rated at 6.49 (SD 1.69), and 66.7% subjects suffered headaches of moderate intensity. After 8 weeks, statistically significant improvements were noted. OAA manipulative treatment and combined therapy treatments proved to be more effective than suboccipital soft tissue inhibition for tension-type headache. The treatment with suboccipital soft tissue inhibition, despite producing less significant results, also has positive effects on different aspects of headache. PMID:25440210

  7. Immunoglobulin specificity of low grade B cell gastrointestinal lymphoma of mucosa-associated lymphoid tissue (MALT) type.

    PubMed Central

    Hussell, T.; Isaacson, P. G.; Crabtree, J. E.; Dogan, A.; Spencer, J.

    1993-01-01

    The specificity of the tumor cell immunoglobulin in three cases of low grade B cell gastrointestinal mucosa-associated lymphoid tissue (MALT) lymphoma has been studied. Using anti-idiotypic antibodies to detect the reactivity of tumor immunoglobulin in tissue sections from the patients and other individuals, we observed specificity for normal tissue components in all three cases studied. Reactivity in one case was with follicular dendritic cells, in the second case with a novel antigen on mucosal post capillary venules, and, in the third case, a broad pattern of reactivity was observed. This study suggests that autoimmunity may play a role in the pathogenesis of gastric lymphoma. Images Figure 2 Figure 3 Figure 4 PMID:8424461

  8. The feasibility of non-contact ultrasound for medical imaging

    NASA Astrophysics Data System (ADS)

    Clement, G. T.; Nomura, H.; Adachi, H.; Kamakura, T.

    2013-09-01

    High intensity focused ultrasound in air may provide a means for medical and biological imaging without direct coupling of an ultrasound probe. In this study, an approach based on highly focused ultrasound in air is described and the feasibility of the technique is assessed. The overall method is based on the observations that (1) ultrasound in air has superior focusing ability and stronger nonlinear harmonic generation as compared to tissue propagation and (2) a tightly focused field directed into tissue causes point-like spreading that may be regarded as a source for generalized diffraction tomography. Simulations of a spherically-curved transducer are performed, where the transducer's radiation pattern is directed from air into tissue. It is predicted that a focal pressure of 162 dB (2.5 kPa) is sufficient to direct ultrasound through the body, and provide a small but measurable signal (?1 mPa) upon exit. Based on the simulations, a 20 cm diameter array consisting of 298 transducers is constructed. For this feasibility study, a 40 kHz resonance frequency is selected based on the commercial availability of such transducers. The array is used to focus through water and acrylic phantoms, and the time history of the exiting signal is evaluated. Sufficient data are acquired to demonstrate a low-resolution tomographic reconstruction. Finally, to demonstrate the feasibility to record a signal in vivo, a 75 mm × 55 mm section of a human hand is imaged in a C-mode configuration.

  9. Active Ultrasound Pattern Injection System (AUSPIS) for Interventional Tool Guidance

    PubMed Central

    Guo, Xiaoyu; Kang, Hyun-Jae; Etienne-Cummings, Ralph; Boctor, Emad M.

    2014-01-01

    Accurate tool tracking is a crucial task that directly affects the safety and effectiveness of many interventional medical procedures. Compared to CT and MRI, ultrasound-based tool tracking has many advantages, including low cost, safety, mobility and ease of use. However, surgical tools are poorly visualized in conventional ultrasound images, thus preventing effective tool tracking and guidance. Existing tracking methods have not yet provided a solution that effectively solves the tool visualization and mid-plane localization accuracy problem and fully meets the clinical requirements. In this paper, we present an active ultrasound tracking and guiding system for interventional tools. The main principle of this system is to establish a bi-directional ultrasound communication between the interventional tool and US imaging machine within the tissue. This method enables the interventional tool to generate an active ultrasound field over the original imaging ultrasound signals. By controlling the timing and amplitude of the active ultrasound field, a virtual pattern can be directly injected into the US machine B mode display. In this work, we introduce the time and frequency modulation, mid-plane detection, and arbitrary pattern injection methods. The implementation of these methods further improves the target visualization and guiding accuracy, and expands the system application beyond simple tool tracking. We performed ex vitro and in vivo experiments, showing significant improvements of tool visualization and accurate localization using different US imaging platforms. An ultrasound image mid-plane detection accuracy of ±0.3 mm and a detectable tissue depth over 8.5 cm was achieved in the experiment. The system performance is tested under different configurations and system parameters. We also report the first experiment of arbitrary pattern injection to the B mode image and its application in accurate tool tracking. PMID:25337784

  10. Active ultrasound pattern injection system (AUSPIS) for interventional tool guidance.

    PubMed

    Guo, Xiaoyu; Kang, Hyun-Jae; Etienne-Cummings, Ralph; Boctor, Emad M

    2014-01-01

    Accurate tool tracking is a crucial task that directly affects the safety and effectiveness of many interventional medical procedures. Compared to CT and MRI, ultrasound-based tool tracking has many advantages, including low cost, safety, mobility and ease of use. However, surgical tools are poorly visualized in conventional ultrasound images, thus preventing effective tool tracking and guidance. Existing tracking methods have not yet provided a solution that effectively solves the tool visualization and mid-plane localization accuracy problem and fully meets the clinical requirements. In this paper, we present an active ultrasound tracking and guiding system for interventional tools. The main principle of this system is to establish a bi-directional ultrasound communication between the interventional tool and US imaging machine within the tissue. This method enables the interventional tool to generate an active ultrasound field over the original imaging ultrasound signals. By controlling the timing and amplitude of the active ultrasound field, a virtual pattern can be directly injected into the US machine B mode display. In this work, we introduce the time and frequency modulation, mid-plane detection, and arbitrary pattern injection methods. The implementation of these methods further improves the target visualization and guiding accuracy, and expands the system application beyond simple tool tracking. We performed ex vitro and in vivo experiments, showing significant improvements of tool visualization and accurate localization using different US imaging platforms. An ultrasound image mid-plane detection accuracy of ±0.3 mm and a detectable tissue depth over 8.5 cm was achieved in the experiment. The system performance is tested under different configurations and system parameters. We also report the first experiment of arbitrary pattern injection to the B mode image and its application in accurate tool tracking. PMID:25337784

  11. 11?-Hydroxysteroid dehydrogenase type 1 shRNA ameliorates glucocorticoid-induced insulin resistance and lipolysis in mouse abdominal adipose tissue.

    PubMed

    Wang, Ying; Yan, Chaoying; Liu, Limei; Wang, Wei; Du, Hanze; Fan, Winnie; Lutfy, Kabirullah; Jiang, Meisheng; Friedman, Theodore C; Liu, Yanjun

    2015-01-01

    Long-term glucocorticoid exposure increases the risk for developing type 2 diabetes. Prereceptor activation of glucocorticoid availability in target tissue by 11?-hydroxysteroid dehydrogenase type 1 (11?-HSD1) coupled with hexose-6-phosphate dehydrogenase (H6PDH) is an important mediator of the metabolic syndrome. We explored whether the tissue-specific modulation of 11?-HSD1 and H6PDH in adipose tissue mediates glucocorticoid-induced insulin resistance and lipolysis and analyzed the effects of 11?-HSD1 inhibition on the key lipid metabolism genes and insulin-signaling cascade. We observed that corticosterone (CORT) treatment increased expression of 11?-HSD1 and H6PDH and induced lipase HSL and ATGL with suppression of p-Thr(172) AMPK in adipose tissue of C57BL/6J mice. In contrast, CORT induced adipose insulin resistance, as reflected by a marked decrease in IR and IRS-1 gene expression with a reduction in p-Thr(308) Akt/PKB. Furthermore, 11?-HSD1 shRNA attenuated CORT-induced 11?-HSD1 and lipase expression and improved insulin sensitivity with a concomitant stimulation of pThr(308) Akt/PKB and p-Thr(172) AMPK within adipose tissue. Addition of CORT to 3T3-L1 adipocytes enhanced 11?-HSD1 and H6PDH and impaired p-Thr(308) Akt/PKB, leading to lipolysis. Knockdown of 11?-HSD1 by shRNA attenuated CORT-induced lipolysis and reversed CORT-mediated inhibition of pThr(172) AMPK, which was accompanied by a parallel improvement of insulin signaling response in these cells. These findings suggest that elevated adipose 11?-HSD1 expression may contribute to glucocorticoid-induced insulin resistance and adipolysis. PMID:25389364

  12. Ultrasound catheters for circumferential cardiac ablation

    NASA Astrophysics Data System (ADS)

    Diederich, Chris J.; Nau, William H.; Taylor, Kevin; Maguire, Mark T.; Picazo, Guillermo; Gangu, Madhuri; Lesh, Michael D.

    1999-05-01

    The purpose of this study was to investigate performance characteristics of a catheter-based ultrasound applicator intended for circumferential ablation of cardiac tissue. The catheter design integrates a cylindrical ultrasound transducer within a distendable water filled balloon in order to produce circumferential lesions at sites in the atria (i.e., pulmonary vein ostia), intended for treatment of certain atrial arrhythmias. Biothermal simulations were used to investigate thermal lesion depths corresponding to variations in applied power, duration, balloon diameter, and acoustic efficiency. Prototype applicators of varying frequency (7 - 12 MHz) and balloon diameter were constructed and characterized using measurements of acoustic efficiency and rotational beam plots. In vitro studies were performed in freshly excised beef hearts to characterize the radial penetration, axial length, and angular uniformity of thermal lesions produced by these applicators. Selected applicators were tested in vivo within pulmonary veins, coronary sinus, and atrial appendage of canine and porcine hearts. These preliminary efforts have indicated that circumferential ablation of cardiac tissue using ultrasound balloon catheters is feasible, and devices between 7 - 12 MHz with balloon diameters of 1.5 - 2.0 cm are capable of producing uniform lesions between 1 - 5 mm depth or greater for treatment durations of 120 seconds or less.

  13. Computer-Aided Diagnosis of Prostate Cancer with Emphasis on Ultrasound-Based Approaches: A Review

    Microsoft Academic Search

    Mehdi Moradi; Parvin Mousavi; Purang Abolmaesumi

    2007-01-01

    This paper reviews the state of the art in computer-aided diagnosis of prostate cancer and focuses, in particular, on ultrasound-based techniques for detection of cancer in prostate tissue. The current standard procedure for diagnosis of prostate cancer, i.e., ultrasound-guided biopsy followed by histopathological analysis of tissue samples, is invasive and produces a high rate of false negatives resulting in the

  14. In Vitro and In Vivo Potential of RH Strain of Toxoplasma gondii (Type I) in Tissue Cyst Forming

    PubMed Central

    ASGARI, Qasem; KESHAVARZ, Hossein; SHOJAEE, Saeedeh; MOTAZEDIAN, Mohammad Hossein; MOHEBALI, Mehdi; MIRI, Ramin; MEHRABANI, Davood; REZAEIAN, Mostafa

    2013-01-01

    Background Based on recent studies, there are controversial reports on the capacity of tissue cyst forming of Toxoplasma gondii RH strain. In this study, the capacity was evaluated by in vivo and in vitro experiments. Methods RH strain was subcutaneously inoculated to ten Wistar rats. After one month, their blood, brain, tongue and diaphragm were collected and evaluated by MAT, PCR, pathological and bioassay methods. The parasite was cultivated in the cell monolayer. To change to bradyzoite, the media pH was altered to 6.8. Biological aspect of the bradyzoites was evaluated by incubation in acidic pepsin and it's inoculation in ten BALB/c mice. Results All rats showed antibodies to Toxoplasma at titers ?1:320 but no DNA and tissue cyst were detected in the tissues. Following intraperitoneal inoculation of rats’ brain homogenate into BALB/c mice, no infection was established in none of the animals. During presence of cell culture, in acid media for a 3-5 days period, cyst-like structures were noticed when they were stained with PAS. The visible bradyzoites in the cysts that were incubated in acid pepsin medium were not able to kill any mice. Conclusion This study confirmed that Iranian RH strain has lost the potential of tissue cyst forming in rats and bradyzoites cultivated in cell culture lost their resistance to acidic condition, so this strain can be a candidate for future vaccine researches. PMID:24454428

  15. Multisectored interstitial ultrasound applicators for dynamic angular control of thermal therapy.

    PubMed

    Kinsey, Adam M; Diederich, Chris J; Tyreus, P Daniel; Nau, William H; Rieke, Viola; Pauly, Kim Butts

    2006-05-01

    Dynamic angular control of thermal ablation and hyperthermia therapy with current interstitial heating technology is limited in capability, and often relies upon nonadjustable angular power deposition patterns and/or mechanical manipulation of the heating device. The objective of this study was to investigate the potential of multisectored tubular interstitial ultrasound devices to provide control of the angular heating distribution without device manipulation. Multisectored tubular transducers with independent sector power control were incorporated into modified versions of internally cooled (1.9 mm OD) and catheter-cooled (2.4 mm OD) interstitial ultrasound applicators in this work. The heating capabilities of these multisectored devices were evaluated by measurements of acoustic output properties, measurements of thermal lesions produced in ex vivo tissue samples, biothermal simulations of thermal ablation and hyperthermia treatments, and MR temperature imaging of ex vivo and in vivo experiments. Acoustic beam measurements of each applicator type displayed a 35 degrees -40 degrees acoustic dead zone between each independent sector, with negligible mechanical or electrical coupling. Thermal lesions produced in ex vivo liver tissue with one, two, or three sectors activated ranged from 13-18 mm in radius with contiguous zones of coagulation between active sectors. The simulations demonstrated the degree of angular control possible by using variable power levels applied to each sector, variable duration of applied constant power to individual sectors, respectively, or a multipoint temperature controller to vary the power applied to each sector. Despite the acoustic dead zone between sectors, the simulations also showed that the variance from the maximum lesion radius with three elements activated is within 4%-13% for tissue perfusions from 1-10 kg m(-3) s(-1). Simulations of hyperthermia with maximum tissue temperatures of 45 degrees C and 48 degrees C displayed radial penetration up to 2 cm of the 40 degrees C steady-state contour. Thermal characterizations of trisectored applicators in ex vivo and in vivo muscle, using real-time MR thermal imaging, reinforced angular controllability and negligible radial variance of the heating pattern from the applicators, demonstrated effective heating penetration, and displayed MR compatibility. The multisectored interstitial ultrasound applicators developed in this study demonstrated a significant degree of dynamic angular control of a heating pattern without device manipulation, while maintaining heat penetration consistent with previously reported results from other interstitial ultrasound applicators. PMID:16752571

  16. Effects of Shiga Toxin Type 2 on a Bioengineered Three-Dimensional Model of Human Renal Tissue

    PubMed Central

    DesRochers, Teresa M.; Kimmerling, Erica Palma; Jandhyala, Dakshina M.; El-Jouni, Wassim; Zhou, Jing; Thorpe, Cheleste M.; Leong, John M.

    2014-01-01

    Shiga toxins (Stx) are a family of cytotoxic proteins that can cause hemolytic-uremic syndrome (HUS), a thrombotic microangiopathy, following infections by Shiga toxin-producing Escherichia coli (STEC). Renal failure is a key feature of HUS and a major cause of childhood renal failure worldwide. There are currently no specific therapies for STEC-associated HUS, and the mechanism of Stx-induced renal injury is not well understood primarily due to a lack of fully representative animal models and an inability to monitor disease progression on a molecular or cellular level in humans at early stages. Three-dimensional (3D) tissue models have been shown to be more in vivo-like in their phenotype and physiology than 2D cultures for numerous disease models, including cancer and polycystic kidney disease. It is unknown whether exposure of a 3D renal tissue model to Stx will yield a more in vivo-like response than 2D cell culture. In this study, we characterized Stx2-mediated cytotoxicity in a bioengineered 3D human renal tissue model previously shown to be a predictor of drug-induced nephrotoxicity and compared its response to Stx2 exposure in 2D cell culture. Our results demonstrate that although many mechanistic aspects of cytotoxicity were similar between 3D and 2D, treatment of the 3D tissues with Stx resulted in an elevated secretion of the kidney injury marker 1 (Kim-1) and the cytokine interleukin-8 compared to the 2D cell cultures. This study represents the first application of 3D tissues for the study of Stx-mediated kidney injury. PMID:25312954

  17. Ultrasound-based guidance of intensity-modulated radiation therapy

    SciTech Connect

    Fung, Albert Y.C. [Department of Radiation Oncology, Nebraska Medical Center, Omaha, NE (United States)]. E-mail: afung@unmc.edu; Ayyangar, Komanduri M. [Department of Radiation Oncology, Nebraska Medical Center, Omaha, NE (United States); Djajaputra, David [Department of Radiation Oncology, Nebraska Medical Center, Omaha, NE (United States); Nehru, Ramasamy M. [Department of Radiation Oncology, Nebraska Medical Center, Omaha, NE (United States); Enke, Charles A. [Department of Radiation Oncology, Nebraska Medical Center, Omaha, NE (United States)

    2006-04-01

    In ultrasound-guided intensity-modulated radiation therapy (IMRT) of prostate cancer, ultrasound imaging ascertains the anatomical position of patients during x-ray therapy delivery. The ultrasound transducers are made of piezoelectric ceramics. The same crystal is used for both ultrasound production and reception. Three-dimensional (3D) ultrasound devices capture and correlate series of 2-dimensional (2D) B-mode images. The transducers are often arranged in a convex array for focusing. Lower frequency reaches greater depth, but results in low resolution. For clear image, some gel is usually applied between the probe and the skin contact surface. For prostate positioning, axial and sagittal scans are performed, and the volume contours from computed tomography (CT) planning are superimposed on the ultrasound images obtained before radiation delivery at the linear accelerator. The planning volumes are then overlaid on the ultrasound images and adjusted until they match. The computer automatically deduces the offset necessary to move the patient so that the treatment area is in the correct location. The couch is translated as needed. The currently available commercial equipment can attain a positional accuracy of 1-2 mm. Commercial manufacturer designs differ in the detection of probe coordinates relative to the isocenter. Some use a position-sensing robotic arm, while others have infrared light-emitting diodes or pattern-recognition software with charge-couple-device cameras. Commissioning includes testing of image quality and positional accuracy. Ultrasound is mainly used in prostate positioning. Data for 7825 daily fractions of 234 prostate patients indicated average 3D inter-fractional displacement of about 7.8 mm. There was no perceivable trend of shift over time. Scatter plots showed slight prevalence toward superior-posterior directions. Uncertainties of ultrasound guidance included tissue inhomogeneities, speckle noise, probe pressure, and inter-observer variation. Some published studies detected improvement in treatment based on gastrointestinal toxicity and the reduction of prostate movement.

  18. Clinical combination of multiphoton tomography and high frequency ultrasound imaging for evaluation of skin diseases

    NASA Astrophysics Data System (ADS)

    König, K.; Speicher, M.; Koehler, M. J.; Scharenberg, R.; Elsner, P.; Kaatz, M.

    2010-02-01

    For the first time, high frequency ultrasound imaging, multiphoton tomography, and dermoscopy were combined in a clinical study. Different dermatoses such as benign and malign skin cancers, connective tissue diseases, inflammatory skin diseases and autoimmune bullous skin diseases have been investigated with (i) state-of-the-art and highly sophisticated ultrasound systems for dermatology, (ii) the femtosecond-laser multiphoton tomograph DermaInspectTM and (iii) dermoscopes. Dermoscopy provides two-dimensional color imaging of the skin surface with a magnification up to 70x. Ultrasound images are generated from reflections of the emitted ultrasound signal, based on inhomogeneities of the tissue. These echoes are converted to electrical signals. Depending on the ultrasound frequency the penetration depth varies from about 1 mm to 16 mm in dermatological application. The 100-MHz-ultrasound system provided an axial resolution down to 16 ?m and a lateral resolution down to 32 ?m. In contrast to the wide-field ultrasound images, multiphoton tomography provided horizontal optical sections of 0.36×0.36 mm2 down to 200 ?m tissue depth with submicron resolution. The autofluorescence of mitochondrial coenzymes, melanin, and elastin as well as the secondharmonic- generation signal of the collagen network were imaged. The combination of ultrasound and multiphoton tomography provides a novel opportunity for diagnostics of skin disorders.

  19. Noninfectious X4 but not R5 human immunodeficiency virus type 1 virions inhibit humoral immune responses in human lymphoid tissue ex vivo

    NASA Technical Reports Server (NTRS)

    Fitzgerald, Wendy; Sylwester, Andrew W.; Grivel, Jean-Charles; Lifson, Jeffrey D.; Margolis, Leonid B.

    2004-01-01

    Ex vivo human immunodeficiency virus type 1 (HIV-1) infection of human lymphoid tissue recapitulates some aspects of in vivo HIV-1 infection, including a severe depletion of CD4(+) T cells and suppression of humoral immune responses to recall antigens or to polyclonal stimuli. These effects are induced by infection with X4 HIV-1 variants, whereas infection with R5 variants results in only mild depletion of CD4(+) T cells and no suppression of immune responses. To study the mechanisms of suppression of immune responses in this ex vivo system, we used aldrithiol-2 (AT-2)-inactivated virions that have functional envelope glycoproteins but are not infectious and do not deplete CD4(+) T cells in human lymphoid tissues ex vivo. Nevertheless, AT-2-inactivated X4 (but not R5) HIV-1 virions, even with only a brief exposure, inhibit antibody responses in human lymphoid tissue ex vivo, similarly to infectious virus. This phenomenon is mediated by soluble immunosuppressive factor(s) secreted by tissue exposed to virus.

  20. Cross-talks between microRNAs and mRNAs in pancreatic tissues of streptozotocin-induced type 1 diabetic mice

    PubMed Central

    TIAN, CAIMING; OUYANG, XIAOXI; LV, QING; ZHANG, YAOU; XIE, WEIDONG

    2015-01-01

    Network cross-talks between microRNAs (miRNAs) and mRNAs may be useful to elucidate the pathological mechanisms of pancreatic islet cells in diabetic individuals. The aim of the present study was to investigate the cross-talks between miRNAs and mRNAs in pancreatic tissues of streptozotocin-induced diabetic mice through microarray and bioinformatic methods. Based on the miRNA microarray, 64 upregulated and 72 downregulated miRNAs were observed in pancreatic tissues in diabetic mice compared to the normal controls. Based on the mRNA microarrray, 507 upregulated mRNAs and 570 downregulated mRNAs were identified in pancreatic tissues in diabetic mice compared to the normal controls. Notably, there were 246 binding points between upregulated miRNA and downregulated mRNAs; simultaneously, there were 583 binding points between downregulated miRNA and upregulated mRNAs. These changed mRNA may potentially involve the following signaling pathways: Insulin secretion, pancreatic secretion, mammalian target of rapamycin signaling pathway, forkhead box O signaling pathway and phosphatidylinositol 3-kinase-protein kinase B signaling. The fluctuating effects of miRNAs and matched mRNAs indicated that miRNAs may have wide cross-talks with mRNAs in pancreatic tissues of type 1 diabetic mice. The cross-talks may play important roles in contributing to impaired islet functions and the development of diabetes. However, further functional validation should be conducted in the future.

  1. Segmentation of 2D fetal ultrasound images by exploiting context information using conditional random fields.

    PubMed

    Gupta, Lalit; Sisodia, Rajendra Singh; Pallavi, V; Firtion, Celine; Ramachandran, Ganesan

    2011-01-01

    This paper proposes a novel approach for segmenting fetal ultrasound images. This problem presents a variety of challenges including high noise, low contrast, and other US imaging properties such as similarity between texture and gray levels of two organs/ tissues. In this paper, we have proposed a Conditional Random Field (CRF) based framework to handle challenges in segmenting fetal ultrasound images. Clinically, it is known that fetus is surrounded by specific maternal tissues, amniotic fluid and placenta. We exploit this context information using CRFs for segmenting the fetal images accurately. The proposed CRF framework uses wavelet based texture features for representing the ultrasound image and Support Vector Machines (SVM) for initial label prediction. Initial results on a limited dataset of real world ultrasound images of fetus are promising. Results show that proposed method could handle the noise and similarity between fetus and its surroundings in ultrasound images. PMID:22256004

  2. Discrete echo signal modeling of ultrasound imaging systems

    NASA Astrophysics Data System (ADS)

    Chen, Ming; Zhang, Cishen

    2008-03-01

    In this paper, a discrete model representing the pulse-tissue interaction in the medical ultrasound scanning and imaging process is developed. The model is based on discretizing the acoustical wave equation and is in terms of convolution between the input ultrasound pulses and the tissue mass density variation. Such a model can provide a useful means for ultrasound echo signal processing and imaging. Most existing models used for ultrasound imaging are based on frequency domain transform. A disadvantage of the frequency domain transform is that it is only applicable to shift-invariant models. Thus it has ignored the shift-variant nature of the original acoustic wave equation where the tissue compressibility and mass density distributions are spatial-variant factors. The discretized frequency domain model also obscures the compressibility and mass density representations of the tissue, which may mislead the physical understanding and interpretation of the image obtained. Moreover, only the classical frequency domain filtering methods have been applied to the frequency domain model for acquiring some tissue information from the scattered echo signals. These methods are non-parametric and require a prior knowledge of frequency spectra of the transmitted pulses. Our proposed model technique will lead to discrete, multidimensional, shift-variant and parametric difference or convolution equations with the transmitted pulse pressure as the input, the measurement data of the echo signals as the output, and functions of the tissue compressibility and mass density distributions as shift-variant parameters that can be readily identified from input-output measurements. The proposed model represents the entire multiple scattering process, and hence overcomes the key limitation in the current ultrasound imaging methods.

  3. Despeckle Filtering of Ultrasound Images

    Microsoft Academic Search

    Christos P. Loizou; Constantinos S. Pattichis

    \\u000a It is well known that speckle is a multiplicative noise that degrades the visual evaluation in ultrasound imaging. This necessitates\\u000a the need for robust despeckling techniques for both routine clinical practice and tele-consultation. The recent advancements\\u000a in ultrasound instrumentation and portable ultrasound devices necessitate the need of more robust despeckling techniques for\\u000a enhanced ultrasound medical imaging for both routine clinical

  4. ?-Type Zr-Nb-Ti biomedical materials with high plasticity and low modulus for hard tissue replacements.

    PubMed

    Nie, Li; Zhan, Yongzhong; Hu, Tong; Chen, Xiaoxian; Wang, Chenghui

    2014-01-01

    In order to develop new biomedical materials for hard tissue replacements, Zr-20Nb-xTi (x=0, 3, 7, 11 and 15) alloys with required properties were designed and prepared by using the vacuum arc melting method for the first time. Phase analysis and microstructural observation showed that all the as cast samples consisted of equiaxed ?-Zr phase. The mechanical properties and fracture behaviors of the Zr-20Nb-xTi alloys have been analyzed. It is found that these alloys exhibit high plasticity, moderate compressive strength (1044-1325MPa) and yield stress (854-1080MPa), high elastic energy (12-20MJ/m(3)) and low Young's modulus (28-31GPa). This good combination of mechanical properties makes them potential biomedical materials for hard tissue replacement. PMID:24036526

  5. Biaxial Mechanical Testing of Posterior Sclera using High-Resolution Ultrasound Speckle Tracking for Strain Measurements

    PubMed Central

    Cruz-Perez, Benjamin; Tang, Junhua; Morris, Hugh J.; Palko, Joel R.; Pan, Xueliang; Hart, Richard T.; Liu, Jun

    2014-01-01

    This study aimed to characterize the mechanical responses of the sclera, the white outer coat of the eye, under equal-biaxial loading with unrestricted shear. An ultrasound speckle tracking technique was used to measure tissue deformation through sample thickness, expanding the capabilities of surface strain techniques. Eight porcine scleral samples were tested within 72 hours postmortem. High resolution ultrasound scans of scleral cross-sections along the two loading axes were acquired at 25 consecutive biaxial load levels. An additional repeat of the biaxial loading cycle was performed to measure a third normal strain emulating a strain gauge rosette for calculating the in-plane shear. The repeatability of the strain measurements during identical biaxial ramps was evaluated. A correlation-based ultrasound speckle tracking algorithm was used to compute the displacement field and determine the distributive strains in the sample cross-sections. A Fung type constitutive model including a shear term was used to determine the material constants of each individual specimen by fitting the model parameters to the experimental stress-strain data. A non-linear stress-strain response was observed in all samples. The meridian direction had significantly larger strains than the circumferential direction during equal-biaxial loadings (P’s<0.05). The stiffness along the two directions were also significantly different (P=0.02) but highly correlated (R2=0.8). These results showed that the mechanical properties of the porcine sclera were nonlinear and anisotropic under biaxial loading. This work has also demonstrated the feasibility of using ultrasound speckle tracking for strain measurements during mechanical testing. PMID:24438767

  6. Two types of ferrochelatase in photosynthetic and nonphotosynthetic tissues of cucumber: their difference in phylogeny, gene expression, and localization.

    PubMed

    Suzuki, Takuo; Masuda, Tatsuru; Singh, Davinder Pal; Tan, Fui-Ching; Tsuchiya, Tohru; Shimada, Hiroshi; Ohta, Hiroyuki; Smith, Alison G; Takamiya, Ken-ichiro

    2002-02-15

    Ferrochelatase catalyzes the insertion of Fe(2+) into protoporphyrin IX to generate protoheme. In higher plants, there is evidence for two isoforms of this enzyme that fulfill different roles. Here, we describe the isolation of a second ferrochelatase cDNA from cucumber (CsFeC2) that was less similar to a previously isolated isoform (CsFeC1) than it was to some ferrochelatases from other higher plants. In in vitro import experiments, the two cucumber isoforms showed characteristics similar to their respective ferrochelatase counterparts of Arabidopsis thaliana. The C-terminal region of CsFeC2 but not CsFeC1 contained a conserved motif found in light-harvesting chlorophyll proteins, and CsFeC2 belonged to a phylogenetic group of plant ferrochelatases containing this conserved motif. We demonstrate that CsFeC2 was localized predominantly in thylakoid membranes as an intrinsic protein, and forming complexes probably with the C-terminal conserved motif, but a minor portion was also detected in envelope membranes. CsFeC2 mRNA was detected in all tissues and was light-responsive in cotyledons, whereas CsFeC1 mRNA was detected in nonphotosynthetic tissues and was not light-responsive. Interestingly, tissue-, light-, and cycloheximide-dependent expressions of the two isoforms of ferrochelatase were similar to those of two glutamyl-tRNA reductase isoforms involved in the early step of tetrapyrrole biosynthesis, suggesting the existence of distinctly controlled tetrapyrrole biosynthetic pathways in photosynthetic and nonphotosynthetic tissues. PMID:11675381

  7. Component tissues of different morphological types of tomato fruit and their qualitative and quantitative effects on quality of processed product 

    E-print Network

    Wagner, Alfred Bernhart

    1972-01-01

    , and pigment content of component tissues need to be related. Relating these data to various other chemical and physical attributes of both raw and processed tomatoes would be of interest and fundamental to the knowledge of tomato quality. Citations follow... color of fully ripened tomatoes. Pigments In the tomato, a complex system of pigmentation is responsible for fruit color. The major components of this pigment system are lycopene (red), beta-carotene (yellow), and other related carotenoid pigments...

  8. Detection of Human PapillomavirusType 16 DNA Sequences in Paraffin-Embedded Tissues from the Female Urinary Tract

    Microsoft Academic Search

    Anna Maria Aglianò; Paola Gazzaniga; Mauro Cervigni; Angela Gradilone; Maria Napolitano; Laura Iolanda Pastore; Vittorio Manzari; Luigi Frati; Aldo Vecchione

    1994-01-01

    We investigated the presence of human papiilomavirus-related DNA sequences (HPV 6,11,16 and 18) in 33 formalin-fixed paraffin-embedded biopsies from the urinary tract of female patients with recurrent and persistent urethritis and cystitis, using the polymerase chain reaction (PCR). The samples for PCR reaction were selected among tissues examined for histological diagnosis on the basis of the presence of microscopic changes

  9. Fundamental Neurological Research and Human Neurosurgery Using Intense Ultrasound

    Microsoft Academic Search

    W. J. Fry; F. J. Fry

    1960-01-01

    Focused high intensity ultrasound can be used, under accurately controlled dosage conditions, to produce either temporary or permanent changes in practically any desired brain structure. Volumes of tissue smaller than one tenth of a cubic millimeter can be affected in deep brain structures of experimental animals (cats and monkeys), and regions as large as desired can be changed by moving

  10. Endobronchial ultrasound-guided diagnosis of pulmonary artery tumor embolus.

    PubMed

    Vial, Macarena R; Sarkiss, Mona; Lazarus, Donald R; Eapen, George

    2015-05-01

    A patient diagnosed with pulmonary embolism had persistent symptoms despite adequate therapy. Tissue sampling with endobronchial ultrasound-guided needle aspiration revealed endovascular metastasis from a prior early-stage colorectal cancer. We describe the challenges in the diagnosis and workup of suspected tumor emboli. PMID:25952219

  11. Transcranial Ultrasound in Acute Stroke: From Diagnosis to Therapy

    Microsoft Academic Search

    Carlos A. Molina; Andrei V. Alexandrov

    2007-01-01

    In the last few years, several studies have improved our knowledge and understanding of the dynamic nature of the recanalization process during stroke thrombolysis. Transcranial Doppler ultrasound provides a unique opportunity to assess several aspects of clot dissolution by means of continuous monitoring of recanalization during and after administration of tissue plasminogen activator. This approach allows us to evaluate at

  12. Performance testing of medical ultrasound equipment: fundamental vs. harmonic mode

    Microsoft Academic Search

    M. C. van Wijk; J. M. Thijssen

    2002-01-01

    Assessment of the performance of medical ultrasound equipment is generally based on the image quality in fundamental mode. Recent development of the so-called tissue harmonic imaging (THI) mode induces the need for assessment of differences in the quality of imaging in THI vs. fundamental imaging mode. Quality features to be tested are sensitivity (penetration depth), spatial resolution, contrast resolution, lesion

  13. A wall-less vessel phantom for Doppler ultrasound studies

    Microsoft Academic Search

    D. W. Rickey; P. A. Picot; D. A. Christopher; A. Fenster

    1995-01-01

    Doppler ultrasound flow measurement techniques are often validated using phantoms that simulate the vasculature, surrounding tissue and blood. Many researchers use rubber tubing to mimic blood vessels because of the realistic acoustic impedance, robust physical properties and wide range of available sizes. However, rubber tubing has a very high acoustic attenuation, which may introduce artefacts into the Doppler measurements. We

  14. Synergy and Applications of Combined Ultrasound, Elasticity, and Photoacoustic Imaging

    Microsoft Academic Search

    S. Y. Emelianov; S. R. Aglyamov; A. B. Karpiouk; S. Mallidi; S. Sethuraman; J. Shah; R. W. Smalling; J. M. Rubin; W. G. Scott

    Abstract—An advanced in-vivo imaging technology; namely, combined ultrasound, elasticity and photoacoustic imaging, capable of visualizing both structural and functional properties ofliving tissue, is presented. This hybrid imaging technology is based on the fusion of the complementary imaging modalities and takes full advantage of the ,many ,synergistic features of these systems. To highlight fundamental differences and similarities between the imaging systems

  15. Ultrasound internal tattooing Olivier Couturea

    E-print Network

    Paris 7 - Denis Diderot, Université

    Ultrasound internal tattooing Olivier Couturea and Magalie Faivre ESPCI, Paris 75005, France ultrasound-inducible droplets carrying large payloads of fluorescent markers and the in vivo proof of concept of their remote and controlled deposition via focused ultrasound. The droplets are monodispersed multiple

  16. The RUSH Exam: Rapid Ultrasound

    E-print Network

    The RUSH Exam: Rapid Ultrasound in SHock in the Evaluation of the Critically lll Phillips Perera-risk situations. Ultrasound technology has been rapidly integrated into Emergency Department care in the last-directed ultrasound, and this training is now included in all United States Accreditation Council for Graduate Medical

  17. The Chemical Effects of Ultrasound

    E-print Network

    Suslick, Kenneth S.

    The Chemical Effects of Ultrasound Intense ultrasonic waves traveling through liquids generate generators of high-intensity ultrasound (sound pitched above human hearing at fre quencies greater than 16 kilohertz, or 16,000 cycles per second). Today ultrasound is applied in hos pitals for medical imaging

  18. Robotically assisted ultrasound interventions

    NASA Astrophysics Data System (ADS)

    Ding, Jienan; Swerdlow, Dan; Wang, Shuxin; Wilson, Emmanuel; Tang, Jonathan; Cleary, Kevin

    2008-03-01

    The goal of this project is to develop a robotic system to assist the physician in minimally invasive ultrasound interventions. In current practice, the physician must manually hold the ultrasound probe in one hand and manipulate the needle with the other hand, which can be challenging, particularly when trying to target small lesions. To assist the physician, the robot should not only be capable of providing the spatial movement needed, but also be able to control the contact force between the ultrasound probe and patient. To meet these requirements, we are developing a prototype system based on a six degree of freedom parallel robot. The system will provide high bandwidth, precision motion, and force control. In this paper we report on our progress to date, including the development of a PC-based control system and the results of our initial experiments.

  19. Adiponectin as a link between type 2 diabetes and vascular NADPH oxidase activity in the human arterial wall: the regulatory role of perivascular adipose tissue.

    PubMed

    Antonopoulos, Alexios S; Margaritis, Marios; Coutinho, Patricia; Shirodaria, Cheerag; Psarros, Costas; Herdman, Laura; Sanna, Fabio; De Silva, Ravi; Petrou, Mario; Sayeed, Rana; Krasopoulos, George; Lee, Regent; Digby, Janet; Reilly, Svetlana; Bakogiannis, Constantinos; Tousoulis, Dimitris; Kessler, Benedikt; Casadei, Barbara; Channon, Keith M; Antoniades, Charalambos

    2015-06-01

    Oxidative stress plays a critical role in the vascular complications of type 2 diabetes. We examined the effect of type 2 diabetes on NADPH oxidase in human vessels and explored the mechanisms of this interaction. Segments of internal mammary arteries (IMAs) with their perivascular adipose tissue (PVAT) and thoracic adipose tissue were obtained from 386 patients undergoing coronary bypass surgery (127 with type 2 diabetes). Type 2 diabetes was strongly correlated with hypoadiponectinemia and increased vascular NADPH oxidase-derived superoxide anions (O2?(-)). The genetic variability of the ADIPOQ gene and circulating adiponectin (but not interleukin-6) were independent predictors of NADPH oxidase-derived O2?(-). However, adiponectin expression in PVAT was positively correlated with vascular NADPH oxidase-derived O2?(-). Recombinant adiponectin directly inhibited NADPH oxidase in human arteries ex vivo by preventing the activation/membrane translocation of Rac1 and downregulating p22(phox) through a phosphoinositide 3-kinase/Akt-mediated mechanism. In ex vivo coincubation models of IMA/PVAT, the activation of arterial NADPH oxidase triggered a peroxisome proliferator-activated receptor-?-mediated upregulation of the adiponectin gene in the neighboring PVAT via the release of vascular oxidation products. We demonstrate for the first time in humans that reduced adiponectin levels in individuals with type 2 diabetes stimulates vascular NADPH oxidase, while PVAT "senses" the increased NADPH oxidase activity in the underlying vessel and responds by upregulating adiponectin gene expression. This PVAT-vessel interaction is identified as a novel therapeutic target for the prevention of vascular complications of type 2 diabetes. PMID:25552596

  20. Elastography: A New Ultrasound and MRI Procedure

    SciTech Connect

    Pavan, Theo Z.; Vieira, Silvio L.; Carneiro, Antonio A. O. [Departamento de Fisica e Matematica, Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto Universidade de Sao Paulo. Av Bandeirantes, 3900, Ribeirao Preto, SP (Brazil)

    2008-08-11

    Elastography is an imaging technique whereby local tissue strains are estimated from small displacements of internal tissue structure. These displacements are generated from a weak, quasi-static or dynamic stress field. Displacement evaluation through ultrasound is based on time delay estimation between speckle patterns of echo maps acquired for different levels of tissue deformation. A classical model of deformation is applying a quasi-static compression on a sample during echoes acquisition. The elastogram map corresponds to the spatial derivation of the displacement map. By magnetic resonance, the displacement is evaluated from a map of phase acquired using a sequence gradient echo synchronized with a mechanical end sinusoidal excitation. The map of shear elastic modulus is obtained from the phase map.