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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. 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.

  4. Ultrasound tomography of breast tissue

    NASA Astrophysics Data System (ADS)

    Duric, Nebojsa; Littrup, Peter J.; Holsapple, Earle; Babkin, Alex; Duncan, Robert; Kalinin, Arkady; Pevzner, Roman; Tokarev, Michael

    2003-05-01

    The Karmanos Cancer Institute is developing an ultrasound device for measuring and imaging acoustic parameters of human tissue. This paper discusses the experimental results relating to tomographic reconstructions of phantoms and tissue. The specimens were scanned by the prototype scanner at a frequency of 1.5 MHz using 2 microsecond pulses. The receivers and transmitters were positioned along a ring trajectory having a diameter of 20 cm. The ring plane is translated in the vertical direction allowing for 3-D reconstructions from stacked 2-D planes of data. All ultrasound scans were performed at 10 millimeter slice thickness to generate multiple tomographic images. In a previous SPIE paper we presented preliminary results of ultrasound tomographic reconstruction of formalin-fixed breast tissue. We now present new results from data acquired with the scanner. Images were constructed using both reflection-based and transmission based algorithms. The resulting images demonstrate the ability to detect sub-mm features and to measure acoustic properties such as sound speed. Comparison with conventional ultrasound indicates the potential for better margin definition and acoustic characterization of tissue.

  5. Application of tissue characterization in intravascular ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Mullen, William L.; Fitzgerald, Peter J.; Yock, Paul G.

    1994-05-01

    Current intravascular ultrasound imaging technology is able to determine the extent and distribution of pathologic processes within the vessel wall, but is not highly sensitive in discriminating between certain types of tissue. `Tissue characterization' refers to a set of computer-based techniques that utilize features of the ultrasound signal beyond basic amplitude to help define the composition of the tissue of interest. This technique involves quantitative analysis of the ultrasound signals reflected from tissue before these signals pass through the processing steps in the ultrasound instrument.

  6. Experimental research on wild-type p53 plasmid transfected into retinoblastoma cells and tissues using an ultrasound microbubble intensifier.

    PubMed

    Luo, J; Zhou, X; Diao, L; Wang, Z

    2010-01-01

    The transfection efficiency of wild-type p53 (wtp53) was investigated in retinoblastoma (RB) Y79 cells using an ultrasound microbubble technique. A human RB nude mouse xenograft tumour model was also used to investigate whether this technique could deliver wtp53 into solid tumours. Reverse transcription-polymerase chain reaction (RT-PCR) demonstrated that wtp53 was successfully transfected into Y79 cells in the plasmid with microbubbles and ultrasound group and in the plasmid with liposomes group, but not in the plasmid with ultrasound group or in the untreated control group. Flow cytometry showed that apoptosis was highest in the microbubbles and ultrasound group (25.58%) compared with the plasmid with liposomes group (19.50%), and the other two groups (< 10%). RT-PCR also showed that the wtp53 gene was successfully transfected into solid tumours in the plasmid with microbubbles and ultrasound group. This study provides preliminary evidence in support of a potential new approach to RB gene therapy. PMID:20819437

  7. Experimental research on wild-type p53 plasmid transfected into retinoblastoma cells and tissues using an ultrasound microbubble intensifier.

    PubMed

    Luo, J; Zhou, X; Diao, L; Wang, Z

    2010-01-01

    The transfection efficiency of wild-type p53 (wtp53) was investigated in retinoblastoma (RB) Y79 cells using an ultrasound microbubble technique. A human RB nude mouse xenograft tumour model was also used to investigate whether this technique could deliver wtp53 into solid tumours. Reverse transcription-polymerase chain reaction (RT-PCR) demonstrated that wtp53 was successfully transfected into Y79 cells in the plasmid with microbubbles and ultrasound group and in the plasmid with liposomes group, but not in the plasmid with ultrasound group or in the untreated control group. Flow cytometry showed that apoptosis was highest in the microbubbles and ultrasound group (25.58%) compared with the plasmid with liposomes group (19.50%), and the other two groups (< 10%). RT-PCR also showed that the wtp53 gene was successfully transfected into solid tumours in the plasmid with microbubbles and ultrasound group. This study provides preliminary evidence in support of a potential new approach to RB gene therapy.

  8. Tissue types (image)

    MedlinePlus

    There are 4 basic types of tissue: connective tissue, epithelial tissue, muscle tissue, and nervous tissue. Connective tissue supports other tissues and binds them together (bone, blood, and lymph tissues). Epithelial tissue ...

  9. Stimulation of Tissue Healing by Ultrasound: Physical Mechanisms of Action

    NASA Astrophysics Data System (ADS)

    Rodríguez, O.; Chong, J.; Monreal, R.

    2004-09-01

    Even though the use of ultrasound in medicine is better known by its results in diagnostic procedures, the employ of this type of mechanical energy with therapeutic purposes is been used in new and impressive applications. To obtain or to improve tissue healing in many ailments it is used a lot of approaches, from the employ of antibiotics when it is considered by the presence of an infection in the wound, to several types of physical stimulation. One of them is ultrasound. This paper consider some of the most important mechanisms of action of ultrasound in tissue that can be related whit the repair processes and specifies levels of activation of many paths of action. Especial emphasis has received the stimulation of bone repair by ultrasound.

  10. 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.

  11. Effects of ultrasound and ultrasound contrast agent on vascular tissue

    PubMed Central

    2012-01-01

    Background Ultrasound (US) imaging can be enhanced using gas-filled microbubble contrast agents. Strong echo signals are induced at the tissue-gas interface following microbubble collapse. Applications include assessment of ventricular function and virtual histology. Aim While ultrasound and US contrast agents are widely used, their impact on the physiological response of vascular tissue to vasoactive agents has not been investigated in detail. Methods and results In the present study, rat dorsal aortas were treated with US via a clinical imaging transducer in the presence or absence of the US contrast agent, Optison. Aortas treated with both US and Optison were unable to contract in response to phenylephrine or to relax in the presence of acetylcholine. Histology of the arteries was unremarkable. When the treated aortas were stained for endothelial markers, a distinct loss of endothelium was observed. Importantly, terminal deoxynucleotidyl transferase mediated dUTP nick-end-labeling (TUNEL) staining of treated aortas demonstrated incipient apoptosis in the endothelium. Conclusions Taken together, these ex vivo results suggest that the combination of US and Optison may alter arterial integrity and promote vascular injury; however, the in vivo interaction of Optison and ultrasound remains an open question. PMID:22805356

  12. 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

  13. Tissue harmonic synthetic aperture ultrasound imaging.

    PubMed

    Hemmsen, Martin Christian; Rasmussen, Joachim Hee; Jensen, Jørgen Arendt

    2014-10-01

    Synthetic aperture sequential beamforming (SASB) and tissue harmonic imaging (THI) are combined to improve the image quality of medical ultrasound imaging. The technique is evaluated in a comparative study against dynamic receive focusing (DRF). The objective is to investigate if SASB combined with THI improves the image quality compared to DRF-THI. The major benefit of SASB is a reduced bandwidth between the probe and processing unit. A BK Medical 2202 Ultraview ultrasound scanner was used to acquire beamformed RF data for offline evaluation. The acquisition was made interleaved between methods, and data were recorded with and without pulse inversion for tissue harmonic imaging. Data were acquired using a Sound Technology 192 element convex array transducer from both a wire phantom and a tissue mimicking phantom to investigate spatial resolution and penetration. In vivo scans were also performed for a visual comparison. The spatial resolution for SASB-THI is on average 19% better than DRI-THI, and the investigation of penetration showed equally good signal-to-noise ratio. In vivo B-mode scans were made and compared. The comparison showed that SASB-THI reduces the artifact and noise interference and improves image contrast and spatial resolution.

  14. Ovarian tissue characterization in ultrasound: a review.

    PubMed

    Acharya, U Rajendra; Molinari, Filippo; Sree, S Vinitha; Swapna, G; Saba, Luca; Guerriero, Stefano; Suri, Jasjit S

    2015-06-01

    Ovarian cancer is the most common cause of death among gynecological malignancies. We discuss different types of clinical and nonclinical features that are used to study and analyze the differences between benign and malignant ovarian tumors. Computer-aided diagnostic (CAD) systems of high accuracy are being developed as an initial test for ovarian tumor classification instead of biopsy, which is the current gold standard diagnostic test. We also discuss different aspects of developing a reliable CAD system for the automated classification of ovarian cancer into benign and malignant types. A brief description of the commonly used classifiers in ultrasound-based CAD systems is also given.

  15. Ovarian tissue characterization in ultrasound: a review.

    PubMed

    Acharya, U Rajendra; Molinari, Filippo; Sree, S Vinitha; Swapna, G; Saba, Luca; Guerriero, Stefano; Suri, Jasjit S

    2015-06-01

    Ovarian cancer is the most common cause of death among gynecological malignancies. We discuss different types of clinical and nonclinical features that are used to study and analyze the differences between benign and malignant ovarian tumors. Computer-aided diagnostic (CAD) systems of high accuracy are being developed as an initial test for ovarian tumor classification instead of biopsy, which is the current gold standard diagnostic test. We also discuss different aspects of developing a reliable CAD system for the automated classification of ovarian cancer into benign and malignant types. A brief description of the commonly used classifiers in ultrasound-based CAD systems is also given. PMID:25230716

  16. Ultrasound

    MedlinePlus

    Ultrasound is a type of imaging. It uses high-frequency sound waves to look at organs and ... liver, and other organs. During pregnancy, doctors use ultrasound to view the fetus. Unlike x-rays, ultrasound ...

  17. Guiding tissue regeneration with ultrasound in vitro and in vivo

    NASA Astrophysics Data System (ADS)

    Dalecki, Diane; Comeau, Eric S.; Raeman, Carol H.; Child, Sally Z.; Hobbs, Laura; Hocking, Denise C.

    2015-05-01

    Developing new technologies that enable the repair or replacement of injured or diseased tissues is a major focus of regenerative medicine. This paper will discuss three ultrasound technologies under development in our laboratories to guide tissue regeneration both in vitro and in vivo. A critical obstacle in tissue engineering is the need for rapid and effective tissue vascularization strategies. To address this challenge, we are developing acoustic patterning techniques for microvascular tissue engineering. Acoustic radiation forces associated with ultrasound standing wave fields provide a rapid, non-invasive approach to spatially pattern cells in three dimensions without affecting cell viability. Acoustic patterning of endothelial cells leads to the rapid formation of microvascular networks throughout the volumes of three-dimensional hydrogels, and the morphology of the resultant microvessel networks can be controlled by design of the ultrasound field. A second technology under development uses ultrasound to noninvasively control the microstructure of collagen fibers within engineered tissues. The microstructure of extracellular matrix proteins provides signals that direct cell functions critical to tissue regeneration. Thus, controlling collagen microfiber structure with ultrasound provides a noninvasive approach to regulate the mechanical properties of biomaterials and control cellular responses. The third technology employs therapeutic ultrasound to enhance the healing of chronic wounds. Recent studies demonstrate increased granulation tissue thickness and collagen deposition in murine dermal wounds exposed to pulsed ultrasound. In summary, ultrasound technologies offer noninvasive approaches to control cell behaviors and extracellular matrix organization and thus hold great promise to advance tissue regeneration in vitro and in vivo.

  18. 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.

  19. Computer-aided tissue characterization using ultrasound-induced thermal effects: analytical formulation and in-vitro animal study

    NASA Astrophysics Data System (ADS)

    Daoud, Mohammad I.; Mousavi, Parvin; Imani, Farhad; Rohling, Robert; Abolmaesumi, Purang

    2011-03-01

    Ultrasound radio-frequency (RF) time series analysis provides an effective tissue characterization method to differentiate between healthy and cancerous prostate tissues. In this paper, an analytical model is presented that partially describes the variations in tissue acoustic properties that accompany ultrasound RF time series acquisition procedures. These ultrasound-induced effects, which depend on tissue mechanical and thermophysical properties, are hypothesized to be among the major contributors to the tissue typing capabilities of the RF time series analysis. The model is used to derive two tissue characterization features. The two features are used with a support vector machine classifier to characterize three animal tissue types: chicken breast, bovine liver, and bovine steak. Accuracy values as high as 90% are achieved when the proposed features are employed to differentiate these tissue types. The proposed model may provide a framework to optimize the ultrasound RF time series analysis for future clinical procedures.

  20. Multimodal classification of prostate tissue: a feasibility study on combining multiparametric MRI and ultrasound

    NASA Astrophysics Data System (ADS)

    Ashab, Hussam Al-Deen; Haq, Nandinee Fariah; Nir, Guy; Kozlowski, Piotr; Black, Peter; Jones, Edward C.; Goldenberg, S. Larry; Salcudean, Septimiu E.; Moradi, Mehdi

    2015-03-01

    The common practice for biopsy guidance is through transrectal ultrasound, with the fusion of ultrasound and MRI-based targets when available. However, ultrasound is only used as a guidance modality in MR-targeted ultrasound-guided biopsy, even though previous work has shown the potential utility of ultrasound, particularly ultrasound vibro-elastography, as a tissue typing approach. We argue that multiparametric ultrasound, which includes B-mode and vibro-elastography images, could contain information that is not captured using multiparametric MRI (mpMRI) and therefore play a role in refining the biopsy and treatment strategies. In this work, we combine mpMRI with multiparametric ultrasound features from registered tissue areas to examine the potential improvement in cancer detection. All the images were acquired prior to radical prostatectomy and cancer detection was validated based on 36 whole mount histology slides. We calculated a set of 24 texture features from vibro-elastography and B-mode images, and five features from mpMRI. Then we used recursive feature elimination (RFE) and sparse regression through LASSO to find an optimal set of features to be used for tissue classification. We show that the set of these selected features increases the area under ROC curve from 0.87 with mpMRI alone to 0.94 with the selected mpMRI and multiparametric ultrasound features, when used with support vector machine classification on features extracted from peripheral zone. For features extracted from the whole-gland, the area under the curve was 0.75 and 0.82 for mpMRI and mpMRI along with ultrasound, respectively. These preliminary results provide evidence that ultrasound and ultrasound vibro-elastography could be used as modalities for improved cancer detection in combination with MRI.

  1. 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.

  2. Tissue Bioeffects during Ultrasound-mediated Drug Delivery

    NASA Astrophysics Data System (ADS)

    Sutton, Jonathan

    Ultrasound has been developed as both a valuable diagnostic tool and a potent promoter of beneficial tissue bioeffects for the treatment of cardiovascular disease. Vascular effects can be mediated by mechanical oscillations of circulating microbubbles, or ultrasound contrast agents, which may also encapsulate and shield a therapeutic agent in the bloodstream. Oscillating microbubbles can create stresses directly on nearby tissue or induce fluid effects that effect drug penetration into vascular tissue, lyse thrombi, or direct drugs to optimal locations for delivery. These investigations have spurred continued research into alternative therapeutic applications, such as bioactive gas delivery. This dissertation addresses a fundamental hypothesis in biomedical ultrasound: ultrasound-mediated drug delivery is capable of increasing the penetration of drugs across different physiologic barriers within the cardiovascular system, such as the vascular endothelium, blood clots, and smooth muscle cells.

  3. Therapeutic ultrasound applications in craniofacial growth, healing and tissue engineering.

    PubMed

    El-Bialy, Tarek

    2007-09-01

    Previous reports have shown that therapeutic ultrasound enhances healing of fractured bone as well as cut tendons. Moreover, it has been shown that therapeutic ultrasound enhances bone formation during distraction osteogenesis that is also known as Ilizarove technique. It has been recently reported that therapeutic ultrasound enhances tooth formation and eruption during mandible distraction osteogenesis in rabbits. This enhanced tooth formation and eruption was caused by new dental tissue formation, known as dentin and cementum. This led to a clinical trial in human that showed that therapeutic ultrasound can enhance repairing tooth root resorption caused by orthodontic treatment. This discovery can lead to many applications of ultrasound in the dental as well as in the craniofacial reconstructions. This paper provides an overview of the molecular basis of the achieved clinical results. Moreover, potential future application will be elaborated.

  4. Potential for tissue characterization of plaque and arterial wall using intravascular ultrasound

    NASA Astrophysics Data System (ADS)

    Sudhir, Krishnakutty; Fitzgerald, Peter J.; Yock, Paul G.

    1993-09-01

    Current intravascular ultrasound imaging technology is able to determine the extent and distribution of pathologic processes within the vessel wall, but is not highly sensitive in discriminating between different types of pathologic tissue. `Tissue characterization' refers to a set of computer-based techniques that utilize features of the ultrasound signal beyond basic amplitude to help define the structure of the tissue of interest. Although preliminary results with this approach are encouraging, additional work is needed to define its clinical application in vascular disease.

  5. 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.

  6. 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

  7. 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.

  8. Effects of an implant on temperature distribution in tissue during ultrasound diathermy.

    PubMed

    Sun, Ming-Kuan; Shieh, Jay; Chen, Chuin-Shan; Chiang, Hongsen; Huang, Chang-Wei; Chen, Wen-Shiang

    2016-09-01

    The effects of an implant on temperature distribution in a tissue-mimicking hydrogel phantom during the application of therapeutic ultrasound were investigated. In vitro experiments were conducted to compare the influences of plastic and metal implants on ultrasound diathermy and to calibrate parameters in finite element simulation models. The temperature histories and characteristics of the opaque (denatured) areas in the hydrogel phantoms predicted by the numerical simulations show good correlation with those observed in the in vitro experiments. This study provides an insight into the temperature profile in the vicinity of an implant by therapeutic ultrasound heating typically used for physiotherapy. A parametric study was conducted through numerical simulations to investigate the effects of several factors, such as implant material type, ultrasound operation frequency, implant thickness and tissue thickness on the temperature distribution in the hydrogel phantom. The results indicate that the implant material type and implant thickness are the main parameters influencing the temperature distribution. In addition, once the implant material and ultrasound operation frequency are chosen, an optimal implant thickness can be obtained so as to avoid overheating injuries in tissue. PMID:27150744

  9. Estimation of Nonlinear Elasticity Parameter of Tissues by Ultrasound

    NASA Astrophysics Data System (ADS)

    Nitta, Naotaka; Shiina, Tsuyoshi

    2002-05-01

    In this paper, a new parameter that quantifies the intensity of tissue nonlinear elasticity is introduced as the nonlinear elasticity parameter. This parameter is defined based on the empirical information that the nonlinear elastic behavior of soft tissues exhibits an exponential character. To visualize the quantitative nonlinear elasticity parameter, an ultrasonic imaging procedure involving the three-dimensional finite element method (3-D FEM) is presented. Experimental investigations that visualize the nonlinear elasticity parameter distribution of a chicken gizzard and a pig kidney embedded in a gelatin-based phantom were performed. The values extracted by ultrasound and 3-D FEM were compared with those measured by the direct mechanical compression test. Experimental results revealed that the nonlinear elasticity parameter values extracted by ultrasound and 3-D FEM exhibited good agreement with those measured by the mechanical compression test, and that the intensity of tissue nonlinear elasticity could be visualized quantitatively by the defined nonlinear elasticity parameter.

  10. [Ultrasound tissue emulsification of brain tumors].

    PubMed

    Tertsch, D; Bönicke, R; Brinke, G; Kazmirzak, W; Senitz, D

    1986-01-01

    A report is given on the design of an equipment combination developed in co-operation with the Central Institute for Welding Technology of the GDR, by means of which cerebral tumour tissue can be emulsified and sucked off. The suitability of the equipment was tested experimentally and confirmed in clinical application.

  11. Ultrasound physiotherapy treatment and calibration measurements in simulated tissue.

    PubMed

    Bydder, E L; Grant, S M

    1989-03-01

    The absorption, heating and relative intensities of ultrasonic beams used for physiotherapy are studied in water and in simulated tissue as a function of position in relation to the transducer head. It is found that the heating effects are significantly different from the beam profile shape. The effective area and depth of ultrasonic physiotherapy treatment is established for various situations, and tissue temperature rise curves are obtained. The results are appropriate for treatment planning. As an example, the typical volume of tissue effectively treated by ultrasound is a cylinder 6 to 8 cm in diameter and 1 cm deep.

  12. Use of stationary focused ultrasound fields for characterization of tissue and localized tissue ablation

    NASA Astrophysics Data System (ADS)

    Winey, Brian Andrew

    Ultrasound-induced blood stasis has been observed for more than 30 years. The physical understanding of the phenomenon has not been fully explored. Analytical descriptions of the acoustic interaction with spheres in suspension have been derived but the physical implications and limitations have not been demonstrated. The analytical expressions will be tested against physical observations using numerical simulations. The simulations will begin with stationary spheres and continue with the inclusion of moving spheres and a moving suspending fluid. To date, experimental observations of acoustically induced blood stasis have been either in vitro or invasive. We demonstrate ultrasound-induced blood stasis in murine normal leg muscle versus tumor-bearing legs, observed through noninvasive measurements of optical spectroscopy, and discuss possible diagnostic uses for this effect of ultrasound. We derive the optimal optical wavelengths for measuring the effects of the ultrasound at small source detector separations. Using optical oximetry performed at the optimal wavelengths, we demonstrate that effects of ultrasound can be used to differentiate tumor from normal leg muscle tissue in mice. To provide a statistical analysis of the experiments, we propose a novel diagnostic algorithm that quantitatively differentiates tumor from nontumor with maximum specificity 0.83, maximum sensitivity 0.79, and area under receiver-operating-characteristics curve 0.90. Ultrasound has long been known to cause tissue heating when applied in high intensities. More recently, interest has arisen in the area of High Intensity Focused Ultrasound (HIFU) for localized tissue heating effects, specifically thermal ablation. All present techniques employ focused traveling high intensity acoustic waves to create a region of elevated temperature. Such high intensity traveling waves can be damaging to normal tissue in the vicinity of the focal region, and have demonstrated surface burns and caused

  13. Nakagami imaging for detecting thermal lesions induced by high-intensity focused ultrasound in tissue.

    PubMed

    Rangraz, Parisa; Behnam, Hamid; Tavakkoli, Jahan

    2014-01-01

    High-intensity focused ultrasound induces focalized tissue coagulation by increasing the tissue temperature in a tight focal region. Several methods have been proposed to monitor high-intensity focused ultrasound-induced thermal lesions. Currently, ultrasound imaging techniques that are clinically used for monitoring high-intensity focused ultrasound treatment are standard pulse-echo B-mode ultrasound imaging, ultrasound temperature estimation, and elastography-based methods. On the contrary, the efficacy of two-dimensional Nakagami parametric imaging based on the distribution of the ultrasound backscattered signals to quantify properties of soft tissue has recently been evaluated. In this study, ultrasound radio frequency echo signals from ex vivo tissue samples were acquired before and after high-intensity focused ultrasound exposures and then their Nakagami parameter and scaling parameter of Nakagami distribution were estimated. These parameters were used to detect high-intensity focused ultrasound-induced thermal lesions. Also, the effects of changing the acoustic power of the high-intensity focused ultrasound transducer on the Nakagami parameters were studied. The results obtained suggest that the Nakagami distribution's scaling and Nakagami parameters can effectively be used to detect high-intensity focused ultrasound-induced thermal lesions in tissue ex vivo. These parameters can also be used to understand the degree of change in tissue caused by high-intensity focused ultrasound exposures, which could be interpreted as a measure of degree of variability in scatterer concentration in various parts of the high-intensity focused ultrasound lesion. PMID:24264647

  14. Ultrasound therapy applicators for controlled thermal modification of tissue

    NASA Astrophysics Data System (ADS)

    Burdette, E. Clif; Lichtenstiger, Carol; Rund, Laurie; Keralapura, Mallika; Gossett, Chad; Stahlhut, Randy; Neubauer, Paul; Komadina, Bruce; Williams, Emery; Alix, Chris; Jensen, Tor; Schook, Lawrence; Diederich, Chris J.

    2011-03-01

    Heat therapy has long been used for treatments in dermatology and sports medicine. The use of laser, RF, microwave, and more recently, ultrasound treatment, for psoriasis, collagen reformation, and skin tightening has gained considerable interest over the past several years. Numerous studies and commercial devices have demonstrated the efficacy of these methods for treatment of skin disorders. Despite these promising results, current systems remain highly dependent on operator skill, and cannot effectively treat effectively because there is little or no control of the size, shape, and depth of the target zone. These limitations make it extremely difficult to obtain consistent treatment results. The purpose of this study was to determine the feasibility for using acoustic energy for controlled dose delivery sufficient to produce collagen modification for the treatment of skin tissue in the dermal and sub-dermal layers. We designed and evaluated a curvilinear focused ultrasound device for treating skin disorders such as psoriasis, stimulation of wound healing, tightening of skin through shrinkage of existing collagen and stimulation of new collagen formation, and skin cancer. Design parameters were examined using acoustic pattern simulations and thermal modeling. Acute studies were performed in 201 freshly-excised samples of young porcine underbelly skin tissue and 56 in-vivo treatment areas in 60- 80 kg pigs. These were treated with ultrasound (9-11MHz) focused in the deep dermis. Dose distribution was analyzed and gross pathology assessed. Tissue shrinkage was measured based on fiducial markers and video image registration and analyzed using NIH Image-J software. Comparisons were made between RF and focused ultrasound for five energy ranges. In each experimental series, therapeutic dose levels (60degC) were attained at 2-5mm depth. Localized collagen changes ranged from 1-3% for RF versus 8-15% for focused ultrasound. Therapeutic ultrasound applied at high

  15. Can ultrasound be used to stimulate nerve tissue?

    PubMed Central

    Norton, Stephen J

    2003-01-01

    Background The stimulation of nerve or cortical tissue by magnetic induction is a relatively new tool for the non-invasive study of the brain and nervous system. Transcranial magnetic stimulation (TMS), for example, has been used for the functional mapping of the motor cortex and may have potential for treating a variety of brain disorders. Methods and Results A new method of stimulating active tissue is proposed by propagating ultrasound in the presence of a magnetic field. Since tissue is conductive, particle motion created by an ultrasonic wave will induce an electric current density generated by Lorentz forces. An analytical derivation is given for the electric field distribution induced by a collimated ultrasonic beam. An example shows that peak electric fields of up to 8 V/m appear to be achievable at the upper range of diagnostic intensities. This field strength is about an order of magnitude lower than fields typically associated with TMS; however, the electric field gradients induced by ultrasound can be quite high (about 60 kV/m2 at 4 MHz), which theoretically play a more important role in activation than the field magnitude. The latter value is comparable to TMS-induced gradients. Conclusion The proposed method could be used to locally stimulate active tissue by inducing an electric field in regions where the ultrasound is focused. Potential advantages of this method compared to TMS is that stimulation of cortical tissue could be highly localized as well as achieved at greater depths in the brain than is currently possible with TMS. PMID:12702213

  16. Ultrasound of soft tissue masses of the hand

    PubMed Central

    2012-01-01

    Most soft tissue mass lesions of the hand are benign. Ganglia are the commonest lesions encountered, followed by giant cell tumors of the tendon sheath. Malignant tumors are rare. Often a specific diagnosis can be achieved on imaging by considering the location and anatomical relations of the lesion within the hand or wrist, and assessing its morphology. Magnetic resonance imaging is an excellent modality for evaluating soft tissue tumors with its multiplanar capability and ability to characterize tissue. Ultrasound plays a complementary role to MRI. It is often the initial modality used for assessing masses as it is cheap and available, and allows reliable differentiation of cystic from solid lesions, along with a real time assessment of vascularity. This review describes the US appearances of the most frequently encountered soft tissue masses of the wrist and hand, correlating the findings with MRI where appropriate. PMID:26673615

  17. Characterizing tissue with acoustic parameters derived from ultrasound data

    NASA Astrophysics Data System (ADS)

    Littrup, Peter J.; Duric, Nebojsa; Leach, Richard, Jr.; Azevedo, Steve G.; Candy, James V.; Moore, Thomas; Chambers, David H.; Mast, Jeffrey E.; Holsapple, Earle

    2002-04-01

    In contrast to standard reflection ultrasound (US), transmission US holds the promise of more thorough tissue characterization by generating quantitative acoustic parameters. We compare results from a conventional US scanner with data acquired using an experimental circular scanner operating at frequencies of 0.3 - 1.5 MHz. Data were obtained on phantoms and a normal, formalin-fixed, excised breast. Both reflection and transmission-based algorithms were used to generate images of reflectivity, sound speed and attenuation.. Images of the phantoms demonstrate the ability to detect sub-mm features and quantify acoustic properties such as sound speed and attenuation. The human breast specimen showed full field evaluation, improved penetration and tissue definition. Comparison with conventional US indicates the potential for better margin definition and acoustic characterization of masses, particularly in the complex scattering environments of human breast tissue. The use of morphology, in the context of reflectivity, sound speed and attenuation, for characterizing tissue, is discussed.

  18. Characterizing Tissue with Acoustic Parameters Derived from Ultrasound Data

    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

    In contrast to standard reflection ultrasound (US), transmission US holds the promise of more thorough tissue characterization by generating quantitative acoustic parameters. We compare results from a conventional US scanner with data acquired using an experimental circular scanner operating at frequencies of 0.3 - 1.5 MHz. Data were obtained on phantoms and a normal, formalin-fixed, excised breast. Both reflection and transmission-based algorithms were used to generate images of reflectivity, sound speed and attenuation.. Images of the phantoms demonstrate the ability to detect sub-mm features and quantify acoustic properties such as sound speed and attenuation. The human breast specimen showed full field evaluation, improved penetration and tissue definition. Comparison with conventional US indicates the potential for better margin definition and acoustic characterization of masses, particularly in the complex scattering environments of human breast tissue. The use of morphology, in the context of reflectivity, sound speed and attenuation, for characterizing tissue, is discussed.

  19. Diffraction tomography applied to simulated ultrasound through breast tissue

    NASA Astrophysics Data System (ADS)

    Chambers, David H.

    2002-11-01

    Diffraction tomography is used to obtain images of sound speed and attenuation of a slice of breast tissue obtained from the Visible Woman data set. Simulated ultrasound data was generated using an acoustic propagation code run on the ASCI Blue Pacific computer at Lawrence Livermore National Laboratory. Data was generated for a slice of healthy tissue, and a slice with simulated lesions to determine the ability of the imaging method to detect various abnormalities in the breast. In addition, the time reversal operator for the slice was constructed from the data and the eigenfunctions backpropagated into the slice as first suggested by Mast [Mast, Nachman, and Waag, J. Acoust. Soc. Am. 102(2)] to identify structures associated with each time reversal mode for both the healthy tissue and tissue with lesions.

  20. Types of muscle tissue (image)

    MedlinePlus

    The 3 types of muscle tissue are cardiac, smooth, and skeletal. Cardiac muscle cells are located in ... heart, appear striated, and are under involuntary control. Smooth muscle fibers are located in walls of hollow ...

  1. Measurement of Mechanical Properties of Soft Tissue with Ultrasound Vibrometry

    NASA Astrophysics Data System (ADS)

    Nenadich, I.; Bernal, M.; Greenleaf, J. F.

    The cardiovascular diseases atherosclerosis, coronary artery disease, hypertension and heart failure have been related to stiffening of vessels and myocardium. Noninvasive measurements of mechanical properties of cardiovascular tissue would facilitate detection and treatment of disease in early stages, thus reducing mortality and possibly reducing cost of treatment. While techniques capable of measuring tissue elasticity have been reported, the knowledge of both elasticity and viscosity is necessary to fully characterize mechanical properties of soft tissues. In this article, we summarize the Shearwave Dispersion Ultrasound Vibrometry (SDUV) method developed by our group and report on advances made in characterizing stiffness of large vessels and myocardium. The method uses radiation forceFadiation force to excite shear waves in soft tissue and pulse echo ultrasound to measure the motion. The speed of propagation of shear waves at different frequencies is used to generate dispersions curves for excised porcine left-ventricular free-wall myocardium and carotid arteries. An antisymmetric Lamb wave model was fitted to the LV myocardium dispersion curves to obtain elasticity and viscosity moduli. The results suggest that the speed of shear wave propagation in four orthogonal directions on the surface of the excised myocardium is similar. These studies show that the SDUV method has potential for clinical application in noninvasive quantification of elasticity and viscosity of vessels and myocardium.

  2. The disruption of tissue structure using high intensity pulsed ultrasound

    NASA Astrophysics Data System (ADS)

    Fowlkes, J. Brian; Parsons, Jessica E.; Xu, Zhen; Cooper, Michol; Tran, Binh C.; Hall, Timothy L.; Roberts, William W.; Cain, Charles A.

    2005-04-01

    Recent investigations of pulsed ultrasound at high acoustic intensities have revealed a regime in which significant breakdown of tissue structure can be achieved. This therapeutic modality, which might be termed histotripsy, is dependent on the presence of highly active cavitation evidenced by significant temporal fluctuations in acoustic backscatter. In the presence of tissue interfaces, erosion can result yielding, for example, well-defined perforations potentially useful in creating temporary shunts for the treatment of hypoplastic left heart syndrome. When applied in bulk tissue, the process results in a near emulsification with little structural integrity remaining or chance of cellular survival. In each case, the process is dependent on acoustic parameters of the field to not only produce damage for a given pulse but also to sustain the cavitation nuclei population for subsequent pulses. Fluctuations in acoustic backscatter indicate both initiation and extinction of the appropriate cavitation activity during application of therapeutic ultrasound, which leads to a potential feedback mechanism to minimize acoustic exposure. This presentation will discuss the observed tissue damage as affected by acoustic parameters and the ability to monitor the presence of cavitation activity expected to be responsible for these effects. [Work supported by NIH grants RO1 RR14450.

  3. 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.

  4. Low-intensity pulsed ultrasound in dentofacial tissue engineering.

    PubMed

    Tanaka, Eiji; Kuroda, Shingo; Horiuchi, Shinya; Tabata, Akira; El-Bialy, Tarek

    2015-04-01

    Oral and maxillofacial diseases affect millions of people worldwide and hence tissue engineering can be considered an interesting and clinically relevant approach to regenerate orofacial tissues after being affected by different diseases. Among several innovations for tissue regeneration, low-intensity pulsed ultrasound (LIPUS) has been used extensively in medicine as a therapeutic, operative, and diagnostic tool. LIPUS is accepted to promote bone fracture repair and regeneration. Furthermore, the effect of LIPUS on soft tissues regeneration has been paid much attention, and many studies have performed to evaluate the potential use of LIPUS to tissue engineering soft tissues. The present article provides an overview about the status of LIPUS stimulation as a tool to be used to enhance regeneration/tissue engineering. This review consists of five parts. Part 1 is a brief introduction of the acoustic description of LIPUS and mechanical action. In Part 2, biological problems in dentofacial tissue engineering are proposed. Part 3 explores biologic mechanisms of LIPUS to cells and tissues in living body. In Part 4, the effectiveness of LIPUS on cell metabolism and tissue regeneration in dentistry are summarized. Finally, Part 5 relates the possibility of clinical application of LIPUS in orthodontics. The present review brings out better understanding of the bioeffect of LIPUS therapy on orofacial tissues which is essential to the successful integration of management remedies for tissue regeneration/engineering. To develop an evidence-based approach to clinical management and treatment of orofacial degenerative diseases using LIPUS, we would like to be in full pursuit of LIPUS biotherapy. Still, there are many challenges for this relatively new strategy, but the up to date achievements using it promises to go far beyond the present possibilities.

  5. 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.

  6. 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.

  7. Dual-focus therapeutic ultrasound transducer for production of broad tissue lesions.

    PubMed

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

    2010-11-01

    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

  8. Characterization of various tissue mimicking materials for medical ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Thouvenot, Audrey; Poepping, Tamie; Peters, Terry M.; Chen, Elvis C. S.

    2016-04-01

    Tissue mimicking materials are physical constructs exhibiting certain desired properties, which are used in machine calibration, medical imaging research, surgical planning, training, and simulation. For medical ultrasound, those specific properties include acoustic propagation speed and attenuation coefficient over the diagnostic frequency range. We investigated the acoustic characteristics of polyvinyl chloride (PVC) plastisol, polydimethylsiloxane (PDMS), and isopropanol using a time-of-light technique, where a pulse was passed through a sample of known thickness contained in a water bath. The propagation speed in PVC is approximately 1400ms-1 depending on the exact chemical composition, with the attenuation coefficient ranging from 0:35 dB cm-1 at 1MHz to 10:57 dB cm-1 at 9 MHz. The propagation speed in PDMS is in the range of 1100ms-1, with an attenuation coefficient of 1:28 dB cm-1 at 1MHz to 21:22 dB cm-1 at 9 MHz. At room temperature (22 °C), a mixture of water-isopropanol (7:25% isopropanol by volume) exhibits a propagation speed of 1540ms-1, making it an excellent and inexpensive tissue-mimicking liquid for medical ultrasound imaging.

  9. 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.

  10. Medical ultrasound: imaging of soft tissue strain and elasticity

    PubMed Central

    Wells, Peter N. T.; Liang, Hai-Dong

    2011-01-01

    After X-radiography, ultrasound is now the most common of all the medical imaging technologies. For millennia, manual palpation has been used to assist in diagnosis, but it is subjective and restricted to larger and more superficial structures. Following an introduction to the subject of elasticity, the elasticity of biological soft tissues is discussed and published data are presented. The basic physical principles of pulse-echo and Doppler ultrasonic techniques are explained. The history of ultrasonic imaging of soft tissue strain and elasticity is summarized, together with a brief critique of previously published reviews. The relevant techniques—low-frequency vibration, step, freehand and physiological displacement, and radiation force (displacement, impulse, shear wave and acoustic emission)—are described. Tissue-mimicking materials are indispensible for the assessment of these techniques and their characteristics are reported. Emerging clinical applications in breast disease, cardiology, dermatology, gastroenterology, gynaecology, minimally invasive surgery, musculoskeletal studies, radiotherapy, tissue engineering, urology and vascular disease are critically discussed. It is concluded that ultrasonic imaging of soft tissue strain and elasticity is now sufficiently well developed to have clinical utility. The potential for further research is examined and it is anticipated that the technology will become a powerful mainstream investigative tool. PMID:21680780

  11. Medical ultrasound: imaging of soft tissue strain and elasticity.

    PubMed

    Wells, Peter N T; Liang, Hai-Dong

    2011-11-01

    After X-radiography, ultrasound is now the most common of all the medical imaging technologies. For millennia, manual palpation has been used to assist in diagnosis, but it is subjective and restricted to larger and more superficial structures. Following an introduction to the subject of elasticity, the elasticity of biological soft tissues is discussed and published data are presented. The basic physical principles of pulse-echo and Doppler ultrasonic techniques are explained. The history of ultrasonic imaging of soft tissue strain and elasticity is summarized, together with a brief critique of previously published reviews. The relevant techniques-low-frequency vibration, step, freehand and physiological displacement, and radiation force (displacement, impulse, shear wave and acoustic emission)-are described. Tissue-mimicking materials are indispensible for the assessment of these techniques and their characteristics are reported. Emerging clinical applications in breast disease, cardiology, dermatology, gastroenterology, gynaecology, minimally invasive surgery, musculoskeletal studies, radiotherapy, tissue engineering, urology and vascular disease are critically discussed. It is concluded that ultrasonic imaging of soft tissue strain and elasticity is now sufficiently well developed to have clinical utility. The potential for further research is examined and it is anticipated that the technology will become a powerful mainstream investigative tool.

  12. 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

  13. Nonlinear viscoelastic properties of tissue assessed by ultrasound.

    PubMed

    Sinkus, Ralph; Bercoff, Jeremy; Tanter, Mickaël; Gennisson, Jean-Luc; El-Khoury, Carl; Servois, Vincent; Tardivon, Anne; Fink, Mathias

    2006-11-01

    A technique to assess qualitatively the presence of higher-order viscoelastic parameters is presented. Low-frequency, monochromatic elastic waves are emitted into the material via an external vibrator. The resulting steady-state motion is detected in real time via an ultra fast ultrasound system using classical, one-dimensional (1-D) ultrasound speckle correlation for motion estimation. Total data acquisition lasts only for about 250 ms. The spectrum of the temporal displacement data at each image point is used for analysis. The presence of nonlinear effects is detected by inspection of the ratio of the second harmonics amplitude with respect to the total amplitude summed up to the second harmonic. Results from a polyacrylamide-based phantom indicate a linear response (i.e., the absence of higher harmonics) for this type of material at 65 Hz mechanical vibration frequency and about 100 microm amplitude. A lesion, artificially created by injection of glutaraldehyde into a beef specimen, shows the development of higher harmonics at the location of injection as a function of time. The presence of upper harmonics is clearly evident at the location of a malignant lesion within a mastectomy.

  14. Nonlinear viscoelastic properties of tissue assessed by ultrasound.

    PubMed

    Sinkus, Ralph; Bercoff, Jeremy; Tanter, Mickaël; Gennisson, Jean-Luc; El-Khoury, Carl; Servois, Vincent; Tardivon, Anne; Fink, Mathias

    2006-11-01

    A technique to assess qualitatively the presence of higher-order viscoelastic parameters is presented. Low-frequency, monochromatic elastic waves are emitted into the material via an external vibrator. The resulting steady-state motion is detected in real time via an ultra fast ultrasound system using classical, one-dimensional (1-D) ultrasound speckle correlation for motion estimation. Total data acquisition lasts only for about 250 ms. The spectrum of the temporal displacement data at each image point is used for analysis. The presence of nonlinear effects is detected by inspection of the ratio of the second harmonics amplitude with respect to the total amplitude summed up to the second harmonic. Results from a polyacrylamide-based phantom indicate a linear response (i.e., the absence of higher harmonics) for this type of material at 65 Hz mechanical vibration frequency and about 100 microm amplitude. A lesion, artificially created by injection of glutaraldehyde into a beef specimen, shows the development of higher harmonics at the location of injection as a function of time. The presence of upper harmonics is clearly evident at the location of a malignant lesion within a mastectomy. PMID:17091837

  15. 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

  16. 3D ultrasound to stereoscopic camera registration through an air-tissue boundary.

    PubMed

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

    2010-01-01

    A novel registration method between 3D ultrasound and stereoscopic cameras is proposed based on tracking a registration tool featuring both ultrasound fiducials and optical markers. The registration tool is pressed against an air-tissue boundary where it can be seen both in ultrasound and in the camera view. By localizing the fiducials in the ultrasound volume, knowing the registration tool geometry, and tracking the tool with the cameras, a registration is found. This method eliminates the need for external tracking, requires minimal setup, and may be suitable for a range of minimally invasive surgeries. A study of the appearance of ultrasound fiducials on an air-tissue boundary is presented, and an initial assessment of the ability to localize the fiducials in ultrasound with sub-millimeter accuracy is provided. The overall accuracy of registration (1.69 +/- 0.60 mm) is a noticeable improvement over other reported methods and warrants patient studies.

  17. AUGMENTATION OF LIMB PERFUSION AND REVERSAL OF TISSUE ISCHEMIA PRODUCED BY ULTRASOUND-MEDIATED MICROBUBBLE CAVITATION

    PubMed Central

    Belcik, J. Todd; Mott, Brian H.; Xie, Aris; Zhao, Yan; Kim, Sajeevani; Lindner, Nathan J.; Ammi, Azzdine; Linden, Joel M.; Lindner, Jonathan R.

    2015-01-01

    Background Ultrasound can increase tissue blood flow in part through the intravascular shear produced by oscillatory pressure fluctuations. We hypothesized that ultrasound-mediated increases in perfusion can be augmented by microbubble contrast agents that undergo ultrasound-mediated cavitation, and sought to characterize the biologic mediators. Methods and Results Contrast ultrasound perfusion imaging of hindlimb skeletal muscle and femoral artery diameter measurement were performed in non-ischemic mice after unilateral 10 min exposure to intermittent ultrasound alone (mechanical index [MI] 0.6 or 1.3) or ultrasound with lipid microbubbles (2×108 I.V.). Studies were also performed after inhibiting shear- or pressure-dependent vasodilator pathways, and in mice with hindlimb ischemia. Ultrasound alone produced a 2-fold increase (p<0.05) in muscle perfusion regardless of ultrasound power. Ultrasound-mediated augmentation in flow was greater with microbubbles (3-fold and 10-fold higher than control for MI 0.6 and 1.3, respectively; p<0.05), as was femoral artery dilation. Inhibition of endothelial nitric oxide synthase (eNOS) attenuated flow augmentation produced by ultrasound and microbubbles by 70% (p<0.01), whereas inhibition of adenosine-A2a receptors and epoxyeicosatrienoic acids had minimal effect. Limb nitric oxide (NO) production and muscle phospho-eNOS increased in a stepwise fashion by ultrasound and ultrasound with microbubbles. In mice with unilateral hindlimb ischemia (40–50% reduction in flow), ultrasound (MI 1.3) with microbubbles increased perfusion by 2-fold to a degree that was greater than the control non-ischemic limb. Conclusions Increases in muscle blood flow during high-power ultrasound are markedly amplified by the intravascular presence of microbubbles and can reverse tissue ischemia. These effects are most likely mediated by cavitation-related increases in shear and activation of eNOS. PMID:25834183

  18. Heating in vascular tissue and flow-through tissue phantoms induced by focused ultrasound

    NASA Astrophysics Data System (ADS)

    Huang, Jinlan

    High intensity focused ultrasound (HIFU) can be used to control bleeding, both from individual blood vessels as well as from gross damage to the capillary bed. This process, called acoustic hemostasis, is being studied in the hope that such a method would ultimately provide a lifesaving treatment during the so-called "golden hour", a brief grace period after a severe trauma in which prompt therapy can save the life of an injured person. Thermal effects play a major role in occlusion of small vessels and also appear to contribute to the sealing of punctures in major blood vessels. However, aggressive ultrasound-induced tissue heating can also impact healthy tissue and can lead to deleterious mechanical bioeffects. Moreover, the presence of vascularity can limit one's ability to elevate the temperature of blood vessel walls owing to convective heat transport. In an effort to better understand the heating process in tissues with vascular structure we have developed a numerical simulation that couples models for ultrasound propagation, acoustic streaming, ultrasound heating and blood cooling in Newtonian viscous media. The 3-D simulation allows for the study of complicated biological structures and insonation geometries. We have also undertaken a series of in vitro experiments, in non-uniform flow-through tissue phantoms, designed to provide a ground truth verification of the model predictions. The calculated and measured results were compared over a range of values for insonation pressure, insonation time, and flow rate; we show good agreement between predictions and measurements. We then conducted a series of simulations that address two limiting problems of interest: hemostasis in small and large vessels. We employed realistic human tissue properties and considered more complex geometries. Results show that the heating pattern in and around a blood vessel is different for different vessel sizes, flow rates and for varying beam orientations relative to the flow axis

  19. 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

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

    PubMed Central

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

    2015-01-01

    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

  1. Ultrasound Imaging Techniques for Spatiotemporal Characterization of Composition, Microstructure, and Mechanical Properties in Tissue Engineering.

    PubMed

    Deng, Cheri X; Hong, Xiaowei; Stegemann, Jan P

    2016-08-01

    Ultrasound techniques are increasingly being used to quantitatively characterize both native and engineered tissues. This review provides an overview and selected examples of the main techniques used in these applications. Grayscale imaging has been used to characterize extracellular matrix deposition, and quantitative ultrasound imaging based on the integrated backscatter coefficient has been applied to estimating cell concentrations and matrix morphology in tissue engineering. Spectral analysis has been employed to characterize the concentration and spatial distribution of mineral particles in a construct, as well as to monitor mineral deposition by cells over time. Ultrasound techniques have also been used to measure the mechanical properties of native and engineered tissues. Conventional ultrasound elasticity imaging and acoustic radiation force imaging have been applied to detect regions of altered stiffness within tissues. Sonorheometry and monitoring of steady-state excitation and recovery have been used to characterize viscoelastic properties of tissue using a single transducer to both deform and image the sample. Dual-mode ultrasound elastography uses separate ultrasound transducers to produce a more potent deformation force to microscale characterization of viscoelasticity of hydrogel constructs. These ultrasound-based techniques have high potential to impact the field of tissue engineering as they are further developed and their range of applications expands.

  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. Interaction of ultrasound with vortices in type-II superconductors

    SciTech Connect

    Sonin, E.B.

    1996-04-01

    The theory of ultrasound in the mixed state of type-II superconductors is suggested which takes into account the Magnus force on vortices, the anti-Magnus force on ions, and diamagnetism of the mixed state. The acoustic Faraday effect (rotation of polarization of the transverse ultrasonic wave propagating along vortices) is linear in the Magnus force in any regime of the flux flow for wavelengths now used in the ultrasound experiments. Therefore, in contrast to previous predictions, the Faraday effect should be looked for only in clean superconductors with a strong Magnus force. {copyright} {ital 1996 The American Physical Society.}

  4. Novel Applications of Ultrasound Technology to Visualize and Characterize Myofascial Trigger Points and Surrounding Soft Tissue

    PubMed Central

    Sikdar, Siddhartha; Shah, Jay P.; Gebreab, Tadesse; Yen, Ru-Huey; Gilliams, Elizabeth; Danoff, Jerome; Gerber, Lynn H.

    2009-01-01

    Objective Apply ultrasound (US) imaging techniques to better describe the characteristics of myofascial trigger points (MTrPs) and the immediately adjacent soft tissue. Design Descriptive (exploratory) study. Setting Biomedical research center. Participants 9 subjects meeting Travell and Simons’s criteria for MTrPs in a taut band in the upper trapezius. Interventions (None) Main Outcome Measures MTrPs were evaluated by 1) physical examination, 2) pressure algometry, and 3) three types of ultrasound imaging including grayscale (2D US), vibration sonoelastography (VSE), and Doppler. Methods Four sites in each patient were labeled based on physical examination as either active MTrP (spontaneously-painful, A-MTrP), latent MTrP (non-painful, L-MTrP), or normal myofascial tissue. US examination was performed on each subject by a team blinded to the physical findings. A 12-5 MHz US transducer was used. VSE was performed by color Doppler variance imaging while simultaneously inducing vibrations (~92Hz) with a handheld massage vibrator. Each site was assigned a tissue imaging score (TIS) as follows: 0 = uniform echogenicity and stiffness; 1 = focal hypoechoic region with stiff nodule; 2 = multiple hypoechoic regions with stiff nodules. Blood flow in the neighborhood of MTrPs was assessed using Doppler imaging. Each site was assigned a blood flow waveform score (BFS) as follows: 0 = normal arterial flow in muscle; 1 = elevated diastolic flow; 2 = high-resistance flow waveform with retrograde diastolic flow. Results MTrPs appeared as focal, hypoechoic regions on 2D US, indicating local changes in tissue echogenicity, and as focal regions of reduced vibration amplitude on VSE, indicating a localized stiff nodule. MTrPs were elliptical in shape, with a size of 0.16 ± 0.11 cm2. There were no significant differences in size between A-MTrPs and L-MTrPs. Sites containing MTrPs were more likely to have higher TIS compared to normal myofascial tissue (p<0.002). Small arteries (or

  5. Ultrasound-guided characterization of interstitial ablated tissue using RF time series: feasibility study.

    PubMed

    Imani, Farhad; Abolmaesumi, Purang; Wu, Mark Z; Lasso, Andras; Burdette, Everett C; Ghoshal, Goutam; Heffter, Tamas; Williams, Emery; Neubauer, Paul; Fichtinger, Gabor; Mousavi, Parvin

    2013-06-01

    This paper presents the results of a feasibility study to demonstrate the application of ultrasound RF time series imaging to accurately differentiate ablated and nonablated tissue. For 12 ex vivo and two in situ tissue samples, RF ultrasound signals are acquired prior to, and following, high-intensity ultrasound ablation. Spatial and temporal features of these signals are used to characterize ablated and nonablated tissue in a supervised-learning framework. In cross-validation evaluation, a subset of four features extracted from RF time series produce a classification accuracy of 84.5%, an area under ROC curve of 0.91 for ex vivo data, and an accuracy of 85% for in situ data. Ultrasound RF time series is a promising approach for characterizing ablated tissue.

  6. Ultrasound

    MedlinePlus

    Ultrasound is a useful procedure for monitoring the baby's development in the uterus. Ultrasound uses inaudible sound waves to produce a two- ... sound waves and appear dark or black. An ultrasound can supply vital information about a mother's pregnancy ...

  7. Investigation of Post-mortem Tissue Effects Using Long-time Decorrelation Ultrasound

    NASA Astrophysics Data System (ADS)

    Csány, Gergely; Balogh, Lajos; Gyöngy, Miklós

    Decorrelation ultrasound is being increasingly used to investigate long-term biological phenomena. In the current work, ultrasound image sequences of mice who did not survive anesthesia (in a separate investigation) were analyzed and post-mortem tissue effects were observed via decorrelation calculation. A method was developed to obtain a quantitative parameter characterizing the rate of decorrelation. The results show that ultrasound decorrelation imaging is an effective method of observing post-mortem tissue effects and point to further studies elucidating the mechanism behind these effects.

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

    PubMed

    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. Modeling Transversely Isotropic, Viscoelastic, Incompressible Tissue-like Materials with Application in Ultrasound Shear Wave Elastography

    PubMed Central

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

    2015-01-01

    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. PMID:25591921

  10. 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.

  11. 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

  12. Development of a Mechanical Scanning-type Intravascular Ultrasound System Using a Miniature Ultrasound Motor

    NASA Astrophysics Data System (ADS)

    Tanabe, Masayuki; Xie, Shangping; Tagawa, Norio; Moriya, Tadashi; Furukawa, Yuji

    2007-07-01

    Intravascular ultrasound (IVUS) plays an important role for the detection of arteriosclerosis, which causes the ischemic heart disease. In mechanical scanning-type IVUS, it is necessary to rotate a transducer or a reflecting mirror. A method that involves rotating the transducer using a torque wire causes image distortion (NURD: non uniform rotation distortion). For a method that involves placing an electromagnetic motor on the tip of an IVUS probe is difficult to miniaturize the probe. Our objectives are to miniaturize the probe (1 mm in diameter, 5 mm in length) and to remove NURD. Therefore, we conducted a study to assess the feasibility of attaining these objectives by constructing a prototype IVUS system, in which an ultrasound motor using a stator in the form of a helical coil (abbreviated as CS-USM: coiled stator-ultrasonic motor) is incorporated, and to clarify problems that need to be solved in constructing the probe.

  13. Focusing light in deep tissue with time-reversed ultrasound microbubble encoded light (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Ruan, Haowen; Jang, Mooseok; Yang, Changhuei

    2016-03-01

    Optical scattering of biological tissue limits the penetration depth of conventional optical techniques, which rely on the detection of ballistic photons. Recent developed optical phase conjugation (OPC) technique breaks through this depth limit by shaping an optical wavefront that can "undo" the optical scattering. Assisted with an ultrasound focus, this technique enables optical focusing inside biological tissue in a freely addressable fashion. However, ultrasound modulation efficiency is low and the focusing resolution is limited by the ultrasound. Here we present a new technique, time-reversed ultrasound microbubble encoded (TRUME) optical focusing, which is able to provide high focusing efficiency and sub-ultrasound resolution. This technique achieves the wavefront solution by taking the difference of the optical fields captured outside the sample before and after ultrasound-driven microbubble destruction. A conjugated wavefront was then reconstructed and sent back to the sample to form a focus at the site of microbubble destruction. We experimentally demonstrate that a focus with ~2 um size was formed through a 2-mm thick biological tissue using this method. While the size the microbubble sets the resolution of an individual focus, the scale of the ultrasound focus limits the focusing addressability of this technique. Importantly, by utilizing the nonlinear destruction of microbubbles, the TRUME technique breaks the addressable focus resolution barrier imposed by the ultrasound focus. We experimentally demonstrate a 2-fold improvement in addressability using this effect. Since microbubbles are widely used as ultrasound contrast agents in human, this technique provides a promising solution for focusing light deep inside biological tissue.

  14. 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

  15. 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.

  16. Cavitation-induced damage in soft tissue phantoms by focused ultrasound bursts

    NASA Astrophysics Data System (ADS)

    Movahed, Pooya; Kreider, Wayne; Maxwell, Adam D.; Bailey, Michael R.; Hutchens, Shelby B.; Freund, Jonathan B.

    2015-11-01

    Cavitation in soft tissues, similar to that in purely hydrodynamic configurations, is thought to cause tissue injury in therapeutic ultrasound treatments. Our goal is to generalize bubble dynamics models to represent this phenomenon, which we pursue experimentally with observations in tissue-mimicking polyacrylamide and agarose phantoms and semi-analytic generalization of Rayleigh-Plesset-type bubble dynamics models. The phantoms were imaged with high-speed cameras while subjected to a series of multiple pressure wave bursts, of the kind being considered specifically for burst-wave lithotripsy (BWL). The experimental observations show bubble activation at multiple sites during the initial pulses. After multiple pulses, a further onset of cavitation is observed at some new locations suggesting material failure due to fatigue under cyclic loading. A nonlinear strain-energy with strain hardening is used to represent the elasticity of the surrounding medium. Griffith's fracture criterion is then applied in order to determine the onset of material damage. The damaged material is then represented as a Newtonian fluid. By assuming that such a decrease in the fracture toughness occurs under cyclic loading, the fatigue behavior observed in the experiments can be reproduced by our model. This work was supported by NIH grant NIDDK PO1-DK043881.

  17. A reusable perfusion supporting tissue-mimicking material for ultrasound hyperthermia phantoms.

    PubMed

    Chin, R B; Madsen, E L; Zagzebski, J A; Jadvar, H; Wu, X K; Frank, G R

    1990-01-01

    A new ultrasonically and thermodynamically tissue-mimicking material is reported. The material is well suited for use in phantoms for testing ultrasound hyperthermia systems or related predictive models. Controlled convective heat transfer effects, mimicking to some extent perfusive heat transfer in tissues, can be instituted in the material with appropriate fluid sources and sinks. The material consists of closely packed agar spheres varying in diameters from 0.3-3.6 mm. The interstitial space between spheres is filled with 10% n-propanol solution. The material has two practical advantages over the solid-gel-type tissue-mimicking materials. The first advantage is that it allows rapid return of a hyperthermia phantom to thermal equilibrium following a heating test by rapid circulation of the perfusion fluid. The second advantage is that the material is in a "liquid" form. It can be easily siphoned in and out of phantom containers of any geometric shape for different purposes without change in its physical properties. Methods for measuring ultrasonic and thermodynamic properties of the material and the results of the measurements are reported. The physical parameters measured are the intensity attenuation and absorption coefficients, the ultrasonic speed, the thermal conductivity, specific-heat capacity and the mass density. Temperature measurements in a hyperthermia phantom made of the material are also reported. PMID:2385195

  18. Structural Quality Control of Swiss-Type Cheese with Ultrasound

    NASA Astrophysics Data System (ADS)

    Eskelinen, J.; Alavuotunki, A.; Hæggström, E.; Alatossava, T.

    2007-03-01

    A study on structural quality control of Swiss-type cheese with ultrasound is presented. We used a longitudinal mode pulse-echo setup using 1-2MHz ultrasonic frequencies to detect cheese-eyes and ripening induced cracks. Results show that the ultrasonic method posses good potential to monitor the cheese structure during the ripening process. Preliminary results indicate that maturation stage could be monitored with ultrasonic velocity measurements. Further studies to verify the method's on-line potential to detect low-structural-quality cheeses are planned.

  19. PE-CMOS based C-scan ultrasound for foreign object detection in soft tissue.

    PubMed

    Liu, Chu-Chuan; Lo, Shih-Chung Ben; Freedman, Matthew T; Lasser, Marvin E; Kula, John; Sarcone, Anita; Wang, Yue

    2010-01-01

    In this paper, we introduce a C-scan ultrasound prototype and three imaging modalities for the detection of foreign objects inserted in porcine soft tissue. The object materials include bamboo, plastics, glass and aluminum alloys. The images of foreign objects were acquired using the C-scan ultrasound, a portable B-scan ultrasound, film-based radiography, and computerized radiography. The C-scan ultrasound consists of a plane wave transducer, a compound acoustic lens system, and a newly developed ultrasound sensor array based on the complementary metal-oxide semiconductor coated with piezoelectric material (PE-CMOS). The contrast-to-noise ratio (CNR) of the images were analyzed to quantitatively evaluate the detectability using different imaging modalities. The experimental results indicate that the C-scan prototype has better CNR values in 4 out of 7 objects than other modalities. Specifically, the C-scan prototype provides more detail information of the soft tissues without the speckle artifacts that are commonly seen with conventional B-scan ultrasound, and has the same orientation as the standard radiographs but without ionizing radiation.

  20. Estimating elastic properties of tissues from standard 2D ultrasound images

    NASA Astrophysics Data System (ADS)

    Kybic, Jan; Smutek, Daniel

    2005-04-01

    We propose a way of measuring elastic properties of tissues in-vivo, using standard medical image ultrasound machine without any special hardware. Images are acquired while the tissue is being deformed by a varying pressure applied by the operator on the hand-held ultrasound probe. The local elastic shear modulus is either estimated from a local displacement field reconstructed by an elastic registration algorithm, or both the modulus and the displacement are estimated simultaneously. The relation between modulus and displacement is calculated using a finite element method (FEM). The estimation algorithms were tested on both synthetic, phantom and real subject data.

  1. Ultrasound Technologies for the Spatial Patterning of Cells and Extracellular Matrix Proteins and the Vascularization of Engineered Tissue

    NASA Astrophysics Data System (ADS)

    Garvin, Kelley A.

    Technological advancements in the field of tissue engineering could save the lives of thousands of organ transplant patients who die each year while waiting for donor organs. Currently, two of the primary challenges preventing tissue engineers from developing functional replacement tissues and organs are the need to recreate complex cell and extracellular microenvironments and to vascularize the tissue to maintain cell viability and function. Ultrasound is a form of mechanical energy that can noninvasively and nondestructively interact with tissues at the cell and protein level. In this thesis, novel ultrasound-based technologies were developed for the spatial patterning of cells and extracellular matrix proteins and the vascularization of three-dimensional engineered tissue constructs. Acoustic radiation forces associated with ultrasound standing wave fields were utilized to noninvasively control the spatial organization of cells and cell-bound extracellular matrix proteins within collagen-based engineered tissue. Additionally, ultrasound induced thermal mechanisms were exploited to site-specifically pattern various extracellular matrix collagen microstructures within a single engineered tissue construct. Finally, ultrasound standing wave field technology was used to promote the rapid and extensive vascularization of three-dimensional tissue constructs. As such, the ultrasound technologies developed in these studies have the potential to provide the field of tissue engineering with novel strategies to spatially pattern cells and extracellular matrix components and to vascularize engineered tissue, and thus, could advance the fabrication of functional replacement tissues and organs in the field of tissue engineering.

  2. 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.

  3. Radio Frequency Ultrasound Time Series Signal Analysis to Evaluate High-intensity Focused Ultrasound Lesion Formation Status in Tissue

    PubMed Central

    Mobasheri, Saeedeh; Behnam, Hamid; Rangraz, Parisa; Tavakkoli, Jahan

    2016-01-01

    High-intensity focused ultrasound (HIFU) is a novel treatment modality used by scientists and clinicians in the recent decades. This modality has had a great and significant success as a noninvasive surgery technique applicable in tissue ablation therapy and cancer treatment. In this study, radio frequency (RF) ultrasound signals were acquired and registered in three stages of before, during, and after HIFU exposures. Different features of RF time series signals including the sum of amplitude spectrum in the four quarters of the frequency range, the slope, and intercept of the best-fit line to the entire power spectrum and the Shannon entropy were utilized to distinguish between the HIFU-induced thermal lesion and the normal tissue. We also examined the RF data, frame by frame to identify exposure effects on the formation and characteristics of a HIFU thermal lesion at different time steps throughout the treatment. The results obtained showed that the spectrum frequency quarters and the slope and intercept of the best fit line to the entire power spectrum both increased two times during the HIFU exposures. The Shannon entropy, however, decreased after the exposures. In conclusion, different characteristics of RF time series signal possess promising features that can be used to characterize ablated and nonablated tissues and to distinguish them from each other in a quasi-quantitative fashion. PMID:27186536

  4. High resolution ultrasound elastomicroscopy imaging of soft tissues: system development and feasibility

    NASA Astrophysics Data System (ADS)

    Zheng, Y. P.; Bridal, S. L.; Shi, J.; Saied, A.; Lu, M. H.; Jaffre, B.; Mak, A. F. T.; Laugier, P.

    2004-09-01

    Research in elasticity imaging typically relies on 1-10 MHz ultrasound. Elasticity imaging at these frequencies can provide strain maps with a resolution in the order of millimetres, but this is not sufficient for applications to skin, articular cartilage or other fine structures. We developed a prototype high resolution elastomicroscopy system consisting of a 50 MHz ultrasound backscatter microscope system and a calibrated compression device using a load cell to measure the pressure applied to the specimen, which was installed between a rigidly fixed face-plate and a specimen platform. Radiofrequency data were acquired in a B-scan format (10 mm wide × 3 mm deep) in specimens of mouse skin and bovine patellar cartilage. The scanning resolution along the B-scan plane direction was 50 µm, and the ultrasound signals were digitized at 500 MHz to achieve a sensitivity better than 1 µm for the axial displacement measurement. Because of elevated attenuation of ultrasound at high frequencies, special consideration was necessary to design a face-plate permitting efficient ultrasound transmission into the specimen and relative uniformity of the compression. Best results were obtained using a thin plastic film to cover a specially shaped slit in the face-plate. Local tissue strain maps were constructed by applying a cross-correlation tracking method to signals obtained at the same site at different compression levels. The speed of sound in the tissue specimen (1589.8 ± 7.8 m s-1 for cartilage and 1532.4 ± 4.4 m s-1 for skin) was simultaneously measured during the compression test. Preliminary results demonstrated that this ultrasound elastomicroscopy technique was able to map deformations of the skin and articular cartilage specimens to high resolution, in the order of 50 µm. This system can also be potentially used for the assessment of other biological tissues, bioengineered tissues or biomaterials with fine structures.

  5. Dynamic contrast-enhanced ultrasound for quantification of tissue perfusion.

    PubMed

    Fröhlich, Eckhart; Muller, Reinhold; Cui, Xin-Wu; Schreiber-Dietrich, Dagmar; Dietrich, Christoph F

    2015-02-01

    Dynamic contrast-enhanced ultrasound (US) imaging, a technique that uses microbubble contrast agents with diagnostic US, has recently been technically summarized and reviewed by a European Federation of Societies for Ultrasound in Medicine and Biology position paper. However, the practical applications of this imaging technique were not included. This article reviews and discusses the published literature on the clinical use of dynamic contrast-enhanced US. This review finds that dynamic contrast-enhanced US imaging is the most sensitive cross-sectional real-time method for measuring the perfusion of parenchymatous organs noninvasively. It can measure parenchymal perfusion and therefore can differentiate between benign and malignant tumors. The most important routine clinical role of dynamic contrast-enhanced US is the prediction of tumor responses to chemotherapy within a very short time, shorter than using Response Evaluation Criteria in Solid Tumors criteria. Other applications found include quantifying the hepatic transit time, diabetic kidneys, transplant grafts, and Crohn disease. In addition, the problems involved in using dynamic contrast-enhanced US are discussed.

  6. 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

  7. High intensity focused ultrasound as a tool for tissue engineering: Application to cartilage.

    PubMed

    Nover, Adam B; Hou, Gary Y; Han, Yang; Wang, Shutao; O'Connell, Grace D; Ateshian, Gerard A; Konofagou, Elisa E; Hung, Clark T

    2016-02-01

    This article promotes the use of High Intensity Focused Ultrasound (HIFU) as a tool for affecting the local properties of tissue engineered constructs in vitro. HIFU is a low cost, non-invasive technique used for eliciting focal thermal elevations at variable depths within tissues. HIFU can be used to denature proteins within constructs, leading to decreased permeability and potentially increased local stiffness. Adverse cell viability effects remain restricted to the affected area. The methods described in this article are explored through the scope of articular cartilage tissue engineering and the fabrication of osteochondral constructs, but may be applied to the engineering of a variety of different tissues. PMID:26724968

  8. The effects of ultrasound and light on indocyanine-green-treated tumour cells and tissues.

    PubMed

    Nomikou, Nikolitsa; Sterrett, Christine; Arthur, Ciara; McCaughan, Bridgeen; Callan, John F; McHale, Anthony P

    2012-08-01

    Photodynamic therapy (PDT) is emerging as a treatment modality for the management of neoplastic disease. Despite considerable clinical success, its application for the treatment of deep-seated lesions is constrained by the inability of visible light to penetrate deeply into tissues. An emerging alternative approach exploits the fact that many photosensitisers respond to ultrasound, eliciting cytotoxic effects on target cells and tissues; this has become known as sonodynamic therapy (SDT). The objectives of this study were 1) to determine whether the IR-absorbing dye, indocyanine green (ICG), can be employed as a sonosensitiser and 2) to determine whether ultrasound can be used to enhance ICG-mediated PDT. Exposing ICG-treated mouse fibrosarcoma cells to ultrasound at an energy density of 30 J cm(-2) decreased cell viability by 65 %. Prior exposure of ICG-treated cells to light (λ 830 nm) and subsequent treatment with ultrasound led to a 90 % decrease in cell viability. In combination treatments a synergistic effect was observed at lower doses of ultrasound. Microscopic examination of cell populations treated with light or ultrasound demonstrated the production of intracellular reactive oxygen species (ROS). Using a mouse tumour model, treatment with light, ultrasound, or a combination thereof led to respective decreases in tumour growth of 42, 67, and 98 % at day 27 post-treatment. These results could provide a means of circumventing light-penetration issues that currently challenge the widespread use of PDT in the treatment of cancer.

  9. Can pulsed ultrasound increase tissue damage during ischemia? A study of the effects of ultrasound on infarcted and non-infarcted myocardium in anesthetized pigs

    PubMed Central

    Olivecrona, Göran K; Härdig, Bjarne Madsen; Roijer, Anders; Block, Mattias; Grins, Edgars; Persson, Hans W; Johansson, Leif; Olsson, Bertil

    2005-01-01

    Background The same mechanisms by which ultrasound enhances thrombolysis are described in connection with non-beneficial effects of ultrasound. The present safety study was therefore designed to explore effects of beneficial ultrasound characteristics on the infarcted and non-infarcted myocardium. Methods In an open chest porcine model (n = 17), myocardial infarction was induced by ligating a coronary diagonal branch. Pulsed ultrasound of frequency 1 MHz and intensity 0.1 W/cm2 (ISATA) was applied during one hour to both infarcted and non-infarcted myocardial tissue. These ultrasound characteristics are similar to those used in studies of ultrasound enhanced thrombolysis. Using blinded assessment technique, myocardial damage was rated according to histopathological criteria. Results Infarcted myocardium exhibited a significant increase in damage score compared to non-infarcted myocardium: 6.2 ± 2.0 vs. 4.3 ± 1.5 (mean ± standard deviation), (p = 0.004). In the infarcted myocardium, ultrasound exposure yielded a further significant increase of damage scores: 8.1 ± 1.7 vs. 6.2 ± 2.0 (p = 0.027). Conclusion Our results suggest an instantaneous additive effect on the ischemic damage in myocardial tissue when exposed to ultrasound of stated characteristics. The ultimate damage degree remains to be clarified. PMID:15831106

  10. Localized Ablation of Thyroid Tissue by High-Intensity Focused Ultrasound: an Alternative to Surgery?

    NASA Astrophysics Data System (ADS)

    Esnault, Olivier; Franc, Brigitte; Chapelon, Jean-Yves; Lacoste, Francois

    2006-05-01

    PURPOSE: The aim of this study was to evaluate the feasibility of using a High-intensity focused ultrasound (HIFU) device to obtain a localised destruction of the thyroid with no damage to adjacent tissues. MATERIALS AND METHODS: The ewe model was used because its thyroid gland is easily accessible with ultrasound. The animals were anaesthetised with 10 mg / kg IV injection of Penthothal. The HIFU pulses were generated by a 3-MHz spherical transducer under ultrasound guidance. Macroscopic and microscopic tissue lesions were identified after formalin fixation of the anterior part of the ewe's neck. RESULTS: After determining the optimal instrument settings to obtain localized thyroid ablation, the repeatability of the method was evaluated using a HIFU prototype designed specifically for human use: in 13 ewes (26 treated lobes), an average of 20 (range: 14-27) ultrasound pulses (pulse duration: 3 s) per lobe covering a mean volume of 0.5 cm3 (range: 0.3-0.7 cm3) were delivered. The ewes were sacrificed 2-5 weeks after treatment delivery. No damage to the nerves, trachea, esophagus or muscle was observed. Only 3 ewes suffered superficial skin burns. The desired thyroid lesions were obtained in 25/26 treated lobes, as demonstrated by fibrotic tissues, which replaced necrotic areas. CONCLUSION: These results obtained in the ewe model show that thyroid lesions of defined volume can be induced safely and suggest that the HIFU device is now ready for human trials.

  11. 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.

  12. 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

  13. Heterogeneous Tissue Characterization Using Ultrasound: A Comparison of Fractal Analysis Backscatter Models on Liver Tumors.

    PubMed

    Al-Kadi, Omar S; Chung, Daniel Y F; Coussios, Constantin C; Noble, J Alison

    2016-07-01

    Assessment of tumor tissue heterogeneity via ultrasound has recently been suggested as a method for predicting early response to treatment. The ultrasound backscattering characteristics can assist in better understanding the tumor texture by highlighting the local concentration and spatial arrangement of tissue scatterers. However, it is challenging to quantify the various tissue heterogeneities ranging from fine to coarse of the echo envelope peaks in tumor texture. Local parametric fractal features extracted via maximum likelihood estimation from five well-known statistical model families are evaluated for the purpose of ultrasound tissue characterization. The fractal dimension (self-similarity measure) was used to characterize the spatial distribution of scatterers, whereas the lacunarity (sparsity measure) was applied to determine scatterer number density. Performance was assessed based on 608 cross-sectional clinical ultrasound radiofrequency images of liver tumors (230 and 378 representing respondent and non-respondent cases, respectively). Cross-validation via leave-one-tumor-out and with different k-fold methodologies using a Bayesian classifier was employed for validation. The fractal properties of the backscattered echoes based on the Nakagami model (Nkg) and its extend four-parameter Nakagami-generalized inverse Gaussian (NIG) distribution achieved best results-with nearly similar performance-in characterizing liver tumor tissue. The accuracy, sensitivity and specificity of Nkg/NIG were 85.6%/86.3%, 94.0%/96.0% and 73.0%/71.0%, respectively. Other statistical models, such as the Rician, Rayleigh and K-distribution, were found to not be as effective in characterizing subtle changes in tissue texture as an indication of response to treatment. Employing the most relevant and practical statistical model could have potential consequences for the design of an early and effective clinical therapy. PMID:27056610

  14. Ultrasound elastography assessment of bone/soft tissue interface

    NASA Astrophysics Data System (ADS)

    Parmar, Biren J.; Yang, Xu; Chaudhry, Anuj; Shafeeq Shajudeen, Peer; Nair, Sanjay P.; Weiner, Bradley K.; Tasciotti, Ennio; Krouskop, Thomas A.; Righetti, Raffaella

    2016-01-01

    We report on the use of elastographic imaging techniques to assess the bone/soft tissue interface, a region that has not been previously investigated but may provide important information about fracture and bone healing. The performance of axial strain elastograms and axial shear strain elastograms at the bone/soft tissue interface was studied ex vivo on intact and fractured canine and ovine tibias. Selected ex vivo results were corroborated on intact sheep tibias in vivo. The elastography results were statistically analyzed using elastographic image quality tools. The results of this study demonstrate distinct patterns in the distribution of the normalized local axial strains and axial shear strains at the bone/soft tissue interface with respect to the background soft tissue. They also show that the relative strength and distribution of the elastographic parameters change in the presence of a fracture and depend on the degree of misalignment between the fracture fragments. Thus, elastographic imaging modalities might be used in the future to obtain information regarding the integrity of bones and to assess the severity of fractures, alignment of bone fragments as well as to follow bone healing.

  15. 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 ...

  16. Limited damage of tissue mimic caused by a collapsing bubble under low-frequency ultrasound exposure.

    PubMed

    Yoshida, Kenji; Obata, Kazuya; Tsukamoto, Akira; Ushida, Takashi; Watanabe, Yoshiaki

    2014-08-01

    In this study, we investigated the bubble induced serious damage to tissue mimic exposed to 27-kHz ultrasound. The initial bubble radius ranged from 80 to 100 μm, which corresponded approximately to the experimentally-evaluated resonant radius of the given ultrasound frequency. The tissue mimic consisted of 10 wt% gelatine gel covered with cultured canine kidney epithelial cells. The collapsing bubble behaviour during the ultrasound exposure with negative peak pressures of several hundred kPa was captured by a high-speed camera system. After ultrasound exposure, a cell viability test was conducted based on microscopic bright-field images and fluorescence images for living and dead cells. In the viability test, cells played a role in indicating the damaged area. The bubble oscillations killed the cells, and on occasion detached layers of cultured cells from the gel. The damaged area was comparable or slightly larger than the initial bubble size, and smaller than the maximum bubble size. We concluded that only a small area in close proximity to the bubble could be damaged even above transient cavitation threshold.

  17. 3-D ultrasound-guided robotic needle steering in biological tissue.

    PubMed

    Adebar, Troy K; Fletcher, Ashley E; Okamura, Allison M

    2014-12-01

    Robotic needle steering systems have the potential to greatly improve medical interventions, but they require new methods for medical image guidance. Three-dimensional (3-D) ultrasound is a widely available, low-cost imaging modality that may be used to provide real-time feedback to needle steering robots. Unfortunately, the poor visibility of steerable needles in standard grayscale ultrasound makes automatic segmentation of the needles impractical. A new imaging approach is proposed, in which high-frequency vibration of a steerable needle makes it visible in ultrasound Doppler images. Experiments demonstrate that segmentation from this Doppler data is accurate to within 1-2 mm. An image-guided control algorithm that incorporates the segmentation data as feedback is also described. In experimental tests in ex vivo bovine liver tissue, a robotic needle steering system implementing this control scheme was able to consistently steer a needle tip to a simulated target with an average error of 1.57 mm. Implementation of 3-D ultrasound-guided needle steering in biological tissue represents a significant step toward the clinical application of robotic needle steering.

  18. Noninvasive surgery of prostate tissue by high-intensity focused ultrasound: an updated report

    NASA Astrophysics Data System (ADS)

    Sanghvi, Narendra T.; Syrus, J.; Foster, Richard S.; Bihrle, Richard; Casey, Richard W.; Uchida, Toyoak

    2000-05-01

    High Intensity Focused Ultrasound (HIFU) has been clinically used for the treatment of benign prostatic hyperplasia (BPH) and it is experimentally applied for the treatment of localized prostate caner (PC). Recent advances in the transducer material and technology have permitted to combine the ultrasound visualization capability and HIFU on the same ceramic crystal. Also, the transducer efficiency has increased to a level that a smaller size intracavity probe can be made to produce sufficient acoustic power required for the focused ultrasound surgery of the prostate. Using this technology, 4 MHz mechanically scanning transrectal ultrasound probes has been designed. The transrectal probes are used with Sonablate (SB-200, manufactured by Focus Surgery, Inc., Indianapolis, IN) device. The SB-200 produces both transverse and longitudinal images of the prostate. The transverse and longitudinal images are used for selection of tissue volume, treatment planning and monitoring of tissue during the HIFU treatment cycle. The paper reviews the present operation of the device and recent clinical protocol that has improved efficiency, efficacy and safety of the device. The two years follow-up clinical results from the multi-site US Pilot Study (USPS) and The Male Health Centre are compared with the Kitasato-study (Kitasato School of Medicine, Sagamihara, Japan).

  19. Optimization of contrast resolution by genetic algorithm in ultrasound tissue harmonic imaging.

    PubMed

    Ménigot, Sébastien; Girault, Jean-Marc

    2016-09-01

    The development of ultrasound imaging techniques such as pulse inversion has improved tissue harmonic imaging. Nevertheless, no recommendation has been made to date for the design of the waveform transmitted through the medium being explored. Our aim was therefore to find automatically the optimal "imaging" wave which maximized the contrast resolution without a priori information. To overcome assumption regarding the waveform, a genetic algorithm investigated the medium thanks to the transmission of stochastic "explorer" waves. Moreover, these stochastic signals could be constrained by the type of generator available (bipolar or arbitrary). To implement it, we changed the current pulse inversion imaging system by including feedback. Thus the method optimized the contrast resolution by adaptively selecting the samples of the excitation. In simulation, we benchmarked the contrast effectiveness of the best found transmitted stochastic commands and the usual fixed-frequency command. The optimization method converged quickly after around 300 iterations in the same optimal area. These results were confirmed experimentally. In the experimental case, the contrast resolution measured on a radiofrequency line could be improved by 6% with a bipolar generator and it could still increase by 15% with an arbitrary waveform generator.

  20. Effects of Ultrasound Frequency and Tissue Stiffness on the Histotripsy Intrinsic Threshold for Cavitation

    PubMed Central

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

    2015-01-01

    Histotripsy is an ultrasound ablation method that depends on the initiation of a cavitation bubble cloud to fractionate soft tissue. Previous work has demonstrated 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 vs. pressure amplitude. The results demonstrated 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 showed 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 24.7–30.6 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 impacted by tissue stiffness or ultrasound frequency in hundreds of kHz to MHz range. PMID:25766571

  1. 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.

  2. Effects of Tissue Stiffness, Ultrasound Frequency, and Pressure on Histotripsy-induced Cavitation Bubble Behavior

    PubMed Central

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

    2015-01-01

    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 microns. 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 causes 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

  3. Nonlinearity parameter B/A of biological tissue ultrasound imaging in echo mode

    SciTech Connect

    Toulemonde, M. Varray, F.; Bernard, A.; Basset, O.; Cachard, C.

    2015-10-28

    The nonlinearity B/A parameter influences the distortion of ultrasound waves during their propagation in tissue. Normal and pathological media have different B/A values and this parameter may be used to characterize them. In this paper the multitaper coherent plane wave compounding (MCPWC) is combined with the extended comparative method (ECM) to estimate the B/A parameter in simulation and acquisition. Using plane wave transmission and orthogonal apodization during beam forming improves the B/A estimation and delineation.

  4. Is Duplex-Ultrasound a useful tool in defining rejection episodes in composite tissue allograft transplants?

    PubMed

    Loizides, Alexander; Kronberger, Irmgard-Elisabeth; Plaikner, Michaela; Gruber, Hannes

    2015-12-01

    Immunologic reactions in transplanted organs are in more or less all allograft patients detectable: clear parameters exist as e.g. in renal transplants where the clearance power reduces by rejection. On the contrary, in composite tissue allografts clear and objective indicators stating a rejection episode lack. We present the case of a hand-transplanted subject with signs of acute transplant rejection diagnosed by means of Duplex Ultrasound and confirmed by biopsy.

  5. EGFP gene transfection into the synovial joint tissues of rats with rheumatoid arthritis by ultrasound-mediated microbubble destruction

    PubMed Central

    JING, XIANG-XIANG; LIU, JIE; YANG, BING-ANG; FU, SHAO-QING; WU, TANG-NA; WANG, DONG-LIN

    2014-01-01

    The aim of the present study was to explore the feasibility of enhancing green fluorescent protein (EGFP) gene transfection into the synovial joint tissues of rats with rheumatoid arthritis (RA) by ultrasound-mediated microbubble destruction. An optimal SonoVue dose was determined using 40 normal rats categorized into five groups according to the various doses of microbubbles used. At 1 week after ultrasound irradiation, the rats were sacrificed. Damage to the joint synovial tissues was observed with hematoxylin and eosin histopathological staining under a microscope. A further 44 normal rats were used to establish a rat model of RA, and were then categorized into four groups: EGFP, ultrasound + EGFP, microbubbles + EGFP and ultrasound + microbubbles + EGFP. The last group was irradiated with ultrasound for 10 min following the injection of 300 μl SonoVue and 10 μg EGFP into the joint cavity. Rats were sacrificed after 3 days and synovial tissue was collected from the knee joints for observation of EGFP with fluorescence microscopy and analysis by quantitative polymerase chain reaction. EGFP expression was observed in the synovial tissues of all groups. However, high EGFP expression levels were observed in the ultrasound + microbubbles + EGFP group. No statistically significant differences (P>0.05) were observed in the EGFP expression levels between the EGFP, ultrasound + EGFP and microbubbles + EGFP groups. However, EGFP expression levels in the EGFP, ultrasound + EGFP and microbubbles + EGFP groups significantly differed (P<0.05) from that in the ultrasound + microbubbles + EGFP group. Therefore, ultrasound-mediated microbubble destruction improved EGFP transfection efficiency into the joint synovial tissues of rats with RA. PMID:24940446

  6. Why Are Short Pulses More Efficient in Tissue Erosion Using Pulsed Cavitational Ultrasound Therapy (Histotripsy)?

    NASA Astrophysics Data System (ADS)

    Wang, Tzu-Yin; Maxwell, Adam D.; Park, Simone; Xu, Zhen; Fowlkes, J. Brian; Cain, Charles A.

    2010-03-01

    Histotripsy produces mechanical tissue fractionation through controlled cavitation. The histotripsy induced tissue erosion is more efficient with shorter (i.e., 3-6 cycles) rather than longer (i.e. 24 cycles) pulses. In this study, we investigated the reasons behind this observation by studying dynamics of the cavitating bubble clouds and individual bubbles during and after a therapy pulse. Bubble clouds were generated at a gel-water interface using 5 to 30-cycle 1 MHz pulses at P-/P+>19/125-MPa pressure and 1-kHz pulse repetition frequency. The evolution of the overall bubble cloud and individual bubbles were studied using high speed photography. Results show that: 1) within the first 10-15 cycles, the overall cloud grew to its maximum size; the individual bubbles underwent violent expansion and collapse, and grew in size with each cycle of ultrasound; 2) between the 15th cycle and the end of the pulse, the overall cloud size did not change even if further cycles of ultrasound were delivered; the individual bubbles no longer underwent violent collapse; 3) after the pulse, the overall cloud gradually dissolved; the individual bubbles may coalesce into larger bubbles for 0-40 μs, and then gradually dissolved. These observations suggest that violent growth and collapse of individual bubbles occur within the first few cycles of ultrasound pulse most often. This may explain why extremely short pulses are more energy efficient in histotripsy-induced tissue erosion.

  7. METHODS FOR USING 3-D ULTRASOUND SPECKLE TRACKING IN BIAXIAL MECHANICAL TESTING OF BIOLOGICAL TISSUE SAMPLES

    PubMed Central

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

    2014-01-01

    Being multilayered and anisotropic, biological tissues such as cardiac and arterial walls are structurally complex, making 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

  8. Experimental Evaluation of Ultrasound-Guided 3D Needle Steering in Biological Tissue

    PubMed Central

    Abayazid, Momen; Vrooijink, Gustaaf J.; Patil, Sachin; Alterovitz, Ron; Misra, Sarthak

    2014-01-01

    Purpose In this paper, we present a system capable of automatically steering bevel-tip flexible needles under ultrasound guidance towards stationary and moving targets in gelatin phantoms and biological tissue while avoiding stationary and moving obstacles. We use three-dimensional (3D) ultrasound to track the needle tip during the procedure. Methods Our system uses a fast sampling-based path planner to compute and periodically update a feasible path to the target that avoids obstacles. We then use a novel control algorithm to steer the needle along the path in a manner that reduces the number of needle rotations, thus reducing tissue damage. We present experimental results for needle insertion procedures for both stationary and moving targets and obstacles for up to 90 mm of needle insertion. Results We obtained a mean targeting error of 0.32 ± 0.10 mm and 0.38 ± 0.19 mm in gelatin-based phantom and biological tissue, respectively. Conclusions The achieved submillimeter accuracy suggests that our approach is sufficient to target the smallest lesions (ϕ2 mm) that can be detected using state-of-the-art ultrasound imaging systems. PMID:24562744

  9. Thermal contribution of compact bone to intervening tissue-like media exposed to planar ultrasound.

    PubMed

    Moros, Eduardo G; Novak, Petr; Straube, William L; Kolluri, Prashant; Yablonskiy, Dmitriy A; Myerson, Robert J

    2004-03-21

    The presence of bone in the ultrasound beam path raises concerns, both in diagnostic and therapeutic applications, because significant temperature elevations may be induced at nearby soft tissue-bone interfaces due the facts that ultrasound is (i) highly absorbed in bone and (ii) reflected at soft tissue-bone interfaces in various degrees depending on angle of incidence. Consequently, in ultrasonic thermal therapy, the presence of bone in the ultrasound beam path is considered a major disadvantage and it is usually avoided. However, based on clinical experience and previous theoretical studies, we hypothesized that the presence of bone in superficial unfocused ultrasound hyperthermia can actually be exploited to induce more uniform and enhanced (with respect to the no-bone situation) temperature distributions in superficial target volumes. In particular, we hypothesize that the presence of underlying bone in superficial target volume enhances temperature elevation not only by additional direct power deposition from acoustic reflection, but also from thermal diffusion from the underlying bone. Here we report laboratory results that corroborate previous computational studies and strengthen the above-stated hypothesis. Three different temperature measurement techniques, namely, thermometric (using fibre-optic temperature probes), thermographic (using an infrared camera) and magnetic resonance imaging (using proton resonance frequency shifts), were used in high-power short-exposure, and in low-power extended-exposure, experiments using a 19 mm diameter planar transducer operating at 1.0 and 3.3 MHz (frequencies of clinical relevance). The measurements were performed on three technique-specific phantoms (with and without bone inclusions) and experimental set-ups that resembled possible superficial ultrasound hyperthermia clinical situations. Results from all three techniques were in general agreement and clearly showed that significantly higher heating rates (greater

  10. Thermal contribution of compact bone to intervening tissue-like media exposed to planar ultrasound

    NASA Astrophysics Data System (ADS)

    Moros, Eduardo G.; Novak, Petr; Straube, William L.; Kolluri, Prashant; Yablonskiy, Dmitriy A.; Myerson, Robert J.

    2004-03-01

    The presence of bone in the ultrasound beam path raises concerns, both in diagnostic and therapeutic applications, because significant temperature elevations may be induced at nearby soft tissue-bone interfaces due the facts that ultrasound is (i) highly absorbed in bone and (ii) reflected at soft tissue-bone interfaces in various degrees depending on angle of incidence. Consequently, in ultrasonic thermal therapy, the presence of bone in the ultrasound beam path is considered a major disadvantage and it is usually avoided. However, based on clinical experience and previous theoretical studies, we hypothesized that the presence of bone in superficial unfocused ultrasound hyperthermia can actually be exploited to induce more uniform and enhanced (with respect to the no-bone situation) temperature distributions in superficial target volumes. In particular, we hypothesize that the presence of underlying bone in superficial target volume enhances temperature elevation not only by additional direct power deposition from acoustic reflection, but also from thermal diffusion from the underlying bone. Here we report laboratory results that corroborate previous computational studies and strengthen the above-stated hypothesis. Three different temperature measurement techniques, namely, thermometric (using fibre-optic temperature probes), thermographic (using an infrared camera) and magnetic resonance imaging (using proton resonance frequency shifts), were used in high-power short-exposure, and in low-power extended-exposure, experiments using a 19 mm diameter planar transducer operating at 1.0 and 3.3 MHz (frequencies of clinical relevance). The measurements were performed on three technique-specific phantoms (with and without bone inclusions) and experimental set-ups that resembled possible superficial ultrasound hyperthermia clinical situations. Results from all three techniques were in general agreement and clearly showed that significantly higher heating rates (greater

  11. A simplified training method for soft tissue foreign body detection using ultrasound in emergency medicine residency program.

    PubMed

    Farahmand, Shervin; Bagheri-Hariri, Shahram; Mehran, Sadjad; Arbab, Mona; Khazaeipour, Zahra; Basir-Ghafouri, Hamed; Saeedi, Morteza

    2014-08-01

    Using ultrasound for detecting soft tissue foreign bodies seems to be the preferred choice with minimum invasion and easy availability at the bedside in emergency departments. In this study, a workshop (1 hour of lecture presentation and 3 hours of interactive hands-on) was designed to evaluate the efficacy of a short course of simple interactive training to improve the ability of emergency medicine residents to detect foreign bodies with ultrasound. Eight pieces of fresh full thickness (10 × 10 × 10 cm) lamb leg muscle were used in this study. Five different types of foreign bodies, including: a piece of glass (5 × 5 × 4 mm), wood (5 × 5 × 4 mm), gravel (5 mm diameter), plastic (5 × 5 × 2 mm) and a nail (25 mm in length) were placed deep inside each lamb leg. An ultrasound machine with a 7.5 MHz linear probe was used in this study. 35 emergency medicine residents (12 PGY1, 11 PGY2 and 12 PGY3) were enrolled in this study. Pretest and post-test results were compared and analyzed. Among all 35 participants in the training session, foreign body detection was significantly improved after the workshop (p < 0.001). Overall sensitivity and specificity for differentiating the presence and absence of a foreign body with 95% confidence were 60% (75% for PGY3) and 85.7% (91.7% for PGY3), respectively. The overall accuracy increased from 20.2% to 72.8% due to this session. This study supported the possibility of using ultrasound to detect foreign bodies by emergency physicians with a very short training course. This is highly beneficial for overcrowded emergency departments.

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

    PubMed

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

    2013-02-01

    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 -60dB 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 20-60MHz phantom and ex vivo results. A simulation study shows that the range side lobe level of CPI-CTHI is 16dB lower than PI-CTHI, assuming that the transducer translates incident positions by 50μm 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 12dB lower range side lobe level and a 7dB higher echo signal to noise ratio than PI-CTHI, while the lateral resolution and side lobe level are 50μm finer and -3dB 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 200μm in diameter with 6dB 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.

  13. On ultrasound waves guided by bones with coupled soft tissues: a mechanism study and in vitro calibration.

    PubMed

    Chen, Jiangang; Su, Zhongqing

    2014-07-01

    The influence of soft tissues coupled with cortical bones on precision of quantitative ultrasound (QUS) has been an issue in the clinical bone assessment in conjunction with the use of ultrasound. In this study, the effect arising from soft tissues on propagation characteristics of guided ultrasound waves in bones was investigated using tubular Sawbones phantoms covered with a layer of mimicked soft tissue of different thicknesses and elastic moduli, and an in vitro porcine femur in terms of the axial transmission measurement. Results revealed that presence of soft tissues can exert significant influence on the propagation of ultrasound waves in bones, leading to reduced propagation velocities and attenuated wave magnitudes compared with the counterparts in a free bone in the absence of soft tissues. However such an effect is not phenomenally dependent on the variations in thickness and elastic modulus of the coupled soft tissues, making it possible to compensate for the coupling effect regardless of the difference in properties of the soft tissues. Based on an in vitro calibration, this study proposed quantitative compensation for the effect of soft tissues on ultrasound waves in bones, facilitating development of high-precision QUS.

  14. Investigation of optimal method for inducing harmonic motion in tissue using a linear ultrasound phased array--a simulation study.

    PubMed

    Heikkilä, Janne; Hynynen, Kullervo

    2006-04-01

    Many noninvasive ultrasound techniques have been developed to explore mechanical properties of soft tissues. One of these methods, Localized Harmonic Motion Imaging (LHMI), has been proposed to be used for ultrasound surgery monitoring. In LHMI, dynamic ultrasound radiation-force stimulation induces displacements in a target that can be measured using pulse-echo imaging and used to estimate the elastic properties of the target. In this initial, simulation study, the use of a one-dimensional phased array is explored for the induction of the tissue motion. The study compares three different dual-frequency and amplitude-modulated single-frequency methods for the inducing tissue motion. Simulations were computed in a homogeneous soft-tissue volume. The Rayleigh integral was used in the simulations of the ultrasound fields and the tissue displacements were computed using a finite-element method (FEM). The simulations showed that amplitude-modulated sonication using a single frequency produced the largest vibration amplitude of the target tissue. These simulations demonstrate that the properties of the tissue motion are highly dependent on the sonication method and that it is important to consider the full three-dimensional distribution of the ultrasound field for controlling the induction of tissue motion.

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

    NASA Astrophysics Data System (ADS)

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

    2009-09-01

    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.

  16. Ultrasound-guided three-dimensional needle steering in biological tissue with curved surfaces

    PubMed Central

    Abayazid, Momen; Moreira, Pedro; Shahriari, Navid; Patil, Sachin; Alterovitz, Ron; Misra, Sarthak

    2015-01-01

    In this paper, we present a system capable of automatically steering a bevel-tipped flexible needle under ultrasound guidance toward a physical target while avoiding a physical obstacle embedded in gelatin phantoms and biological tissue with curved surfaces. An ultrasound pre-operative scan is performed for three-dimensional (3D) target localization and shape reconstruction. A controller based on implicit force control is developed to align the transducer with curved surfaces to assure the maximum contact area, and thus obtain an image of sufficient quality. We experimentally investigate the effect of needle insertion system parameters such as insertion speed, needle diameter and bevel angle on target motion to adjust the parameters that minimize the target motion during insertion. A fast sampling-based path planner is used to compute and periodically update a feasible path to the target that avoids obstacles. We present experimental results for target reconstruction and needle insertion procedures in gelatin-based phantoms and biological tissue. Mean targeting errors of 1.46 ± 0.37 mm, 1.29 ± 0.29 mm and 1.82 ± 0.58 mm are obtained for phantoms with inclined, curved and combined (inclined and curved) surfaces, respectively, for insertion distance of 86–103 mm. The achieved targeting errors suggest that our approach is sufficient for targeting lesions of 3 mm radius that can be detected using clinical ultrasound imaging systems. PMID:25455165

  17. Trans-urethral ultrasound (TUUS) imaging for visualization and analysis of the prostate and associated tissues

    NASA Astrophysics Data System (ADS)

    Holmes, David R., III; Robb, Richard A.

    2000-04-01

    Accurate assessment of pathological conditions in the prostate is difficult. Screening methods include palpation if the prostate gland, blood chemical testing, and diagnostic imaging. Trans-rectal Ultrasound (TRUS) is commonly used for the assessment of pathological conditions, however, TRUS is severely constrained by the relative distal location of the imaging probe. Trans-urethral Ultrasound (TUUS) may overcome some limitations of TRUS. A TUUS catheter was used to image the prostate, rectum, bladder, ureter, neuro-vascular bundles, arteries, and surrounding tissue. In addition, 360 degrees rotational scans were recorded for reconstruction into 3D volumes. Segmentation was challenging, however, new techniques such as active contour methods show potential. 3D visualizations, including both volume and surface rendering, were provided to clinicians off-line. On-line 3D visualization techniques are currently being developed. Potential applications of TUUS include: prostate cancer diagnosis and staging as well as image guided biopsy and therapy.

  18. NOTE: Acoustical properties of selected tissue phantom materials for ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Zell, K.; Sperl, J. I.; Vogel, M. W.; Niessner, R.; Haisch, C.

    2007-10-01

    This note summarizes the characterization of the acoustic properties of four materials intended for the development of tissue, and especially breast tissue, phantoms for the use in photoacoustic and ultrasound imaging. The materials are agar, silicone, polyvinyl alcohol gel (PVA) and polyacrylamide gel (PAA). The acoustical properties, i.e., the speed of sound, impedance and acoustic attenuation, are determined by transmission measurements of sound waves at room temperature under controlled conditions. Although the materials are tested for application such as photoacoustic phantoms, we focus here on the acoustic properties, while the optical properties will be discussed elsewhere. To obtain the acoustic attenuation in a frequency range from 4 MHz to 14 MHz, two ultrasound sources of 5 MHz and 10 MHz core frequencies are used. For preparation, each sample is cast into blocks of three different thicknesses. Agar, PVA and PAA show similar acoustic properties as water. Within silicone polymer, a significantly lower speed of sound and higher acoustical attenuation than in water and human tissue were found. All materials can be cast into arbitrary shapes and are suitable for tissue-mimicking phantoms. Due to its lower speed of sound, silicone is generally less suitable than the other presented materials.

  19. Echogenicity in transrectal ultrasound is determined by sound speed of prostate tissue components.

    PubMed

    Tanoue, Hideki; Hagiwara, Yoshihiro; Kobayashi, Kazuto; Saijo, Yoshifumi

    2012-01-01

    Typically, conventional transrectal ultrasound (TRUS) imaging of the cancer tissue is hypoechoic in echo texture. However, TRUS does not reliably distinguish between cancerous and non-cancerous tissue in the prostate. In the present study, sound speed of prostate needle biopsy specimens were measured by ultrasound speed microscope (USM) to construct a database for interpreting clinical TRUS images. Biopsy specimens were formalin-fixed and sectioned approximately 5 µm in thickness. They were mounted on glass slides without cover slips. The ultrasonic transducer with the central frequency of 120 MHz was mechanically scanned over the specimen to measure sound speed distribution. Echo intensity of TRUS images were qualitatively classified into three categories; hyperechoic, iso-echoic and hypoechoic areas. Sound speed was 1596.9 ± 28.2 m/s in hyperechoic, 1571.2 ± 35.8 m/s in iso-echoic and 1562.6 ± 35.1 m/s in hypoechoic area, respectively. However, echo intensity showed no significant relationship to malignancy of prostatic tissue. Echo intensity of TRUS is significantly affected with tissue components and USM findings would provide important information for interpretation of TRUS images. PMID:23365928

  20. 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.

  1. A theoretical and experimental investigation of nonlinear propagation of ultrasound through tissue mimicking media

    NASA Astrophysics Data System (ADS)

    Rielly, Matthew Robert

    An existing numerical model (known as the Bergen code) is used to investigate finite amplitude ultrasound propagation through multiple layers of tissue-like media. This model uses a finite difference method to solve the nonlinear parabolic KZK wave equation. The code is modified to include an arbitrary frequency dependence of absorption and transmission effects for wave propagation across a plane interface at normal incidence. In addition the code is adapted to calculate the total intensity loss associated with the absorption of the fundamental and nonlinearly generated harmonics. Measurements are also taken of the axial nonlinear pressure field generated from a circular focused, 2.25 MHz source, through single and multiple layered tissue mimicking fluids, for source pressures in the range from 13 kPa to 310 kPa. Two tissue mimicking fluids are developed to provide acoustic properties similar to amniotic fluid and a typical soft tissue. The values of the nonlinearity parameter, sound velocity and frequency dependence of attenuation for both fluids are presented, and the measurement procedures employed to obtain these characteristics are described in detail. These acoustic parameters, together with the measured source conditions are used as input to the numerical model, allowing the experimental conditions to be simulated. Extensive comparisons are made between the model's predictions and the axial pressure field measurements. Results are presented in the frequency domain showing the fundamental and three subsequent harmonic amplitudes on axis, as a function of axial distance. These show that significant nonlinear distortion can occur through media with characteristics typical of tissue. Time domain waveform comparisons are also made. An excellent agreement is found between theory and experiment indicating that the model can be used to predict nonlinear ultrasound propagation through multiple layers of tissue-like media. The numerical code is also used to model the

  2. Ultrasound Elastography for Estimation of Regional Strain of Multilayered Hydrogels and Tissue-Engineered Cartilage.

    PubMed

    Chung, Chen-Yuan; Heebner, Joseph; Baskaran, Harihara; Welter, Jean F; Mansour, Joseph M

    2015-12-01

    Tissue-engineered (TE) cartilage constructs tend to develop inhomogeneously, thus, to predict the mechanical performance of the tissue, conventional biomechanical testing, which yields average material properties, is of limited value. Rather, techniques for evaluating regional and depth-dependent properties of TE cartilage, preferably non-destructively, are required. The purpose of this study was to build upon our previous results and to investigate the feasibility of using ultrasound elastography to non-destructively assess the depth-dependent biomechanical characteristics of TE cartilage while in a sterile bioreactor. As a proof-of-concept, and to standardize an assessment protocol, a well-characterized three-layered hydrogel construct was used as a surrogate for TE cartilage, and was studied under controlled incremental compressions. The strain field of the construct predicted by elastography was then validated by comparison with a poroelastic finite-element analysis (FEA). On average, the differences between the strains predicted by elastography and the FEA were within 10%. Subsequently engineered cartilage tissue was evaluated in the same test fixture. Results from these examinations showed internal regions where the local strain was 1-2 orders of magnitude greater than that near the surface. These studies document the feasibility of using ultrasound to evaluate the mechanical behaviors of maturing TE constructs in a sterile environment.

  3. 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.

  4. Ultrasound and clinical evaluation of soft-tissue versus hardware biceps tenodesis: is hardware tenodesis worth the cost?

    PubMed

    Elkousy, Hussein; Romero, Jose A; Edwards, T Bradley; Gartsman, Gary M; O'Connor, Daniel P

    2014-02-01

    This study assesses the failure rate of soft-tissue versus hardware fixation of biceps tenodesis by ultrasound to determine if the expense of a hardware tenodesis technique is warranted. Seventy-two patients that underwent arthroscopic biceps tenodesis over a 3-year period were evaluated using postoperative ultrasonography and clinical examination. The tenodesis technique employed was either a soft-tissue technique with sutures or an interference screw technique using hardware based on surgeon preference. Patient age was 57.9 years on average with ultrasound and clinical examination done at an average of 9.3 months postoperatively. Thirty-one patients had a hardware technique and 41 a soft-tissue technique. Overall, 67.7% of biceps tenodesis done with hardware were intact, compared with 75.6% for the soft-tissue technique by ultrasound (P = .46). Clinical evaluation indicated that 80.7% of hardware techniques and 78% of soft-tissue techniques were intact. Average material cost to the hospital for the hardware technique was $514.32, compared with $32.05 for the soft-tissue technique. Biceps tenodesis success, as determined by clinical deformity and ultrasound, was not improved using hardware as compared to soft-tissue techniques. Soft-tissue techniques are equally efficacious and more cost effective than hardware techniques.

  5. Synergistic ablation of liver tissue and liver cancer cells with high-intensity focused ultrasound and ethanol.

    PubMed

    Hoang, Nguyen H; Murad, Hakm Y; Ratnayaka, Sithira H; Chen, Chong; Khismatullin, Damir B

    2014-08-01

    We investigated the combined effect of ethanol and high-intensity focused ultrasound (HIFU), first, on heating and cavitation bubble activity in tissue-mimicking phantoms and porcine liver tissues and, second, on the viability of HepG2 liver cancer cells. Phantoms or porcine tissues were injected with ethanol and then subjected to HIFU at acoustic power ranging from 1.2 to 20.5 W (HIFU levels 1-7). Cavitation events and the temperature around the focal zone were measured with a passive cavitation detector and embedded type K thermocouples, respectively. HepG2 cells were subjected to 4% ethanol solution in growth medium (v/v) just before the cells were exposed to HIFU at 2.7, 8.7 or 12.0 W for 30 s. Cell viability was measured 2, 24 and 72 h post-treatment. The results indicate that ethanol and HIFU have a synergistic effect on liver cancer ablation as manifested by greater temperature rise and lesion volume in liver tissues and reduced viability of liver cancer cells. This effect is likely caused by reduction of the cavitation threshold in the presence of ethanol and the increased rate of ethanol diffusion through the cell membrane caused by HIFU-induced streaming, sonoporation and heating.

  6. Ultrasound Shear Wave Simulation of Breast Tumor Using Nonlinear Tissue Elasticity

    PubMed Central

    Park, Dae Woo

    2016-01-01

    Shear wave elasticity imaging (SWEI) can assess the elasticity of tissues, but the shear modulus estimated in SWEI is often less sensitive to a subtle change of the stiffness that produces only small mechanical contrast to the background tissues. Because most soft tissues exhibit mechanical nonlinearity that differs in tissue types, mechanical contrast can be enhanced if the tissues are compressed. In this study, a finite element- (FE-) based simulation was performed for a breast tissue model, which consists of a circular (D: 10 mm, hard) tumor and surrounding tissue (soft). The SWEI was performed with 0% to 30% compression of the breast tissue model. The shear modulus of the tumor exhibited noticeably high nonlinearity compared to soft background tissue above 10% overall applied compression. As a result, the elastic modulus contrast of the tumor to the surrounding tissue was increased from 0.46 at 0% compression to 1.45 at 30% compression. PMID:27293476

  7. Ultrasound Applied to Subcutaneous Fat Tissue Measurements in International Elite Canoeists.

    PubMed

    Kopinski, S; Engel, T; Cassel, M; Fröhlich, K; Mayer, F; Carlsohn, A

    2015-12-01

    Subcutaneous adipose tissue (SAT) measurements with ultrasound have recently been introduced to assess body fat in elite athletes. However, appropriate protocols and data on various groups of athletes are missing. We investigated intra-rater reliability of SAT measurements using ultrasound in elite canoe athletes. 25 international level canoeists (18 male, 7 female; 23±4 years; 81±11 kg; 1.83±0.09 m; 20±3 training h/wk) were measured on 2 consecutive days. SAT was assessed with B-mode ultrasound at 8 sites (ISAK): triceps, subscapular, biceps, iliac crest, supraspinal, abdominal, front thigh, medial calf, and quantified using image analysis software. Data was analyzed descriptively (mean±SD, [range]). Coefficient of variation (CV%), intraclass correlation coefficient (ICC, 2.1) and absolute (LoA) and ratio limits of agreement (RLoA) were calculated for day-to-day reliability. Mean sum of SAT thickness was 30.0±19.4 mm [8.0, 80.1 mm], with 3.9±1.8 mm [1.2 mm subscapular, 8.0 mm abdominal] for individual sites. CV for the sum of sites was 4.7%, ICC 0.99, LoA 1.7±3.6 mm, RLoA 0.940 ( *  /÷1.155). Measuring SAT with ultrasound has proved to have excellent day-to-day reliability in elite canoe athletes. Recommendations for standardization of the method will further increase accuracy and reproducibility. PMID:26332903

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

    PubMed

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

    2007-07-01

    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.

  9. Modeling elastic waves in coupled media: Estimate of soft tissue influence and application to quantitative ultrasound.

    PubMed

    Chen, Jiangang; Cheng, Li; Su, Zhongqing; Qin, Ling

    2013-02-01

    The effect of medium coupling on propagation of elastic waves is a general concern in a variety of engineering and bio-medical applications. Although some theories and analytical models are available for describing waves in multi-layered engineering structures, they do not focus on canvassing ultrasonic waves in human bones with coupled soft tissues, where the considerable differences in acoustic impedance between bone and soft tissue may pose a challenge in using these models (the soft tissues having an acoustic impedance around 80% less than that of a typical bone). Without proper treatment of this coupling effect, the precision of quantitative ultrasound (QUS) for clinical bone assessment can be compromised. The coupling effect of mimicked soft tissues on the first-arriving signal (FAS) and second-arriving signal (SAS) in a series of synthesized soft-tissue-bone phantoms was investigated experimentally and calibrated quantitatively. Understanding of the underlying mechanism of the coupling effect was supplemented by a dedicated finite element analysis. As revealed, the medium coupling impacts influence on different wave modes to different degrees: for FAS and SAS, the most significant changes take place when the soft tissues are initially introduced, and the decrease in signal peak energy continues with increase in the thickness or elastic modulus of the soft tissues, but the changes in propagation velocity fluctuate within 5% regardless of further increase in the thickness or elastic modulus of the soft tissues. As an application, the calibrated effects were employed to enhance the precision of SAS-based QUS when used for predicting the simulated healing status of a mimicked bone fracture, to find prediction of healing progress of bone fracture based on changes in velocity of the FAS or the SAS is inaccurate without taking into account the effect of soft tissue coupling, entailing appropriate compensation for the coupling effect.

  10. Ultrasound beam simulations in inhomogeneous tissue geometries using the hybrid angular spectrum method.

    PubMed

    Vyas, Urvi; Christensen, Douglas

    2012-06-01

    The angular spectrum method is a fast, accurate and computationally efficient method for modeling wave propagation. However, the traditional angular spectrum method assumes that the region of propagation has homogenous properties. In this paper, the angular spectrum method is extended to calculate ultrasound wave propagation in inhomogeneous tissue geometries, important for clinical efficacy, patient safety, and treatment reliability in MR-guided focused ultrasound surgery. The inhomogeneous tissue region to be modeled is segmented into voxels, each voxel having a unique speed of sound, attenuation coefficient, and density. The pressure pattern in the 3-D model is calculated by alternating between the space domain and the spatial-frequency domain for each plane of voxels in the model. The new technique was compared with the finite-difference time-domain technique for a model containing attenuation, refraction, and reflection and for a segmented human breast model; although yielding essentially the same pattern, it results in a reduction in calculation times of at least two orders of magnitude.

  11. 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 (λ=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.

  12. Temperature Increase Dependence on Ultrasound Attenuation Coefficient in Innovative Tissue-mimicking Materials

    NASA Astrophysics Data System (ADS)

    Cuccaro, R.; Magnetto, C.; Albo, P. A. Giuliano; Troia, A.; Lago, S.

    Although high intensity focused ultrasound beams (HIFU) have found rapid agreement in clinical environment as a tool for non invasive surgical ablation and controlled destruction of cancer cells, some aspects related to the interaction of ultrasonic waves with tissues, such as the conversion of acoustic energy into heat, are not thoroughly understood. In this work, innovative tissue-mimicking materials (TMMs), based on Agar and zinc acetate, have been used to conduct investigations in order to determine a relation between the sample attenuation coefficient and its temperature increase measured in the focus region when exposed to an HIFU beam. An empirical relation has been deduced establishing useful basis for further processes of validations of numerical models to be adopted for customizing therapeutic treatments.

  13. Interlaced photoacoustic and ultrasound imaging system with real-time coregistration for ovarian tissue characterization

    PubMed Central

    Alqasemi, Umar; Li, Hai; Yuan, Guangqian; Kumavor, Patrick; Zanganeh, Saeid; Zhu, Quing

    2014-01-01

    Abstract. Coregistered ultrasound (US) and photoacoustic imaging are emerging techniques for mapping the echogenic anatomical structure of tissue and its corresponding optical absorption. We report a 128-channel imaging system with real-time coregistration of the two modalities, which provides up to 15 coregistered frames per second limited by the laser pulse repetition rate. In addition, the system integrates a compact transvaginal imaging probe with a custom-designed fiber optic assembly for in vivo detection and characterization of human ovarian tissue. We present the coregistered US and photoacoustic imaging system structure, the optimal design of the PC interfacing software, and the reconfigurable field programmable gate array operation and optimization. Phantom experiments of system lateral resolution and axial sensitivity evaluation, examples of the real-time scanning of a tumor-bearing mouse, and ex vivo human ovaries studies are demonstrated. PMID:25069009

  14. Changes in backscatter of liver tissue due to thermal coagulation induced by focused ultrasound.

    PubMed

    Shishitani, Takashi; Matsuzawa, Ryo; Yoshizawa, Shin; Umemura, Shin-ichiro

    2013-08-01

    Ultrasonic imaging has advantages in its self-consistency in guiding and monitoring ultrasonic treatment such as high-intensity focused ultrasound (HIFU) treatment. Changes in ultrasonic backscatter of tissues due to HIFU treatment have been observed, but their mechanism is still under discussion. In this paper, ultrasonic backscatter of excised and degassed porcine liver tissue was observed before and after HIFU exposure using a diagnostic scanner, and its acoustic impedance was mapped using an ultrasonic microscope. The histology of its pathological specimen was also observed using an optical microscope. The observed decrease in backscatter intensity due to HIFU exposure was consistent with a spatial Fourier analysis of the histology, which also showed changes due to the exposure. The observed increase in acoustic impedance due to the exposure was also consistent with the histological change assuming that the increase was primarily caused by the increase in the concentration of hepatic cells.

  15. [Bases for the formation of an ultrasound diagnostic image of orbital tissue].

    PubMed

    Kharlap, S I; Vashkulatova, E A; Safonova, T N; Skvortsova, N V

    2010-01-01

    The paper touches upon the specific features of the structure of orbital formations, by considering their anatomic topography and biophysical properties. By studying the results of investigations of the morphological and biophysical studies of orbital tissues, the authors analyze their features and compare their relationships. These results unraveling each of the considered orbital anatomic elements from the acoustic profile ranges may be useful in understanding the nature of clinical changes, which will be able to interpret these or those diagnostic signs--guides and to trace their evolution. In addition, this approach can help interpret the texture of an ultrasound digital image of eye socket soft tissue and permit one to look at pathological clinical manifestations from the so-called biophysical essence. This will allow additional information to be gleaned, by analyzing the usual signs.

  16. Feasibility of freehand ultrasound to measure anatomical features associated with deep tissue injury risk.

    PubMed

    Akins, Jonathan S; Vallely, Jaxon J; Karg, Patricia E; Kopplin, Kara; Gefen, Amit; Poojary-Mazzotta, Prerna; Brienza, David M

    2016-09-01

    Deep tissue injuries (DTI) are severe forms of pressure ulcers that start internally and are difficult to diagnose. Magnetic resonance imaging (MRI) is the currently preferred imaging modality to measure anatomical features associated with DTI, but is not a clinically feasible risk assessment tool. B-mode ultrasound (US) is proposed as a practical, alternative technology suitable for bedside or outpatient clinic use. The goal of this research was to confirm US as an imaging modality for acquiring measurements of anatomical features associated with DTI. Tissue thickness measurements using US were reliable (ICC=.948) and highly correlated with MRI measurements (muscle r=.988, p ≤ .001; adipose r=.894, p ≤ .001; total r=.919; p ≤ .001). US measures of muscle tissue thickness were 5.4mm (34.1%) higher than MRI, adipose tissue thickness measures were 1.6mm (11.9%) lower, and total tissue thickness measures were 3.8mm (12.8%) higher. Given the reliability and ability to identify high-risk anatomies, as well as the cost effectiveness and availability, US measurements show promise for use in future development of a patient-specific, bedside, biomechanical risk assessment tool to guide clinicians in appropriate interventions to prevent DTI. PMID:27387907

  17. Biomechanical assessment of plantar foot tissue in diabetic patients using an ultrasound indentation system.

    PubMed

    Zheng, Y P; Choi, Y K; Wong, K; Chan, S; Mak, A F

    2000-03-01

    The biomechanical properties of plantar tissues were investigated for four older neuropathic diabetic patients and four healthy younger subjects. Indentation tests were performed at four high-pressure areas with three postures in each subject. The tissue thickness and effective Young's modulus were measured by an ultrasound (US) indentation system. The system comprised a pen-size probe having a US transducer at the tip and a load cell connected in series with it. Results showed that the plantar soft tissues of the elderly diabetic patients were significantly stiffer and thinner when compared with the healthy young subjects. For the diabetic subjects tested, the Young's modulus at the 1st metatarsal head was significantly larger than those at the other three sites. This site-dependence was not observed in the healthy young subjects. The plantar tissue became significantly stiffer in the healthy young subjects as a result of posture changes. This posture-dependence of the Young's modulus was not established for the elderly diabetic group.

  18. Development of an ultrasound sensitive oxygen carrier for oxygen delivery to hypoxic tissue.

    PubMed

    Eisenbrey, John R; Albala, Lorenzo; Kramer, Michael R; Daroshefski, Nick; Brown, David; Liu, Ji-Bin; Stanczak, Maria; O'Kane, Patrick; Forsberg, Flemming; Wheatley, Margaret A

    2015-01-15

    Radiation therapy is frequently used in the treatment of malignancies, but tumors are often more resistant than the surrounding normal tissue to radiation effects, because the tumor microenvironment is hypoxic. This manuscript details the fabrication and characterization of an ultrasound-sensitive, injectable oxygen microbubble platform (SE61O2) for overcoming tumor hypoxia. SE61O2 was fabricated by first sonicating a mixture of Span 60 and water-soluble vitamin E purged with perfluorocarbon gas. SE61O2 microbubbles were separated from the foam by flotation, then freeze dried under vacuum to remove all perfluorocarbon, and reconstituted with oxygen. Visually, SE61O2 microbubbles were smooth, spherical, with an average diameter of 3.1 μm and were reconstituted to a concentration of 6.5 E7 microbubbles/ml. Oxygen-filled SE61O2 provides 16.9 ± 1.0 dB of enhancement at a dose of 880 μl/l (5.7 E7 microbubbles/l) with a half-life under insonation of approximately 15 min. In in vitro release experiments, 2 ml of SE61O2 (1.3 E8 microbubbles) triggered with ultrasound was found to elevate oxygen partial pressures of 100ml of degassed saline 13.8 mmHg more than untriggered bubbles and 20.6 mmHg more than ultrasound triggered nitrogen-filled bubbles. In preliminary in vivo delivery experiments, triggered SE61O2 resulted in a 30.4 mmHg and 27.4 mmHg increase in oxygen partial pressures in two breast tumor mouse xenografts.

  19. Low intensity pulsed ultrasound increases the mechanical properties of the healing tissues at bone-tendon junction.

    PubMed

    Lu, Min-Hua; Zheng, Yong-Ping; Huang, Qing-Hua; Lu, Hong-Bin; Qin, Ling

    2009-01-01

    The re-establishment of bone-tendon junction (BTJ) tissues is involved in many trauma and reconstructive surgeries. A direct BTJ repair requires a long period of immobilization which may be associated with a postoperative weak knee. In this study, we investigated if low-intensity pulsed ultrasound treatment increases the material properties of healing tissues at bone-tendon junction (BTJ) after partial patellectomy using rabbit models. Standard partial patellectomy was conducted on one knee of twenty four rabbits which were randomly divided into an ultrasound group and a control group. The bony changes of BTJ complexes around the BTJ healing interface were measured by anteroposterior x-ray radiographs; then the volumetric bone-mineral density (BMD) of the new bone was assessed using a peripheral computed tomography scanner (pQCT). The stiffness of patellar cartilage, fibrocartilage at the healing interface and the tendon were measured in situ using a novel noncontact ultrasound water jet indentation system. Not only significantly more newly formed bone at the BTJ healing interface but also increased stiffness of the junction tissues were found in the ultrasound group compared with the controls at week 18. In addition, the ultrasound group also showed significantly 44% higher BMD at week 6 than controls.

  20. Effect of hydrodynamic cavitation in the tissue erosion by pulsed high-intensity focused ultrasound (pHIFU)

    NASA Astrophysics Data System (ADS)

    Zhou, Yufeng; Gao, Xiaobin Wilson

    2016-09-01

    High-intensity focused ultrasound (HIFU) is emerging as an effective therapeutic modality in clinics. Besides the thermal ablation, tissue disintegration is also possible because of the interaction between the distorted HIFU bursts and either bubble cloud or boiling bubble. Hydrodynamic cavitation is another type of cavitation and has been employed widely in industry, but its role in mechanical erosion to tissue is not clearly known. In this study, the bubble dynamics immediately after the termination of HIFU exposure in the transparent gel phantom was captured by high-speed photography, from which the bubble displacement towards the transducer and the changes of bubble size was quantitatively determined. The characteristics of hydrodynamic cavitation due to the release of the acoustic radiation force and relaxation of compressed surrounding medium were found to associate with the number of pulses delivered and HIFU parameters (i.e. pulse duration and pulse repetition frequency). Because of the initial big bubble (~1 mm), large bubble expansion (up to 1.76 folds), and quick bubble motion (up to ~1 m s-1) hydrodynamic cavitation is significant after HIFU exposure and may lead to mechanical erosion. The shielding effect of residual tiny bubbles would reduce the acoustic energy delivered to the pre-existing bubble at the focus and, subsequently, the hydrodynamic cavitation effect. Tadpole shape of mechanical erosion in ex vivo porcine kidney samples was similar to the contour of bubble dynamics in the gel. Liquefied tissue was observed to emit towards the transducer through the punctured tissue after HIFU exposure in the sonography. In summary, the release of HIFU exposure-induced hydrodynamic cavitation produces significant bubble expansion and motion, which may be another important mechanism of tissue erosion. Understanding its mechanism and optimizing the outcome would broaden and enhance HIFU applications.

  1. Effect of hydrodynamic cavitation in the tissue erosion by pulsed high-intensity focused ultrasound (pHIFU)

    NASA Astrophysics Data System (ADS)

    Zhou, Yufeng; Gao, Xiaobin Wilson

    2016-09-01

    High-intensity focused ultrasound (HIFU) is emerging as an effective therapeutic modality in clinics. Besides the thermal ablation, tissue disintegration is also possible because of the interaction between the distorted HIFU bursts and either bubble cloud or boiling bubble. Hydrodynamic cavitation is another type of cavitation and has been employed widely in industry, but its role in mechanical erosion to tissue is not clearly known. In this study, the bubble dynamics immediately after the termination of HIFU exposure in the transparent gel phantom was captured by high-speed photography, from which the bubble displacement towards the transducer and the changes of bubble size was quantitatively determined. The characteristics of hydrodynamic cavitation due to the release of the acoustic radiation force and relaxation of compressed surrounding medium were found to associate with the number of pulses delivered and HIFU parameters (i.e. pulse duration and pulse repetition frequency). Because of the initial big bubble (~1 mm), large bubble expansion (up to 1.76 folds), and quick bubble motion (up to ~1 m s‑1) hydrodynamic cavitation is significant after HIFU exposure and may lead to mechanical erosion. The shielding effect of residual tiny bubbles would reduce the acoustic energy delivered to the pre-existing bubble at the focus and, subsequently, the hydrodynamic cavitation effect. Tadpole shape of mechanical erosion in ex vivo porcine kidney samples was similar to the contour of bubble dynamics in the gel. Liquefied tissue was observed to emit towards the transducer through the punctured tissue after HIFU exposure in the sonography. In summary, the release of HIFU exposure-induced hydrodynamic cavitation produces significant bubble expansion and motion, which may be another important mechanism of tissue erosion. Understanding its mechanism and optimizing the outcome would broaden and enhance HIFU applications.

  2. Error in Estimates of Tissue Material Properties from Shear Wave Dispersion Ultrasound Vibrometry

    PubMed Central

    Urban, Matthew W.; Chen, Shigao; Greenleaf, James F.

    2009-01-01

    Shear wave velocity measurements are used in elasticity imaging to find the shear elasticity and viscosity of tissue. A technique called shear wave dispersion ultrasound vibrometry (SDUV) has been introduced to use the dispersive nature of shear wave velocity to locally estimate the material properties of tissue. Shear waves are created using a multifrequency ultrasound radiation force, and the propagating shear waves are measured a few millimeters away from the excitation point. The shear wave velocity is measured using a repetitive pulse-echo method and Kalman filtering to find the phase of the harmonic shear wave at 2 different locations. A viscoelastic Voigt model and the shear wave velocity measurements at different frequencies are used to find the shear elasticity (μ1) and viscosity (μ2) of the tissue. The purpose of this paper is to report the accuracy of the SDUV method over a range of different values of μ1 and μ2. A motion detection model of a vibrating scattering medium was used to analyze measurement errors of vibration phase in a scattering medium. To assess the accuracy of the SDUV method, we modeled the effects of phase errors on estimates of shear wave velocity and material properties while varying parameters such as shear stiffness and viscosity, shear wave amplitude, the distance between shear wave measurements (Δr), signal-to-noise ratio (SNR) of the ultrasound pulse-echo method, and the frequency range of the measurements. We performed an experiment in a section of porcine muscle to evaluate variation of the aforementioned parameters on the estimated shear wave velocity and material property measurements and to validate the error prediction model. The model showed that errors in the shear wave velocity and material property estimates were minimized by maximizing shear wave amplitude, pulse-echo SNR, Δr, and the bandwidth used for shear wave measurements. The experimental model showed optimum performance could be obtained for Δr = 3-6 mm

  3. Paraffin-gel tissue-mimicking material for ultrasound-guided needle biopsy phantom.

    PubMed

    Vieira, Sílvio L; Pavan, Theo Z; Junior, Jorge E; Carneiro, Antonio A O

    2013-12-01

    Paraffin-gel waxes have been investigated as new soft tissue-mimicking materials for ultrasound-guided breast biopsy training. Breast phantoms were produced with a broad range of acoustical properties. The speed of sound for the phantoms ranged from 1425.4 ± 0.6 to 1480.3 ± 1.7 m/s at room temperature. The attenuation coefficients were easily controlled between 0.32 ± 0.27 dB/cm and 2.04 ± 0.65 dB/cm at 7.5 MHz, depending on the amount of carnauba wax added to the base material. The materials do not suffer dehydration and provide adequate needle penetration, with a Young's storage modulus varying between 14.7 ± 0.2 kPa and 34.9 ± 0.3 kPa. The phantom background material possesses long-term stability and can be employed in a supine position without changes in geometry. These results indicate that paraffin-gel waxes may be promising materials for training radiologists in ultrasound biopsy procedures.

  4. Primary Mucosa-Associated Lymphoid Tissue Lymphoma of Thyroid with the Serial Ultrasound Findings

    PubMed Central

    Jeon, Eon Ju; Shon, Ho Sang; Jung, Eui Dal

    2016-01-01

    Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) of the thyroid gland is uncommon. Even though its natural history is not well defined, it is known to be indolent course. We present a case of primary MALT thyroid lymphoma with the serial sonographic findings in the patient presenting as the focal nodule. A 45-year-old woman visited our hospital for neck examination. Initially, fine-needle aspiration cytology in the focal hypoechoic lesion in the left thyroid lobe on ultrasound sonography was performed and consistent with Hashimoto's thyroiditis. However, the results of serial ultrasounds and core-needle biopsy revealed an extranodal marginal zone lymphoma of MALT on 4-year follow-up. Patients with a focal hypoechoic nodule with linear echogenic strands and segmental pattern in the background of Hashimoto's thyroiditis on ultrasonography should undergo careful surveillance for malignancy. Serial sonographic features in this case are meaningful in the understanding of the natural history of the extranodal marginal zone lymphoma of MALT of the thyroid. PMID:27099797

  5. Interrogating the viscoelastic properties of tissue using viscoelastic response (VISR) ultrasound

    NASA Astrophysics Data System (ADS)

    Selzo, Mallory Renee

    Affecting approximately 1 in 3,500 newborn males, Duchenne muscular dystrophy (DMD) is one of the most common lethal genetic disorders in humans. Boys with DMD suffer progressive loss of muscle strength and function, leading to wheelchair dependence, cardiac and respiratory compromise, and death during young adulthood. There are currently no treatments that can halt or reverse the disease progression, and translating prospective treatments into clinical trials has been delayed by inadequate outcome measures. Current outcome measures, such as functional and muscle strength assessments, lack sensitivity to individual muscles, require subjective effort of the child, and are impacted by normal childhood growth and development. The goal of this research is to develop Viscoelastic Response (VisR) ultrasound which can be used to delineate compositional changes in muscle associated with DMD. In VisR, acoustic radiation force (ARF) is used to produce small, localized displacements within the muscle. Using conventional ultrasound to track the motion, the displacement response of the tissue can be evaluated against a mechanical model. In order to develop signal processing techniques and assess mechanical models, finite element method simulations are used to model the response of a viscoelastic material to ARF excitations. Results are then presented demonstrating VisR differentiation of viscoelastic changes with progressive dystrophic degeneration in a dog model of DMD. Finally, clinical feasibility of VisR imaging is demonstrated in two boys with DMD.

  6. VISUALIZING THE STRESS DISTRIBUTION WITHIN VASCULAR TISSUES USING INTRAVASCULAR ULTRASOUND ELASTOGRAPHY: A PRELIMINARY INVESTIGATION

    PubMed Central

    Richards, Michael S.; Perucchio, Renato; Doyley, Marvin M.

    2015-01-01

    A methodology for computing the stress distribution of vascular tissue using finite element-based, intravascular ultrasound (IVUS) reconstruction elastography is described. This information could help cardiologists detect life-threatening atherosclerotic plaques and predict their propensity to rupture. The calculation of vessel stresses requires the measurement of strain from the ultrasound images, a calibrating pressure measurement and additional model assumptions. In this work, we conducted simulation studies to investigate the effect of varying the model assumptions, specifically Poisson’s ratio and the outer boundary conditions, on the resulting stress fields. In both simulation and phantom studies, we created vessel geometries with two fibrous cap thicknesses to determine if we could detect a difference in peak stress (spatially) between the two. The results revealed that (i) Poisson’s ratios had negligible impact on the accuracy of stress elastograms, (ii) the outer boundary condition assumption had the greatest effect on the resulting modulus and stress distributions and (iii) in simulation and in phantom experiments, our stress imaging technique was able to detect an increased peak stress for the vessel geometry with the smaller cap thickness. This work is a first step toward understanding and creating a robust stress measurement technique for evaluating atherosclerotic plaques using IVUS elastography. PMID:25837424

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Ultrasound for noninvasive control of laser-induced tissue heating and coagulation

    NASA Astrophysics Data System (ADS)

    Kleffner, Bernhard; Kriegerowski, Martin; Oltrup, Theo; Bende, Thomas; Jean, Benedikt J.

    1996-05-01

    The application of lasers to achieve localized thermal tissue damage is a common technique in minimally invasive surgery. Currently, there is no control during these treatments. In glaucoma therapy the laser energy applied and the beam direction are estimated prior to treatment, according to clinical experience and anatomic norm values. This lack of on-line control may limit success and lead to side effects. Precision and efficiency of treatment could be improved markedly by analysis of spatially resolved, temperature-dependent data obtained by Ultrasound Reflectometry. Thermally induced changes, as well as their localization were detected qualitatively in B-scan. Quantification was achieved by integration of high frequency RF-signals with the following resolution: spatial 50 micrometers , temporal 200 microsecond(s) , temperature 0.5 degree(s). The presented method is suitable for a non-invasive on-line therapy control.

  9. 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.

  10. Comparison between shear wave dispersion magneto motive ultrasound and transient elastography for measuring tissue-mimicking phantom viscoelasticity.

    PubMed

    Almeida, Thiago W J; Sampaio, Diego R Thomaz; Bruno, Alexandre Colello; Pavan, Theo Z; Carneiro, Antonio A O

    2015-12-01

    Several methods have been developed over the last several years to analyze the mechanical properties of soft tissue. Elastography, for example, was proposed to evaluate soft tissue stiffness in an attempt to reduce the need for invasive procedures, such as breast biopsies; however, its qualitative nature and the fact that it is operator-dependent have proven to be limitations of the technique. Quantitative shearwave- based techniques have been proposed to obtain information about tissue stiffness independent of the operator. This paper describes shear wave dispersion magnetomotive ultrasound (SDMMUS), a new shear-wave-based method in which a viscoelastic medium labeled with iron oxide nanoparticles is displaced by an external tone burst magnetic field. As in magnetomotive ultrasound (MMUS), SDMMUS uses ultrasound to detect internal mechanical vibrations induced by the interaction between a magnetic field and magnetic nanoparticles. These vibrations generated shear waves that were evaluated to estimate the viscoelastic properties of tissue-mimicking phantoms. These phantoms were manufactured with different concentrations of gelatin and labeled with iron oxide nanoparticles. The elasticity and viscosity obtained with SDMMUS agreed well with the results obtained by traditional ultrasound-based transient elastography.

  11. 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.

  12. Computer-aided diagnosis of peripheral soft tissue masses based on ultrasound imaging.

    PubMed

    Chiou, Hong-Jen; Chen, Chih-Yen; Liu, Tzu-Chiang; Chiou, See-Ying; Wang, Hsin-Kai; Chou, Yi-Hong; Chiang, Huihua Kenny

    2009-07-01

    Medical ultrasound (US) has been widely used for distinguishing benign from malignant peripheral soft tissue tumors. However, diagnosis by US is subjective and depends on the experience of the radiologists. The rarity of peripheral soft tissue tumors can make them easily neglected and this frequently leads to delayed diagnosis, which results in a much higher death rate than with other tumors. In this paper, we developed a computer-aided diagnosis (CAD) system to diagnose peripheral soft tissue masses on US images. We retrospectively evaluated 49 cases of pathologically proven peripheral soft tissue masses (32 benign, 17 malignant). The proposed CAD system includes three main procedures: image pre-processing and region-of-interest (ROI) segmentation, feature extraction and statistics-based discriminant analysis (DA). We developed a depth-normalization factor (DNF) to compensate for the influence of the depth setting on the apparent size of the ROI. After image pre-processing and normalization, five features, namely area (A), boundary transition ratio (T), circularity (C), high intensity spots (H) and uniformity (U), were extracted from the US images. A DA function was then employed to analyze these features. A CAD algorithm was then devised for differentiating benign from malignant masses. The CAD system achieved an accuracy of 87.8%, a sensitivity of 88.2%, a specificity of 87.5%, a positive predictive value (PPV) 78.9% and a negative predictive value (NPV) 93.3%. These results indicate that the CAD system is valuable as a means of providing a second diagnostic opinion when radiologists carry out peripheral soft tissue mass diagnosis.

  13. Pulsed ultrasound enhances the delivery of nitric oxide from bubble liposomes to ex vivo porcine carotid tissue.

    PubMed

    Sutton, J T; Raymond, J L; Verleye, M C; Pyne-Geithman, G J; Holland, C K

    2014-01-01

    Ultrasound-mediated drug delivery is a novel technique for enhancing the penetration of drugs into diseased tissue beds noninvasively. By encapsulating drugs into microsized and nanosized liposomes, the therapeutic can be shielded from degradation within the vasculature until delivery to a target site by ultrasound exposure. Traditional in vitro or ex vivo techniques to quantify this delivery profile include optical approaches, cell culture, and electrophysiology. Here, we demonstrate an approach to characterize the degree of nitric oxide (NO) delivery to porcine carotid tissue by direct measurement of ex vivo vascular tone. An ex vivo perfusion model was adapted to assess ultrasound-mediated delivery of NO. This potent vasodilator was coencapsulated with inert octafluoropropane gas to produce acoustically active bubble liposomes. Porcine carotid arteries were excised post mortem and mounted in a physiologic buffer solution. Vascular tone was assessed in real time by coupling the artery to an isometric force transducer. NO-loaded bubble liposomes were infused into the lumen of the artery, which was exposed to 1 MHz pulsed ultrasound at a peak-to-peak acoustic pressure amplitude of 0.34 MPa. Acoustic cavitation emissions were monitored passively. Changes in vascular tone were measured and compared with control and sham NO bubble liposome exposures. Our results demonstrate that ultrasound-triggered NO release from bubble liposomes induces potent vasorelaxation within porcine carotid arteries (maximal relaxation 31%± 8%), which was significantly stronger than vasorelaxation due to NO release from bubble liposomes in the absence of ultrasound (maximal relaxation 7%± 3%), and comparable with relaxation due to 12 μM sodium nitroprusside infusions (maximal relaxation 32%± 3%). This approach is a valuable mechanistic tool for assessing the extent of drug release and delivery to the vasculature caused by ultrasound.

  14. Implementation of a Rotational Ultrasound Biomicroscopy System Equipped with a High-Frequency Angled Needle Transducer — Ex Vivo Ultrasound Imaging of Porcine Ocular Posterior Tissues

    PubMed Central

    Bok, Tae-Hoon; Kim, Juho; Bae, Jinho; Lee, Chong Hyun; Paeng, Dong-Guk

    2014-01-01

    The mechanical scanning of a single element transducer has been mostly utilized for high-frequency ultrasound imaging. However, it requires space for the mechanical motion of the transducer. In this paper, a rotational scanning ultrasound biomicroscopy (UBM) system equipped with a high-frequency angled needle transducer is designed and implemented in order to minimize the space required. It was applied to ex vivo ultrasound imaging of porcine posterior ocular tissues through a minimal incision hole of 1 mm in diameter. The retina and sclera for the one eye were visualized in the relative rotating angle range of 270° ∼ 330° and at a distance range of 6 ∼ 7 mm, whereas the tissues of the other eye were observed in relative angle range of 160° ∼ 220° and at a distance range of 7.5 ∼ 9 mm. The layer between retina and sclera seemed to be bent because the distance between the transducer tip and the layer was varied while the transducer was rotated. Certin features of the rotation system such as the optimal scanning angle, step angle and data length need to be improved for ensure higher accuracy and precision. Moreover, the focal length should be considered for the image quality. This implementation represents the first report of a rotational scanning UBM system. PMID:25254305

  15. Non-invasive assessment of negative pressure wound therapy using high frequency diagnostic ultrasound: oedema reduction and new tissue accumulation.

    PubMed

    Young, Stephen R; Hampton, Sylvie; Martin, Robin

    2013-08-01

    Tissue oedema plays an important role in the pathology of chronic and traumatic wounds. Negative pressure wound therapy (NPWT) is thought to contribute to active oedema reduction, yet few studies have showed this effect. In this study, high frequency diagnostic ultrasound at 20 MHz with an axial resolution of 60 µm was used to assess the effect of NPWT at - 80 mmHg on pressure ulcers and the surrounding tissue. Wounds were monitored in four patients over a 3-month period during which changes in oedema and wound bed thickness (granulation tissue) were measured non-invasively. The results showed a rapid reduction of periwound tissue oedema in all patients with levels falling by a mean of 43% after 4 days of therapy. A 20% increase in the thickness of the wound bed was observed after 7 days due to new granulation tissue formation. Ultrasound scans through the in situ gauze NPWT filler also revealed the existence of macrodeformation in the tissue produced by the negative pressure. These preliminary studies suggest that non-invasive assessment using high frequency diagnostic ultrasound could be a valuable tool in clinical studies of NPWT.

  16. Achondrogenesis type 2 diagnosed by transvaginal ultrasound at 12 weeks' gestation.

    PubMed

    Soothill, P W; Vuthiwong, C; Rees, H

    1993-06-01

    Ultrasound examination at 12 weeks' gestation revealed severe generalised subcutaneous oedema in a pregnancy at risk for achondrogenesis type II. Transvaginal scanning confirmed the oedema and suggested abnormal limb development. The prenatal diagnosis was confirmed by X-ray examination after transvaginal termination. PMID:8372079

  17. Determining temperature distribution in tissue in the focal plane of the high (>100 W/cm(2)) intensity focused ultrasound beam using phase shift of ultrasound echoes.

    PubMed

    Karwat, Piotr; Kujawska, Tamara; Lewin, Peter A; Secomski, Wojciech; Gambin, Barbara; Litniewski, Jerzy

    2016-02-01

    In therapeutic applications of High Intensity Focused Ultrasound (HIFU) the guidance of the HIFU beam and especially its focal plane is of crucial importance. This guidance is needed to appropriately target the focal plane and hence the whole focal volume inside the tumor tissue prior to thermo-ablative treatment and beginning of tissue necrosis. This is currently done using Magnetic Resonance Imaging that is relatively expensive. In this study an ultrasound method, which calculates the variations of speed of sound in the locally heated tissue volume by analyzing the phase shifts of echo-signals received by an ultrasound scanner from this very volume is presented. To improve spatial resolution of B-mode imaging and minimize the uncertainty of temperature estimation the acoustic signals were transmitted and received by 8 MHz linear phased array employing Synthetic Transmit Aperture (STA) technique. Initially, the validity of the algorithm developed was verified experimentally in a tissue-mimicking phantom heated from 20.6 to 48.6 °C. Subsequently, the method was tested using a pork loin sample heated locally by a 2 MHz pulsed HIFU beam with focal intensity ISATA of 129 W/cm(2). The temperature calibration of 2D maps of changes in the sound velocity induced by heating was performed by comparison of the algorithm-determined changes in the sound velocity with the temperatures measured by thermocouples located in the heated tissue volume. The method developed enabled ultrasound temperature imaging of the heated tissue volume from the very inception of heating with the contrast-to-noise ratio of 3.5-12 dB in the temperature range 21-56 °C. Concurrently performed, conventional B-mode imaging revealed CNR close to zero dB until the temperature reached 50 °C causing necrosis. The data presented suggest that the proposed method could offer an alternative to MRI-guided temperature imaging for prediction of the location and extent of the thermal lesion prior to applying the

  18. Determining temperature distribution in tissue in the focal plane of the high (>100 W/cm(2)) intensity focused ultrasound beam using phase shift of ultrasound echoes.

    PubMed

    Karwat, Piotr; Kujawska, Tamara; Lewin, Peter A; Secomski, Wojciech; Gambin, Barbara; Litniewski, Jerzy

    2016-02-01

    In therapeutic applications of High Intensity Focused Ultrasound (HIFU) the guidance of the HIFU beam and especially its focal plane is of crucial importance. This guidance is needed to appropriately target the focal plane and hence the whole focal volume inside the tumor tissue prior to thermo-ablative treatment and beginning of tissue necrosis. This is currently done using Magnetic Resonance Imaging that is relatively expensive. In this study an ultrasound method, which calculates the variations of speed of sound in the locally heated tissue volume by analyzing the phase shifts of echo-signals received by an ultrasound scanner from this very volume is presented. To improve spatial resolution of B-mode imaging and minimize the uncertainty of temperature estimation the acoustic signals were transmitted and received by 8 MHz linear phased array employing Synthetic Transmit Aperture (STA) technique. Initially, the validity of the algorithm developed was verified experimentally in a tissue-mimicking phantom heated from 20.6 to 48.6 °C. Subsequently, the method was tested using a pork loin sample heated locally by a 2 MHz pulsed HIFU beam with focal intensity ISATA of 129 W/cm(2). The temperature calibration of 2D maps of changes in the sound velocity induced by heating was performed by comparison of the algorithm-determined changes in the sound velocity with the temperatures measured by thermocouples located in the heated tissue volume. The method developed enabled ultrasound temperature imaging of the heated tissue volume from the very inception of heating with the contrast-to-noise ratio of 3.5-12 dB in the temperature range 21-56 °C. Concurrently performed, conventional B-mode imaging revealed CNR close to zero dB until the temperature reached 50 °C causing necrosis. The data presented suggest that the proposed method could offer an alternative to MRI-guided temperature imaging for prediction of the location and extent of the thermal lesion prior to applying the

  19. 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.

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

    PubMed

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

    2007-02-01

    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 in the fast time (A-line) of ultrasound echoes, which are difficult to estimate. In slow time (repetitive ultrasound echoes) of the echoes, the motion also is presented as oscillatory phase shifts, from which the amplitude and phase of the harmonic motion can be estimated with the least mean squared error by Kalman filter. This technique can be used to estimate the traveling speed of a harmonic shear wave by tracking its phase changes during propagation. The shear wave propagation speed can be used to solve for the elasticity and viscosity of tissue as reported in our earlier study. Validation and in vitro experiments indicate that the method provides excellent estimations for very small (submicron) harmonic vibrations and has potential for noninvasive and quantitative stiffness measurements of tissues such as artery.

  1. 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.

  2. 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.

  3. Feasibility of coded vibration in a vibro-ultrasound system for tissue elasticity measurement.

    PubMed

    Zhao, Jinxin; Wang, Yuanyuan; Yu, Jinhua; Li, Tianjie; Zheng, Yong-Ping

    2016-07-01

    The ability of various methods for elasticity measurement and imaging is hampered by the vibration amplitude on biological tissues. Based on the inference that coded excitation will improve the performance of the cross-correlation function of the tissue displacement waves, the idea of exerting encoded external vibration on tested samples for measuring its elasticity is proposed. It was implemented by integrating a programmable vibration generation function into a customized vibro-ultrasound system to generate Barker coded vibration for elasticity measurement. Experiments were conducted on silicone phantoms and porcine muscles. The results showed that coded excitation of the vibration enhanced the accuracy and robustness of the elasticity measurement especially in low signal-to-noise ratio scenarios. In the phantom study, the measured shear modulus values with coded vibration had an R(2 )= 0.993 linear correlation to that of referenced indentation, while for single-cycle pulse the R(2) decreased to 0.987. In porcine muscle study, the coded vibration also obtained a shear modulus value which is more accurate than the single-cycle pulse by 0.16 kPa and 0.33 kPa at two different depths. These results demonstrated the feasibility and potentiality of the coded vibration for enhancing the quality of elasticity measurement and imaging. PMID:27475130

  4. Heating of tissues in vivo by pulsed focused ultrasound to stimulate enhanced HSP expression

    NASA Astrophysics Data System (ADS)

    Kujawska, Tamara; Wójcik, Janusz; Nowicki, Andrzej

    2011-09-01

    The main aim of this work was numerical modeling of temperature fields induced in soft tissues in vivo by pulsed focused ultrasound during neurodegenerative disease treatment and experimental verification of the proposed model for a rat liver. The new therapeutic approach to neurodegenerative diseases consists of stimulation of enhanced expression of the Heat Shock Proteins (HSP) which are responsible for immunity of cells to stress. During therapy the temperature rise in tissues in vivo should not exceed 6 °C above level of the thermal norm (37 °C). First, the 3D acoustic pressure field, and the rate of heat production per unit volume due to that field, were calculated using our 3D numerical solver capable of predicting nonlinear propagation of pulsed high intensity waves generated from circular focused acoustic sources in multilayer configuration of attenuating media. The two-layer configuration of media (water—rat liver) assumed in calculations fairly well approximated both the real anatomic dimensions of rat liver and the geometric scheme of our experimental set-up. A numerical solution of the Pennes bio-heat transfer equation which accounted for the effects of heat diffusion, blood perfusion and metabolism rates, was employed to calculate the temperature fields induced in the rat liver by the ultrasonic beam. The numerical simulation results were verified experimentally using a thermocouple inserted in the liver of a rat under anesthesia at the beam focus. The quantitative analysis of the obtained results enabled estimation of the effects of several acoustic and thermal parameters of the rat liver in vivo on the temperature rise, as well as determination of exposure time for ultrasonic beams with varied acoustic power generated by a 2-MHz circular transducer of 15-mm diameter and 25-mm focal length, in order to avoid the tissue overheating that leads to cells necrosis, which would be unacceptable in neurodegenerative disease treatment.

  5. 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 μg/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.

  6. 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.

  7. High-speed observation of cavitation bubble clouds near a tissue boundary in high-intensity focused ultrasound fields.

    PubMed

    Chen, Hong; Li, Xiaojing; Wan, Mingxi; Wang, Supin

    2009-03-01

    Cavitation bubble clouds generated near a tissue boundary by high-intensity focused ultrasound (HIFU) were studied using high-speed photography. In all, 171 image series were captured during the initial 100 ms of continuous HIFU exposure, which showed that cavitation bubble clouds at the tissue boundary organized into two structures - "cone-shape bubble cloud structure" recorded in 146 image series and "crown-shape bubble cloud structure" recorded in 18 image series. The remaining 7 image series showed the interchanging of these two structures. It was found that when cavitation bubbles first appeared at the tissue boundary, they developed to cone-shape bubble cloud. The cone-shape bubble cloud structure was characterized by a nearly fixed tip in front of the tissue boundary. When the cavitation bubbles initially appeared away from the tissue boundary they evolved into a crown-shape bubble cloud. Deformation of tissue boundary was shown in all the recorded image series.

  8. High-speed observation of cavitation bubble clouds near a tissue boundary in high-intensity focused ultrasound fields.

    PubMed

    Chen, Hong; Li, Xiaojing; Wan, Mingxi; Wang, Supin

    2009-03-01

    Cavitation bubble clouds generated near a tissue boundary by high-intensity focused ultrasound (HIFU) were studied using high-speed photography. In all, 171 image series were captured during the initial 100 ms of continuous HIFU exposure, which showed that cavitation bubble clouds at the tissue boundary organized into two structures - "cone-shape bubble cloud structure" recorded in 146 image series and "crown-shape bubble cloud structure" recorded in 18 image series. The remaining 7 image series showed the interchanging of these two structures. It was found that when cavitation bubbles first appeared at the tissue boundary, they developed to cone-shape bubble cloud. The cone-shape bubble cloud structure was characterized by a nearly fixed tip in front of the tissue boundary. When the cavitation bubbles initially appeared away from the tissue boundary they evolved into a crown-shape bubble cloud. Deformation of tissue boundary was shown in all the recorded image series. PMID:19041998

  9. Ultrasound-mediated gene transfer (sonoporation) in fibrin-based matrices: potential for use in tissue regeneration.

    PubMed

    Nomikou, Nikolitsa; Feichtinger, Georg A; Redl, Heinz; McHale, Anthony P

    2016-01-01

    It has been suggested that gene transfer into donor cells is an efficient and practical means of locally supplying requisite growth factors for applications in tissue regeneration. Here we describe, for the first time, an ultrasound-mediated system that can non-invasively facilitate gene transfer into cells entrapped within fibrin-based matrices. Since ultrasound-mediated gene transfer is enhanced using microbubbles, we compared the efficacy of neutral and cationic forms of these reagents on the ultrasound-stimulated gene transfer process in gel matrices. In doing so we demonstrated the beneficial effects associated with the use of cationic microbubble preparations that interact directly with cells and nucleic acid within matrices. In some cases, gene expression was increased two-fold in gel matrices when cationic microbubbles were compared with neutral microbubbles. In addition, incorporating collagen into fibrin gels yielded a 25-fold increase in gene expression after application of ultrasound to microbubble-containing matrices. We suggest that this novel system may facilitate non-invasive temporal and spatial control of gene transfer in gel-based matrices for the purposes of tissue regeneration.

  10. Towards the feasibility of using ultrasound to determine mechanical properties of tissues in a bioreactor.

    PubMed

    Mansour, Joseph M; Gu, Di-Win Marine; Chung, Chen-Yuan; Heebner, Joseph; Althans, Jake; Abdalian, Sarah; Schluchter, Mark D; Liu, Yiying; Welter, Jean F

    2014-10-01

    Our ultimate goal is to non-destructively evaluate mechanical properties of tissue-engineered (TE) cartilage using ultrasound (US). We used agarose gels as surrogates for TE cartilage. Previously, we showed that mechanical properties measured using conventional methods were related to those measured using US, which suggested a way to non-destructively predict mechanical properties of samples with known volume fractions. In this study, we sought to determine whether the mechanical properties of samples, with unknown volume fractions could be predicted by US. Aggregate moduli were calculated for hydrogels as a function of SOS, based on concentration and density using a poroelastic model. The data were used to train a statistical model, which we then used to predict volume fractions and mechanical properties of unknown samples. Young's and storage moduli were measured mechanically. The statistical model generally predicted the Young's moduli in compression to within <10% of their mechanically measured value. We defined positive linear correlations between the aggregate modulus predicted from US and both the storage and Young's moduli determined from mechanical tests. Mechanical properties of hydrogels with unknown volume fractions can be predicted successfully from US measurements. This method has the potential to predict mechanical properties of TE cartilage non-destructively in a bioreactor. PMID:25092421

  11. Classification algorithm of ovarian tissue based on co-registered ultrasound and photoacoustic tomography

    NASA Astrophysics Data System (ADS)

    Li, Hai; Kumavor, Patrick D.; Alqasemi, Umar; Zhu, Quing

    2014-03-01

    Human ovarian tissue features extracted from photoacoustic spectra data, beam envelopes and co-registered ultrasound and photoacoustic images are used to characterize cancerous vs. normal processes using a support vector machine (SVM) classifier. The centers of suspicious tumor areas are estimated from the Gaussian fitting of the mean Radon transforms of the photoacoustic image along 0 and 90 degrees. Normalized power spectra are calculated using the Fourier transform of the photoacoustic beamformed data across these suspicious areas, where the spectral slope and 0-MHz intercepts are extracted. Image statistics, envelope histogram fitting and maximum output of 6 composite filters of cancerous or normal patterns along with other previously used features are calculated to compose a total of 17 features. These features are extracted from 169 datasets of 19 ex vivo ovaries. Half of the cancerous and normal datasets are randomly chosen to train a SVM classifier with polynomial kernel and the remainder is used for testing. With 50 times data resampling, the SVM classifier, for the training group, gives 100% sensitivity and 100% specificity. For the testing group, it gives 89.68+/- 6.37% sensitivity and 93.16+/- 3.70% specificity. These results are superior to those obtained earlier by our group using features extracted from photoacoustic raw data or image statistics only.

  12. 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.

  13. Quality assurance for ultrasound scanners using a durable tissue-mimicking phantom and radial MTF

    NASA Astrophysics Data System (ADS)

    Kaar, Marcus; Semturs, Friedrich; Figl, Michael; Hoffmann, Rainer; Hummel, Johann

    2014-03-01

    For the use in routine technical quality assurance (TQA) we developed a tissue-mimicking phantom and an evaluation algorithm. Key properties of US phantom materials are sound velocity and acoustic attenuation. For daily clinical use the material also has to be nontoxic, durable and easy in handling and maintenance. The base material of our phantom is Poly(vinyl alcohol) (PVA), a synthetic polymer. By freezing the phantom body during the production process, it changes its sound velocity to closely match the one of the human body. The phantom's base form is a cuboid containing a large anechoic cylindric target. In routine QA it is required to gain comparable and reproducible results from a single image. To determine spatial resolution of phantom images, we calculate a modulation transfer function (MTF). We developed an algorithm, that calculates a radial MTF from a circular structure representing spatial resolution averaged across all directions. For evaluation of the algorithm, we created a set of synthetic images. A comparison of the results from a traditional slanted edge algorithm and our solution showed a close correlation. The US phantom was imaged with a commercial US-scanner at different sound frequencies. The computed MTFs of higher frequency images show higher transfer percentages in all spatial frequencies than the MTFs of lower frequency images. The results suggest that the proposed method produces clear statements about the spatial resolution of evaluated imaging devices. We therefore consider the method as suitable for application in technical quality assurance of diagnostic ultrasound scanners.

  14. Towards the feasibility of using ultrasound to determine mechanical properties of tissues in a bioreactor

    PubMed Central

    Mansour, Joseph M.; Gu, Di-Win Marine; Chung, Chen-Yuan; Heebner, Joseph; Althans, Jake; Abdalian, Sarah; Schluchter, Mark D.; Liu, Yiying; Welter, Jean F.

    2016-01-01

    Introduction Our ultimate goal is to non-destructively evaluate mechanical properties of tissue-engineered (TE) cartilage using ultrasound (US). We used agarose gels as surrogates for TE cartilage. Previously, we showed that mechanical properties measured using conventional methods were related to those measured using US, which suggested a way to non-destructively predict mechanical properties of samples with known volume fractions. In this study, we sought to determine whether the mechanical properties of samples, with unknown volume fractions could be predicted by US. Methods Aggregate moduli were calculated for hydrogels as a function of SOS, based on concentration and density using a poroelastic model. The data were used to train a statistical model, which we then used to predict volume fractions and mechanical properties of unknown samples. Young's and storage moduli were measured mechanically. Results The statistical model generally predicted the Young's moduli in compression to within < 10% of their mechanically measured value. We defined positive linear correlations between the aggregate modulus predicted from US and both the storage and Young's moduli determined from mechanical tests. Conclusions Mechanical properties of hydrogels with unknown volume fractions can be predicted successfully from US measurements. This method has the potential to predict mechanical properties of TE cartilage non-destructively in a bioreactor. PMID:25092421

  15. Towards the feasibility of using ultrasound to determine mechanical properties of tissues in a bioreactor.

    PubMed

    Mansour, Joseph M; Gu, Di-Win Marine; Chung, Chen-Yuan; Heebner, Joseph; Althans, Jake; Abdalian, Sarah; Schluchter, Mark D; Liu, Yiying; Welter, Jean F

    2014-10-01

    Our ultimate goal is to non-destructively evaluate mechanical properties of tissue-engineered (TE) cartilage using ultrasound (US). We used agarose gels as surrogates for TE cartilage. Previously, we showed that mechanical properties measured using conventional methods were related to those measured using US, which suggested a way to non-destructively predict mechanical properties of samples with known volume fractions. In this study, we sought to determine whether the mechanical properties of samples, with unknown volume fractions could be predicted by US. Aggregate moduli were calculated for hydrogels as a function of SOS, based on concentration and density using a poroelastic model. The data were used to train a statistical model, which we then used to predict volume fractions and mechanical properties of unknown samples. Young's and storage moduli were measured mechanically. The statistical model generally predicted the Young's moduli in compression to within <10% of their mechanically measured value. We defined positive linear correlations between the aggregate modulus predicted from US and both the storage and Young's moduli determined from mechanical tests. Mechanical properties of hydrogels with unknown volume fractions can be predicted successfully from US measurements. This method has the potential to predict mechanical properties of TE cartilage non-destructively in a bioreactor.

  16. Comb-push Ultrasound Shear Elastography (CUSE): A Novel Method for Two-dimensional Shear Elasticity Imaging of Soft Tissues

    PubMed Central

    Song, Pengfei; Zhao, Heng; Manduca, Armando; Urban, Matthew W.; Greenleaf, James F.; Chen, Shigao

    2012-01-01

    Fast and accurate tissue elasticity imaging is essential in studying dynamic tissue mechanical properties. Various ultrasound shear elasticity imaging techniques have been developed in the last two decades. However, to reconstruct a full field-of-view 2D shear elasticity map, multiple data acquisitions are typically required. In this paper, a novel shear elasticity imaging technique, comb-push ultrasound shear elastography (CUSE), is introduced in which only one rapid data acquisition (less than 35 ms) is needed to reconstruct a full field-of-view 2D shear wave speed map (40 mm × 38 mm). Multiple unfocused ultrasound beams arranged in a comb pattern (comb-push) are used to generate shear waves. A directional filter is then applied upon the shear wave field to extract the left-to-right (LR) and right-to-left (RL) propagating shear waves. Local shear wave speed is recovered using a time-of-flight method based on both LR and RL waves. Finally a 2D shear wave speed map is reconstructed by combining the LR and RL speed maps. Smooth and accurate shear wave speed maps are reconstructed using the proposed CUSE method in two calibrated homogeneous phantoms with different moduli. Inclusion phantom experiments demonstrate that CUSE is capable of providing good contrast (contrast-to-noise-ratio ≥ 25 dB) between the inclusion and background without artifacts and is insensitive to inclusion positions. Safety measurements demonstrate that all regulated parameters of the ultrasound output level used in CUSE sequence are well below the FDA limits for diagnostic ultrasound. PMID:22736690

  17. Partial shrinkage of venous tissues near valves using High Intensity Focused Ultrasound

    NASA Astrophysics Data System (ADS)

    Pichardo, Samuel; Curiel, Laura; Milleret, René; Pichot, Olivier; Lacoste, François; Chapelon, Jean-Yves

    2005-03-01

    The cross-section of a vein can be reduced by exposing the collagen of the vein wall to high temperature (85° C) for a few seconds. Partial shrinkage of the vein is appropriate for correcting deformations of valvular tissues that can cause the abnormal blood reflux which is the main cause of varicose veins and Superficial Venous Insufficiency. Due to its suitability for inducing localized heating, High Intensity Focused Ultrasound (HIFU) is a good method for correcting valvular tissue. In the present study, the feasibility of using HIFU for inducing partial shrinkage of the saphenous vein wall is demonstrated. The position and size of valvular deformations are well suited to being heated and, consequently, reduced with HIFU. The resulting shrinkage of deformations should restore normal function of the valve. An experimental protocol was used in which several in vitro segments of human saphenous vein were exposed with a monochromatic signal produced by a real-time imaging HIFU probe. The probe has a focal length of 45 mm, a diameter of 52.5 mm and operates at 3 MHz. Ultrasonic imaging, obtained with an 8-MHz 128-element linear array placed at the centre of the HIFU probe, was used to target the vein. The segment was inserted in a porcine muscle sample, and both were placed into a PVC cylinder. Individual sonications of the vein wall were performed for acoustic power values ranging between 8.75 and 35 W at a constant sonication duration of 5 s. Different durations ranging between 3 and 7 s at constant power were also tested. Finally, a long duration of 18 s was tested while the focal point was displaced along the vein wall at a speed of 0.5 mm/s. Results showed that shrinkage of the vein wall was observed using echographic and macroscopic analysis. In particular, the vein diameter was reduced by 15% for a sonication-duration of 18 s with continuous displacement of the focal point. Results showed that HIFU is suitable for partial shrinkage of the saphenous vein and

  18. In-vivo investigation of material quality of bone tissue by measuring apparent phalangeal ultrasound transmission velocity.

    PubMed

    Kann, P; Schulz, U; Klaus, D; Piepkorn, B; Beyer, J

    1995-01-01

    The square of ultrasound transmission velocity in a material is related to the modulus of elasticity, which is known to be an indicator of stability in bone. The aim of our study was to use ultrasound transmission velocity to obtain information about the material properties of bone tissue, keeping other factors possibly influencing ultrasound transmission as constant as possible. Apparent phalangeal ultrasound transmission velocity (APU) measured in 54 isolated, fresh pig phalanges was shown to be independent of bone mineral density (BMD) measured by SPA. Fastest sound transmission led exclusively through cortical bone so that intertrabecular connectivity in spongious bone could not influence the result. In humans APU was measured in the mediolateral direction at the midphalanx of the middle finger. In 53 healthy subjects (15-81 years old; 27 women, 26 men), there was a decrease of APU with age (r = -0.30, p < 0.05). Further, when comparing the results of both hands intraindividually almost identical values indicated constant intraindividual architecture of bone at this location. There was no evidence for a relation of APU to physical load comparing dominant and nondominant hand and relating the results to subjectively estimated physical load. In a second group of 43 perimenopausal women (47-60 years old), APU, which again decreased with age (r = -0.33, p < 0.05), was found not to be correlated to BMD measured by SPA at the distal forearm (cortical bone).(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Adipose tissue angiogenesis: impact on obesity and type-2 diabetes.

    PubMed

    Corvera, Silvia; Gealekman, Olga

    2014-03-01

    The growth and function of tissues are critically dependent on their vascularization. Adipose tissue is capable of expanding many-fold during adulthood, therefore requiring the formation of new vasculature to supply growing and proliferating adipocytes. The expansion of the vasculature in adipose tissue occurs through angiogenesis, where new blood vessels develop from those pre-existing within the tissue. Inappropriate angiogenesis may underlie adipose tissue dysfunction in obesity, which in turn increases type-2 diabetes risk. In addition, genetic and developmental factors involved in vascular patterning may define the size and expandability of diverse adipose tissue depots, which are also associated with type-2 diabetes risk. Moreover, the adipose tissue vasculature appears to be the niche for pre-adipocyte precursors, and factors that affect angiogenesis may directly impact the generation of new adipocytes. Here we review recent advances on the basic mechanisms of angiogenesis, and on the role of angiogenesis in adipose tissue development and obesity. A substantial amount of data points to a deficit in adipose tissue angiogenesis as a contributing factor to insulin resistance and metabolic disease in obesity. These emerging findings support the concept of the adipose tissue vasculature as a source of new targets for metabolic disease therapies. This article is part of a Special Issue entitled: Modulation of Adipose Tissue in Health and Disease.

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

    PubMed Central

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

    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 changes. This method is applied to investigate trapezius muscle tissue response – especially with respect to specific regional deformation and deformation rates – during concentric shoulder elevation in patients with chronic trapezius myalgia and healthy controls before and after pain provocation. Methods Patients with trapezius myalgia and healthy controls were analyzed using an ultrasound system equipped with tissue velocity imaging (TVI). The patients performed a standardized 3-cm concentric shoulder elevation before and after pain provocation/exercise at a standardized elevation tempo (30 bpm). A standardized region of interest (ROI), an ellipsis with a size that captures the upper and lower fascia of the trapezius muscle (4 cm width) at rest, was placed in the first frame of the loop registration of the elevation. The ROI was re-anchored frame by frame following the same anatomical landmark in the basal fascia during all frames of the concentric phase. In cardiac measurement, tissue velocities are measured in the axial projection towards and against the probe where red colour represents shortening and red lengthening. In the case of measuring the trapezius muscle, tissue deformation measurements are made orthogonally, thus, indirectly. Based on the assumption of muscle volume incompressibility, blue represents tissue contraction and red relaxation. Within the ROI, two variables were calculated as a function of time: deformation and deformation rate. Hereafter, max, mean, and quadratic mean values (RMS) of each variable were calculated and compared before

  1. Diagnostic nerve ultrasound in Charcot-Marie-Tooth disease type 1B.

    PubMed

    Cartwright, Michael S; Brown, Martin E; Eulitt, Patrick; Walker, Francis O; Lawson, Victoria H; Caress, James B

    2009-07-01

    Ultrasound is emerging as a useful tool for evaluation of neuromuscular conditions, because it can provide high-resolution anatomic information to complement electrodiagnostic data. There have been few studies in which ultrasound was used to assess the peripheral nerves of individuals with Charcot-Marie-Tooth (CMT) disease and none involving CMT type 1B. In this study we compared nerve cross-sectional area in individuals from a single large family with CMT 1B with normal, healthy controls. We also assessed for cranial nerve enlargement in those with CMT 1B with cranial neuropathies compared to those with CMT 1B without cranial neuropathies. Individuals with CMT 1B have significantly larger median and vagus nerves than healthy controls, but no difference was seen in cranial nerve size between those with versus those without cranial neuropathies. This is the first study to characterize the ultrasonographic findings in the peripheral nerves of individuals with CMT 1B.

  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.

  4. 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

  5. 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

  6. Achondrogenesis type IB (Fraccaro): study of collagen in the tissue and in chondrocytes cultured in agarose.

    PubMed

    Freisinger, P; Stanescu, V; Jacob, B; Cohen-Solal, L; Maroteaux, P; Bonaventure, J

    1994-02-15

    A lethal chondrodysplasia characterized by extreme micromelia was diagnosed by ultrasound examination in two sibs whose nonconsanguineous parents were healthy. Radiographic and histopathologic data indicated that the two foetuses (18 and 21 weeks old) had achondrogenesis type IB (Fraccaro). Quantitation of total collagen extractable from dried cartilage samples demonstrated a 50% decrease when compared to an age-related control. This decrease was essentially related to type II collagen. Nevertheless, the alpha chains and the CB peptides of type II collagen had a normal electrophoretic mobility. A significant amount of collagen type I was also detected. The electrophoretic pattern of collagens type IX and XI did not differ significantly from control sample. The extracellular matrix elaborated by patient chondrocytes cultured in agarose for 10-12 days, contained less collagen type II than normal cells. Labelling with 14C-proline of cultured cells showed the presence of procollagen and type II collagen chains with a normal electrophoretic mobility, but an alpha 2(I) chain was detectable in the patient material, indicating the presence of collagen type I which supported the tissue findings. The significance of the type II collagen reduction in the patient's cartilage is unclear but it is unlikely to be the primary defect in achondrogenesis type I. PMID:8160740

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

    PubMed

    Maleke, C; Konofagou, E E

    2008-03-21

    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 in bovine liver samples in vitro. The feasibility of HMI for characterizing mechanical tissue properties has previously been demonstrated. Here, a confocal transducer, combining a 4.68 MHz therapy (FUS) and a 7.5 MHz diagnostic (pulse-echo) transducer, was used. The therapy transducer was driven by a low-frequency AM continuous signal at 25 Hz, producing a stable harmonic radiation force oscillating at the modulation frequency. A pulser/receiver was used to drive the pulse-echo transducer at a pulse repetition frequency (PRF) of 5.4 kHz. Radio-frequency (RF) signals were acquired using a standard pulse-echo technique. The temperature near the ablation region was simultaneously monitored. Both RF signals and temperature measurements were obtained before, during and after sonication. The resulting axial tissue displacement was estimated using one-dimensional cross correlation. When temperature at the focal zone was above 48 degrees C during heating, the coagulation necrosis occurred and tissue damage was irreversible. The HMI displacement profiles in relation to the temperature and sonication durations were analyzed. At the beginning of heating, the temperature at the focus increased sharply, while the tissue stiffness decreased resulting in higher HMI displacements. This was confirmed by an increase of 0.8 microm degrees C(-1)(r=0.93, p<.005). After sustained heating, the tissue became irreversibly stiffer, followed by an associated decrease in the HMI displacement (-0.79 microm degrees C(-1), r=-0.92, p<0.001). Repeated

  8. Ultrasound pregnancy

    MedlinePlus

    Pregnancy sonogram; Obstetric ultrasonography; Obstetric sonogram; Ultrasound - pregnancy; IUGR - ultrasound; Intrauterine growth - ultrasound; Polyhydramnios - ultrasound; Oligohydramnios - ultrasound; Placenta previa - ultrasound; Multiple ...

  9. Quantitative Imaging of Young's Modulus of Soft Tissues from Ultrasound Water Jet Indentation: A Finite Element Study

    PubMed Central

    Lu, Min-Hua; Mao, Rui; Lu, Yin; Liu, Zheng; Wang, Tian-Fu; Chen, Si-Ping

    2012-01-01

    Indentation testing is a widely used approach to evaluate mechanical characteristics of soft tissues quantitatively. Young's modulus of soft tissue can be calculated from the force-deformation data with known tissue thickness and Poisson's ratio using Hayes' equation. Our group previously developed a noncontact indentation system using a water jet as a soft indenter as well as the coupling medium for the propagation of high-frequency ultrasound. The novel system has shown its ability to detect the early degeneration of articular cartilage. However, there is still lack of a quantitative method to extract the intrinsic mechanical properties of soft tissue from water jet indentation. The purpose of this study is to investigate the relationship between the loading-unloading curves and the mechanical properties of soft tissues to provide an imaging technique of tissue mechanical properties. A 3D finite element model of water jet indentation was developed with consideration of finite deformation effect. An improved Hayes' equation has been derived by introducing a new scaling factor which is dependent on Poisson's ratios v, aspect ratio a/h (the radius of the indenter/the thickness of the test tissue), and deformation ratio d/h. With this model, the Young's modulus of soft tissue can be quantitatively evaluated and imaged with the error no more than 2%. PMID:22927890

  10. Research of Ultrasound-Mediated Transdermal Drug Delivery System Using Cymbal-Type Piezoelectric Composite Transducer

    NASA Astrophysics Data System (ADS)

    Huan, Huiting; Gao, Chunming; Liu, Lixian; Sun, Qiming; Zhao, Binxing; Yan, Laijun

    2015-06-01

    Transdermal drug delivery (TDD) implemented by especially low-frequency ultrasound is generally known as sonophoresis or phonophoresis which has drawn considerable wide attention. However, TDD has not yet achieved its full potential as an alternative to conventional drug delivery methods due to its bulky instruments. In this paper, a cymbal-type piezoelectric composite transducer (CPCT) which has advantages over a traditional ultrasound generator in weight, flexibility, and power consumption, is used as a substitute ultrasonicator to realize TDD. First, theoretical research on a CPCT based on the finite element analysis was carried out according to which a series of applicable CPCTs with bandwidths of 20 kHz to 100 kHz were elaborated. Second, a TDD experimental setup was built with previously fabricated CPCTs aimed at the administration of glucose. Finally, the TDD performance of glucose molecule transport in porcine skin was measured in vitro by quantifying the concentration of glucose, and the time variation curves were subsequently obtained. During the experiment, the driving wave form, frequency, and power consumption of the transducers were selected as the main elements which determined the efficacy of glucose delivery. The results indicate that the effectiveness of the CPCT-based delivery is constrained more by the frequency and intensity of ultrasound rather than the driving waveform. The light-weight, flexibility, and low-power consumption of a CPCT can potentially achieve effective TDD.

  11. Stereotypic Laryngeal and Respiratory Motor Patterns Generate Different Call Types in Rat Ultrasound Vocalization

    PubMed Central

    RIEDE, TOBIAS

    2014-01-01

    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

  12. In vitro study of ultrasound radiation force-driven twinkling sign using PVA-H gel and glass beads tissue-mimicking phantom.

    PubMed

    Liu, Lei; Funamoto, Kenichi; Ozawa, Kei; Ohta, Makoto; Hayase, Toshiyuki; Ogasawara, Masafumi

    2013-07-01

    The twinkling sign observed in ultrasound coded-excitation imaging (e.g., GE B-Flow) has been reported in previous research as a potential phenomenon to detect micro calcification in soft tissue. However, the mechanism of the twinkling sign has not been clearly understood yet. We conducted an in vitro experiment to clarify the mechanism of the twinkling sign by measuring a soft tissue-mimicking phantom with ultrasonic and optical devices. A soft tissue-mimicking phantom was made of poly(vinyl alcohol) hydro (PVA-H) gel and 200-μm-diameter glass beads. We applied ultrasound to the phantom using medical ultrasound diagnostic equipment to observe the twinkling sign of glass beads. Optical imaging with a laser sheet and a high-speed camera was performed to capture the scatter lights of the glass beads with and without ultrasound radiation. The scatter lights from the glass beads were quantified and analyzed to evaluate their oscillations driven by the ultrasound radiation force. The twinkling sign from the glass beads embedded in the PVA-H gel soft tissue phantom was observed in ultrasound B-Flow color imaging. The intensity and oscillation of the scattered lights from the glass beads showed significant difference between the cases with and without ultrasound radiation. The results showed a close relationship between the occurrence of the twinkling sign and the variations of the scatter lights of glass beads, indicating that ultrasound radiation force-driven micro oscillation causes the twinkling sign of micro calcification in soft tissue.

  13. 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

  14. Non-contact, Ultrasound-based Indentation Method for Measuring Elastic Properties of Biological Tissues Using Harmonic Motion Imaging (HMI)

    PubMed Central

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

    2015-01-01

    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 RF 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 actual 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. PMID:25776065

  15. 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.

  16. 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

    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)

  17. 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.

  18. The use of twinkling artifact of Doppler imaging to monitor cavitation in tissue during high intensity focused ultrasound therapy

    PubMed Central

    Khokhlova, Tatiana; Li, Tong; Sapozhnikov, Oleg; Hwang, Joo Ha

    2015-01-01

    In high intensity focused ultrasound (HIFU) therapy, it is important to monitor the presence and activity of microbubbles in tissue during treatment. The current methods, - passive cavitation detection (PCD) and B-mode imaging - have limited sensitivity, especially to small-size, non-violently-collapsing microbubbles. Here, a new method for microbubble detection is proposed, based on “twinkling” artifact (TA) of Doppler imaging. TA occurs when Color Doppler ultrasound is used to image hard objects in tissue (e.g., kidney stones), and is displayed as brightly colored spots. As demonstrated recently, TA can be explained by irregular scattering of the Doppler ensemble pulses from the fluctuating microbubbles trapped in crevices of the kidney stone. In this work, TA was used to detect cavitation in tissue and in polyacrylamide gel phantoms during pulsed 1 MHz HIFU exposures with different peak negative pressures (1.5–11 MPa). At each pressure level, the probability of cavitation occurrence was characterized using TA and the broadband signals recorded by PCD, aligned confocally with the HIFU transducer. The results indicate that TA is more sensitive to the onset of cavitation than conventional PCD detection, and allows for accurate spatial localization of the bubbles. Work supported by RFBR and NIH (EB007643, 1K01EB015745, R01CA154451). PMID:26185591

  19. Noninvasive assessment of the activity of the shoulder girdle muscles using ultrasound real-time tissue elastography.

    PubMed

    Ishikawa, Hiroaki; Muraki, Takayuki; Sekiguchi, Yusuke; Ishijima, Takahiro; Morise, Shuhei; Yamamoto, Nobuyuki; Itoi, Eiji; Izumi, Shin-Ichi

    2015-10-01

    The purpose of this study was to clarify whether the activity of the shoulder girdle muscles could be estimated by measuring the elasticity of these muscles under several levels of muscle contraction through ultrasound real-time tissue elastography (RTE). Ten healthy men performed submaximal voluntary contractions (MVC) in each manual muscle testing position for the middle deltoid, upper trapezius, supraspinatus, levator scapulae, and rhomboid major. The elasticity of these muscles was measured using ultrasound RTE during the task. The strain ratio of the muscle to an acoustic coupler was calculated as an assessment index of the muscle elasticity. Higher strain ratio values imply lower elasticity. In addition, the electromyographic activity was recorded from surface electrodes attached only to the middle deltoid and upper trapezius. The strain ratios were negatively correlated with the normalized root mean square values for the middle deltoid (r=-0.659, p<0.001) and upper trapezius (r=-0.554, p<0.001). The strain ratios of all the muscles decreased with an increase from 10% MVC force to 30% MVC force. Ultrasound RTE may be useful for noninvasively assessing the activity of the shoulder girdle muscles at certain shoulder positions with low levels of muscle contraction. PMID:26263838

  20. Non-invasive characterization of polyurethane-based tissue constructs in a rat abdominal repair model using high frequency ultrasound elasticity imaging.

    PubMed

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

    2013-04-01

    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

  1. Design and implementation of therapeutic ultrasound generating circuit for dental tissue formation and tooth-root healing.

    PubMed

    Woon Tiong Ang; Scurtescu, C; Wing Hoy; El-Bialy, T; Ying Yin Tsui; Jie Chen

    2010-02-01

    Biological tissue healing has recently attracted a great deal of research interest in various medical fields. Trauma to teeth, deep and root caries, and orthodontic treatment can all lead to various degrees of root resorption. In our previous study, we showed that low-intensity pulsed ultrasound (LIPUS) enhances the growth of lower incisor apices and accelerates their rate of eruption in rabbits by inducing dental tissue growth. We also performed clinical studies and demonstrated that LIPUS facilitates the healing of orthodontically induced teeth-root resorption in humans. However, the available LIPUS devices are too large to be used comfortably inside the mouth. In this paper, the design and implementation of a low-power LIPUS generator is presented. The generator is the core of the final intraoral device for preventing tooth root loss and enhancing tooth root tissue healing. The generator consists of a power-supply subsystem, an ultrasonic transducer, an impedance-matching circuit, and an integrated circuit composed of a digital controller circuitry and the associated driver circuit. Most of our efforts focus on the design of the impedance-matching circuit and the integrated system-on-chip circuit. The chip was designed and fabricated using 0.8- ¿m high-voltage technology from Dalsa Semiconductor, Inc. The power supply subsystem and its impedance-matching network are implemented using discrete components. The LIPUS generator was tested and verified to function as designed and is capable of producing ultrasound power up to 100 mW in the vicinity of the transducer's resonance frequency at 1.5 MHz. The power efficiency of the circuitry, excluding the power supply subsystem, is estimated at 70%. The final products will be tailored to the exact size of teeth or biological tissue, which is needed to be used for stimulating dental tissue (dentine and cementum) healing.

  2. Use of shock-wave heating for faster and safer ablation of tissue volumes in high intensity focused ultrasound therapy

    NASA Astrophysics Data System (ADS)

    Khokhlova, V.; Yuldashev, P.; Sinilshchikov, I.; Partanen, A.; Khokhlova, T.; Farr, N.; Kreider, W.; Maxwell, A.; Sapozhnikov, O.

    2015-10-01

    Simulation of enhanced heating of clinically relevant tissue volumes using nonlinear ultrasound waves generated by a multi-element HIFU phased array were conducted based on the combined Westervelt and bio-heat equations. A spatial spectral approach using the fast Fourier transform algorithm and a corresponding analytic solution to the bioheat equation were used to optimize temperature modeling in tissue. Localized shock-wave heating within a much larger treated tissue volume and short, single HIFU pulses within a much longer overall exposure time were accounted for in the algorithm. Separation of processes with different time and spatial scales made the calculations faster and more accurate. With the proposed method it was shown that for the same time-average power, the use of high peak power pulsing schemes that produce high-amplitude shocks at the focus result in faster tissue heating compared to harmonic, continuous-wave sonications. Nonlinear effects can significantly accelerate volumetric heating while also permitting greater spatial control to reduce the impact on surrounding tissues. Such studies can be further used to test and optimize various steering trajectories of shock-wave sonications for faster and more controlled treatment of tissue volumes.

  3. 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.

  4. Effects of non contact low-frequency ultrasound on healing of suspected deep tissue injury: a retrospective analysis.

    PubMed

    Honaker, Jeremy S; Forston, Michael R; Davis, Emily A; Wiesner, Michelle M; Morgan, Jennifer A

    2013-02-01

    The purpose of this study was to assess the effectiveness of non contact low-frequency ultrasound on the healing of suspected deep tissue injury (SDTI). Participants were adults ranging in age from 28 to 93 years old, with multiple diagnoses including anaemia, diabetes mellitus and hypertension. Data were examined retrospectively on 85 patients (intervention group = 43 and non intervention group = 42) with 127 SDTI (intervention group = 64 and non intervention group = 63). Participants in both groups received standard of care for treating pressure ulcers. A severity score was used to assess SDTI severity before treatment and healing/progression after treatment. This scale measures surface area, wound colour/tissue assessment, and skin integrity with potential scores of 3 to 18 (higher scores indicate greater severity). A significant difference in changes in wound severity was found (t = 5·67, P < 0.000). Difference in mean change scores was 2·52 on the 3-18 severity scale. The decrease in wound severity for the intervention group was 1·45. Severity in the non intervention group increased by 1·06. This exploratory study of the effect of the non contact low-frequency ultrasound provides initial findings that support its use with SDTI.

  5. 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

    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

  6. Human monocytes can produce tissue-type plasminogen activator

    PubMed Central

    1989-01-01

    Evidence has previously been presented that monocytes and macrophages produce urokinase-type plasminogen activator. We have shown for the first time that human monocytes, when stimulated appropriately in vitro, can produce tissue type-plasminogen activator (t-PA) of 70 kD. Detection of t-PA mRNA was consistent with the biochemical and immunological characterization of t-PA produced by human monocytes. PMID:2494295

  7. Two types of brown adipose tissue in humans.

    PubMed

    Lidell, Martin E; Betz, Matthias J; Enerbäck, Sven

    2014-01-01

    During the last years the existence of metabolically active brown adipose tissue in adult humans has been widely accepted by the research community. Its unique ability to dissipate chemical energy stored in triglycerides as heat makes it an attractive target for new drugs against obesity and its related diseases. Hence the tissue is now subject to intense research, the hypothesis being that an expansion and/or activation of the tissue is associated with a healthy metabolic phenotype. Animal studies provide evidence for the existence of at least two types of brown adipocytes. Apart from the classical brown adipocyte that is found primarily in the interscapular region where it constitutes a thermogenic organ, a second type of brown adipocyte, the so-called beige adipocyte, can appear within white adipose tissue depots. The fact that the two cell types develop from different precursors suggests that they might be recruited and stimulated by different cues and therefore represent two distinct targets for therapeutic intervention. The aim of this commentary is to discuss recent work addressing the question whether also humans possess two types of brown adipocytes and to highlight some issues when looking for molecular markers for such cells.

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

    SciTech Connect

    HUANG, LIANJIE; PRATT, R. GERHARD; DURIC, NEB; LITTRUP, PETER

    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. High-frequency ultrasound for monitoring changes in liver tissue during preservation

    NASA Astrophysics Data System (ADS)

    Vlad, Roxana M.; Czarnota, Gregory J.; Giles, Anoja; Sherar, Michael D.; Hunt, John W.; Kolios, Michael C.

    2005-01-01

    Currently the only method to assess liver preservation injury is based on liver appearance and donor medical history. Previous work has shown that high-frequency ultrasound could detect ischemic cell death due to changes in cell morphology. In this study, we use high-frequency ultrasound integrated backscatter to assess liver damage in experimental models of liver ischemia. Ultimately, our goal is to predict organ suitability for transplantation using high-frequency imaging and spectral analysis techniques. To examine the effects of liver ischemia at different temperatures, livers from Wistar rats were surgically excised, immersed in phosphate buffer saline and stored at 4 and 20 °C for 24 h. To mimic organ preservation, livers were excised, flushed with University of Wisconsin (UW) solution and stored at 4 °C for 24 h. Preservation injury was simulated by either not flushing livers with UW solution or, before scanning, allowing livers to reach room temperature. Ultrasound images and corresponding radiofrequency data were collected over the ischemic period. No significant increase in integrated backscatter (~2.5 dBr) was measured for the livers prepared using standard preservation conditions. For all other ischemia models, the integrated backscatter increased by 4-9 dBr demonstrating kinetics dependent on storage conditions. The results provide a possible framework for using high-frequency imaging to non-invasively assess liver preservation injury.

  10. Interaction of vortices with ultrasound and the acoustic Faraday effect in type-II superconductors

    SciTech Connect

    Dominguez, D.; Bulaevskii, L.; Ivlev, B. |; Maley, M.; Bishop, A.R.

    1996-03-01

    We study the interaction of sound waves with vortices in type-II superconductors, taking into account pinning and electrodynamic forces between vortices and crystal displacements. We propose ultrasound techniques as a method for obtaining information about vortex dynamics. This is particularly appropiate at low temperatures where transport measurements are ineffective. The changes in sound velocity and attenuation due to vortices, can provide information on the elastic constants of the vortex system and on vortex dissipation, respectively. At low temperatures the Magnus force acting on vortices leads to the {ital acoustic} {ital Faraday} {ital effect}: there is a rotation of the polarization plane of tranverse sound waves propagating along the magnetic field. This effect is linear in the Magnus force and magnetic field in crystals with equivalent {ital a} and {ital b} axes for a field parallel to the {ital c} axis. We discuss how this effect can be measured by means of either pulse-echo techniques or standing sound waves. Also, we show that an ac electromagnetic field acting on the vortex system can generate ultrasound. We calculate the amplitude of the generated sound waves in the linear regime and compare with recent experiments. {copyright} {ital 1996 The American Physical Society.}

  11. 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.

  12. 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.

  13. Effect of substrate choice and tissue type on tissue preparation for spectral histopathology by Raman microspectroscopy.

    PubMed

    Fullwood, Leanne M; Griffiths, Dave; Ashton, Katherine; Dawson, Timothy; Lea, Robert W; Davis, Charles; Bonnier, Franck; Byrne, Hugh J; Baker, Matthew J

    2014-01-21

    Raman spectroscopy is a non-destructive, non-invasive, rapid and economical technique which has the potential to be an excellent method for the diagnosis of cancer and understanding disease progression through retrospective studies of archived tissue samples. Historically, biobanks are generally comprised of formalin fixed paraffin preserved tissue and as a result these specimens are often used in spectroscopic research. Tissue in this state has to be dewaxed prior to Raman analysis to reduce paraffin contributions in the spectra. However, although the procedures are derived from histopathological clinical practice, the efficacy of the dewaxing procedures that are currently employed is questionable. Ineffective removal of paraffin results in corruption of the spectra and previous experiments have shown that the efficacy can depend on the dewaxing medium and processing time. The aim of this study was to investigate the influence of commonly used spectroscopic substrates (CaF2, Spectrosil quartz and low-E slides) and the influence of different histological tissue types (normal, cancerous and metastatic) on tissue preparation and to assess their use for spectral histopathology. Results show that CaF2 followed by Spectrosil contribute the least to the spectral background. However, both substrates retain paraffin after dewaxing. Low-E substrates, which exhibit the most intense spectral background, do not retain wax and resulting spectra are not affected by paraffin peaks. We also show a disparity in paraffin retention depending upon the histological identity of the tissue with abnormal tissue retaining more paraffin than normal.

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

    SciTech Connect

    Gonsalves, K.E.; Chen, X.; Rangarajan, S.P.

    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.

  15. Heart rate, conduction and ultrasound abnormalities in adults with joint hypermobility syndrome/Ehlers-Danlos syndrome, hypermobility type.

    PubMed

    Camerota, Filippo; Castori, Marco; Celletti, Claudia; Colotto, Marco; Amato, Silvia; Colella, Alessandra; Curione, Mario; Danese, Chiara

    2014-07-01

    Joint hypermobility syndrome (JHS) and Ehlers-Danlos syndrome, hypermobility type (EDS-HT) are two clinically overlapping heritable connective tissue disorders strongly associating with pain, fatigue and other secondary aspects. Though not considered a diagnostic criterion for most EDS subtypes, cardiovascular involvement is a well-known complication in EDS. A case-control study was carried out on 28 adults with JHS/EDS-HT diagnosed according to current criteria, compared to 29 healthy subjects evaluating resting electrocardiographic (ECG), 24-h ECG and resting heart ultrasound data. Results obtained in the ECG studies showed a moderate excess in duration of the PR interval and P wave, an excess of heart conduction and rate abnormalities and an increased rate of mitral and tricuspid valve insufficiency often complicating with "true" mitral valve prolapse in the ecocardiographic study. These variable ECG subclinical anomalies reported in our sample may represent the resting surrogate of such a subnormal cardiovascular response to postural changes that are known to be present in patients with JHS/EDS-HT. Our findings indicate the usefulness of a full cardiologic evaluation of adults with JHS/EDS-HT for the correct management. PMID:24752348

  16. Enhancement of photoacoustic tomography in the tissue with speed-of-sound variance using ultrasound computed tomography

    NASA Astrophysics Data System (ADS)

    Cheng, Ren-Xiang; Chao, Tao; Xiao-Jun, Liu

    2015-11-01

    The speed-of-sound variance will decrease the imaging quality of photoacoustic tomography in acoustically inhomogeneous tissue. In this study, ultrasound computed tomography is combined with photoacoustic tomography to enhance the photoacoustic tomography in this situation. The speed-of-sound information is recovered by ultrasound computed tomography. Then, an improved delay-and-sum method is used to reconstruct the image from the photoacoustic signals. The simulation results validate that the proposed method can obtain a better photoacoustic tomography than the conventional method when the speed-of-sound variance is increased. In addition, the influences of the speed-of-sound variance and the fan-angle on the image quality are quantitatively explored to optimize the image scheme. The proposed method has a good performance even when the speed-of-sound variance reaches 14.2%. Furthermore, an optimized fan angle is revealed, which can keep the good image quality with a low cost of hardware. This study has a potential value in extending the biomedical application of photoacoustic tomography. Projection supported by the National Basic Research Program of China (Grant No. 2012CB921504), the National Natural Science Foundation of China (Grant Nos. 11422439, 11274167, and 11274171), and the Specialized Research Fund for the Doctoral Program of Higher Education, China (Grant No. 20120091110001).

  17. Ultrasound assisted optical elastography for measurement of tissue stiffness: contribution to the measurement from scattering coefficient variation

    NASA Astrophysics Data System (ADS)

    Bharat Chandran, R. S.; Usha Devi, C.; Vasu, R. M.; Sood, A. K.

    2007-05-01

    In ultrasound assisted optical elastography (UAOE) the amplitude of vibration inside the object introduced by an ultrasound (US) beam is read out by a coherent light beam. The measurement is the depth of modulation in the intensity autocorrelation of light that intercepted the insonified region and detected at the boundary. It is observed that the measured depth of modulation is owing to refractive index modulation and scattering coefficient modulation, in addition to the tissue-particle vibration. Since elasticity is measured from the amplitude of vibration it is essential to characterize and separate the contribution to the modulation from refractive index and scattering coefficient modulations. In this work we report the contribution of the scattering coefficient modulation in the insonified region to the measured modulation in the autocorrelation. We found through simulation studies that the contribution from scattering coefficient is small compared to the vibration. In addition, this contribution becomes smaller as the stiffness in the region increases. We also provide a means of quantifying this contribution so that the effect of vibration amplitude can be separated from the overall measured modulation depth.

  18. Improved Human Bone Marrow Mesenchymal Stem Cell Osteogenesis in 3D Bioprinted Tissue Scaffolds with Low Intensity Pulsed Ultrasound Stimulation

    PubMed Central

    Zhou, Xuan; Castro, Nathan J.; Zhu, Wei; Cui, Haitao; Aliabouzar, Mitra; Sarkar, Kausik; Zhang, Lijie Grace

    2016-01-01

    3D printing and ultrasound techniques are showing great promise in the evolution of human musculoskeletal tissue repair and regeneration medicine. The uniqueness of the present study was to combine low intensity pulsed ultrasound (LIPUS) and advanced 3D printing techniques to synergistically improve growth and osteogenic differentiation of human mesenchymal stem cells (MSC). Specifically, polyethylene glycol diacrylate bioinks containing cell adhesive Arginine-Glycine-Aspartic acid-Serene (RGDS) peptide and/or nanocrystalline hydroxyapatite (nHA) were used to fabricate 3D scaffolds with different geometric patterns via novel table-top stereolithography 3D printer. The resultant scaffolds provide a highly porous and interconnected 3D environment to support cell proliferation. Scaffolds with small square pores were determined to be the optimal geometric pattern for MSC attachment and growth. The optimal LIPUS working parameters were determined to be 1.5 MHz, 20% duty cycle with 150 mW/cm2 intensity. Results demonstrated that RGDS peptide and nHA containing 3D printed scaffolds under LIPUS treatment can greatly promote MSC proliferation, alkaline phosphatase activity, calcium deposition and total protein content. These results illustrate the effectiveness of the combination of LIPUS and biomimetic 3D printing scaffolds as a valuable combinatorial tool for improved MSC function, thus make them promising for future clinical and various regenerative medicine application. PMID:27597635

  19. Improved Human Bone Marrow Mesenchymal Stem Cell Osteogenesis in 3D Bioprinted Tissue Scaffolds with Low Intensity Pulsed Ultrasound Stimulation.

    PubMed

    Zhou, Xuan; Castro, Nathan J; Zhu, Wei; Cui, Haitao; Aliabouzar, Mitra; Sarkar, Kausik; Zhang, Lijie Grace

    2016-01-01

    3D printing and ultrasound techniques are showing great promise in the evolution of human musculoskeletal tissue repair and regeneration medicine. The uniqueness of the present study was to combine low intensity pulsed ultrasound (LIPUS) and advanced 3D printing techniques to synergistically improve growth and osteogenic differentiation of human mesenchymal stem cells (MSC). Specifically, polyethylene glycol diacrylate bioinks containing cell adhesive Arginine-Glycine-Aspartic acid-Serene (RGDS) peptide and/or nanocrystalline hydroxyapatite (nHA) were used to fabricate 3D scaffolds with different geometric patterns via novel table-top stereolithography 3D printer. The resultant scaffolds provide a highly porous and interconnected 3D environment to support cell proliferation. Scaffolds with small square pores were determined to be the optimal geometric pattern for MSC attachment and growth. The optimal LIPUS working parameters were determined to be 1.5 MHz, 20% duty cycle with 150 mW/cm(2) intensity. Results demonstrated that RGDS peptide and nHA containing 3D printed scaffolds under LIPUS treatment can greatly promote MSC proliferation, alkaline phosphatase activity, calcium deposition and total protein content. These results illustrate the effectiveness of the combination of LIPUS and biomimetic 3D printing scaffolds as a valuable combinatorial tool for improved MSC function, thus make them promising for future clinical and various regenerative medicine application. PMID:27597635

  20. Improved Human Bone Marrow Mesenchymal Stem Cell Osteogenesis in 3D Bioprinted Tissue Scaffolds with Low Intensity Pulsed Ultrasound Stimulation.

    PubMed

    Zhou, Xuan; Castro, Nathan J; Zhu, Wei; Cui, Haitao; Aliabouzar, Mitra; Sarkar, Kausik; Zhang, Lijie Grace

    2016-09-06

    3D printing and ultrasound techniques are showing great promise in the evolution of human musculoskeletal tissue repair and regeneration medicine. The uniqueness of the present study was to combine low intensity pulsed ultrasound (LIPUS) and advanced 3D printing techniques to synergistically improve growth and osteogenic differentiation of human mesenchymal stem cells (MSC). Specifically, polyethylene glycol diacrylate bioinks containing cell adhesive Arginine-Glycine-Aspartic acid-Serene (RGDS) peptide and/or nanocrystalline hydroxyapatite (nHA) were used to fabricate 3D scaffolds with different geometric patterns via novel table-top stereolithography 3D printer. The resultant scaffolds provide a highly porous and interconnected 3D environment to support cell proliferation. Scaffolds with small square pores were determined to be the optimal geometric pattern for MSC attachment and growth. The optimal LIPUS working parameters were determined to be 1.5 MHz, 20% duty cycle with 150 mW/cm(2) intensity. Results demonstrated that RGDS peptide and nHA containing 3D printed scaffolds under LIPUS treatment can greatly promote MSC proliferation, alkaline phosphatase activity, calcium deposition and total protein content. These results illustrate the effectiveness of the combination of LIPUS and biomimetic 3D printing scaffolds as a valuable combinatorial tool for improved MSC function, thus make them promising for future clinical and various regenerative medicine application.

  1. Combined ultrasound and photoacoustic imaging to noninvasively assess burn injury and selectively monitor a regenerative tissue-engineered construct.

    PubMed

    Nam, Seung Yun; Chung, Eunna; Suggs, Laura J; Emelianov, Stanislav Y

    2015-06-01

    Current biomedical imaging tools have limitations in accurate assessment of the severity of open and deep burn wounds involving excess bleeding and severe tissue damage. Furthermore, sophisticated imaging techniques are needed for advanced therapeutic approaches such as noninvasive monitoring of stem cells seeded and applied in a biomedical 3D scaffold to enhance wound repair. This work introduces a novel application of combined ultrasound (US) and photoacoustic (PA) imaging to assess both burn injury and skin tissue regeneration. Tissue structural damage and bleeding throughout the epidermis and dermis till the subcutaneous skin layer were imaged noninvasively by US/PA imaging. Gold nanoparticle-labeled adipose-derived stem cells (ASCs) within a PEGylated fibrin 3D gel were implanted in a rat model of cutaneous burn injury. ASCs were successfully tracked till 2 weeks and were distinguished from host tissue components (e.g., epidermis, fat, and blood vessels) through spectroscopic PA imaging. The structure and function of blood vessels (vessel density and perfusion) in the wound bed undergoing skin tissue regeneration were monitored both qualitatively and semi-quantitatively by the developed imaging approach. Imaging-based analysis demonstrated ASC localization in the top layer of skin and a higher density of regenerating blood vessels in the treated groups. This was corroborated with histological analysis showing localization of fluorescently labeled ASCs and smooth muscle alpha actin-positive blood vessels. Overall, the US/PA imaging-based strategy coupled with gold nanoparticles has a great potential for stem cell therapies and tissue engineering due to its noninvasiveness, safety, selectivity, and ability to provide long-term monitoring. PMID:25384558

  2. Controlling the spatial organization of cells and extracellular matrix proteins in engineered tissues using ultrasound standing wave fields

    PubMed Central

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

    2010-01-01

    Tissue engineering holds great potential for saving the lives of thousands of organ transplant patients who die each year while waiting for donor organs. However, to successfully fabricate tissues and organs in vitro, methodologies that recreate appropriate extracellular microenvironments to promote tissue regeneration are needed. In this study, we have developed an application of ultrasound standing wave field (USWF) technology to the field of tissue engineering. Acoustic radiation forces associated with USWF were used to non-invasively control the spatial distribution of mammalian cells and cell-bound extracellular matrix proteins within three-dimensional collagen-based engineered tissues. Cells were suspended in unpolymerized collagen solutions and were exposed to a continuous wave USWF, generated using a 1 MHz source, for 15 min at room temperature. Collagen polymerization occurred during USWF exposure resulting in the formation of three-dimensional collagen gels with distinct bands of aggregated cells. The density of cell bands was dependent on both the initial cell concentration and the pressure amplitude of the USWF. Importantly, USWF exposure did not decrease cell viability, but rather enhanced cell function. Alignment of cells into loosely clustered, planar cell bands significantly increased levels of cell-mediated collagen gel contraction and collagen fiber reorganization as compared to sham-exposed samples with a homogeneous cell distribution. Additionally, the extracellular matrix protein, fibronectin, was localized to cell banded areas by binding the protein to the cell surface prior to USWF exposure. By controlling cell and extracellular organization, this application of USWF technology is a promising approach for engineering tissues in vitro. PMID:20870341

  3. INVESTIGATION INTO THE MECHANISMS OF TISSUE ATOMIZATION BY HIGH INTENSITY FOCUSED ULTRASOUND

    PubMed Central

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

    2014-01-01

    Ultrasonic atomization, or the emission of a fog of droplets, was recently proposed to explain tissue fractionation in boiling histotripsy. However, even though liquid atomization has been studied extensively, the mechanisms of tissue atomization remain unclear. In this paper, high-speed photography and overpressure were used to evaluate the role of bubbles in tissue atomization. As the static pressure increased, the degree of fractionation decreased, and the ex vivo tissue became thermally denatured. The effect of surface wetness on atomization was also evaluated in vivo and in tissue-mimicking gels where surface wetness was found to enhance atomization by forming surface instabilities that augment cavitation. In addition, experimental results indicated that wetting collagenous tissues, such as the liver capsule, allowed atomization to breach such barriers. These results highlight the importance of bubbles and surface instabilities in atomization and could be used to enhance boiling histotripsy for transition to clinical use. PMID:25662182

  4. Non-invasive determination of tissue thermal parameters from high intensity focused ultrasound treatment monitored by volumetric MRI thermometry.

    PubMed

    Dragonu, Iulius; de Oliveira, Philippe Lourenço; Laurent, Christophe; Mougenot, Charles; Grenier, Nicolas; Moonen, Chrit T W; Quesson, Bruno

    2009-10-01

    A method is proposed for estimating the perfusion rate, thermal diffusivity, and the absorption coefficient that influence the local temperature during high intensity focused ultrasound (HIFU) thermotherapy procedures. For this purpose, HIFU heating experiments (N = 100) were performed ex vivo on perfused porcine kidney (N = 5) under different flow conditions. The resulting spatio-temporal temperature variations were measured non-invasively by rapid volumetric MR-temperature imaging. The bio-heat transfer (BHT) model was adapted to describe the spatio-temporal evolution of tissue temperature in the cortex. Absorption and perfusion coefficients were determined by fitting the integrated thermal load (spatial integration of the thermal maps) curves in time with an analytical solution of the BHT equation proposed for single point HIFU heating. Thermal diffusivity was determined independently by analyzing the spatial spread of the temperature in time during the cooling period. Absorption coefficient and thermal diffusivity were found to be independent of flow, with mean and average values of 11.0 +/- 1.85 mm(3) x K x J(-1) and 0.172 +/- 0.003 mm(2) x s(-1), respectively. A linear dependence of the calculated perfusion rate with flow was observed with a slope of 9.20 +/- 0.75 mm(-3). The perfusion was found to act as a scaling term with respect to temperature but with no effect on the spatial spread of temperature which only depends on the thermal diffusivity. All results were in excellent agreement with the BHT model, indicating that this model is suitable to predict the evolution of temperature in perfused organs. This quantitative approach allows for determination of tissue thermal parameters with excellent precision (within 10%) and may thus help in quantifying the influence of perfusion during MR guided high intensity focused ultrasound (MRgHIFU).

  5. Wavelet-transform-based active imaging of cavitation bubbles in tissues induced by high intensity focused ultrasound.

    PubMed

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

    2016-08-01

    Cavitation detection and imaging are essential for monitoring high-intensity focused ultrasound (HIFU) therapies. In this paper, an active cavitation imaging method based on wavelet transform is proposed to enhance the contrast between the cavitation bubbles and surrounding tissues. The Yang-Church model, which is a combination of the Keller-Miksis equation with the Kelvin-Voigt equation for the pulsations of gas bubbles in simple linear viscoelastic solids, is utilized to construct the bubble wavelet. Experiments with porcine muscles demonstrate that image quality is associated with the initial radius of the bubble wavelet and the scale. Moreover, the Yang-Church model achieves a somewhat better performance compared with the Rayleigh-Plesset-Noltingk-Neppiras-Poritsky model. Furthermore, the pulse inversion (PI) technique is combined with bubble wavelet transform to achieve further improvement. The cavitation-to-tissue ratio (CTR) of the best tissue bubble wavelet transform (TBWT) mode image is improved by 5.1 dB compared with that of the B-mode image, while the CTR of the best PI-based TBWT mode image is improved by 7.9 dB compared with that of the PI-based B-mode image. This work will be useful for better monitoring of cavitation in HIFU-induced therapies.

  6. 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 μs 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.

  7. 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

  8. Wavelet-transform-based active imaging of cavitation bubbles in tissues induced by high intensity focused ultrasound.

    PubMed

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

    2016-08-01

    Cavitation detection and imaging are essential for monitoring high-intensity focused ultrasound (HIFU) therapies. In this paper, an active cavitation imaging method based on wavelet transform is proposed to enhance the contrast between the cavitation bubbles and surrounding tissues. The Yang-Church model, which is a combination of the Keller-Miksis equation with the Kelvin-Voigt equation for the pulsations of gas bubbles in simple linear viscoelastic solids, is utilized to construct the bubble wavelet. Experiments with porcine muscles demonstrate that image quality is associated with the initial radius of the bubble wavelet and the scale. Moreover, the Yang-Church model achieves a somewhat better performance compared with the Rayleigh-Plesset-Noltingk-Neppiras-Poritsky model. Furthermore, the pulse inversion (PI) technique is combined with bubble wavelet transform to achieve further improvement. The cavitation-to-tissue ratio (CTR) of the best tissue bubble wavelet transform (TBWT) mode image is improved by 5.1 dB compared with that of the B-mode image, while the CTR of the best PI-based TBWT mode image is improved by 7.9 dB compared with that of the PI-based B-mode image. This work will be useful for better monitoring of cavitation in HIFU-induced therapies. PMID:27586712

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

    NASA Astrophysics Data System (ADS)

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

    2010-03-01

    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.

  10. 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 μs 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

  11. An improved tissue-mimicking polyacrylamide hydrogel phantom for visualizing thermal lesions with high-intensity focused ultrasound.

    PubMed

    Guntur, Sitaramanjaneya Reddy; Choi, Min Joo

    2014-11-01

    A recipe was created to improve the tissue-mimicking (TM) bovine serum albumin (BSA) polyacrylamide hydrogel (PAG) reported in our previous study (Choi MJ, Guntur SR, Lee KI, Paeng DG, Coleman AJ. Ultrasound Med Biol 2013; 29:439-448). In that work, the concentration of acrylamide in TM BSA PAG was increased to make its attenuation coefficient the same as that of a tissue. However, this increase made the PAG stiffer and less homogeneous. In addition, the increase in acrylamide caused a significant increase in temperature over the denaturation threshold of BSA during polymerization, which required forced cooling so that the PAG did not become opaque at room temperature after polymerization. To eliminate those shortcomings, we substituted the increased acrylamide with a viscous polysaccharide liquid (corn syrup). The concentration of corn syrup was optimized to 20% (w/v, tested in the volume of 50 mL), so that the acoustic properties of the PAG would be close to those of human liver. The improved TM (iTM) BSA PAG constructed in this study had a speed of sound of 1588 ± 9 m/s, an attenuation coefficient of 0.51 ± 0.06 dB cm(-1) at 1 MHz and a backscattering coefficient of 0.22 ± 0.09 × 10(-3) sr(-1) cm(-1) MHz(-1). The density and acoustic impedance were 1057 kg/m(3) and 1.68 MRayl, respectively, and the non-linear parameter (B/A) was 5.9 ± 0.3. The thermal, optical and mechanical properties were almost the same as those of the BSA PAG (Lafon et al.2005). Experimental verification indicated that the thermal lesions visualized in the proposed iTM BSA PAG by high-intensity focused ultrasound were highly reproducible. In conclusion, iTM BSA PAG was proven to eliminate TM BSA PAG shortcomings effectively and is expected to be a promising test phantom for clinical high-intensity focused ultrasound device. PMID:25220272

  12. Pathologic evaluation of a new endoscopic ultrasound needle designed to obtain core tissue samples: A pilot study

    PubMed Central

    Adler, Douglas G.; Witt, Benjamin; Chadwick, Barbara; Wells, Jason; Taylor, Linda Jo; Dimaio, Christopher; Schmidt, Robert

    2016-01-01

    Background and Objectives: Standard endoscopic ultrasound-fine-needle aspiration (EUS-FNA) needles are in widespread use. Meaningful differences between the available needles have been difficult to identify. Recently, a new EUS needle (Shark Core®, Covidien, Dublin, Leinster, Ireland), has been introduced in an attempt to improve diagnostic accuracy, tissue yield, and to potentially obtain a core tissue sample. We performed a pilot study prospectively to evaluate this new needle when compared to a standard EUS-FNA needle. Materials and Methods: Analysis of the first 15 patients undergoing EUS-FNA with the Shark Core needle was performed and it was compared to EUS-FNA in 15 patients who underwent EUS-FNA with a standard needle. Results: The Shark Core needle required fewer needle passes to obtain diagnostic adequacy than the standard needle [(χ2(1) = 11.3, P < 0.001]. The Shark Core needle required 1.5 passes to reach adequacy, whereas the standard needle required three passes. For cases with cell blocks, the Shark Core needle produced diagnostic material in 85% of cases [95% confidence interval (CI): 54–98], whereas the standard needle produced diagnostic material in 38% of the cases (95% CI: 9-76). The Shark Core needle produced actual tissue cores 82% of the time (95% CI: 48–98) and the standard needle produced no tissue cores (95% CI: 0-71) (P = 0.03). Conclusion: This pilot study found that the Shark Core needle had a high rate of producing adequate cytologic material for the diagnosis of pancreatic and peri-pancreatic lesions sampled by EUS with fewer passes required to obtain a definitive diagnosis and with a high rate of tissue cores being obtained when compared to a standard FNA needle. PMID:27386475

  13. Evaluation of ultrasound and glucose synergy effect on the optical clearing and light penetration for human colon tissue using SD-OCT.

    PubMed

    Zhao, Qingliang; Wei, Huajiang; He, Yonghong; Ren, Qiushi; Zhou, Chuanqing

    2014-11-01

    Topical application optical clearing agents (OCAs) can effectively enhance the tissue optical clearing on the human colon tissue, which has been demonstrated in our previous studies. Nevertheless, the strong light scattering still limits the diffusion rate of OCAs and penetration depth of light into the tissue. In this study, in order to further increase the diffusion of the OCA of glucose into tissue, we employ a method to improve the glucose permeability and light penetration with ultrasound (sonophoretic delivery, SP) and glucose (G) synergy on human normal and cancerous colon tissues in vitro, which was measured and quantified with spectral-domain optical coherence tomography (SD-OCT) technology. To evaluate the effect of ultrasound mediation, the percentages of OCT signal enhancement (PSE) and 1/e light-penetration depth were calculated for G alone and ultrasound-G treatments. The PSE was calculated at approximately 313 μm from the sample tissue surface. For normal and cancerous colon tissues the PSE were about 91.1 ± 10.6% and 65.3% ± 12.3% with 30% G/SP, but for the 30% G alone treatment it was about 78.6 ± 11.2% and 54.5% ± 9.3%, respectively. The max value of 1/e light-penetration depth for normal colon tissue was 0.47 ± 0.02 mm with 30% G alone and 0.60 ± 0.05 mm (p < 0.05)with 30% G/SP synergy. However, for the cancerous colon tissue the max value was 0.45 ± 0.01 mm and 0.57 ± 0.03 mm (p < 0.05), respectively. The obtained permeability coefficients showed a significant enhancement with ultrasound mediation. The mean permeability coefficients of 30% G/SP in normal and cancerous colon tissues were (6.3 ± 0.16) × 10(-6) cm/s and (12.1 ± 0.34) × 10(-6) cm/s (p < 0.05), respectively. These preliminary experiments showed that ultrasound can effectively enhance the tissue optical clearing and glucose diffusion rate as well as increase the light-penetration depth into biotissues.

  14. Influence of Skin and Subcutaneous Tissue on High-Intensity Focused Ultrasound Beam: Experimental Quantification and Numerical Modeling.

    PubMed

    Grisey, Anthony; Heidmann, Marc; Letort, Veronique; Lafitte, Pauline; Yon, Sylvain

    2016-10-01

    High-intensity focused ultrasound (HIFU) enables the non-invasive thermal ablation of tumors. However, numerical simulations of the treatment remain complex and difficult to validate in clinically relevant situations. In this context, needle hydrophone measurements of the acoustic field downstream of seven rabbit tissue layers comprising skin, subcutaneous fat and muscle were performed in different geometrical configurations. Increasing curvature and thickness of the sample were found to decrease the focusing of the beam: typically, a curvature of 0.05 mm(-1) decreased the maximum pressure by 45% and doubled the focal area. A numerical model based on k-Wave Toolbox was found to be in very good agreement with the reported measurements. It was used to extrapolate the effect of the superficial tissues on peak positive and peak negative pressure at focus, which affects both cavitation and target heating. The shape of the interface was found to have a strong influence on the values, and it is therefore an important parameter to monitor or to control in the clinical practice. This also highlights the importance of modeling realistic configurations when designing treatment procedures. PMID:27471120

  15. Characterization of tissue-simulating phantom materials for ultrasound-guided needle procedures

    NASA Astrophysics Data System (ADS)

    Buchanan, Susan; Moore, John; Lammers, Deanna; Baxter, John; Peters, Terry

    2012-02-01

    Needle biopsies are standard protocols that are commonly performed under ultrasound (US) guidance or computed tomography (CT)1. Vascular access such as central line insertions, and many spinal needle therapies also rely on US guidance. Phantoms for these procedures are crucial as both training tools for clinicians and research tools for developing new guidance systems. Realistic imaging properties and material longevity are critical qualities for needle guidance phantoms. However, current commercially available phantoms for use with US guidance have many limitations, the most detrimental of which include harsh needle tracks obfuscating US images and a membrane comparable to human skin that does not allow seepage of inner media. To overcome these difficulties, we tested a variety of readily available media and membranes to evaluate optimal materials to fit our current needs. It was concluded that liquid hand soap was the best medium, as it instantly left no needle tracks, had an acceptable depth of US penetration and portrayed realistic imaging conditions, while because of its low leakage, low cost, acceptable durability and transparency, the optimal membrane was 10 gauge vinyl.

  16. Evidence for two types of brown adipose tissue in humans.

    PubMed

    Lidell, Martin E; Betz, Matthias J; Dahlqvist Leinhard, Olof; Heglind, Mikael; Elander, Louise; Slawik, Marc; Mussack, Thomas; Nilsson, Daniel; Romu, Thobias; Nuutila, Pirjo; Virtanen, Kirsi A; Beuschlein, Felix; Persson, Anders; Borga, Magnus; Enerbäck, Sven

    2013-05-01

    The previously observed supraclavicular depot of brown adipose tissue (BAT) in adult humans was commonly believed to be the equivalent of the interscapular thermogenic organ of small mammals. This view was recently disputed on the basis of the demonstration that this depot consists of beige (also called brite) brown adipocytes, a newly identified type of brown adipocyte that is distinct from the classical brown adipocytes that make up the interscapular thermogenic organs of other mammals. A combination of high-resolution imaging techniques and histological and biochemical analyses showed evidence for an anatomically distinguishable interscapular BAT (iBAT) depot in human infants that consists of classical brown adipocytes, a cell type that has so far not been shown to exist in humans. On the basis of these findings, we conclude that infants, similarly to rodents, have the bona fide iBAT thermogenic organ consisting of classical brown adipocytes that is essential for the survival of small mammals in a cold environment.

  17. 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.

  18. Quantitative ultrasound bone measurements in pre-pubertal children with type 1 diabetes.

    PubMed

    Chobot, Agata P; Haffke, Anna; Polanska, Joanna; Halaba, Zenon P; Deja, Grazyna; Jarosz-Chobot, Przemyslawa; Pluskiewicz, Wojciech

    2012-07-01

    This case-control study aimed to assess bone status in children with type 1 diabetes mellitus (T1DM). Fifty-seven pre-pubertal patients (37 boys, aged 7.9 ± 2.5 years, T1DM duration 3.1 ± 1.6 years) and 171 age-matched healthy controls (111 boys) were studied. Quantitative ultrasound (QUS) was used to measure amplitude dependent speed of sound (Ad-SoS) at hand phalanges (expressed as standard deviation score [SDS]). Anthropometric and disease-related data (including mean HbA(1c) from whole T1DM duration [T], last year [Y], examination day [D]) were collected. Mean Ad-SoS SDS in patients -0.13 ± 1.32 (95% confidence interval [CI] -0.48, 0.22) was similar to that of controls. Subgroups discriminated according to HbA(1c) D, Y and T (cut-off 7.0%) did not differ regarding analyzed parameters. In patients, Ad-SoS SDS was comparable for both genders. Multivariable stepwise regression analysis showed significant negative influence of diabetes duration on Ad-SoS SDS. QUS findings in pre-pubertal children with T1DM do not differ from those in healthy children. Disease duration seems to affect negatively Ad-SoS SDS. However, independent prospective studies are needed to elucidate the true associations.

  19. 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.

  20. Adult human adipose tissue contains several types of multipotent cells.

    PubMed

    Tallone, Tiziano; Realini, Claudio; Böhmler, Andreas; Kornfeld, Christopher; Vassalli, Giuseppe; Moccetti, Tiziano; Bardelli, Silvana; Soldati, Gianni

    2011-04-01

    Multipotent mesenchymal stromal cells (MSCs) are a type of adult stem cells that can be easily isolated from various tissues and expanded in vitro. Many reports on their pluripotency and possible clinical applications have raised hopes and interest in MSCs. In an attempt to unify the terminology and the criteria to label a cell as MSC, in 2006 the International Society for Cellular Therapy (ISCT) proposed a standard set of rules to define the identity of these cells. However, MSCs are still extracted from different tissues, by diverse isolation protocols, are cultured and expanded in different media and conditions. All these variables may have profound effects on the selection of cell types and the composition of heterogeneous subpopulations, on the selective expansion of specific cell populations with totally different potentials and ergo, on the long-term fate of the cells upon in vitro culture. Therefore, specific molecular and cellular markers that identify MSCs subsets as well as standardization of expansion protocols for these cells are urgently needed. Here, we briefly discuss new useful markers and recent data supporting the rapidly emerging concept that many different types of progenitor cells are found in close association with blood vessels. This knowledge may promote the necessary technical improvements required to reduce variability and promote higher efficacy and safety when isolating and expanding these cells for therapeutic use. In the light of the discussed data, particularly the identification of new markers, and advances in the understanding of fundamental MSC biology, we also suggest a revision of the 2006 ISCT criteria.

  1. Influence of temperature-dependent thermal parameters on temperature elevation of tissue exposed to high-intensity focused ultrasound: numerical simulation.

    PubMed

    Guntur, Sitaramanjaneya Reddy; Choi, Min Joo

    2015-03-01

    High-intensity focused ultrasound (HIFU) has been used successfully as a non-invasive modality in treating solid tumors. The temperature rise HIFU irradiation causes in a tissue depends on the thermal properties of the tissue. This study was motivated by our observation that the thermal properties of a tissue vary significantly with temperature (Guntur SR, Lee KI, Paeng DG, Coleman AJ, Choi MJ. Ultrasound Med Biol 2013;39:1771-1784). This research investigated how significantly the alteration of tissue thermal parameters, in the ranges of values measured at 25°C-90°C, affects prediction of the temperature elevation of tissue under the same HIFU exposure. The numerical simulation was performed by coupling a non-linear Khokhlov-Zabolotskaya-Kuznetsov equation with a bio-heat transfer function. In the conventional method of prediction, the thermal parameters were set as constants measured at room temperature (25°C). This study compared the conventional prediction with those predicted with different thermal parameters measured at the various temperatures up to 90°C. The results indicated that the conventional method significantly overestimated the rise in focal temperature in the liver tissue exposed to a clinical HIFU field, compared with the prediction made using thermal parameters measured at temperatures that cause thermal denaturation. This finding suggests that temperature-dependent thermal parameters should be considered in predicting the temperature rise in a tissue to avoid use of an insufficient thermal dose in treatment planning for HIFU surgery.

  2. 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 μm, axial resolution=40 μm). 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

  3. 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 μm, axial resolution = 40 μm). 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

  4. CONTRAST-ENHANCED ULTRASOUND ASSESSMENT OF IMPAIRED ADIPOSE TISSUE AND MUSCLE PERFUSION IN INSULIN-RESISTANT MICE

    PubMed Central

    Belcik, J. Todd; Davidson, Brian P.; Foster, Ted; Qi, Yue; Zhao, Yan; Peters, Dawn; Lindner, Jonathan R.

    2015-01-01

    Background In diabetes mellitus reduced perfusion and capillary surface area in skeletal muscle, which is a major glucose storage site, contributes to abnormal glucose homeostasis. Using contrast-enhanced ultrasound (CEU) we investigated whether abdominal adipose tissue perfusion is abnormal in insulin resistance (IR) and correlates with glycemic control. Methods and Results Abdominal adipose tissue and skeletal muscle CEU perfusion imaging was performed in obese IR (db/db) mice at 11-12 or 14-16 weeks of age, and in control lean mice. Time-intensity data were analyzed to quantify microvascular blood flow (MBF) and capillary blood volume (CBV). Blood glucose response over one hour was measured after insulin challenge (1 u/Kg, I.P.). Compared to control mice, db/db mice at 11-12 and 14-16 weeks had a higher glucose concentration area-under-the-curve after insulin (11.8±2.8, 20.6±4.3, and 28.4±5.9 mg·min/dL [×1000], respectively, p=0.0002), and also had lower adipose MBF (0.094±0.038, 0.035±0.010, and 0.023±0.01 mL/min/g, p=0.0002) and CBV (1.6±0.6, 1.0±0.3, and 0.5±0.1 mL/100 g, p=0.0017). The glucose area-under-the-curve correlated in a non-linear fashion with both adipose and skeletal muscle MBF and CBV. There were significant linear correlations between adipose and muscle MBF (r=0.81) and CBV (r=0.66). Adipocyte cell volume on histology was 25-fold higher in 14-16 week db/db versus control mice. Conclusions Abnormal adipose MBF and CBV in IR can be detected by CEU and correlates with the degree of impairment in glucose storage. Abnormalities in adipose tissue and muscle appear to be coupled. Impaired adipose tissue perfusion is in part explained by an increase in adipocyte size without proportional vascular response. PMID:25855669

  5. 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

  6. 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

  7. Endoscopic ultrasound-guided fine needle aspiration in the differentiation of type 1 and type 2 autoimmune pancreatitis

    PubMed Central

    Ishikawa, Takuya; Itoh, Akihiro; Kawashima, Hiroki; Ohno, Eizaburo; Matsubara, Hiroshi; Itoh, Yuya; Nakamura, Yosuke; Hiramatsu, Takeshi; Nakamura, Masanao; Miyahara, Ryoji; Ohmiya, Naoki; Goto, Hidemi; Hirooka, Yoshiki

    2012-01-01

    AIM: To investigate the usefulness of endoscopic ultra-sound-guided fine needle aspiration (EUS-FNA) in the differentiation of autoimmune pancreatitis (AIP). METHODS: We retrospectively reviewed 47 of 56 AIP patients who underwent EUS-FNA and met the Asian diagnostic criteria. On 47 EUS-FNA specimens, we evaluated the presence of adequate material and characteristic features of lymphoplasmacytic sclerosing pancreatitis (LPSP) and idiopathic duct-centric pancreatitis (IDCP) mentioned in the International Consensus Diagnostic Criteria and examined if these findings make a contribution to the differential diagnosis of type 1 and type 2 AIP. A disposable 22-gauge needle was used for EUS-FNA. RESULTS: Adequate specimens including pancreatic tissue for differentiating AIP from cancer were obtained from 43 of 47 patients who underwent EUS-FNA. EUS-FNA was performed from the pancreatic head in 21 cases, which is known to be technically difficult when performed by core biopsy; there was no significant difference in the results compared with pancreatic body-tail. Nine of 47 patients met level 1 findings of LPSP and 5 patients met level 2 findings of LPSP. No one met level 1 findings of IDCP, but 3 patients met level 2 findings of IDCP. Of 10 seronegative cases, 2 cases were diagnosed with “definitive type 1 AIP”, and 3 cases were diagnosed with “probable type 2 AIP” when considering both the level 2 histological findings and response to steroids. CONCLUSION: EUS-FNA is useful in the differentiation of type 1 and type 2 AIP, particularly in seronegative cases. PMID:22876041

  8. Doppler Ultrasound Detection of Preclinical Changes in Foot Arteries in Early Stage of Type 2 Diabetes

    PubMed Central

    Leoniuk, Jolanta; Łukasiewicz, Adam; Szorc, Małgorzata; Sackiewicz, Izabela; Janica, Jacek; Łebkowska, Urszula

    2014-01-01

    Summary Background There are few reports regarding the changes within the vessels in the initial stage of type 2 diabetes. The aim of this study was to estimate the hemodynamic and morphological parameters in foot arteries in type 2 diabetes subjects and to compare these parameters to those obtained in a control group of healthy volunteers. Material/Methods Ultrasound B-mode, color Doppler and pulse wave Doppler imaging of foot arteries was conducted in 37 diabetic patients and 36 non-diabetic subjects to determine their morphological (total vascular diameter and flow lumen diameter) and functional parameters (spectral analysis). Results In diabetic patients, the overall vascular diameter and wall thickness were statistically significantly larger when compared to the control group in the right dorsalis pedis artery (P=0.01; P=0.001), left dorsalis pedis artery (P=0.007; P=0.006), right posterior tibial artery (P=0.005; P=0.0005), and left posterior tibial artery (P=0.007; P=0.0002). No significant differences were observed in both groups in flow lumen diameters and blood flow parameters (PSV, EDV, PI, RI). In the diabetic group, the level of HbA1c positively correlated with flow resistance index in the right dorsalis pedis artery (r=0.38; P=0.02), right posterior tibial artery (r=0.38; P=0.02) and left posterior tibial artery (r=0.42; P=0.009). The pulsatility index within the dorsalis pedis artery decreased with increased trophic skin changes (r=–0.431, P=0.009). Conclusions In the diabetic group, overall artery diameters larger than and flow lumina comparable to the control group suggest vessel wall thickening occurring in the early stage of diabetes. Doppler flow parameters are comparable in both groups. In the diabetic group, the level of HbA1c positively correlated with flow resistance index and negative correlation was observed between the intensity of trophic skin changes and the pulsatility index. PMID:25202434

  9. TU-F-12A-09: GLCM Texture Analysis for Normal-Tissue Toxicity: A Prospective Ultrasound Study of Acute Toxicity in Breast-Cancer Radiotherapy

    SciTech Connect

    Liu, T; Yang, X; Curran, W; Torres, M

    2014-06-15

    Purpose: To evaluate the morphologic and structural integrity of the breast glands using sonographic textural analysis, and identify potential early imaging signatures for radiation toxicity following breast-cancer radiotherapy (RT). Methods: Thirty-eight patients receiving breast RT participated in a prospective ultrasound imaging study. Each participant received 3 ultrasound scans: 1 week before RT (baseline), and at 6-week and 3-month follow-ups. Patients were imaged with a 10-MHz ultrasound on the four quadrant of the breast. A second order statistical method of texture analysis, called gray level co-occurrence matrix (GLCM), was employed to assess RT-induced breast-tissue toxicity. The region of interest (ROI) was 28 mm × 10 mm in size at a 10 mm depth under the skin. Twenty GLCM sonographic features, ratios of the irradiated breast and the contralateral breast, were used to quantify breast-tissue toxicity. Clinical assessment of acute toxicity was conducted using the RTOG toxicity scheme. Results: Ninety-seven ultrasound studies (776 images) were analyzed; and 5 out of 20 sonographic features showed significant differences (p < 0.05) among the baseline scans, the acute toxicity grade 1 and 2 groups. These sonographic features quantified the degree of tissue damage through homogeneity, heterogeneity, randomness, and symmetry. Energy ratio value decreased from 108±0.05 (normal) to 0.99±0.05 (Grade 1) and 0.84±0.04 (Grade 2); Entropy ratio value increased from 1.01±0.01 to 1.02±0.01 and 1.04±0.01; Contrast ratio value increased from 1.03±0.03 to 1.07±0.06 and 1.21±0.09; Variance ratio value increased from 1.06±0.03 to 1.20±0.04 and 1.42±0.10; Cluster Prominence ratio value increased from 0.98±0.02 to 1.01±0.04 and 1.25±0.07. Conclusion: This work has demonstrated that the sonographic features may serve as imaging signatures to assess radiation-induced normal tissue damage. While these findings need to be validated in a larger cohort, they suggest

  10. The speed of sound and attenuation of an IEC agar-based tissue-mimicking material for high frequency ultrasound applications.

    PubMed

    Sun, Chao; Pye, Stephen D; Browne, Jacinta E; Janeczko, Anna; Ellis, Bill; Butler, Mairead B; Sboros, Vassilis; Thomson, Adrian J W; Brewin, Mark P; Earnshaw, Charles H; Moran, Carmel M

    2012-07-01

    This study characterized the acoustic properties of an International Electromechanical Commission (IEC) agar-based tissue mimicking material (TMM) at ultrasound frequencies in the range 10-47 MHz. A broadband reflection substitution technique was employed using two independent systems at 21°C ± 1°C. Using a commercially available preclinical ultrasound scanner and a scanning acoustic macroscope, the measured speeds of sound were 1547.4 ± 1.4 m∙s(-1) and 1548.0 ± 6.1 m∙s(-1), respectively, and were approximately constant over the frequency range. The measured attenuation (dB∙cm(-1)) was found to vary with frequency f (MHz) as 0.40f + 0.0076f(2). Using this polynomial equation and extrapolating to lower frequencies give values comparable to those published at lower frequencies and can estimate the attenuation of this TMM in the frequency range up to 47 MHz. This characterisation enhances understanding in the use of this TMM as a tissue equivalent material for high frequency ultrasound applications.

  11. Intravascular ultrasound area strain imaging used to characterize tissue components and assess vulnerability of atherosclerotic plaques in a rabbit model.

    PubMed

    Hu, Xiao-Bo; Zhang, Peng-Fei; Su, Hai-Jun; Yi, Xin; Chen, Liang; Rong, Yuan-Yuan; Zhang, Ke; Li, Xuan; Wang, Lin; Sun, Chun-Li; Cai, Xiao-Jun; Li, Li; Song, Jian-Tao; Dai, Xiao-Min; Sui, Xiao-Di; Zhang, Yun; Zhang, Mei

    2011-10-01

    The purpose of this study was to investigate the association of area strain and tissue components and vulnerability of atherosclerotic plaques in a rabbit model. Forty purebred New Zealand rabbits underwent balloon-induced abdominal aorta endothelium injury, then a high-cholesterol diet for 24 weeks. Intravascular ultrasound (IVUS) images of abdominal aortas were acquired in situ and two consecutive frames near the end-diastole were used to construct an IVUS elastogram. Histologic slices matched with corresponding IVUS images were stained for fatty and collagen components, smooth muscle cells (SMCs) and macrophages. Regions-of-interest (ROIs) in plaques were classified as fibrous, fibro-fatty or fatty according to histologic study. Vulnerability indexes of ROIs were calculated as (fat + macrophage)/(collagen + SMCs). The area strain of these ROIs was calculated by use of an in-house-designed software system with a block-matching-based algorithm. Area strain was significantly higher in fatty ROIs (0.056 ± 0.003) than in fibrous (0.019 ± 0.002, p < 0.001) or fibro-fatty ROIs (0.033 ± 0.003, p < 0.001). The sensitivity and specificity of area strain for fatty ROIs characterization was 75.0% and 80.2% (area under the curve [AUC] 0.858, 95% confidence interval [CI] = 0.800-0.916, p < 0.001) and 75.0% and 75.3% (AUC 0.859, 95% CI = 0.801-0.917, p < 0.001) for fibrous ROIs, as demonstrated by receiver operating characteristic curve analysis. Area strain was positively correlated with vulnerability index (r(2) = 0.495, p < 0.001), fatty components (r(2) = 0.332, p < 0.001) and macrophage infiltration (r(2) = 0.406, p < 0.001); and negatively correlated with collagen and SMC composition (r(2) = 0.115 and r(2) = 0.169, p < 0.001, respectively). Area strain calculation with IVUS elastography based on digital B-mode analysis is feasible and can be useful for tissue characterization and plaque vulnerability assessment. PMID:21856069

  12. Effect of biological characteristics of different types of uterine fibroids, as assessed with T2-weighted magnetic resonance imaging, on ultrasound-guided high-intensity focused ultrasound ablation.

    PubMed

    Zhao, Wen-Peng; Chen, Jin-Yun; Chen, Wen-Zhi

    2015-02-01

    The aims of this study were to assess the effects of the biological characteristics of different types of uterine fibroids, as assessed with T2-weighted magnetic resonance imaging (MRI), on ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation. Thirty-five patients with 39 symptomatic uterine fibroids who underwent myomectomy or hysterectomy were enrolled. Before surgery, the uterine fibroids were subdivided into hypo-intense, iso-intense, heterogeneous hyper-intense and homogeneous hyper-intense categories based on signal intensity on T2-weighted MRI. Tissue density and moisture content were determined in post-operative samples and normal uterine tissue, the isolated uterine fibroids were subjected to USgHIFU, and the extent of ablation was measured using triphenyltetrazolium chloride. Hematoxylin and eosin staining and sirius red staining were undertaken to investigate the organizational structure of the uterine fibroids. Estrogen and progesterone receptor expression was assayed via immunohistochemical staining. The mean diameter of uterine fibroids was 6.9 ± 2.8 cm. For all uterine fibroids, the average density and moisture content were 10.7 ± 0.7 mg/mL and 75.7 ± 2.4%, respectively; and for the homogeneous hyper-intense fibroids, 10.3 ± 0.5 mg/mL and 76.6 ± 2.3%. The latter subgroup had lower density and higher moisture content compared with the other subgroups. After USgHIFU treatment, the extent of ablation of the hyper-intense fibroids was 102.7 ± 42.1 mm(2), which was significantly less than those of the hypo-intense and heterogeneous hyper-intense fibroids. Hematoxylin and eosin staining and sirius red staining revealed that the homogeneous hyper-intense fibroids had sparse collagen fibers and abundant cells. Immunohistochemistry results revealed that estrogen and progesterone receptors were highly expressed in the homogeneous hyper-intense fibroids. This study revealed that lower density, higher moisture content, sparse collagen

  13. Effect of biological characteristics of different types of uterine fibroids, as assessed with T2-weighted magnetic resonance imaging, on ultrasound-guided high-intensity focused ultrasound ablation.

    PubMed

    Zhao, Wen-Peng; Chen, Jin-Yun; Chen, Wen-Zhi

    2015-02-01

    The aims of this study were to assess the effects of the biological characteristics of different types of uterine fibroids, as assessed with T2-weighted magnetic resonance imaging (MRI), on ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation. Thirty-five patients with 39 symptomatic uterine fibroids who underwent myomectomy or hysterectomy were enrolled. Before surgery, the uterine fibroids were subdivided into hypo-intense, iso-intense, heterogeneous hyper-intense and homogeneous hyper-intense categories based on signal intensity on T2-weighted MRI. Tissue density and moisture content were determined in post-operative samples and normal uterine tissue, the isolated uterine fibroids were subjected to USgHIFU, and the extent of ablation was measured using triphenyltetrazolium chloride. Hematoxylin and eosin staining and sirius red staining were undertaken to investigate the organizational structure of the uterine fibroids. Estrogen and progesterone receptor expression was assayed via immunohistochemical staining. The mean diameter of uterine fibroids was 6.9 ± 2.8 cm. For all uterine fibroids, the average density and moisture content were 10.7 ± 0.7 mg/mL and 75.7 ± 2.4%, respectively; and for the homogeneous hyper-intense fibroids, 10.3 ± 0.5 mg/mL and 76.6 ± 2.3%. The latter subgroup had lower density and higher moisture content compared with the other subgroups. After USgHIFU treatment, the extent of ablation of the hyper-intense fibroids was 102.7 ± 42.1 mm(2), which was significantly less than those of the hypo-intense and heterogeneous hyper-intense fibroids. Hematoxylin and eosin staining and sirius red staining revealed that the homogeneous hyper-intense fibroids had sparse collagen fibers and abundant cells. Immunohistochemistry results revealed that estrogen and progesterone receptors were highly expressed in the homogeneous hyper-intense fibroids. This study revealed that lower density, higher moisture content, sparse collagen

  14. Real-Time Tissue Change Monitoring on the Sonablate® 500 during High Intensity Focused Ultrasound (HIFU) Treatment of Prostate Cancer

    NASA Astrophysics Data System (ADS)

    Chen, Wo-Hsing; Sanghvi, Narendra T.; Carlson, Roy; Uchida, Toyoaki

    2011-09-01

    Sonablate® 500 (SB-500) HIFU devices have been successfully used to treat prostate cancer non-invasively. In addition, Visually Directed HIFU with the SB-500 has demonstrated higher efficacy. Visually Directed HIFU works by displaying hyperechoic changes on the B-mode ultrasound images. However, small changes in the grey-scale images are not detectable by Visually Directed HIFU. To detect all tissue changes reliably, the SB-500 was enhanced with quantitative, real-time Tissue Change Monitoring (TCM) software. TCM uses pulse-echo ultrasound backscattered RF signals in 2D to estimate changes in the tissue properties caused by HIFU. The RF signal energy difference is calculated in selected frequency bands (pre and post HIFU) for each treatment site. The results are overlaid on the real-time ultrasound image in green, yellow and orange to represent low, medium and high degree of change in backscattered energy levels. The color mapping scheme was derived on measured temperature and backscattered RF signals from in vitro chicken tissue experiments. The TCM software was installed and tested in a clinical device to obtain human RF data. Post HIFU contrast enhanced MRI scans verified necrotic regions of the prostate. The color mapping success rate at higher HIFU power levels was 94% in the initial clinical test. Based on these results, TCM software has been released for wider usage. The clinical studies with TCM in Japan and The Bahamas have provided the following PSA (ng/ml) results. Japan (n = 97), PSA pre-treatment/post-treatment; minimum 0.7/0.0, maximum 76.0/4.73, median 6.89/0.07, standard deviation 11.19/0.62. The Bahamas (n = 59), minimum 0.4/0.0, maximum 13.0/1.4, median 4.7/0.1, standard deviation 2.8/0.3.

  15. 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.

  16. Opto-acoustic diagnostics of the thermal action of high-intensity focused ultrasound on biological tissues: the possibility of its applications and model experiments

    SciTech Connect

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

    2006-12-31

    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. (special issue devoted to multiple radiation scattering in random media)

  17. Quantification of petroleum-type hydrocarbons in avian tissue

    USGS Publications Warehouse

    Gay, M.L.; Belisle, A.A.; Patton, J.F.

    1980-01-01

    Summary: Methods were developed for the analysis of 16 hydrocarbons in avian tissue. Mechanical extraction with pentane was followed by clean-up on Florisil and Silicar. Residues were determined by gas--liquid chromatography and gas-liquid, chromatography-mass spectrometry. The method was applied to the analysis of liver, kidney, fat, and brain tissue of mallard ducks (Anas platyrhynchos) fed a mixture of hydrocarbons. Measurable concentrations of all compounds analyzed were present in all tissues except brain. Highest concentrations were in fat.

  18. Automated 3D ultrasound image segmentation to aid breast cancer image interpretation.

    PubMed

    Gu, Peng; Lee, Won-Mean; Roubidoux, Marilyn A; Yuan, Jie; Wang, Xueding; Carson, Paul L

    2016-02-01

    Segmentation of an ultrasound image into functional tissues is of great importance to clinical diagnosis of breast cancer. However, many studies are found to segment only the mass of interest and not all major tissues. Differences and inconsistencies in ultrasound interpretation call for an automated segmentation method to make results operator-independent. Furthermore, manual segmentation of entire three-dimensional (3D) ultrasound volumes is time-consuming, resource-intensive, and clinically impractical. Here, we propose an automated algorithm to segment 3D ultrasound volumes into three major tissue types: cyst/mass, fatty tissue, and fibro-glandular tissue. To test its efficacy and consistency, the proposed automated method was employed on a database of 21 cases of whole breast ultrasound. Experimental results show that our proposed method not only distinguishes fat and non-fat tissues correctly, but performs well in classifying cyst/mass. Comparison of density assessment between the automated method and manual segmentation demonstrates good consistency with an accuracy of 85.7%. Quantitative comparison of corresponding tissue volumes, which uses overlap ratio, gives an average similarity of 74.54%, consistent with values seen in MRI brain segmentations. Thus, our proposed method exhibits great potential as an automated approach to segment 3D whole breast ultrasound volumes into functionally distinct tissues that may help to correct ultrasound speed of sound aberrations and assist in density based prognosis of breast cancer.

  19. Automated 3D ultrasound image segmentation for assistant diagnosis of breast cancer

    NASA Astrophysics Data System (ADS)

    Wang, Yuxin; Gu, Peng; Lee, Won-Mean; Roubidoux, Marilyn A.; Du, Sidan; Yuan, Jie; Wang, Xueding; Carson, Paul L.

    2016-04-01

    Segmentation of an ultrasound image into functional tissues is of great importance to clinical diagnosis of breast cancer. However, many studies are found to segment only the mass of interest and not all major tissues. Differences and inconsistencies in ultrasound interpretation call for an automated segmentation method to make results operator-independent. Furthermore, manual segmentation of entire three-dimensional (3D) ultrasound volumes is time-consuming, resource-intensive, and clinically impractical. Here, we propose an automated algorithm to segment 3D ultrasound volumes into three major tissue types: cyst/mass, fatty tissue, and fibro-glandular tissue. To test its efficacy and consistency, the proposed automated method was employed on a database of 21 cases of whole breast ultrasound. Experimental results show that our proposed method not only distinguishes fat and non-fat tissues correctly, but performs well in classifying cyst/mass. Comparison of density assessment between the automated method and manual segmentation demonstrates good consistency with an accuracy of 85.7%. Quantitative comparison of corresponding tissue volumes, which uses overlap ratio, gives an average similarity of 74.54%, consistent with values seen in MRI brain segmentations. Thus, our proposed method exhibits great potential as an automated approach to segment 3D whole breast ultrasound volumes into functionally distinct tissues that may help to correct ultrasound speed of sound aberrations and assist in density based prognosis of breast cancer.

  20. 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.

  1. A μCT-based investigation of the influence of tissue modulus variation, anisotropy and inhomogeneity on ultrasound propagation in trabecular bone.

    PubMed

    Pan, Wenlei; Shen, Yi; van Lenthe, G Harry

    2016-07-01

    Ultrasound propagation is widely used in the diagnosis of osteoporosis by providing information on bone mechanical quality. When it loses calcium, the tissue properties will first decrease. However, limited research about the influence of tissue properties on ultrasound propagation have been done due to the cumbersome experiment. The goal of this study was to explore the relationships between tissue modulus (Es) and speed of sound (SOS) through numerical simulations, and to study the influence of Es on the acoustical behavior in characterizing the local structural anisotropy and inhomogeneity. In this work, three-dimensional finite element (FE) simulations were performed on a cubic high-resolution (15μm) bovine trabecular bone sample (4×4×4mm(3), BV/TV=0.18) mapped from micro-computed tomography. Ultrasound excitations of 50kHz, 500kHz and 2MHz were applied in three orthogonal axes and the first arriving signal (FAS) was collected to quantify wave velocity. In this study, a strong power law relationship between Es and SOS was measured with estimated exponential index β=2.08-3.44 for proximal-distal (PD), anterior-posterior (AP) and medial-lateral (ML), respectively (all R(2)>0.95). For various Es, a positive dispersion of sound speed with respect to sound frequency was observed and the velocity dispersion magnitude (VDM) was measured. Also, with Es=15GPa in three orientations, the SOS in PD axis is 2009±120m/s, faster than that of AP (1762±106m/s) and ML (1798±132m/s) (f=2MHz) directions. Besides, the standard deviation of SOS increases with the sound frequency and the Es in all directions except for that at 50kHz. For the mechanical properties, the apparent modulus with certain Es was highest in the longitudinal direction compared with the transverse directions. It indicates that the tissue modulus combining with anisotropy and inhomogeneity has great influence on ultrasound propagation. Simulation results agree well with theoretical and experimental

  2. 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.

  3. The cryopreservation of composite tissues: Principles and recent advancement on cryopreservation of different type of tissues.

    PubMed

    Bakhach, Joseph

    2009-07-01

    Cryopreservation of human cells and tissue has generated great interest in the scientific community since 1949, when the cryoprotective activity of glycerol was discovered. Nowadays, it is possible to reach the optimal conditions for the cryopreservation of a homogeneous cell population or a one cell-layer tissue with the preservation of a high pourcentage of the initial cells. Success is attained when there is a high recovery rate of cell structures and tissue components after thawing. It is more delicate to obtain cryopreservation of composite tissues and much more a whole organ. The present work deals with fundamental principles of the cryobiology of biological structures, with special attention to the transfer of liquids between intra and extracellular compartments and the initiation of the formation and aggregation of ice during freezing. The consequences of various physical and chemical reactions on biological tissue are described for different cryoprotective agents. Finally, we report a review of results on cyropreservation of various tissues, on the one hand, and various organs, on the other. We also report immunomodulation of antigenic responses to cryopreserved cells and organs. PMID:20046674

  4. A Wearable Goggle Navigation System for Dual-Mode Optical and Ultrasound Localization of Suspicious Lesions: Validation Studies Using Tissue-Simulating Phantoms and an Ex Vivo Human Breast Tissue Model

    PubMed Central

    Wang, Dong; Gan, Qi; Ye, Jian; Yue, Jian; Wang, Benzhong; Povoski, Stephen P.; Martin, Edward W.; Hitchcock, Charles L.; Yilmaz, Alper; Tweedle, Michael F.; Shao, Pengfei; Xu, Ronald X.

    2016-01-01

    Surgical resection remains the primary curative treatment for many early-stage cancers, including breast cancer. The development of intraoperative guidance systems for identifying all sites of disease and improving the likelihood of complete surgical resection is an area of active ongoing research, as this can lead to a decrease in the need of subsequent additional surgical procedures. We develop a wearable goggle navigation system for dual-mode optical and ultrasound imaging of suspicious lesions. The system consists of a light source module, a monochromatic CCD camera, an ultrasound system, a Google Glass, and a host computer. It is tested in tissue-simulating phantoms and an ex vivo human breast tissue model. Our experiments demonstrate that the surgical navigation system provides useful guidance for localization and core needle biopsy of simulated tumor within the tissue-simulating phantom, as well as a core needle biopsy and subsequent excision of Indocyanine Green (ICG)—fluorescing sentinel lymph nodes. Our experiments support the contention that this wearable goggle navigation system can be potentially very useful and fully integrated by the surgeon for optimizing many aspects of oncologic surgery. Further engineering optimization and additional in vivo clinical validation work is necessary before such a surgical navigation system can be fully realized in the everyday clinical setting. PMID:27367051

  5. High intensity ultrasound.

    PubMed

    ter Haar, G

    2001-03-01

    High-intensity focused ultrasound (HIFU) is a technique that was first investigated in the 1940s as a method of destroying selective regions within the brain in neuro-surgical An ultrasound beam can be brought to a tight focus at a distance from its source, and if sufficient energy is concentrated within the focus, the cells lying within this focal volume are killed, whereas those lying elsewhere are spared. This is a noninvasive method of producing selective and trackless tissue destruction in deep seated targets in the body, without damage to overlying tissues. This field, known both as HIFU and focused ultrasound surgery (FUS), is reviewed in this article.

  6. Liposome-mediated transfection of wild-type P53 DNA into human prostate cancer cells is improved by low-frequency ultrasound combined with microbubbles

    PubMed Central

    BAI, WEN-KUN; ZHANG, WEI; HU, BING; YING, TAO

    2016-01-01

    Prostate cancer is a common type of cancer in elderly men. The aim of the present study was to evaluate the effects of ultrasound exposure in combination with SonoVue microbubbles on liposome-mediated transfection of wild-type P53 genes into human prostate cancer cells. PC-3 human prostate cancer cells were exposed to ultrasound; duty cycle was controlled at 20% (2 sec on, 8 sec off) for 5 min with and without SonoVue microbubble echo-contrast agent using a digital sonifier (frequency, 21 kHz; intensity, 46 mW/cm2). The cells were divided into eight groups, as follows: Group A (SonoVue + wild-type P53), group B (ultrasound + wild-type P53), group C (SonoVue + ultrasound + wild-type P53), group D (liposome + wild-type P53), group E (liposome + SonoVue + wild-type P53), group F (liposome + wild-type P53 + ultrasound), group G (liposome + wild-type P53 + ultrasound + SonoVue) and the control group (wild-type P53). Following treatment, a hemocytometer was used to measure cell lysis, reverse transcription-quantitative polymerase chain reaction and western blotting were performed to detect P53 gene transfection efficiency, Cell Counting Kit-8 was employed to reveal cell proliferation and Annexin V/propidium iodide staining was used to determine cell apoptosis. Cell lysis was minimal in each group. Wild-type P53 gene and protein expression were significantly increased in the PC-3 cells in group G compared with the control and all other groups (P<0.01). Cell proliferation was significantly suppressed in group G compared with the control group and all other groups (P<0.01). Cell apoptosis levels in group G were significantly improved compared with the control group and all other groups (P<0.01). Thus, the results of the present study indicate that the use of low-frequency and low-energy ultrasound in combination with SonoVue microbubbles may be a potent physical method for increasing liposome gene delivery efficiency. PMID:27313702

  7. Topographical Control of Ocular Cell Types for Tissue Engineering

    PubMed Central

    McHugh, Kevin J.; Saint-Geniez, Magali; Tao, Sarah L.

    2014-01-01

    Visual impairment affects over 285 million people worldwide and has a major impact on an individual’s quality of life. Tissue engineering has the potential to increase quality of life for many of these patients by preventing vision loss or restoring vision using cell-based therapies. However, these strategies will require an understanding of the microenvironmental factors that influence cell behavior. The eye is a well-organized organ whose structural complexity is essential for proper function. Interactions between ocular cells and their highly ordered extracellular matrix are necessary for maintaining key tissue properties including corneal transparency and retinal lamination. Therefore, it is not surprising that culturing these cells in vitro on traditional flat substrates result in irregular morphology. Instead, topographically patterned biomaterials better mimic native extracellular matrix and have been shown to elicit in vivo-like morphology and gene expression which is essential for tissue engineering. Herein we review multiple methods for producing well-controlled topography and discuss optimal biomaterial scaffold design for cells of the cornea, retina, and lens. PMID:23744715

  8. Topographical control of ocular cell types for tissue engineering.

    PubMed

    McHugh, Kevin J; Saint-Geniez, Magali; Tao, Sarah L

    2013-11-01

    Visual impairment affects over 285 million people worldwide and has a major impact on an individual's quality of life. Tissue engineering has the potential to increase the quality of life for many of these patients by preventing vision loss or restoring vision using cell-based therapies. However, these strategies will require an understanding of the microenvironmental factors that influence cell behavior. The eye is a well-organized organ whose structural complexity is essential for proper function. Interactions between ocular cells and their highly ordered extracellular matrix are necessary for maintaining key tissue properties including corneal transparency and retinal lamination. Therefore, it is not surprising that culturing these cells in vitro on traditional flat substrates result in irregular morphology. Instead, topographically patterned biomaterials better mimic native extracellular matrix and have been shown to elicit in vivo-like morphology and gene expression which is essential for tissue engineering. Herein we review multiple methods for producing well-controlled topography and discuss optimal biomaterial scaffold design for cells of the cornea, retina, and lens.

  9. CT-Based Assessment of Relative Soft-Tissue Alteration in Different Types of Ancient Mummies.

    PubMed

    Sydler, Christina; Öhrström, Lena; Rosendahl, Wilfried; Woitek, Ulrich; Rühli, Frank

    2015-06-01

    Mummification leads to alteration of soft-tissue morphology. No research has focused specifically on differences in soft-tissue shrinkage depending on mummification type. This study evaluated whether soft-tissue alteration is dependent on type of mummification. A total of 17 human mummies have been investigated by computed tomography (CT). Samples included artificially embalmed ancient Egyptian mummies, naturally mummified South American corpses, ice mummies (including the Iceman, South Tyrol Museum of Archeology, Bolzano, Italy, ca. 3,300 BC), bog bodies and a desiccated mummy of possibly Asian provenance. The acquired data were compared to four contemporary bodies. The extent of soft-tissue shrinkage was evaluated using CT data. Shrinkage was defined as soft-tissue relative to area of bone (in number of voxels). Measurements were taken at 13 anatomically defined locations. Ice mummies show the highest degree of preservation. This finding is most likely explained due to frozen water within tissues. All other types of mummies show significantly (at P < 0.05) smaller relative area of preserved soft-tissue. Variation between different anatomical structures (e.g., upper lip vs. mid-femur) is significant, unlike variation within one compartment (e.g., proximal vs. distal humerus). Mummification type strongly affects the degree of soft-tissue alteration, surprisingly mostly independent of overall historical age. These results highlight the unique morphological impact of taphonomy on soft-tissue preservation and are of particular interest in tissue research as well as in forensics. PMID:25998649

  10. CT-Based Assessment of Relative Soft-Tissue Alteration in Different Types of Ancient Mummies.

    PubMed

    Sydler, Christina; Öhrström, Lena; Rosendahl, Wilfried; Woitek, Ulrich; Rühli, Frank

    2015-06-01

    Mummification leads to alteration of soft-tissue morphology. No research has focused specifically on differences in soft-tissue shrinkage depending on mummification type. This study evaluated whether soft-tissue alteration is dependent on type of mummification. A total of 17 human mummies have been investigated by computed tomography (CT). Samples included artificially embalmed ancient Egyptian mummies, naturally mummified South American corpses, ice mummies (including the Iceman, South Tyrol Museum of Archeology, Bolzano, Italy, ca. 3,300 BC), bog bodies and a desiccated mummy of possibly Asian provenance. The acquired data were compared to four contemporary bodies. The extent of soft-tissue shrinkage was evaluated using CT data. Shrinkage was defined as soft-tissue relative to area of bone (in number of voxels). Measurements were taken at 13 anatomically defined locations. Ice mummies show the highest degree of preservation. This finding is most likely explained due to frozen water within tissues. All other types of mummies show significantly (at P < 0.05) smaller relative area of preserved soft-tissue. Variation between different anatomical structures (e.g., upper lip vs. mid-femur) is significant, unlike variation within one compartment (e.g., proximal vs. distal humerus). Mummification type strongly affects the degree of soft-tissue alteration, surprisingly mostly independent of overall historical age. These results highlight the unique morphological impact of taphonomy on soft-tissue preservation and are of particular interest in tissue research as well as in forensics.

  11. 3D conformal MRI-controlled transurethral ultrasound prostate therapy: validation of numerical simulations and demonstration in tissue-mimicking gel phantoms.

    PubMed

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

    2010-11-21

    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

  12. Stable isotopes and elasmobranchs: tissue types, methods, applications and assumptions.

    PubMed

    Hussey, N E; MacNeil, M A; Olin, J A; McMeans, B C; Kinney, M J; Chapman, D D; Fisk, A T

    2012-04-01

    Stable-isotope analysis (SIA) can act as a powerful ecological tracer with which to examine diet, trophic position and movement, as well as more complex questions pertaining to community dynamics and feeding strategies or behaviour among aquatic organisms. With major advances in the understanding of the methodological approaches and assumptions of SIA through dedicated experimental work in the broader literature coupled with the inherent difficulty of studying typically large, highly mobile marine predators, SIA is increasingly being used to investigate the ecology of elasmobranchs (sharks, skates and rays). Here, the current state of SIA in elasmobranchs is reviewed, focusing on available tissues for analysis, methodological issues relating to the effects of lipid extraction and urea, the experimental dynamics of isotopic incorporation, diet-tissue discrimination factors, estimating trophic position, diet and mixing models and individual specialization and niche-width analyses. These areas are discussed in terms of assumptions made when applying SIA to the study of elasmobranch ecology and the requirement that investigators standardize analytical approaches. Recommendations are made for future SIA experimental work that would improve understanding of stable-isotope dynamics and advance their application in the study of sharks, skates and rays. PMID:22497393

  13. Type of MRI contrast, tissue gadolinium, and fibrosis.

    PubMed

    Do, Catherine; Barnes, Jeffrey L; Tan, Chunyan; Wagner, Brent

    2014-10-01

    It has been presupposed that the thermodynamic stability constant (K(therm)) of gadolinium-based MRI chelates relate to the risk of precipitating nephrogenic systemic fibrosis. The present study compared low-K(therm) gadodiamide with high-K(therm) gadoteridol in cultured fibroblasts and rats with uninephrectomies. Gadolinium content was assessed using scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy in paraffin-embedded tissues. In vitro, fibroblasts demonstrated dose-dependent fibronectin generation, transforming growth factor-β production, and expression of activated myofibroblast stress fiber protein α-smooth muscle actin. There were negligible differences with respect to toxicity or proliferation between the two contrast agents. In the rodent model, gadodiamide treatment led to greater skin fibrosis and dermal cellularity than gadoteridol. In the kidney, both contrast agents led to proximal tubule vacuolization and increased fibronectin accumulation. Despite large detectable gadolinium signals in the spleen, skin, muscle, and liver from the gadodiamide-treated group, contrast-induced fibrosis appeared to be limited to the skin and kidney. These findings support the hypothesis that low-K(therm) chelates have a greater propensity to elicit nephrogenic systemic fibrosis and demonstrate that certain tissues are resistant to these effects.

  14. Intravascular ultrasound

    MedlinePlus

    IVUS; Ultrasound - coronary artery; Endovascular ultrasound; Intravascular echocardiography ... A tiny ultrasound wand is attached to the top of a thin tube. This tube is called a catheter. The catheter ...

  15. Duplex ultrasound

    MedlinePlus

    Vascular ultrasound; Peripheral vascular ultrasound ... Deane CR, Goss DE. Peripheral arteries and veins. In: Allan PL, Baxter GM, Weston MJ, eds. Allan & Baxter: Clinical Ultrasound . 3rd ed. Philadelphia, PA: Elsevier ...

  16. Prostate Ultrasound

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  17. Ultrasound -- Pelvis

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  18. Hip Ultrasound

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  19. Ultrasound -- Vascular

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  20. Musculoskeletal Ultrasound

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  1. Ultrasound - Scrotum

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  2. Investigation of synthetic aperture methods in ultrasound surface imaging using elementary surface types.

    PubMed

    Kerr, W; Pierce, S G; Rowe, P

    2016-12-01

    Synthetic aperture imaging methods have been employed widely in recent research in non-destructive testing (NDT), but uptake has been more limited in medical ultrasound imaging. Typically offering superior focussing power over more traditional phased array methods, these techniques have been employed in NDT applications to locate and characterise small defects within large samples, but have rarely been used to image surfaces. A desire to ultimately employ ultrasonic surface imaging for bone surface geometry measurement prior to surgical intervention motivates this research, and results are presented for initial laboratory trials of a surface reconstruction technique based on global thresholding of ultrasonic 3D point cloud data. In this study, representative geometry artefacts were imaged in the laboratory using two synthetic aperture techniques; the Total Focusing Method (TFM) and the Synthetic Aperture Focusing Technique (SAFT) employing full and narrow synthetic apertures, respectively. Three high precision metallic samples of known geometries (cuboid, sphere and cylinder) which featured a range of elementary surface primitives were imaged using a 5MHz, 128 element 1D phased array employing both SAFT and TFM approaches. The array was manipulated around the samples using a precision robotic positioning system, allowing for repeatable ultrasound derived 3D surface point clouds to be created. A global thresholding technique was then developed that allowed the extraction of the surface profiles, and these were compared with the known geometry samples to provide a quantitative measure of error of 3D surface reconstruction. The mean errors achieved with optimised SAFT imaging for the cuboidal, spherical and cylindrical samples were 1.3mm, 2.9mm and 2.0mm respectively, while those for TFM imaging were 3.7mm, 3.0mm and 3.1mm, respectively. These results were contrary to expectations given the higher information content associated with the TFM images. However, it was

  3. Investigation of synthetic aperture methods in ultrasound surface imaging using elementary surface types.

    PubMed

    Kerr, W; Pierce, S G; Rowe, P

    2016-12-01

    Synthetic aperture imaging methods have been employed widely in recent research in non-destructive testing (NDT), but uptake has been more limited in medical ultrasound imaging. Typically offering superior focussing power over more traditional phased array methods, these techniques have been employed in NDT applications to locate and characterise small defects within large samples, but have rarely been used to image surfaces. A desire to ultimately employ ultrasonic surface imaging for bone surface geometry measurement prior to surgical intervention motivates this research, and results are presented for initial laboratory trials of a surface reconstruction technique based on global thresholding of ultrasonic 3D point cloud data. In this study, representative geometry artefacts were imaged in the laboratory using two synthetic aperture techniques; the Total Focusing Method (TFM) and the Synthetic Aperture Focusing Technique (SAFT) employing full and narrow synthetic apertures, respectively. Three high precision metallic samples of known geometries (cuboid, sphere and cylinder) which featured a range of elementary surface primitives were imaged using a 5MHz, 128 element 1D phased array employing both SAFT and TFM approaches. The array was manipulated around the samples using a precision robotic positioning system, allowing for repeatable ultrasound derived 3D surface point clouds to be created. A global thresholding technique was then developed that allowed the extraction of the surface profiles, and these were compared with the known geometry samples to provide a quantitative measure of error of 3D surface reconstruction. The mean errors achieved with optimised SAFT imaging for the cuboidal, spherical and cylindrical samples were 1.3mm, 2.9mm and 2.0mm respectively, while those for TFM imaging were 3.7mm, 3.0mm and 3.1mm, respectively. These results were contrary to expectations given the higher information content associated with the TFM images. However, it was

  4. Fourier transform infrared imaging and infrared fiber optic probe spectroscopy identify collagen type in connective tissues.

    PubMed

    Hanifi, Arash; McCarthy, Helen; Roberts, Sally; Pleshko, Nancy

    2013-01-01

    Hyaline cartilage and mechanically inferior fibrocartilage consisting of mixed collagen types are frequently found together in repairing articular cartilage. The present study seeks to develop methodology to identify collagen type and other tissue components using Fourier transform infrared (FTIR) spectral evaluation of matrix composition in combination with multivariate analyses. FTIR spectra of the primary molecular components of repair cartilage, types I and II collagen, and aggrecan, were used to develop multivariate spectral models for discrimination of the matrix components of the tissues of interest. Infrared imaging data were collected from bovine bone, tendon, normal cartilage, meniscus and human repair cartilage tissues, and composition predicted using partial least squares analyses. Histology and immunohistochemistry results were used as standards for validation. Infrared fiber optic probe spectral data were also obtained from meniscus (a tissue with mixed collagen types) to evaluate the potential of this method for identification of collagen type in a minimally-invasive clinical application. Concentration profiles of the tissue components obtained from multivariate analysis were in excellent agreement with histology and immunohistochemistry results. Bone and tendon showed a uniform distribution of predominantly type I collagen through the tissue. Normal cartilage showed a distribution of type II collagen and proteoglycan similar to the known composition, while in repair cartilage, the spectral distribution of both types I and II collagen were similar to that observed via immunohistochemistry. Using the probe, the outer and inner regions of the meniscus were shown to be primarily composed of type I and II collagen, respectively, in accordance with immunohistochemistry data. In summary, multivariate analysis of infrared spectra can indeed be used to differentiate collagen type I and type II, even in the presence of proteoglycan, in connective tissues

  5. Muscle Ultrasound in Patients with Glycogen Storage Disease Types I and III.

    PubMed

    Verbeek, Renate J; Sentner, Christiaan P; Smit, G Peter A; Maurits, Natasha M; Derks, Terry G J; van der Hoeven, Johannes H; Sival, Deborah A

    2016-01-01

    In glycogen storage diseases (GSDs), improved longevity has resulted in the need for neuromuscular surveillance. In 12 children and 14 adults with the "hepatic" (GSD-I) and "myopathic" (GSD-III) phenotypes, we cross-sectionally assessed muscle ultrasound density (MUD) and muscle force. Children with both "hepatic" and "myopathic" GSD phenotypes had elevated MUD values (MUD Z-scores: GSD-I > 2.5 SD vs. GSD-III > 1 SD, p < 0.05) and muscle weakness (GSD-I muscle force; p < 0.05) of myopathic distribution. In "hepatic" GSD-I adults, MUD stabilized (GSD-I adults vs. GSD-I children, not significant), concurring with moderate muscle weakness (GSD-I adults vs. healthy matched pairs, p < 0.05). In "myopathic" GSD-III adults, MUD increased with age (MUD-GSD III vs. age: r = 0.71-0.83, GSD-III adults > GSD-III children, p < 0.05), concurring with pronounced muscle weakness (GSD-III adults vs. GSD-I adults, p < 0.05) of myopathic distribution. Children with "hepatic" and "myopathic" GSD phenotypes were both found to have myopathy. Myopathy stabilizes in "hepatic" GSD-I adults, whereas it progresses in "myopathic" GSD-III adults. Muscle ultrasonography provides an excellent, non-invasive tool for neuromuscular surveillance per GSD phenotype.

  6. Mesothelioma and asbestos fiber type. Evidence from lung tissue analyses.

    PubMed

    McDonald, J C; Armstrong, B; Case, B; Doell, D; McCaughey, W T; McDonald, A D; Sébastien, P

    1989-04-15

    Lung tissue samples from 78 cases from autopsy of mesothelioma in Canada, 1980 through 1984, and from matched referents were examined by optical and analytical transmission electron microscopic study. Concentrations of amosite, crocidolite, and tremolite fibers, and of typical asbestos bodies discriminated sharply between cases and referents. The distributions of chrysotile and anthophyllite/talc fibers and of all other natural and man-made inorganic fibers (greater than or equal to 8 microns) in the two series were quite similar. Relative risk was related to the concentration of long (greater than or equal to 8 microns) amphibole fibers with no additional information provided by shorter fibers. The proportion of long fibers was much higher for amphiboles than chrysotile and, except for chrysotile, systematically higher in cases than referents. Amphibole asbestos fibers could explain most mesothelioma cases in Canada and other inorganic fibers, including chrysotile, very few. Fibrous tremolite, contaminant of many industrial minerals including chrysotile, probably explained most cases in the Quebec mining region and perhaps 20% elsewhere.

  7. [Interpretation of ultrasound findings in otorhinolaryngology : Skin, soft tissue of the neck, lymph nodes, and oncologic follow-up].

    PubMed

    Bozzato, A

    2015-02-01

    A major advantage of head and neck sonography over other imaging methods is that the attending physician performs the examination himself/herself and can directly compare the imaging findings with other clinical and endoscopic findings. Given the "big picture," the physician is thus able to interpret the sonographic findings correctly. The first part of this article gives an exemplary overview of lesions of the skin, neck, and lymph nodes as well as the ensuing oncologic follow-up with ultrasound. In the second part the focus lies on salivary glands, paragangliomas, the esophagus, and vascular pathologies. PMID:25515129

  8. Distortion of intravascular ultrasound images because of nonuniform angular velocity of mechanical-type transducers.

    PubMed

    Kimura, B J; Bhargava, V; Palinski, W; Russo, R J; DeMaria, A N

    1996-08-01

    The purpose of this study was to quantify nonuniform rotation in a current mechanical intravascular ultrasound (IVUS) instrument and its effect on arc, area, and diameter measurements. The accurate reconstruction of IVUS two-dimensional images is dependent on uniform rotation of the catheter tip. Prior investigations suggested that bends in the catheter driveshaft may be responsible for poor torque transmission, nonuniform rotation, and consequent errors in IVUS measurements. Eight 30 MHz mechanically driven IVUS catheters were evaluated in a model simulating the catheter course through the aorta and coronary ostium in a clinical study. Angular velocity and posi-ion profiles of the transducer, image angle, and diameter and area measurement errors were obtained from each catheter by imaging a vascular phantom with eight equispaced echogenic markers from concentric and eccentric positions. Six catheters also were tested for comparison in a simple curvature model. Rotational error was found in all catheters tested and worsened in the aortic model. Maximal angular error, defined as the largest angle between actual and presumed transducer direction, increased when measured in the aortic model as compared with the simple curvature model (17 +/- 12 degrees to 45 +/- 25 degrees; p < 0.05). Angles of 45 degrees were misrepresented with a mean range of values of 26 to 63 degrees. With eccentric catheter placement, area and diameters had average maximal absolute errors of 26% +/- 7.8% and 23% +/- 10%, respectively. In conclusion, nonuniform rotation of mechanical IVUS transducers constitutes a significant potential source of error in IVUS measurement of arcs of calcification, and lumen shape, area, and diameter.

  9. Tissue ablation after 120W greenlight laser vaporization and bipolar plasma vaporization of the prostate: a comparison using transrectal three-dimensional ultrasound volumetry

    NASA Astrophysics Data System (ADS)

    Kranzbühler, Benedikt; Gross, Oliver; Fankhauser, Christian D.; Hefermehl, Lukas J.; Poyet, Cédric; Largo, Remo; Müntener, Michael; Seifert, Hans-Helge; Zimmermann, Matthias; Sulser, Tullio; Müller, Alexander; Hermanns, Thomas

    2012-02-01

    Introduction and objectives: Greenlight laser vaporization (LV) of the prostate is characterized by simultaneous vaporization and coagulation of prostatic tissue resulting in tissue ablation together with excellent hemostasis during the procedure. It has been reported that bipolar plasma vaporization (BPV) of the prostate might be an alternative for LV. So far, it has not been shown that BPV is as effective as LV in terms of tissue ablation or hemostasis. We performed transrectal three-dimensional ultrasound investigations to compare the efficiency of tissue ablation between LV and BPV. Methods: Between 11.2009 and 5.2011, 50 patients underwent pure BPV in our institution. These patients were matched with regard to the pre-operative prostate volume to 50 LV patients from our existing 3D-volumetry-database. Transrectal 3D ultrasound and planimetric volumetry of the prostate were performed pre-operatively, after catheter removal, 6 weeks and 6 months. Results: Median pre-operative prostate volume was not significantly different between the two groups (45.3ml vs. 45.4ml; p=1.0). After catheter removal, median absolute volume reduction (BPV 12.4ml, LV 6.55ml) as well as relative volume reduction (27.8% vs. 16.4%) were significantly higher in the BPV group (p<0.001). After six weeks (42.9% vs. 33.3%) and six months (47.2% vs. 39.7%), relative volume reduction remained significantly higher in the BPV group (p<0.001). Absolute volume reduction was non-significantly higher in the BPV group after six weeks (18.4ml, 13.8ml; p=0.051) and six months (20.8ml, 18ml; p=0.3). Clinical outcome parameters improved significantly in both groups without relevant differences between the groups. Conclusions: Both vaporization techniques result in efficient tissue ablation with initial prostatic swelling. BPV seems to be superior due to a higher relative volume reduction. This difference had no clinical impact after a follow-up of 6M.

  10. A new formalism for the quantification of tissue perfusion by the destruction-replenishment method in contrast ultrasound imaging.

    PubMed

    Arditi, Marcel; Frinking, Peter J A; Zhou, Xiang; Rognin, Nicolas G

    2006-06-01

    A new formalism is presented for the destruction-replenishment perfusion quantification approach at low mechanical index. On the basis of physical considerations, best-fit methods should be applied using perfusion functions with S-shape characteristics. These functions are first described for the case of a geometry with a single flow velocity, then extended to the case of vascular beds with blood vessels having multiple flow velocity values and directions. The principles guiding the analysis are, on one hand, a linearization of video echo signals to overcome the log-compression of the imaging instrument, and, on the other hand, the spatial distribution of the transmit-receive ultrasound beam in the elevation direction. An in vitro model also is described; it was used to confirm experimentally the validity of the approach using a commercial contrast agent. The approach was implemented in the form of a computer program, taking as input a sequence of contrast-specific images, as well as parameters related to the ultrasound imaging equipment used. The generated output is either flow-parameter values computed in regions-of-interest, or parametric flow-images (e.g., mean velocity, mean transit time, mean flow, flow variance, or skewness). This approach thus establishes a base for extracting information about the morphology of vascular beds in vivo, and could allow absolute quantification provided that appropriate instrument calibration is implemented. PMID:16846144

  11. Identification of collagen types in tissues using HPLC-MS/MS.

    PubMed

    Pataridis, Statis; Eckhardt, Adam; Mikulíková, Katerina; Sedláková, Pavla; Miksík, Ivan

    2008-10-01

    A method for the determination and quantification of collagen types I-V in rat tissues has been developed. This method is based on collagen fragmentation by cyanogen bromide followed by trypsin digestion. After that, HPLC-MS/MS (HPLC coupled to an IT mass spectrometer) analyses of the resulting peptide mixtures (peptide maps) were performed. Specific peptides for each collagen type were selected. According to online databases, these peptides are present in human, bovine, and rat collagens. As a result, this method can be potentially applied to other species' tissues as well, such as human tissues, and provides a universal and simple method of quantifying collagen types. The applicability of this method for analyzing collagen types was demonstrated on rat tissues (skin, tendon, and aorta).

  12. Genetic Parameters of Pre-adjusted Body Weight Growth and Ultrasound Measures of Body Tissue Development in Three Seedstock Pig Breed Populations in Korea

    PubMed Central

    Choy, Yun Ho; Mahboob, Alam; Cho, Chung Il; Choi, Jae Gwan; Choi, Im Soo; Choi, Tae Jeong; Cho, Kwang Hyun; Park, Byoung Ho

    2015-01-01

    The objective of this study was to compare the effects of body weight growth adjustment methods on genetic parameters of body growth and tissue among three pig breeds. Data collected on 101,820 Landrace, 281,411 Yorkshire, and 78,068 Duroc pigs, born in Korean swine breeder farms since 2000, were analyzed. Records included body weights on test day and amplitude (A)-mode ultrasound carcass measures of backfat thickness (BF), eye muscle area (EMA), and retail cut percentage (RCP). Days to 90 kg body weight (DAYS90), through an adjustment of the age based on the body weight at the test day, were obtained. Ultrasound measures were also pre-adjusted (ABF, EMA, AEMA, ARCP) based on their test day measures. The (co)variance components were obtained with 3 multi-trait animal models using the REMLF90 software package. Model I included DAYS90 and ultrasound traits, whereas model II and III accounted DAYS90 and pre-adjusted ultrasound traits. Fixed factors were sex (sex) and contemporary groups (herd-year-month of birth) for all traits among the models. Additionally, model I and II considered a linear covariate of final weight on the ultrasound measure traits. Heritability (h2) estimates for DAYS90, BF, EMA, and RCP ranged from 0.36 to 0.42, 0.34 to 0.43, 0.20 to 0.22, and 0.39 to 0.45, respectively, among the models. The h2 estimates of DAYS90 from model II and III were also somewhat similar. The h2 for ABF, AEMA, and ARCP were 0.35 to 0.44, 0.20 to 0.25, and 0.41 to 0.46, respectively. Our heritability estimates varied mostly among the breeds. The genetic correlations (rG) were moderately negative between DAYS90 and BF (−0.29 to −0.38), and between DAYS90 and EMA (−0.16 to −0.26). BF had strong rG with RCP (−0.87 to −0.93). Moderately positive rG existed between DAYS90 and RCP (0.20 to 0.28) and between EMA and RCP (0.35 to 0.44) among the breeds. For DAYS90, model II and III, its correlations with ABF, AEMA, and ARCP were mostly low or negligible except the r

  13. Towards a dosimetric framework for therapeutic ultrasound.

    PubMed

    Shaw, Adam; ter Haar, Gail; Haller, Julian; Wilkens, Volker

    2015-03-01

    There is a need for a coherent set of exposure and dose quantities to describe ultrasound fields in media other than water (including tissue and tissue-simulating materials). This paper proposes an outline dosimetry scheme, with quantities for free field exposure, in situ exposure, dose (both instantaneous and cumulative) and effect, to act as a structure for organising a more complete set of definitions. It also presents findings from a survey of the views of the therapeutic ultrasound community which generally supports the principle of using modified free field quantities to describe the in situ field, and the prioritising of dose quantities which are related to heating and thermal mechanisms. Although there is no one-to-one relationship between any known ultrasound dose quantity and a specific biological effect, this can also be said of radiotherapy and other modalities where weighting factors have been developed to calculate the degree of equivalence between different tissues and radiation types. This same separation is recommended for ultrasound, provided that an appropriate set of recognised 'engineering' quantities can be established for exposure and dose quantities.

  14. Cell-Type-Specific Genome-wide Expression Profiling after Laser Capture Microdissection of Living Tissue

    SciTech Connect

    Marchetti, F; Manohar, C F

    2005-02-09

    The purpose of this technical feasibility study was to develop and evaluate robust microgenomic tools for investigations of genome-wide expression of very small numbers of cells isolated from whole tissue sections. Tissues contain large numbers of cell-types that play varied roles in organ function and responses to endogenous and exogenous toxicants whether bacterial, viral, chemical or radiation. Expression studies of whole tissue biopsy are severely limited because heterogeneous cell-types result in an averaging of molecular signals masking subtle but important changes in gene expression in any one cell type(s) or group of cells. Accurate gene expression analysis requires the study of specific cell types in their tissue environment but without contamination from surrounding cells. Laser capture microdissection (LCM) is a new technology to isolate morphologically distinct cells from tissue sections. Alternative methods are available for isolating single cells but not yet for their reliable genome-wide expression analyses. The tasks of this feasibility project were to: (1) Develop efficient protocols for laser capture microdissection of cells from tissues identified by antibody label, or morphological stain. (2) Develop reproducible gene-transcript analyses techniques for single cell-types and determine the numbers of cells needed for reliable genome-wide analyses. (3) Validate the technology for epithelial and endothelial cells isolated from the gastrointestinal tract of mice.

  15. The role of acoustic nonlinearity in tissue heating behind a rib cage using a high-intensity focused ultrasound phased array

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    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 the 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.

  16. The role of acoustic nonlinearity in tissue heating behind a rib cage using a high-intensity focused ultrasound phased array.

    PubMed

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

    2013-04-21

    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 the 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.

  17. Towards enabling ultrasound guidance in cervical cancer high-dose-rate brachytherapy

    NASA Astrophysics Data System (ADS)

    Wong, Adrian; Sojoudia, Samira; Gaudet, Marc; Yap, Wan Wan; Chang, Silvia D.; Abolmaesumi, Purang; Aquino-Parsons, Christina; Moradi, Mehdi

    2014-03-01

    MRI and Computed Tomography (CT) are used in image-based solutions for guiding High Dose Rate (HDR) brachytherapy treatment of cervical cancer. MRI is costly and CT exposes the patients to ionizing radiation. Ultrasound, on the other hand, is affordable and safe. The long-term goal of our work is to enable the use of multiparametric ultrasound imaging in image-guided HDR for cervical cancer. In this paper, we report the development of enabling technology for ultrasound guidance and tissue typing. We report a system to obtain the 3D freehand transabdominal ultrasound RF signals and B-mode images of the uterus, and a method for registration of ultrasound to MRI. MRI and 3D ultrasound images of the female pelvis were registered by contouring the uterus in the two modalities, creating a surface model, followed by rigid and B-spline deformable registration. The resulting transformation was used to map the location of the tumor from the T2-weighted MRI to ultrasound images and to determine cancerous and normal areas in ultrasound. B-mode images show a contrast for cancer vs. normal tissue. Our study shows the potential and the challenges of ultrasound imaging in guiding cervical cancer treatments.

  18. Tensor based tumor tissue type differentiation using magnetic resonance spectroscopic imaging.

    PubMed

    Bharath, H N; Sima, D M; Sauwen, N; Himmelreich, U; De Lathauwer, L; Van Huffel, S

    2015-08-01

    Magnetic resonance spectroscopic imaging (MRSI) has the potential to characterise different tissue types in brain tumors. Blind source separation techniques are used to extract the specific tissue profiles and their corresponding distribution from the MRSI data. A 3-dimensional MRSI tensor is constructed from in vivo 2D-MRSI data of individual tumor patients. Non-negative canonical polyadic decomposition (NCPD) with common factor in mode-1 and mode-2 and l(1) regularization on mode-3 is applied on the MRSI tensor to differentiate various tissue types. Initial in vivo study shows that NCPD has better performance in identifying tumor and necrotic tissue type in high grade glioma patients compared to previous matrix-based decompositions, such as non-negative matrix factorization and hierarchical non-negative matrix factorization. PMID:26737904

  19. Therapeutic ultrasound reverses peripheral ischemia in type 2 diabetic mice through PI3K-Akt-eNOS pathway

    PubMed Central

    Lu, Zhao-Yang; Li, Rui-Lin; Zhou, Hong-Sheng; Huang, Jing-Juan; Su, Zhi-Xiao; Qi, Jia; Zhang, Lan; Li, Yue; Shi, Yi-Qin; Hao, Chang-Ning; Duan, Jun-Li

    2016-01-01

    Therapeutic ultrasound (TUS) has been demonstrated to improve endothelial nitric oxide synthase (eNOS) activity, which played a crucial role in the regulation of angiogenesis. Diabetes Mellitus (DM) impairs eNOS activity. We tested the hypothesis that DM may retard unilateral hindlimb ischemia-induced angiogenesis by inhibiting eNOS in high-fat diet (HFD)/streptozocin (STZ) induced diabetic mice, and that TUS may reverse DM-related impairment of angiogenesis. C57BL/6 mice were allocated to four groups: (A) mice were fed standard diet (control); (B) mice were fed standard diet and treated with TUS (control+TUS); (C) type-2 DM mice were induced by HFD/STZ (diabetic); and (D) type-2 DM mice and treated with TUS (dabetic+TUS). All mice were surgically induced unilateral limb ischemia. The ischemic skeletal muscles in groups B and D were irradiated with extracorporeal TUS for 9 minutes/day (frequency of 1 MHz, intensity of 0.3 W/cm2) for 14 consecutive days. The result showed that TUS augmented the blood perfusion, increased capillary density accompanied by an upregulation of angiogenic factors and a downregulation of apoptotic proteins in group D relative to group C. In vitro, TUS inhibited the apoptosis, promoted tubule formation, proliferation and migration capacities, increased angiogenic factors expression and reduced apoptotic protein levels in human umbilical vein endothelial cells (HUVECs). Furthermore, TUS can robust reverse the inhibiting effect induced by high glucose (HG) on HUVECs, and these benefits could be blocked by phosphoinositide 3-kinase (PI3K) inhibitor (LY294002) or eNOS inhibitor (L-NAME). Together, TUS restored type-2 DM-mediated inhibition of ischemia-induced angiogenesis, partially via PI3K-Akt-eNOS signal pathway. PMID:27725849

  20. Simultaneous Real-time Monitoring of Thermal and Mechanical Tissue Responses to Pulsed HIFU Using Pulse-Echo Ultrasound

    NASA Astrophysics Data System (ADS)

    Liu, Dalong; Ebbini, Emad S.

    2009-04-01

    Pulsed HIFU beams are being increasingly used in a number of therapeutic applications, including thermal therapy, drug and gene delivery, and hemostasis. This wide range of applications is based on a range of HIFU-tissue interactions from purely thermal to purely mechanical to produce the desired therapeutic effects. We have developed a real-time system for monitoring tissue displacements in response to pulsed HIFU beams at high PRFs. The imaging component of the system comprises an FPGA-based signal processing unit for real-time filtering of M-mode pulse-echo data followed by real-time speckle tracking for tissue displacements before, during, and after exposure to pulsed HIFU. The latter can be used in evaluating temperature and/or viscoelastic response to the applied HIFU beam. The high acquisition rate of the M-mode system, together with the real-time displacement tracking are necessary for simultaneous estimation and separation of the thermal and viscoelastic tissue responses. In addition, the system provides a real-time link to MATLAB-based nonlinear spectral estimation routines for cavitation detection. The system has been tested in vitro bovine heart tissue and the results show that the displacement tracking captures the full dynamics of tissue displacements for the full range of HIFU exposures of interest.

  1. General Ultrasound Imaging

    MedlinePlus

    ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... types of Doppler ultrasound: Color Doppler uses a computer to convert Doppler measurements into an array of ...

  2. Ultrasound mediated delivery of drugs and genes to solid tumors

    PubMed Central

    Frenkel, Victor

    2008-01-01

    It has long been shown that therapeutic ultrasound can be used effectively to ablate solid tumors, and a variety of cancers are presently being treated in the clinic using these types of ultrasound exposures. There is, however, an ever-increasing body of preclinical literature that demonstrates how ultrasound energy can also be used non-destructively for increasing the efficacy of drugs and genes for improving cancer treatment. In this review, a summary of the most important ultrasound mechanisms will be given with a detailed description of how each one can be employed for a variety of applications. This includes the manner by which acoustic energy deposition can be used to create changes in tissue permeability for enhancing the delivery of conventional agents, as well as for deploying and activating drugs and genes via specially tailored vehicles and formulations. PMID:18474406

  3. Adaptive Thermal Therapy using Planar Ultrasound Transducers with Real-time MR Temperature Feedback: Demonstration in Gel Phantoms and Ex-vivo Tissues

    NASA Astrophysics Data System (ADS)

    Tang, Kee; Choy, Vanessa; Chopra, Rajiv; Bronskill, Michael

    2007-05-01

    MRI-guided transurethral ultrasound therapy offers a minimally invasive approach for the treatment of localized prostate cancer. The main goal of this study was to evaluate active temperature feedback on a clinical 1.5T MR imager to control conformal thermal therapy. MR thermometry was performed during heating in both thermal gel phantoms and ex-vivo tissue with a single-element transurethral heating applicator. The applicator rotation rate and power were controlled based on MRI-temperature measurements. The influence of a cooling gradient (to simulate cooling of the rectum or urethra) was also investigated in gel phantoms. The 55°C isotherm generated during heating closely matched the targeted prostate shape, with an average distance error of 0.9 mm ± 0.4 mm in turkey breasts, 1.3 mm ± 0.5 mm in gel phantoms without rectal cooling and 1.4 mm ± 0.6 mm in gel phantoms with rectal cooling. Accurate, MRI-guided, active feedback has been successfully demonstrated experimentally and has the capability to adjust for unpredictable and varying tissue properties during the treatment.

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

    NASA Astrophysics Data System (ADS)

    Paltiel, H. J.; Padua, H. M.; Gargollo, P. C.; Cannon, G. M., Jr.; Alomari, A. I.; Yu, R.; Clement, G. T.

    2011-04-01

    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.

  5. Precise anatomy localization in CT data by an improved probabilistic tissue type atlas

    NASA Astrophysics Data System (ADS)

    Franz, Astrid; Schadewaldt, Nicole; Schulz, Heinrich; Vik, Torbjørn; Bergtholdt, Martin; Bystrov, Daniel

    2016-03-01

    Automated interpretation of CT scans is an important, clinically relevant area as the number of such scans is increasing rapidly and the interpretation is time consuming. Anatomy localization is an important prerequisite for any such interpretation task. This can be done by image-to-atlas registration, where the atlas serves as a reference space for annotations such as organ probability maps. Tissue type based atlases allow fast and robust processing of arbitrary CT scans. Here we present two methods which significantly improve organ localization based on tissue types. A first problem is the definition of tissue types, which until now is done heuristically based on experience. We present a method to determine suitable tissue types from sample images automatically. A second problem is the restriction of the transformation space: all prior approaches use global affine maps. We present a hierarchical strategy to refine this global affine map. For each organ or region of interest a localized tissue type atlas is computed and used for a subsequent local affine registration step. A three-fold cross validation on 311 CT images with different fields-of-view demonstrates a reduction of the organ localization error by 33%.

  6. Comparative analysis of codeword representation by clustering methods for the classification of histological tissue types

    NASA Astrophysics Data System (ADS)

    Saygili, Ahmet; Uysal, Gunalp; Bilgin, Gokhan

    2015-12-01

    In this study, the classification of several histological tissue types, i.e., muscles, nerves, connective and epithelial tissue cells, is studied in high resolutional histological images. In the feature extraction step, bag of features method is utilized to reveal distinguishing features of each tissue cell types. Local small blocks of sub-images/patches are extracted to find discriminative patterns for followed strategy. For detecting points of interest in local patches, Harris corner detection method is applied. Afterwards, discriminative features are extracted using the scale invariant feature transform method using these points of interests. Several code word representations are obtained by clustering approach (using k-means fuzzy c-means, expectation maximization method, Gaussian mixture models) and evaluated in comparative manner. In the last step, the classification of the tissue cells data are performed using k-nearest neighbor and support vector machines methods.

  7. Ultrasound elastographic techniques in focal liver lesions

    PubMed Central

    Conti, Clara Benedetta; Cavalcoli, Federica; Fraquelli, Mirella; Conte, Dario; Massironi, Sara

    2016-01-01

    Elastographic techniques are new ultrasound-based imaging techniques developed to estimate tissue deformability/stiffness. Several ultrasound elastographic approaches have been developed, such as static elastography, transient elastography and acoustic radiation force imaging methods, which include point shear wave and shear wave imaging elastography. The application of these methods in clinical practice aims at estimating the mechanical tissues properties. One of the main settings for the application of these tools has been liver stiffness assessment in chronic liver disease, which has been studied mainly using transient elastography. Another field of application for these techniques is the assessment of focal lesions, detected by ultrasound in organs such as pancreas, prostate, breast, thyroid, lymph nodes. Considering the frequency and importance of the detection of focal liver lesions through routine ultrasound, some studies have also aimed to assess the role that elestography can play in studying the stiffness of different types of liver lesions, in order to predict their nature and thus offer valuable non-invasive methods for the diagnosis of liver masses. PMID:26973405

  8. Ultrasound-image-based Texture Variability along the Carotid Artery Wall in Asymptomatic Subjects with Low and High Stenosis Degrees: Unveiling Morphological Phenomena of the Vulnerable Tissue

    NASA Astrophysics Data System (ADS)

    Golemati, Spyretta; Lehareas, Symeon; Tsiaparas, Nikolaos N.; Nikita, Konstantina S.; Chatziioannou, Achilles; Perrea, Despina N.

    Valid identification of the vulnerable asymptomatic carotid atherosclerosis remains a crucial clinical issue. In this study, texture differences were estimated along the atherosclerotic arterial wall, namely at the plaque, the wall adjacent to it and the plaque shoulder, i.e. the boundary between wall and plaque, in an attempt to reveal morphological phenomena, representative of the high stenosis (considered vulnerable) cases. A total of 25 arteries were interrogated, 11 with low (50-69%) and 14 with high (70-100%) degrees of stenosis. The two groups had similar ages. Texture features were estimated from B-mode ultrasound images, and included four second-order statistical parameters (contrast, correlation, energy and homogeneity), each calculated at four different image directions (00, 450, 900, 1350), yielding a total of 16 features. Texture differences between (a) wall and plaque and (b) wall and plaque shoulder were quantified as the differences in texture feature values for each tissue area normalised by the texture feature value of the wall, which was considered as reference, as illustrated in the following equation: dTFi = (TFi,W - TFi,P/S)/TFi,W, where dTFi the estimated texture difference, TFi,W the texture of the wall, and TFi,P/S the texture of the plaque (P) or the shoulder (S). Significant differences in texture variability of wall vs. shoulder were observed between high and low stenosis cases for 3 features at diastole and 7 features at systole. No differences were observed for wall vs plaque, although wall texture was significantly different than plaque texture, in absolute values. These findings suggest that texture variability along the atherosclerotic wall, which is indicative of tissue discontinuities, and proneness to rupture, can be quantitatively described with texture indices and reveal valuable morphological phenomena of the vulnerable tissue.

  9. Effect of Intravascular Ultrasound-assisted Thoracic Endovascular Aortic Repair for “Complicated” Type B Aortic Dissection

    PubMed Central

    Guo, Bao-Lei; Shi, Zhen-Yu; Guo, Da-Qiao; Wang, Li-Xin; Tang, Xiao; Li, Wei-Miao; Fu, Wei-Guo

    2015-01-01

    Background: Intravascular ultrasound (IVUS) examination can provide useful information during endovascular stent graft repair. However, its actual clinical utility in thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (type B-AD) remains unclear, especially in complicated aortic dissection. We evaluated the effect of IVUS as a complementary tool during TEVAR. Methods: From September 2011 to April 2012, we conducted a prospective cohort study of 47 consecutive patients with “complicated” type B-AD diagnosed. We divided the patients into two groups: IVUS-assisted TEVAR group and TEVAR using angiography alone group. The general procedure of TEVAR was performed. We evaluated the perioperative and follow-up events. Patient demographics, comorbidities, preoperative images, dissection morphology, details of operative strategy, intraoperative events, and postoperative course were recorded. Results: A total of 47 patients receiving TEVAR were enrolled. Among them (females, 8.51%; mean age, 57.38 ± 13.02 years), 13 cases (27.66%) were selected in the IVUS-assisted TEVAR group, and 34 were selected in the TEVAR group. All patients were symptomatic. The average diameter values of IVUS measurements in the landing zone were greater than those estimated by computed tomography angiography (31.82 ± 4.21 mm vs. 30.64 ± 4.13 mm, P < 0.001). The technique success rate was 100%. Among the postoperative outcomes, statistical differences were only observed between the IVUS-assisted TEVAR group and TEVAR group for total operative time and the amount of contrast used (P = 0.013 and P < 0.001, respectively). The follow-up ranged from 15 to 36 months for the IVUS-assisted TEVAR group and from 10 to 35 months for the TEVAR group (P = 0.646). The primary endpoints were no statistical difference in the two groups. Conclusions: Intraoperative IVUS-assisted TEVAR is clinically feasible and safe. For the endovascular repair of “complicated” type B-AD, IVUS may be

  10. 21 CFR 1271.85 - What donor testing is required for different types of cells and tissues?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... of cells and tissues? 1271.85 Section 1271.85 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... FOOD AND DRUG ADMINISTRATION HUMAN CELLS, TISSUES, AND CELLULAR AND TISSUE-BASED PRODUCTS Donor Eligibility § 1271.85 What donor testing is required for different types of cells and tissues? (a) All...

  11. 21 CFR 1271.85 - What donor testing is required for different types of cells and tissues?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... of cells and tissues? 1271.85 Section 1271.85 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... FOOD AND DRUG ADMINISTRATION HUMAN CELLS, TISSUES, AND CELLULAR AND TISSUE-BASED PRODUCTS Donor Eligibility § 1271.85 What donor testing is required for different types of cells and tissues? (a) All...

  12. 21 CFR 1271.85 - What donor testing is required for different types of cells and tissues?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... of cells and tissues? 1271.85 Section 1271.85 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... FOOD AND DRUG ADMINISTRATION HUMAN CELLS, TISSUES, AND CELLULAR AND TISSUE-BASED PRODUCTS Donor Eligibility § 1271.85 What donor testing is required for different types of cells and tissues? (a) All...

  13. 21 CFR 1271.85 - What donor testing is required for different types of cells and tissues?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... of cells and tissues? 1271.85 Section 1271.85 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... FOOD AND DRUG ADMINISTRATION HUMAN CELLS, TISSUES, AND CELLULAR AND TISSUE-BASED PRODUCTS Donor Eligibility § 1271.85 What donor testing is required for different types of cells and tissues? (a) All...

  14. 21 CFR 1271.85 - What donor testing is required for different types of cells and tissues?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... of cells and tissues? 1271.85 Section 1271.85 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... FOOD AND DRUG ADMINISTRATION HUMAN CELLS, TISSUES, AND CELLULAR AND TISSUE-BASED PRODUCTS Donor Eligibility § 1271.85 What donor testing is required for different types of cells and tissues? (a) All...

  15. 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.

  16. Improved cardiac motion detection from ultrasound images using TDIOF: a combined B-mode/ tissue Doppler approach

    NASA Astrophysics Data System (ADS)

    Tavakoli, Vahid; Stoddard, Marcus F.; Amini, Amir A.

    2013-03-01

    Quantitative motion analysis of echocardiographic images helps clinicians with the diagnosis and therapy of patients suffering from cardiac disease. Quantitative analysis is usually based on TDI (Tissue Doppler Imaging) or speckle tracking. These methods are based on two independent techniques - the Doppler Effect and image registration, respectively. In order to increase the accuracy of the speckle tracking technique and cope with the angle dependency of TDI, herein, a combined approach dubbed TDIOF (Tissue Doppler Imaging Optical Flow) is proposed. TDIOF is formulated based on the combination of B-mode and Doppler energy terms in an optical flow framework and minimized using algebraic equations. In this paper, we report on validations with simulated, physical cardiac phantom, and in-vivo patient data. It is shown that the additional Doppler term is able to increase the accuracy of speckle tracking, the basis for several commercially available echocardiography analysis techniques.

  17. Thyroid ultrasound

    PubMed Central

    Chaudhary, Vikas; Bano, Shahina

    2013-01-01

    Thyroid ultrasonography has established itself as a popular and useful tool in the evaluation and management of thyroid disorders. Advanced ultrasound techniques in thyroid imaging have not only fascinated the radiologists but also attracted the surgeons and endocrinologists who are using these techniques in their daily clinical and operative practice. This review provides an overview of indications for ultrasound in various thyroid diseases, describes characteristic ultrasound findings in these diseases, and illustrates major diagnostic pitfalls of thyroid ultrasound. PMID:23776892

  18. Conformal thermal therapy using planar ultrasound transducers and adaptive closed-loop MR temperature control: demonstration in gel phantoms and ex vivo tissues.

    PubMed

    Tang, K; Choy, V; Chopra, R; Bronskill, M J

    2007-05-21

    MRI-guided transurethral ultrasound therapy offers a minimally invasive approach for the treatment of localized prostate cancer. Integrating a multi-element planar transducer with active MR temperature feedback can enable three-dimensional conformal thermal therapy of a target region within the prostate gland while sparing surrounding normal tissues. Continuous measurement of the temperature distribution in tissue enables dynamic compensation for unknown changes in blood flow and tissue properties during treatment. The main goal of this study was to evaluate the feasibility of using active temperature feedback on a clinical 1.5 T MR imager for conformal thermal therapy. MR thermometry was performed during heating in both gel phantoms and excised tissue with a transurethral heating applicator, and the rotation rate and power were varied based on the thermal measurements. The capability to produce a region of thermal damage that matched a target boundary was evaluated. The influence of a cooling gradient (to simulate cooling of the rectum or urethra) on the desired pattern of thermal damage was also investigated in gel phantoms. Results showed high correlation between the desired target boundary and the 55 degrees C isotherm generated during heating with an average distance error of 0.9 mm +/- 0.4 mm (n = 6) in turkey breasts, 1.4 mm +/- 0.6 mm (n = 4) in gel phantoms without rectal cooling and 1.4 mm +/- 0.6 mm (n = 3) in gel phantoms with rectal cooling. The results were obtained using a temporal update rate of 5 s, a spatial resolution of 3 x 3 x 10 mm for the control point, and a temperature uncertainty of approximately 1 degrees C. The performance of the control algorithm under these conditions was comparable to that of simulations conducted previously by our group. Overall, the feasibility of generating targeted regions of thermal damage with a transurethral heating applicator and active MR temperature feedback has been demonstrated experimentally. This method

  19. Conformal thermal therapy using planar ultrasound transducers and adaptive closed-loop MR temperature control: demonstration in gel phantoms and ex vivo tissues

    NASA Astrophysics Data System (ADS)

    Tang, K.; Choy, V.; Chopra, R.; Bronskill, M. J.

    2007-05-01

    MRI-guided transurethral ultrasound therapy offers a minimally invasive approach for the treatment of localized prostate cancer. Integrating a multi-element planar transducer with active MR temperature feedback can enable three-dimensional conformal thermal therapy of a target region within the prostate gland while sparing surrounding normal tissues. Continuous measurement of the temperature distribution in tissue enables dynamic compensation for unknown changes in blood flow and tissue properties during treatment. The main goal of this study was to evaluate the feasibility of using active temperature feedback on a clinical 1.5 T MR imager for conformal thermal therapy. MR thermometry was performed during heating in both gel phantoms and excised tissue with a transurethral heating applicator, and the rotation rate and power were varied based on the thermal measurements. The capability to produce a region of thermal damage that matched a target boundary was evaluated. The influence of a cooling gradient (to simulate cooling of the rectum or urethra) on the desired pattern of thermal damage was also investigated in gel phantoms. Results showed high correlation between the desired target boundary and the 55 °C isotherm generated during heating with an average distance error of 0.9 mm ± 0.4 mm (n = 6) in turkey breasts, 1.4 mm ± 0.6 mm (n = 4) in gel phantoms without rectal cooling and 1.4 mm ± 0.6 mm (n = 3) in gel phantoms with rectal cooling. The results were obtained using a temporal update rate of 5 s, a spatial resolution of 3 × 3 × 10 mm for the control point, and a temperature uncertainty of approximately 1 °C. The performance of the control algorithm under these conditions was comparable to that of simulations conducted previously by our group. Overall, the feasibility of generating targeted regions of thermal damage with a transurethral heating applicator and active MR temperature feedback has been demonstrated experimentally. This method of treatment

  20. Transplantation of adipose tissue protects BB/OK rats from type 1 diabetes development.

    PubMed

    Bahr, Jeanette; Klöting, Nora; Klöting, Ingrid; Follak, Niels

    2011-05-01

    B(io) B(reedding)/O(ttawa) K(alsburg) rats spontaneously develop insulin-dependent type 1 diabetes. Days before BB/OK rats become diabetic, their body seems to be flabby which may be attributed to loss of subcutaneous fat. However, the rats are normoglycemic and manifest 3-4 days later. This observation prompted us to search for possibilities to avoid the loss of adipose tissue. BB/OK rats were subcutaneously grafted with visceral adipose tissue. In total, 34 (71%) out of 48 male and 23 (49%) out of 47 female BB/OK rats grafted with adipose tissue developed type 1 diabetes so that significantly more females than males were protected from diabetes development (p=0.03). In the control group, 17 (85%) out of 20 male and 20 (95%) out of 21 female BB/OK rats were diabetic. Adipose tissue transplantation can protect BB/OK rats from type 1 diabetes development in a sex specific manner. One could conclude that the manipulations have influenced fat accumulation and/or fat metabolism which prevent type 1 diabetes development in about 50% of BB/OK rats. This idea is supported by the finding that a mutation in the leptin receptor of NOD mice suppresses type 1 diabetes progression.

  1. 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.

    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.

  2. Proteomic Analysis of Disease Stratified Human Pancreas Tissue Indicates Unique Signature of Type 1 Diabetes.

    PubMed

    Burch, Tanya C; Morris, Margaret A; Campbell-Thompson, Martha; Pugliese, Alberto; Nadler, Jerry L; Nyalwidhe, Julius O

    2015-01-01

    Type 1 diabetes (T1D) and type 2 diabetes (T2D) are associated with functional beta cell loss due to ongoing inflammation. Despite shared similarities, T1D is an autoimmune disease with evidence of autoantibody production, as well as a role for exocrine pancreas involvement. Our hypothesis is that differential protein expression occurs in disease stratified pancreas tissues and regulated proteins from endocrine and exocrine tissues are potential markers of disease and potential therapeutic targets. The study objective was to identify novel proteins that distinguish the pancreas from donors with T1D from the pancreas from patients with T2D, or autoantibody positive non-diabetic donors. Detailed quantitative comprehensive proteomic analysis was applied to snap frozen human pancreatic tissue lysates from organ donors without diabetes, with T1D-associated autoantibodies in the absence of diabetes, with T1D, or with T2D. These disease-stratified human pancreas tissues contain exocrine and endocrine tissues (with dysfunctional islets) in the same microenvironment. The expression profiles of several of the proteins were further verified by western blot. We identified protein panels that are significantly and uniquely upregulated in the three disease-stratified pancreas tissues compared to non-disease control tissues. These proteins are involved in inflammation, metabolic regulation, and autoimmunity, all of which are pathways linked to, and likely involved in, T1 and T2 diabetes pathogenesis. Several new proteins were differentially upregulated in prediabetic, T1D, and T2D pancreas. The results identify proteins that could serve as novel prognostic, diagnostic, and therapeutic tools to preserve functional islet mass in Type 1 Diabetes.

  3. Hybrid use of combined and sequential delivery of growth factors and ultrasound stimulation in porous multilayer composite scaffolds to promote both vascularization and bone formation in bone tissue engineering.

    PubMed

    Yan, Haoran; Liu, Xia; Zhu, Minghua; Luo, Guilin; Sun, Tao; Peng, Qiang; Zeng, Yi; Chen, Taijun; Wang, Yingying; Liu, Keliang; Feng, Bo; Weng, Jie; Wang, Jianxin

    2016-01-01

    In this study, a multilayer coating technology would be adopted to prepare a porous composite scaffold and the growth factor release and ultrasound techniques were introduced into bone tissue engineering to finally solve the problems of vascularization and bone formation in the scaffold whilst the designed multilayer composite with gradient degradation characteristics in the space was used to match the new bone growth process better. The results of animal experiments showed that the use of low intensity pulsed ultrasound (LIPUS) combined with growth factors demonstrated excellent capabilities and advantages in both vascularization and new bone formation in bone tissue engineering. The degradation of the used scaffold materials could match new bone formation very well. The results also showed that only RGD-promoted cell adhesion was insufficient to satisfy the needs of new bone formation while growth factors and LIPUS stimulation were the key factors in new bone formation.

  4. Characterizing bubble dynamics created by high-intensity focused ultrasound for the delivery of antibacterial nanoparticles into a dental hard tissue.

    PubMed

    Ohl, S W; Shrestha, A; Khoo, B C; Kishen, A

    2010-11-01

    Hig hintensity focused ultrasound (HIFU) has been applied for drug delivery in various disease conditions. Delivery of antibacterial-nanoparticles into dental hard tissues may open up new avenues in the treatment of dental infections. However, the basic mechanism of bubble dynamics, its characterization, and working parameters for effective delivery of nanoparticles, warrants further understanding. This study was conducted to highlight the basic concept of HIFU and the associated bubble dynamics for the delivery of nanoparticles. Characterization experiments to deliver micro-scale particles into simulated tubular channels, activity of ultrasonic bubbles, and pressure measurement inside the HIFU system were conducted. Subsequently, experiments were carried out to test the ability of HIFU to deliver nanoparticles into human dentine using field emission scanning electron micrographs (FESEM) and elemental dispersive X-ray analysis (EDX). The characterization experiments showed that the bubbles collapsing at the opening of tubular channels were able to propel particles along their whole length. The pressure measured showed sufficient negative and positive pressure suggesting that the bubble grew to a certain size before collapsing, thus enabling the particles to be pushed. The FESEM and EDX analysis highlighted the ability of HIFU to deliver nanoparticles deep within the dentinal tubules. This study highlighted the characteristics and the mechanism involved of the bubbles generated by the HIFU and their capability to deliver nanoparticles.

  5. 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...

  6. The discrimination of type I and type II collagen and the label-free imaging of engineered cartilage tissue.

    PubMed

    Su, Ping-Jung; Chen, Wei-Liang; Li, Tsung-Hsien; Chou, Chen-Kuan; Chen, Te-Hsuen; Ho, Yi-Yun; Huang, Chi-Hsiu; Chang, Shwu-Jen; Huang, Yi-You; Lee, Hsuan-Shu; Dong, Chen-Yuan

    2010-12-01

    Using excitation polarization-resolved second harmonic generation (SHG) microscopy, we measured SHG intensity as a function of the excitation polarization angle for type I and type II collagens. We determined the second order susceptibility (χ((2))) tensor ratios of type I and II collagens at each pixel, and displayed the results as images. We found that the χ((2)) tensor ratios can be used to distinguish the two types of collagen. In particular, we obtained χ(zzz)/χ(zxx) = 1.40 ± 0.04 and χ(xzx)/χ(zxx) = 0.53 ± 0.10 for type I collagen from rat tail tendon, and χ(zzz)/χ(zxx) = 1.14 ± 0.09 and χ(xzx)/χ(zxx) = 0.29 ± 0.11 for type II collagen from rat trachea cartilage. We also applied this methodology on the label-free imaging of engineered cartilage tissue which produces type I and II collagen simultaneously. By displaying the χ((2)) tensor ratios in the image format, the variation in the χ((2)) tensor ratios can be used as a contrast mechanism for distinguishing type I and II collagens. PMID:20875682

  7. Effects of low-power LED and therapeutic ultrasound in the tissue healing and inflammation in a tendinitis experimental model in rats.

    PubMed

    Moura Júnior, Manoel de Jesus; Arisawa, Emilia Ângela Loschiavo; Martin, Airton Abrahão; de Carvalho, Janderson Pereira; da Silva, José Mário Nunes; Silva, José Figueiredo; Silveira, Landulfo

    2014-01-01

    This work evaluated the anti-inflammatory response of low-power light-emitting diode (LED) and ultrasound (US) therapies and the quality and rapidness of tendon repair in an experimental model of tendinitis, employing histomorphometry and Raman spectroscopy. Tendinitis was induced by collagenase into the right tendon of 35 male Wistar rats with an average weight of 230 g. The animals were randomly separated into seven groups of five animals each: tendinitis without treatment-control (TD7 and TD14, where 1 and 2 indicated sacrifice on the 7th and 14th day, respectively), tendinitis submitted to US therapy (US7 and US14) and tendinitis submitted to LED therapy (LED7 and LED14). Contralateral tendons of the TD group at the 14th day were used as the healthy group (H). US treatment was applied in pulsed mode at 10 %, 1 MHz frequency, 0.5 W/cm(2), 120 s. LED therapy parameters were 4 J/cm(2), 120 s, daily dose at the same time and same point. Sacrifice was performed on the 7th or 14th day. Histomorphometric analysis showed lower number of fibroblasts on the 14th day of therapy for the US-treated group, compared to the TD and LED, indicating lower tissue inflammation. Raman showed that the LED group had an increase in the amount of collagen I and III from the 7th to the 14th day, which would indicate more organized fibers and a better quality of the healing, and US showed lower collagen I synthesis in the 14th day compared to H, indicating a lower tissue reorganization.

  8. Allelic imbalance of tissue-type plasminogen activator (t-PA) gene expression in human brain tissue.

    PubMed

    Tjarnlund-Wolf, A; Hultman, K; Curtis, M A; Faull, R L M; Medcalf, R L; Jern, C

    2011-06-01

    We have identified a single-nucleotide polymorphism (SNP) in the t-PA enhancer (-7351C>T), which is associated with endothelial t-PA release in vivo. In vitro studies demonstrated that this SNP is functional at the level of transcription. In the brain, t-PA has been implicated in both physiologic and pathophysiologic processes. The aim of the present study was to examine the effect of the t-PA -7351C>T SNP on t-PA gene expression in human brain tissue. Allelic mRNA expression was measured in heterozygous post-mortem brain tissues using quantitative TaqMan genotyping assay. Protein-DNA interactions were assessed using electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP). Significantly higher levels of t-PA mRNA were generated from chromosomes that harboured the wild-type -7351C allele, as compared to those generated from the mutant T allele (for the hippocampus, C to T allelic ratio of ~1.3, p=0.010, n=12; and for the cortex, C to T allelic ratio of ~1.2, p=0.017, n=12). EMSA showed reduced neuronal and astrocytic nuclear protein binding affinity to the T allele, and identified Sp1 and Sp3 as the major transcription factors that bound to the -7351 site. ChIP analyses confirmed that Sp1 recognises this site in intact cells. In conclusion, the t-PA -7351C>T SNP affects t-PA gene expression in human brain tissue. This finding might have clinical implications for neurological conditions associated with enhanced t-PA levels, such as in the acute phase of cerebral ischaemia, and also for stroke recovery.

  9. Introduction to ultrasound elastography

    PubMed Central

    Dobruch-Sobczak, Katarzyna

    2016-01-01

    For centuries tissue palpation has been an important diagnostic tool. During palpation, tumors are felt as tissues harder than the surrounding tissues. The significance of palpation is related to the relationship between mechanical properties of different tissue lesions. The assessment of tissue stiffness through palpation is based on the fact that mechanical properties of tissues are changing as a result of various diseases. A higher tissue stiffness translates into a higher elasticity modulus. In the 90's, ultrasonography was extended by the option of examining the stiffness of tissue by estimating the difference in backscattering of ultrasound in compressed and non-compressed tissue. This modality is referred to as the static, compression elastography and is based on tracking the deformation of tissue subjected to the slowly varying compression through the recording of the backscattered echoes. The displacement is estimated using the methods of cross-correlation between consecutive ultrasonic lines of examined tissue, so calculating the degree of similarity of ultrasonic echoes acquired from tissue before and after the compression was applied. The next step in the development of ultrasound palpation was to apply the local remote tissue compression by using the acoustic radiation force generated through the special beam forming of the ultrasonic beam probing the tissue. The acoustic radiation force causes a slight deformation the tissue thereby forming a shear wave propagating in the tissue at different speeds dependent on the stiffness of the tissue. Shear wave elastography, carries great hopes in the field of quantitative imaging of tissue lesions. This article describes the physical basis of both elastographic methods: compression elastography and shear wave elastography. PMID:27446596

  10. Biomarker-based ovarian carcinoma typing: a histological investigation in the Ovarian Tumor Tissue Analysis consortium

    PubMed Central

    Köbel, Martin; Kalloger, Steve E.; Lee, Sandra; Duggan, Máire A.; Kelemen, Linda E.; Prentice, Leah; Kalli, Kimberly R.; Fridley, Brooke L.; Visscher, Daniel W.; Keeney, Gary L.; Vierkant, Robert A.; Cunningham, Julie M.; Chow, Christine; Ness, Roberta B.; Moysich, Kirsten; Edwards, Robert; Modugno, Francesmary; Bunker, Clareann; Wozniak, Eva L.; Benjamin, Elizabeth; Gayther, Simon A.; Gentry-Maharaj, Aleksandra; Menon, Usha; Gilks, C. Blake; Huntsman, David G.; Ramus, Susan J.; Goode, Ellen L.

    2014-01-01

    Background Ovarian carcinoma is composed of five major histological types which associate with outcome and predict therapeutic response. Our aim was to evaluate histological type assessments across centres participating in the Ovarian Tumor Tissue Analysis (OTTA) consortium using an immunohistochemical (IHC) prediction model. Methods Tissue microarrays (TMAs) and clinical data were available for 524 pathologically confirmed ovarian carcinomas. Centralized IHC was performed for ARID1A, CDKN2A, DKK1, HNF1B, MDM2, PGR, TP53, TFF3, VIM, and WT1, and three histological type assessments were compared: the original pathologic type, an IHC-based calculated type (termed TB_COSPv2), and a WT1-assisted TMA core review. Results The concordance between TB_COSPv2 type and original type was 73%. Applying WT1-assisted core review, the remaining 27% discordant cases subdivided into unclassifiable (6%), TB_COSPv2 error (6%), and original type error (15%). The largest discordant subgroup was classified as endometrioid carcinoma (EC) by original type and as high-grade serous carcinoma (HGSC) by TB_COSPv2. When TB_COSPv2 classification was used, the difference in overall survival of EC compared to HGSC became significant (RR 0.60, 95% CI 0.37–0.93, p=0.021), consistent with previous reports. In addition, 71 cases with unclear original type could be histologically classified by TB_COSPv2. Conclusions Research cohorts, particularly those across different centres within consortia, show significant variability in original histological type diagnosis. Our IHC-based reclassification produced more homogeneous types with respect to outcome than original type. Impact Biomarker-based classification of ovarian carcinomas is feasible, improves comparability of results across research studies, and can reclassify cases which lack reliable original pathology. PMID:23880734

  11. 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. PMID:26090087

  12. Effects of nonlinear propagation in ultrasound contrast agent imaging.

    PubMed

    Tang, Meng-Xing; Kamiyama, Naohisa; Eckersley, Robert J

    2010-03-01

    This paper investigates two types of nonlinear propagation and their effects on image intensity and contrast-to-tissue ratio (CTR) in contrast ultrasound images. Previous studies have shown that nonlinear propagation can occur when ultrasound travels through tissue and microbubble clouds, making tissue farther down the acoustic path appear brighter in pulse inversion (PI) images, thus reducing CTR. In this study, the effect of nonlinear propagation through tissue or microbubbles on PI image intensity and CTR are compared at low mechanical index. A combination of simulation and experiment with SonoVue microbubbles were performed using a microbubble dynamics model, a laboratory ultrasound system and a clinical prototype scanner. The results show that, close to the bubble resonance frequency, nonlinear propagation through a bubble cloud of a few centimeter thickness with a modest concentration (1:10000 dilution of SonoVue microbubbles) is much more significant than through tissue-mimicking material. Consequently, CTR in regions distal to the imaging probe is greatly reduced for nonlinear propagation through the bubble cloud, with as much as a 12-dB reduction compared with nonlinear propagation through tissue-mimicking material. Both types of nonlinear propagation cause only a small change in bubble PI signals at the bubble resonance frequency. When the driving frequency increases beyond bubble resonance, nonlinear propagation through bubbles is greatly reduced in absolute values. However because of a greater reduction in nonlinear scattering from bubbles at higher frequencies, the corresponding CTR is much lower than that at bubble resonance frequency.

  13. Combined ultrasound and MR imaging to guide focused ultrasound therapies in the brain

    NASA Astrophysics Data System (ADS)

    Arvanitis, Costas D.; Livingstone, Margaret S.; McDannold, Nathan

    2013-07-01

    Several emerging therapies with potential for use in the brain, harness effects produced by acoustic cavitation—the interaction between ultrasound and microbubbles either generated during sonication or introduced into the vasculature. Systems developed for transcranial MRI-guided focused ultrasound (MRgFUS) thermal ablation can enable their clinical translation, but methods for real-time monitoring and control are currently lacking. Acoustic emissions produced during sonication can provide information about the location, strength and type of the microbubble oscillations within the ultrasound field, and they can be mapped in real-time using passive imaging approaches. Here, we tested whether such mapping can be achieved transcranially within a clinical brain MRgFUS system. We integrated an ultrasound imaging array into the hemisphere transducer of the MRgFUS device. Passive cavitation maps were obtained during sonications combined with a circulating microbubble agent at 20 targets in the cingulate cortex in three macaques. The maps were compared with MRI-evident tissue effects. The system successfully mapped microbubble activity during both stable and inertial cavitation, which was correlated with MRI-evident transient blood-brain barrier disruption and vascular damage, respectively. The location of this activity was coincident with the resulting tissue changes within the expected resolution limits of the system. While preliminary, these data clearly demonstrate, for the first time, that it is possible to construct maps of stable and inertial cavitation transcranially, in a large animal model, and under clinically relevant conditions. Further, these results suggest that this hybrid ultrasound/MRI approach can provide comprehensive guidance for targeted drug delivery via blood-brain barrier disruption and other emerging ultrasound treatments, facilitating their clinical translation. We anticipate that it will also prove to be an important research tool that will

  14. Combined Ultrasound and MR Imaging to Guide Focused Ultrasound Therapies in the Brain

    PubMed Central

    Arvanitis, Costas D.; Livingstone, Margaret S.; McDannold, Nathan

    2013-01-01

    Purpose Several emerging therapies with potential for use in the brain harness effects produced by acoustic cavitation – the interaction between ultrasound and microbubbles either generated during sonication or introduced into the vasculature. Systems developed for transcranial MRI-guided focused ultrasound (MRgFUS) thermal ablation can enable their clinical translation, but methods for real-time monitoring and control are currently lacking. Acoustic emissions produced during sonication can provide information about the location, strength, and type of the microbubble oscillations within the ultrasound field, and they can be mapped in real-time using passive imaging approaches. Here, we tested whether such mapping can be achieved transcranially within a clinical brain MRgFUS system. Materials and Methods We integrated an ultrasound imaging array into the hemisphere transducer of the MRgFUS device. Passive cavitation maps were obtained during sonications combined with a circulating microbubble agent at 20 targets in the cingulate cortex in three macaques. The maps were compared with MRI-evident tissue effects. Results The system successfully mapped microbubble activity during both stable and inertial cavitation, which was correlated with MRI-evident transient blood-brain barrier disruption and vascular damage, respectively. The location of this activity was coincident with the resulting tissue changes within the expected resolution limits of the system. Conclusion While preliminary, these data clearly demonstrate, for the first time, that is possible to construct maps of stable and inertial cavitation transcranially, in a large animal model, and under clinically relevant conditions. Further, these results suggest that this hybrid ultrasound/MRI approach can provide comprehensive guidance for targeted drug delivery via blood-brain barrier disruption and other emerging ultrasound treatments, facilitating their clinical translation. We anticipate it will also prove to

  15. Role of bone-type tissue-nonspecific alkaline phosphatase and PHOSPO1 in vascular calcification.

    PubMed

    Bobryshev, Yuri V; Orekhov, Alexander N; Sobenin, Igor; Chistiakov, Dimitry A

    2014-01-01

    Matrix vesicle (MV)-mediated mineralization is important for bone ossification. However, under certain circumstances such as atherosclerosis, mineralization may occur in the arterial wall. Bone-type tissue-nonspecific alkaline phosphatase (TNAP) hydrolyzes inorganic pyrophosphate (PPi) and generates inorganic phosphate (Pi), which is essential for MV-mediated hydroxyapatite formation. MVs contain another phosphatase, PHOSPHO1, that serves as an additional supplier of Pi. Activation of bone-type tissue-nonspecific alkaline phosphatase (TNAP) in vascular smooth muscle cells precedes vascular calcification. By degrading PPi, TNAP plays a procalcific role changing the Pi/PPi ratio toward mineralization. A pathologic role of bone-type TNAP and PHOSPHO1 make them to be attractive targets for cardiovascular therapy.

  16. [Ultrasound imaging in laryngology].

    PubMed

    Zajkowski, Piotr; Białek, Ewa J

    2007-01-01

    Modern ultrasound with high resolution transducers, and sensitive power Doppler and color Doppler modes, and other options, such as panoramic and 3D imaging, allows for detailed imaging of many anatomical structures and pathologic lesions of the head and neck. Only the structures situated in the sonographic acoustic shadow: behind bones, calcified cartilages, stones, and behind organs containing gas (f.e. trachea and larynx) can not be visualized. Ultrasound is widely regarded as the first imaging method in the diseases of the thyroid, salivary glands (parotid gland, submandibular gland and sublingual gland), lymph nodes, muscles, soft tissues of the head and neck, and as an valuable adjunct in some laryngeal pathologies. Real time ultrasound examination allows for dynamic assessment of organs and lesions, lets the examiner check the susceptibility of tumors for pressure, which is inaccessible in other imaging methods. Tumors and congenital lesions, inflammation, abscesses, abnormal lymph nodes, cysts, muscle hypertrophy and posttraumatic conditions may be well evaluated with ultrasound. However, most neck tumors (f.e. in the thyroid, salivary glands, and soft tisses) as well as equivocal lymph nodes demand fine needle aspiration biopsy to determine their benign or malignant nature. This paper presents application of ultrasound examination in the head and neck area including limitations of ultrasound diagnostics in many clinical cases. Data taken from Polish and foreign literature and author's experience are included in this paper.

  17. Multi-tissue computational modeling analyzes pathophysiology of type 2 diabetes in MKR mice.

    PubMed

    Kumar, Amit; Harrelson, Thomas; Lewis, Nathan E; Gallagher, Emily J; LeRoith, Derek; Shiloach, Joseph; Betenbaugh, Michael J

    2014-01-01

    Computational models using metabolic reconstructions for in silico simulation of metabolic disorders such as type 2 diabetes mellitus (T2DM) can provide a better understanding of disease pathophysiology and avoid high experimentation costs. There is a limited amount of computational work, using metabolic reconstructions, performed in this field for the better understanding of T2DM. In this study, a new algorithm for generating tissue-specific metabolic models is presented, along with the resulting multi-confidence level (MCL) multi-tissue model. The effect of T2DM on liver, muscle, and fat in MKR mice was first studied by microarray analysis and subsequently the changes in gene expression of frank T2DM MKR mice versus healthy mice were applied to the multi-tissue model to test the effect. Using the first multi-tissue genome-scale model of all metabolic pathways in T2DM, we found out that branched-chain amino acids' degradation and fatty acids oxidation pathway is downregulated in T2DM MKR mice. Microarray data showed low expression of genes in MKR mice versus healthy mice in the degradation of branched-chain amino acids and fatty-acid oxidation pathways. In addition, the flux balance analysis using the MCL multi-tissue model showed that the degradation pathways of branched-chain amino acid and fatty acid oxidation were significantly downregulated in MKR mice versus healthy mice. Validation of the model was performed using data derived from the literature regarding T2DM. Microarray data was used in conjunction with the model to predict fluxes of various other metabolic pathways in the T2DM mouse model and alterations in a number of pathways were detected. The Type 2 Diabetes MCL multi-tissue model may explain the high level of branched-chain amino acids and free fatty acids in plasma of Type 2 Diabetic subjects from a metabolic fluxes perspective.

  18. Multi-Tissue Computational Modeling Analyzes Pathophysiology of Type 2 Diabetes in MKR Mice

    PubMed Central

    Kumar, Amit; Harrelson, Thomas; Lewis, Nathan E.; Gallagher, Emily J.; LeRoith, Derek; Shiloach, Joseph; Betenbaugh, Michael J.

    2014-01-01

    Computational models using metabolic reconstructions for in silico simulation of metabolic disorders such as type 2 diabetes mellitus (T2DM) can provide a better understanding of disease pathophysiology and avoid high experimentation costs. There is a limited amount of computational work, using metabolic reconstructions, performed in this field for the better understanding of T2DM. In this study, a new algorithm for generating tissue-specific metabolic models is presented, along with the resulting multi-confidence level (MCL) multi-tissue model. The effect of T2DM on liver, muscle, and fat in MKR mice was first studied by microarray analysis and subsequently the changes in gene expression of frank T2DM MKR mice versus healthy mice were applied to the multi-tissue model to test the effect. Using the first multi-tissue genome-scale model of all metabolic pathways in T2DM, we found out that branched-chain amino acids' degradation and fatty acids oxidation pathway is downregulated in T2DM MKR mice. Microarray data showed low expression of genes in MKR mice versus healthy mice in the degradation of branched-chain amino acids and fatty-acid oxidation pathways. In addition, the flux balance analysis using the MCL multi-tissue model showed that the degradation pathways of branched-chain amino acid and fatty acid oxidation were significantly downregulated in MKR mice versus healthy mice. Validation of the model was performed using data derived from the literature regarding T2DM. Microarray data was used in conjunction with the model to predict fluxes of various other metabolic pathways in the T2DM mouse model and alterations in a number of pathways were detected. The Type 2 Diabetes MCL multi-tissue model may explain the high level of branched-chain amino acids and free fatty acids in plasma of Type 2 Diabetic subjects from a metabolic fluxes perspective. PMID:25029527

  19. Tracking of adipose tissue-derived progenitor cells using two magnetic nanoparticle types

    NASA Astrophysics Data System (ADS)

    Kasten, Annika; Siegmund, Birte J.; Grüttner, Cordula; Kühn, Jens-Peter; Frerich, Bernhard

    2015-04-01

    Magnetic resonance imaging (MRI) is to be considered as an emerging detection technique for cell tracking experiments to evaluate the fate of transplanted progenitor cells and develop successful cell therapies for tissue engineering. Adipose tissue engineering using adipose tissue-derived progenitor cells has been advocated for the cure of soft tissue defects or for persistent soft tissue augmentation. Adipose tissue-derived progenitor cells were differentiated into the adipogenic lineage and labeled with two different types of magnetic iron oxide nanoparticles in varying concentrations which resulted in a concentration-dependent reduction of gene expression of adipogenic differentiation markers, adiponectin and fatty acid-binding protein 4 (FABP4), whereas the metabolic activity was not altered. As a result, only low nanoparticle concentrations for labeling were used for in vivo experiments. Cells were seeded onto collagen scaffolds and subcutaneously implanted into severe combined immunodeficient (SCID) mice. At 24 h as well as 28 days after implantation, MRI analyses were performed visualizing nanoparticle-labeled cells using T2-weighted sequences. The quantification of absolute volume of the scaffolds revealed a decrease of volume over time in all experimental groups. The distribution of nanoparticle-labeled cells within the scaffolds varied likewise over time.

  20. Ultrasound transmission attenuation tomography using energy-scaled amplitude ratios

    NASA Astrophysics Data System (ADS)

    Chen, Ting; Shin, Junseob; Huang, Lianjie

    2016-04-01

    Ultrasound attenuation of breast tumors is related to their types and pathological states, and can be used to detect and characterize breast cancer. Particularly, ultrasound scattering attenuation can infer the margin properties of breast tumors. Ultrasound attenuation tomography quantitatively reconstructs the attenuation properties of the breast. Our synthetic-aperture breast ultrasound tomography system with two parallel transducer arrays records both ultrasound reflection and transmission signals. We develop an ultrasound attenuation tomography method using ultrasound energy-scaled amplitude decays of ultrasound transmission signals and conduct ultrasound attenuation tomography using a known sound-speed model. We apply our ultrasound transmission attenuation tomography method to a breast phantom dataset, and compare the ultrasound attenuation tomography results with conventional beamforming ultrasound images obtained using reflection signals. We show that ultrasound transmission attenuation tomography complements beamforming images in identifying breast lesions.

  1. Multiplatform analysis of 12 cancer types reveals molecular classification within and across tissues of origin.

    PubMed

    Hoadley, Katherine A; Yau, Christina; Wolf, Denise M; Cherniack, Andrew D; Tamborero, David; Ng, Sam; Leiserson, Max D M; Niu, Beifang; McLellan, Michael D; Uzunangelov, Vladislav; Zhang, Jiashan; Kandoth, Cyriac; Akbani, Rehan; Shen, Hui; Omberg, Larsson; Chu, Andy; Margolin, Adam A; Van't Veer, Laura J; Lopez-Bigas, Nuria; Laird, Peter W; Raphael, Benjamin J; Ding, Li; Robertson, A Gordon; Byers, Lauren A; Mills, Gordon B; Weinstein, John N; Van Waes, Carter; Chen, Zhong; Collisson, Eric A; Benz, Christopher C; Perou, Charles M; Stuart, Joshua M

    2014-08-14

    Recent genomic analyses of pathologically defined tumor types identify "within-a-tissue" disease subtypes. However, the extent to which genomic signatures are shared across tissues is still unclear. We performed an integrative analysis using five genome-wide platforms and one proteomic platform on 3,527 specimens from 12 cancer types, revealing a unified classification into 11 major subtypes. Five subtypes were nearly identical to their tissue-of-origin counterparts, but several distinct cancer types were found to converge into common subtypes. Lung squamous, head and neck, and a subset of bladder cancers coalesced into one subtype typified by TP53 alterations, TP63 amplifications, and high expression of immune and proliferation pathway genes. Of note, bladder cancers split into three pan-cancer subtypes. The multiplatform classification, while correlated with tissue-of-origin, provides independent information for predicting clinical outcomes. All data sets are available for data-mining from a unified resource to support further biological discoveries and insights into novel therapeutic strategies.

  2. AMUM LECTURE: Therapeutic ultrasound

    NASA Astrophysics Data System (ADS)

    Crum, Lawrence A.

    2004-01-01

    The use of ultrasound in medicine is now quite commonplace, especially with the recent introduction of small, portable and relatively inexpensive, hand-held diagnostic imaging devices. Moreover, ultrasound has expanded beyond the imaging realm, with methods and applications extending to novel therapeutic and surgical uses. These applications broadly include: tissue ablation, acoustocautery, lipoplasty, site-specific and ultrasound mediated drug activity, extracorporeal lithotripsy, and the enhancement of natural physiological functions such as wound healing and tissue regeneration. A particularly attractive aspect of this technology is that diagnostic and therapeutic systems can be combined to produce totally non-invasive, imageguided therapy. This general lecture will review a number of these exciting new applications of ultrasound and address some of the basic scientific questions and future challenges in developing these methods and technologies for general use in our society. We shall particularly emphasize the use of High Intensity Focused Ultrasound (HIFU) in the treatment of benign and malignant tumors as well as the introduction of acoustic hemostasis, especially in organs which are difficult to treat using conventional medical and surgical techniques.

  3. What is ultrasound?

    PubMed

    Leighton, Timothy G

    2007-01-01

    This paper is based on material presented at the start of a Health Protection Agency meeting on ultrasound and infrasound. In answering the question 'what is ultrasound?', it shows that the simple description of a wave which transports mechanical energy through the local vibration of particles at frequencies of 20 kHz or more, with no net transport of the particles themselves, can in every respect be misleading or even incorrect. To explain the complexities responsible for this, the description of ultrasound is first built up from the fundamental properties of these local particle vibrations. This progresses through an exposition of the characteristics of linear waves, in order to explain the propensity for, and properties of, the nonlinear propagation which occurs in many practical ultrasonic fields. Given the Health Protection environment which framed the original presentation, explanation and examples are given of how these complexities affect issues of practical importance. These issues include the measurement and description of fields and exposures, and the ability of ultrasound to affect tissue (through microstreaming, streaming, cavitation, heating, etc.). It is noted that there are two very distinct regimes, in terms of wave characteristics and potential for bioeffect. The first concerns the use of ultrasound in liquids/solids, for measurement or material processing. For biomedical applications (where these two processes are termed diagnosis and therapy, respectively), the issue of hazard has been studied in depth, although this has not been done to such a degree for industrial uses of ultrasound in liquids/solids (sonar, non-destructive testing, ultrasonic processing etc.). However, in the second regime, that of the use of ultrasound in air, although the waves in question tend to be of much lower intensities than those used in liquids/solids, there is a greater mismatch between the extent to which hazard has been studied, and the growth in commercial

  4. Assessment of three types of spaceflight hardware for tissue culture studies: Comparison of skeletal tissue growth and differentiation

    NASA Astrophysics Data System (ADS)

    Klement, Brenda J.; Spooner, Brian S.

    1997-01-01

    Three different types of spaceflight hardware, the BioProcessing Module (BPM), the Materials Dispersion Apparatus (MDA), and the Fluid Processing Apparatus (FPA), were assessed for their ability to support pre-metatarsal growth and differentiation in experiments conducted on five space shuttle flights. BPM-cultured pre-metatarsal tissue showed no difference in flight and ground control lengths. Flight and ground controls cultured in the MDA grew 135 μm and 141 μm, respectively, in an 11 day experiment. Only five control rods and three flight rods mineralized. In another MDA experiment, pre-metatarsals were cultured at 4 °C (277K) or 20 °C (293K) for the 16 day mission, then cultured an additional 16 days in laboratory dishes at 37 °C (310K). The 20 °C (293K) cultures died post-flight. The 4 °C (277K) flight pre-metatarsals grew 417 μm more than the 4 °C (277K) ground controls post-flight. In 5 and 6 day experiments done in FPAs, flight rods grew longer than ground control rods. In a 14 day experiment, ground control and flight rods also expanded in length, but there was no difference between them. The pre-metatarsals cultured in the FPAs did not mineralize, or terminally differentiate. These experiments demonstrate, that while supporting pre-metatarsal growth in length, the three types of hardware are not suitable to support routine differentiation.

  5. Modulation of ultrasound to produce multifrequency radiation force1

    PubMed Central

    Urban, Matthew W.; Fatemi, Mostafa; Greenleaf, James F.

    2010-01-01

    Dynamic radiation force has been used in several types of applications, and is performed by modulating ultrasound with different methods. By modulating ultrasound, energy can be transmitted to tissue, in this case a dynamic force to elicit a low frequency cyclic displacement to inspect the material properties of the tissue. In this paper, different types of modulation are explored including amplitude modulation (AM), double sideband suppressed carrier amplitude modulation AM, linear frequency modulation, and frequency-shift keying. Generalized theory is presented for computing the radiation force through the short-term time average of the energy density for these various types of modulation. Examples of modulation with different types of signals including sine waves, square waves, and triangle waves are shown. Using different modulating signals, multifrequency radiation force with different numbers of frequency components can be created, and can be used to characterize tissue mimicking materials and soft tissue. Results for characterization of gelatin phantoms using a method of vibrating an embedded sphere are presented. Different degrees of accuracy were achieved using different modulation techniques and modulating signals. Modulating ultrasound is a very flexible technique to produce radiation force with multiple frequency components that can be used for various applications. PMID:20329821

  6. 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.

  7. Totally anomalous pulmonary venous drainage - supracardiac type: ultrasound assessment of anatomically determined stenosis of the vertical vein collecting pulmonary venous return.

    PubMed

    Mądry, Wojciech; Karolczak, Maciej A

    2012-12-01

    The diagnosis of the congenital heart defects, among others totally anomalous pulmonary venous drainage, is based on echocardiography. While the visualization of intracardiac structures rarely causes significant difficulties, the vessels positioned outside the heart, e.g. the pulmonary veins, are often hidden behind tissues impermeable to ultrasounds, which may necessitate the use of other imaging methods, such as computer tomography, nuclear magnetic resonance or angiocardiography. The serious limitation of these techniques, especially in pediatric age, is the necessity to administer general anesthesia and contrast media. In order to obtain clear images, the appropriate concentration of a contrast agent in the vessels is necessary, which is not always possible in a patient with severe circulatory failure. Therefore, every effort should be made to obtain as much information necessary for treatment determination as possible from echocardiography, in spite of its limitations. A significant morphological factor of totally anomalous pulmonary venous drainage is the connection between the pulmonary and systemic veins, which in the supracardiac type is the vertical vein draining into the left brachiocephalic vein. The narrowing of this connection impedes the return of the blood from the lungs, which leads to the secondary edema and severe, abrupt cardiorespiratory insufficiency. Such a narrowing should be sought for in every case of totally anomalous pulmonary venous drainage since it constitutes an indication for an urgent surgery. On the basis of own experience and information obtained from the pertinent literature, the authors describe the rules and criteria of the diagnosis of this rare supracardiac form of the heart defect with the presence of the vertical vein which may undergo stenosis due to a phenomenon called the anatomical or bronchoarterial vise. It is formed when the vessel "pushes through" a narrow opening bordered by the left pulmonary artery from the

  8. Cell type-specific properties and environment shape tissue specificity of cancer genes

    PubMed Central

    Schaefer, Martin H.; Serrano, Luis

    2016-01-01

    One of the biggest mysteries in cancer research remains why mutations in certain genes cause cancer only at specific sites in the human body. The poor correlation between the expression level of a cancer gene and the tissues in which it causes malignant transformations raises the question of which factors determine the tissue-specific effects of a mutation. Here, we explore why some cancer genes are associated only with few different cancer types (i.e., are specific), while others are found mutated in a large number of different types of cancer (i.e., are general). We do so by contrasting cellular functions of specific-cancer genes with those of general ones to identify properties that determine where in the body a gene mutation is causing malignant transformations. We identified different groups of cancer genes that did not behave as expected (i.e., DNA repair genes being tissue specific, immune response genes showing a bimodal specificity function or strong association of generally expressed genes to particular cancers). Analysis of these three groups demonstrates the importance of environmental impact for understanding why certain cancer genes are only involved in the development of some cancer types but are rarely found mutated in other types of cancer. PMID:26856619

  9. Cell type-specific properties and environment shape tissue specificity of cancer genes.

    PubMed

    Schaefer, Martin H; Serrano, Luis

    2016-02-09

    One of the biggest mysteries in cancer research remains why mutations in certain genes cause cancer only at specific sites in the human body. The poor correlation between the expression level of a cancer gene and the tissues in which it causes malignant transformations raises the question of which factors determine the tissue-specific effects of a mutation. Here, we explore why some cancer genes are associated only with few different cancer types (i.e., are specific), while others are found mutated in a large number of different types of cancer (i.e., are general). We do so by contrasting cellular functions of specific-cancer genes with those of general ones to identify properties that determine where in the body a gene mutation is causing malignant transformations. We identified different groups of cancer genes that did not behave as expected (i.e., DNA repair genes being tissue specific, immune response genes showing a bimodal specificity function or strong association of generally expressed genes to particular cancers). Analysis of these three groups demonstrates the importance of environmental impact for understanding why certain cancer genes are only involved in the development of some cancer types but are rarely found mutated in other types of cancer.

  10. 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. PMID:26075281

  11. Complex heterogeneous tissue constructs containing multiple cell types prepared by inkjet printing technology.

    PubMed

    Xu, Tao; Zhao, Weixin; Zhu, Jian-Ming; Albanna, Mohammad Z; Yoo, James J; Atala, Anthony

    2013-01-01

    This study was designed to develop a versatile method for fabricating complex and heterogeneous three-dimensional (3D) tissue constructs using simultaneous ink-jetting of multiple cell types. Human amniotic fluid-derived stem cells (hAFSCs), canine smooth muscle cells (dSMCs), and bovine aortic endothelial cells (bECs), were separately mixed with ionic cross-linker calcium chloride (CaCl(2)), loaded into separate ink cartridges and printed using a modified thermal inkjet printer. The three cell types were delivered layer-by-layer to pre-determined locations in a sodium alginate-collagen composite located in a chamber under the printer. The reaction between CaCl(2) and sodium alginate resulted in a rapid formation of a solid composite gel and the printed cells were anchored in designated areas within the gel. The printing process was repeated for several cycles leading to a complex 3D multi-cell hybrid construct. The biological functions of the 3D printed constructs were evaluated in vitro and in vivo. Each of the printed cell types maintained their viability and normal proliferation rates, phenotypic expression, and physiological functions within the heterogeneous constructs. The bioprinted constructs were able to survive and mature into functional tissues with adequate vascularization in vivo. These findings demonstrate the feasibility of fabricating complex heterogeneous tissue constructs containing multiple cell types using inkjet printing technology.

  12. Ultrasound physics.

    PubMed

    Shriki, Jesse

    2014-01-01

    Bedside ultrasound has become an important modality for obtaining critical information in the acute care of patients. It is important to understand the physics of ultrasound in order to perform and interpret images at the bedside. The physics of both continuous wave and pulsed wave sound underlies diagnostic ultrasound. The instrumentation, including transducers and image processing, is important in the acquisition of appropriate sonographic images. Understanding how these concepts interplay with each other enables practitioners to obtain the best possible images.

  13. Determination of collagen content, concentration, and sub-types in kidney tissue.

    PubMed

    Samuel, Chrishan S

    2009-01-01

    Fibrosis and sclerosis are widely recognized as hallmarks of progressive renal disease and are caused by the excessive accumulation of connective tissue, mostly collagen. The detection of collagen content, concentration (collagen content/dry weight tissue), and sub-types from kidney tissues is therefore an important part of determining the extent of renal fibrosis in ageing and diseased states. This chapter describes a colorimetric-based hydroxyproline assay used to estimate total collagen content and concentration. Based on the method of Bergman and Loxley (8), this spectrophotometric technique estimates total collagen by measuring the hydroxyproline content of tissue. The assay relies on the fact that the collagen triple helix is one of the few proteins that contain the amino acid hydroxyproline. The second part of this chapter describes the use of sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE) to isolate, detect and quantify changes in the soluble and insoluble interstitial collagen sub-types. This technique complements the hydroxyproline assay by providing a means of identifying which interstitial collagens are altered in renal disease.

  14. Prospective Study for Comparison of Endoscopic Ultrasound-Guided Tissue Acquisition Using 25- and 22-Gauge Core Biopsy Needles in Solid Pancreatic Masses

    PubMed Central

    Lee, Sang Hoon; Lee, Hee Seung; Lee, Hyun Jik; Park, Jeong Yup; Park, Seung Woo; Song, Si Young; Kim, Hoguen; Chung, Jae Bock; Bang, Seungmin

    2016-01-01

    Background and Aims Although thicker needles theoretically allow more tissue to be collected, their decreased flexibility can cause mechanical damage to the endoscope, technical failure, and sample blood contamination. The effects of needle gauge on diagnostic outcomes of endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) of pancreatic mass lesions remain unknown. This study compared procurement rates of histologic cores obtained from EUS-FNB of pancreatic masses using 25- and 22-gauge core biopsy needles. Patients and Methods From March 2014 to July 2014, 66 patients with solid pancreatic mass underwent EUS-FNB with both 25- and 22-gauge core biopsy needles. Among them, 10 patients were excluded and thus 56 patients were eligible for the analyses. Needle sequences were randomly assigned, and two passes were made with each needle, consisting of 10 uniform to-and-fro movements on each pass with 10 mL syringe suction. A pathologist blinded to needle sequence evaluated specimens for the presence of histologic core. Results The mean patient age was 65.8 ± 9.5 years (range, 44–89 years); 35 patients (62.5%) were men. The mean pancreatic mass size was 35.3 ± 17.1 mm (range 14–122.3 mm). Twenty-eight patients (50%) had tumors at the pancreas head or uncinate process. There were no significant differences in procurement rates of histologic cores between 25-gauge (49/56, 87.5%) and 22-gauge (46/56, 82.1%, P = 0.581) needles or diagnostic accuracy using only histologic cores (98% and 95%). There were no technical failures or procedure-related adverse events. Conclusions The 25-gauge core biopsy needle could offer acceptable and comparable outcomes regarding diagnostic performance including histologic core procurement rates compared to the 22-gauge core biopsy needle, although the differences were not statistically significant. Trial Registration ClinicalTrials.gov NCT01795066 PMID:27149404

  15. Tissue Reaction to Different Types of Calcium Hydroxide Paste in Rat.

    PubMed

    Zarei, Mina; Javidi, Maryam; Gharechahi, Maryam; Kateb, Moaied; Zare, Reza; Kelagari, Ziba Shirkhani

    2016-01-01

    The purpose of this study was to compare the biocompatibility of two types of calcium hydroxide paste in subcutaneous tissue in rat. Twenty-two Wistar rats were divided into 4 experimental (n=5 each) and one control (n=2) group. A polyethylene tube filled with either Dentsply or Sure-Paste was implanted in each rat in the experimental groups, while an empty polyethylene tube was used in the control group. After 15 or 60 days, the animals were sacrificed and histopathological examination carried out. Tissue reaction was assessed by inflammatory cell infiltration using a 4-point scoring system, ranging from 0 to 3. Data were analyzed with the Kruskal-Wallis, Wilcoxon, and McNemar tests. Both types of paste induced an inflammatory response at each time point, although the intensity varied. A significant reduction in the number of inflammatory cells was observed at 60 days. Dentsply appeared to induce a more marked inflammatory response at both time points, although the difference was not significant. These results suggest that both types of paste are biocompatible with subcutaneous tissue in rat. PMID:27320294

  16. 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

  17. Wavelet-based feature extraction applied to small-angle x-ray scattering patterns from breast tissue: a tool for differentiating between tissue types.

    PubMed

    Falzon, G; Pearson, S; Murison, R; Hall, C; Siu, K; Evans, A; Rogers, K; Lewis, R

    2006-05-21

    This paper reports on the application of wavelet decomposition to small-angle x-ray scattering (SAXS) patterns from human breast tissue produced by a synchrotron source. The pixel intensities of SAXS patterns of normal, benign and malignant tissue types were transformed into wavelet coefficients. Statistical analysis found significant differences between the wavelet coefficients describing the patterns produced by different tissue types. These differences were then correlated with position in the image and have been linked to the supra-molecular structural changes that occur in breast tissue in the presence of disease. Specifically, results indicate that there are significant differences between healthy and diseased tissues in the wavelet coefficients that describe the peaks produced by the axial d-spacing of collagen. These differences suggest that a useful classification tool could be based upon the spectral information within the axial peaks.

  18. 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

  19. Application of ultrasound as pretreatment for extraction of podophyllotoxin from rhizomes of Podophyllum peltatum.

    PubMed

    Zhao, Shuna; Baik, Oon Doo

    2012-01-01

    The effect of high-power ultrasound pretreatment on the extraction of podophyllotoxin from Podophyllum peltatum was investigated. Direct sonication by an ultrasound probe horn was applied at 24 kHz and a number of factors were investigated: particle size (0.18-0.6 mm), type of solvent (0-100% aqueous ethanol), ultrasonic treatment time (2-40 min), and power of ultrasound (0-100% power intensity, maximum power: 78 W). The optimal condition of ultrasound was achieved with 0.425-0.6 mm particle size, 10 min sonication time, 35 W ultrasound power, and water as the medium. There was no obvious degradation of podophyllotoxin with ultrasound under the applied conditions, and an improvement in extractability was observed. The SEM microscopic structure change of treated samples disclosed the effect of ultrasound on the tissue cells. The increased pore volume and surface area after ultrasonic treatment also confirmed the positive effect of ultrasound pretreatment on the extraction yield of podophyllotoxin from the plant cells.

  20. 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.

  1. Dysmorphic choroid plexuses and hydrocephalus associated with increased nuchal translucency: early ultrasound markers of de novo thanatophoric dysplasia type II with cloverleaf skull (Kleeblattschaedel).

    PubMed

    Tonni, Gabriele; Palmisano, Marcella; Ginocchi, Vladimiro; Ventura, Alessandro; Baldi, Maurizia; Baffico, Ave Maria

    2014-11-01

    Prenatal diagnosis of thanatophoric dysplasia (TD) type II presenting in the first trimester with increased nuchal translucency (NT) and cloverleaf skull (Kleeblattschaedel) have been scantly reported in the medical record. Abnormal choroid plexus has been seen in association with fetal anomalies. Here we described a case of increased NT associated with indented choroid plexuses, early onset hydrocephalus and cloverleaf skull in a fetus subsequently diagnosed at early second trimester to carry a de novo mutation encoding for TD type II. The findings of dysmorphic choroid plexus, early onset hydrocephalus and cloverleaf skull at first trimester scan may be early, useful ultrasound markers of TD type II. Molecular analysis to control for possible overlapping syndromes were performed and resulted negative. Postmortem X-ray and 3D-CT scan confirmed the cloverleaf skull, narrow thorax, straight femur with rhizomelic shortening of the limbs and the presence of a communicating hydrocephalus.

  2. Resolution and quantitative accuracy improvements in ultrasound transmission imaging

    NASA Astrophysics Data System (ADS)

    Chenevert, T. L.

    The type of ultrasound transmission imaging, referred to as ultrasonic computed tomography (UCT), reconstructs distributions of tissue speed of sound and sound attenuation properties from measurements of acoustic pulse time of flight (TCF) and energy received through tissue. Although clinical studies with experimental UCT scanners have demonstrated UCT is sensitive to certain tissue pathologies not easily detected with conventional ultrasound imaging, they have also shown UCT to suffer from artifacts due to physical differences between the acoustic beam and its ray model implicit in image reconstruction algorithms. Artifacts are expressed as large quantitative errors in attenuation images, and poor spatial resolution and size distortion (exaggerated size of high speed of sound regions) in speed of sound images. Methods are introduced and investigated which alleviate these problems in UCT imaging by providing improved measurements of pulse TCF and energy.

  3. Phased-array ultrasound technology enhances accuracy of dual frequency ultrasound measurements - towards improved ultrasound bone diagnostics.

    PubMed

    Linder, Hans; Malo, Markus K H; Liukkonen, Jukka; Jurvelin, Jukka S; Töyräs, Juha

    2016-08-01

    Overlying soft tissues attenuate ultrasound backscattered from bone, complicating diagnostics of osteoporosis at the most important fracture sites. Dual-frequency ultrasound technique (DFUS) has been proposed to solve this problem through determination of thickness and composition of overlying soft tissue. This study applies DFUS technique for the first time with a phased-array transducer to investigate if the thickness of two interfering layers (oil and water) can be accurately determined in a variety of configurations. Results indicate that DFUS may be used with phased-array ultrasound systems, making them a suitable combination to consider in future development of clinical in vivo ultrasound methodologies. PMID:27187271

  4. Phased-array ultrasound technology enhances accuracy of dual frequency ultrasound measurements - towards improved ultrasound bone diagnostics.

    PubMed

    Linder, Hans; Malo, Markus K H; Liukkonen, Jukka; Jurvelin, Jukka S; Töyräs, Juha

    2016-08-01

    Overlying soft tissues attenuate ultrasound backscattered from bone, complicating diagnostics of osteoporosis at the most important fracture sites. Dual-frequency ultrasound technique (DFUS) has been proposed to solve this problem through determination of thickness and composition of overlying soft tissue. This study applies DFUS technique for the first time with a phased-array transducer to investigate if the thickness of two interfering layers (oil and water) can be accurately determined in a variety of configurations. Results indicate that DFUS may be used with phased-array ultrasound systems, making them a suitable combination to consider in future development of clinical in vivo ultrasound methodologies.

  5. Synthesis and metabolism of vertebrate-type steroids by tissues of insects: a critical evaluation.

    PubMed

    Swevers, L; Lambert, J G; De Loof, A

    1991-07-15

    This review covers the synthesis and the metabolism of vertebrate-type steroids (progesterone, testosterone, estradiol, corticosteroids) by insect tissues and discusses the significance of the reactions for insect physiology. Biosynthesis of vertebrate-type steroids from cholesterol hitherto has been demonstrated in only two insect species, i.e. the water beetle Acilius sulcatus (Coleoptera) and the tobacco hornworm Manduca sexta (Lepidoptera). In Acilius, steroid synthesis is associated with exosecretion (chemical defense). Nothing, however, is known about a physiological role of the C21 steroid conjugate present in ovaries and eggs of Manduca. No synthesis of vertebrate-type steroids was observed in any other insect investigated to date. Most metabolic conversions of steroids by insects concerned oxidoreduction of oxygen groups (hydroxysteroid dehydrogenase activity) and (polar and apolar) conjugate formation. All important enzymatic steps involved in synthesis and catabolism, as known from studies with tissues of vertebrates, were not, or hardly observed. The conclusion is drawn that typical vertebrate-type (C21, C19 and C18) steroids probably do not act as physiologically active substances in insects.

  6. Immunohistochemical distribution of type IV collagenase in normal, benign, and malignant breast tissue.

    PubMed Central

    Monteagudo, C.; Merino, M. J.; San-Juan, J.; Liotta, L. A.; Stetler-Stevenson, W. G.

    1990-01-01

    Production of type IV collagenase by tumor cells has been linked to their metastatic potential in several experimental models. A possible role for this enzyme in basement membrane type IV collagen turnover has also been suggested. Two recently developed affinity-purified, monospecific antibodies directed against the amino terminus (H1), or an internal active site domain (metal binding region [MBR]) of human type IV collagenase, were employed in the avidin-biotin-immunoperoxidase technique in formalin-fixed, paraffin-embedded breast tissue samples from 55 patients. Intense cytoplasmic immunostaining of myoepithelial cells was found in normal and hyperplastic tissue, and discontinuous staining was noted in intraductal carcinomas. Luminal epithelial cells were negative or weakly positive in large- or medium-sized ducts but reacted frequently in normal terminal ducts and hyperplastic lesions. Epithelial cells in intraductal carcinomas exhibited immunoreactivity in 20 of 23 cases. Invasive carcinomas were positive in 36 of 40 cases, and metastatic cells in lymph nodes stained in 10 of 12 cases. These results support a role for type IV collagenase in the basement membrane remodeling of normal breast. Our findings suggest that myoepithelial cells play a pivotal role in this enzymatic activity. The high percentage of positive cells in invasive carcinomas and the strong immunoreactivity of lymph node metastases support the role of the enzyme in tumor invasion and metastasis and suggest that tumor cells are the essential source of the enzyme in these processes. Images Figure 1 Figure 2 Figure 3 PMID:2156430

  7. Macrophage-inducible C-type lectin underlies obesity-induced adipose tissue fibrosis.

    PubMed

    Tanaka, Miyako; Ikeda, Kenji; Suganami, Takayoshi; Komiya, Chikara; Ochi, Kozue; Shirakawa, Ibuki; Hamaguchi, Miho; Nishimura, Satoshi; Manabe, Ichiro; Matsuda, Takahisa; Kimura, Kumi; Inoue, Hiroshi; Inagaki, Yutaka; Aoe, Seiichiro; Yamasaki, Sho; Ogawa, Yoshihiro

    2014-09-19

    In obesity, a paracrine loop between adipocytes and macrophages augments chronic inflammation of adipose tissue, thereby inducing systemic insulin resistance and ectopic lipid accumulation. Obese adipose tissue contains a unique histological structure termed crown-like structure (CLS), where adipocyte-macrophage crosstalk is known to occur in close proximity. Here we show that Macrophage-inducible C-type lectin (Mincle), a pathogen sensor for Mycobacterium tuberculosis, is localized to macrophages in CLS, the number of which correlates with the extent of interstitial fibrosis. Mincle induces obesity-induced adipose tissue fibrosis, thereby leading to steatosis and insulin resistance in liver. We further show that Mincle in macrophages is crucial for CLS formation, expression of fibrosis-related genes and myofibroblast activation. This study indicates that Mincle, when activated by an endogenous ligand released from dying adipocytes, is involved in adipose tissue remodelling, thereby suggesting that sustained interactions between adipocytes and macrophages within CLS could be a therapeutic target for obesity-induced ectopic lipid accumulation.

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

    PubMed

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

    2004-12-01

    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 in animal body to time depending degradation and putrefaction, but it is often hard to extract DNA from it because of its highly mineralized structure, which makes DNA extraction and/or amplification hard to carry out. We have performed human nuclear DNA extraction and STR typing in three different cases, on bones and bone fragments from long time dead persons found buried, in the sea, almost completely burnt and whose tissues were already decomposed. We report these caseworks as we would like to show how forensic scientists are improving their skill in identifying people whose corps have undergone several kinds of processes, even independently on the time passed and the level of putrefaction of their tissues.

  9. Comparison of three types of chondrocytes in collagen scaffolds for cartilage tissue engineering.

    PubMed

    Zhang, Lu; Spector, Myron

    2009-08-01

    The objective of this study was to compare the chondrogenesis in type I and II collagen scaffolds seeded with chondrocytes from three types of cartilage, after four weeks of culture: auricular (AU), articular (AR) and meniscal (ME). Related aims were to investigate the expression of a contractile muscle actin isoform, alpha-smooth muscle actin (SMA), in the cells in the scaffold and to determine the presence of a lubricating glycoprotein, lubricin, in the constructs. Adult goat AU, AR and ME chondrocytes were seeded into two types of collagen scaffolds: type II collagen and type I/III collagen. After four weeks of culture, the constructs were prepared for histochemical and immunohistochemical analysis of the distribution of glycosaminoglycan (GAG), types I and II collagen, elastin, SM and lubricin. AU constructs contained substantially more tissue than the AR and ME samples. The AU constructs exhibited neocartilage, but no elastin. There were no notable differences between the type I and II collagen scaffolds. Novel findings were the expression of SMA by the AU cells in the scaffolds and the presence of lubricin in the AR and AU constructs. AU cells have the capability to produce cartilage in collagen scaffolds under conditions in which there is little histogenesis by AR and ME cells.

  10. Survey of current practice in clinical transvaginal ultrasound scanning in the UK.

    PubMed

    Martin, Eleanor; Shaw, Adam; Lees, Christoph

    2015-08-01

    During transvaginal ultrasound scanning, the fetus and other sensitive tissues are placed close to the transducer. Heating of these tissues occurs by direct conduction from the transducer and by absorption of ultrasound in the tissue. The extent of any heating will depend on the equipment and settings used, the duration of the scan, imaging modes and other aspects of scanning practice. To ensure that scans are performed with minimum risk, staff should have an appropriate knowledge of safety and follow guidelines issued by professional bodies. An online survey aiming to document current practice in transvaginal ultrasound in the UK was created and distributed to individuals performing this type of scanning. The survey posed questions about the respondents, the departments where scans were performed, the equipment used, knowledge of ultrasound safety, scanning practice and the frequency, duration and mode of transvaginal ultrasound scans for gynaecology, obstetrics and fertility applications. In all, 294 responses were obtained, mostly from sonographers (94%). From the analysis of the responses, it was clear that there was a good understanding of the general meaning of thermal and mechanical index and high awareness of guidelines issued by professional bodies. However, 40% of respondents stated that they rarely or never monitor Thermal or Mechanical indices during scanning. Scanning practice was consistent in terms of the duration of scans, scan protocols followed and use of imaging modes. The results highlight the importance of continued ultrasound safety training and promotion of safety guidelines to users.

  11. Programmable Real-time Clinical Photoacoustic and Ultrasound Imaging System

    PubMed Central

    Kim, Jeesu; Park, Sara; Jung, Yuhan; Chang, Sunyeob; Park, Jinyong; Zhang, Yumiao; Lovell, Jonathan F.; Kim, Chulhong

    2016-01-01

    Photoacoustic imaging has attracted interest for its capacity to capture functional spectral information with high spatial and temporal resolution in biological tissues. Several photoacoustic imaging systems have been commercialized recently, but they are variously limited by non-clinically relevant designs, immobility, single anatomical utility (e.g., breast only), or non-programmable interfaces. Here, we present a real-time clinical photoacoustic and ultrasound imaging system which consists of an FDA-approved clinical ultrasound system integrated with a portable laser. The system is completely programmable, has an intuitive user interface, and can be adapted for different applications by switching handheld imaging probes with various transducer types. The customizable photoacoustic and ultrasound imaging system is intended to meet the diverse needs of medical researchers performing both clinical and preclinical photoacoustic studies. PMID:27731357

  12. Temporal healing in rat achilles tendon: ultrasound correlations.

    PubMed

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

    2013-03-01

    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.

  13. Basic Principles of Ultrasound

    NASA Astrophysics Data System (ADS)

    Robinson, Teresa M.

    Ultrasound has been used in medicine for at least 50 years. Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. Ultrasound energy is exactly like sound energy, it is a variation in the pressure within a medium. The only difference is that the rate of variation of pressure, the frequency of the wave, is too rapid for humans to hear. Medical ultrasound lies within a frequency range of 30 kHz to 500 MHz. Generally, the lower frequencies (30 kHz to 3 MHz) are for therapeutic purposes, the higher ones (2 to 40 MHz) are for diagnosis (imaging and Doppler), the very highest (50 to 500 MHz) are for microscopic images. For diagnostic purposes two main techniques are employed; the pulse-echo method is used to create images of tissue distribution; the Doppler effect is used to assess tissue movement and blood flow.

  14. Sonophoresis Using Ultrasound Contrast Agents: Dependence on Concentration.

    PubMed

    Park, Donghee; Song, Gillsoo; Jo, Yongjun; Won, Jongho; Son, Taeyoon; Cha, Ohrum; Kim, Jinho; Jung, Byungjo; Park, Hyunjin; Kim, Chul-Woo; Seo, Jongbum

    2016-01-01

    Sonophoresis can increase skin permeability to various drugs in transdermal drug delivery. Cavitation is recognized as the predominant mechanism of sonophoresis. Recently, a new logical approach to enhance the efficiency of transdermal drug delivery was tried. It is to utilize the engineered microbubble and its resonant frequency for increase of cavitation activity. Actively-induced cavitation with low-intensity ultrasound (less than ~1 MPa) causes disordering of the lipid bilayers and the formation of aqueous channels by stable cavitation which indicates a continuous oscillation of bubbles. Furthermore, the mutual interactions of microbubble determined by concentration of added bubble are also thought to be an important factor for activity of stable cavitation, even in different characteristics of drug. In the present study, we addressed the dependence of ultrasound contrast agent concentration using two types of drug on the efficiency of transdermal drug delivery. Two types of experiment were designed to quantitatively evaluate the efficiency of transdermal drug delivery according to ultrasound contrast agent concentration. First, an experiment of optical clearing using a tissue optical clearing agent was designed to assess the efficiency of sonophoresis with ultrasound contrast agents. Second, a Franz diffusion cell with ferulic acid was used to quantitatively determine the amount of drug delivered to the skin sample by sonophoresis with ultrasound contrast agents. The maximum enhancement ratio of sonophoresis with a concentration of 1:1,000 was approximately 3.1 times greater than that in the ultrasound group without ultrasound contrast agent and approximately 7.5 times greater than that in the control group. These results support our hypothesis that sonophoresis becomes more effective in transdermal drug delivery due to the presence of engineered bubbles, and that the efficiency of transdermal drug delivery using sonophoresis with microbubbles depends on the

  15. Sonophoresis Using Ultrasound Contrast Agents: Dependence on Concentration

    PubMed Central

    Park, Donghee; Song, Gillsoo; Jo, Yongjun; Won, Jongho; Son, Taeyoon; Cha, Ohrum; Kim, Jinho; Jung, Byungjo; Park, Hyunjin; Kim, Chul-Woo; Seo, Jongbum

    2016-01-01

    Sonophoresis can increase skin permeability to various drugs in transdermal drug delivery. Cavitation is recognized as the predominant mechanism of sonophoresis. Recently, a new logical approach to enhance the efficiency of transdermal drug delivery was tried. It is to utilize the engineered microbubble and its resonant frequency for increase of cavitation activity. Actively-induced cavitation with low-intensity ultrasound (less than ~1 MPa) causes disordering of the lipid bilayers and the formation of aqueous channels by stable cavitation which indicates a continuous oscillation of bubbles. Furthermore, the mutual interactions of microbubble determined by concentration of added bubble are also thought to be an important factor for activity of stable cavitation, even in different characteristics of drug. In the present study, we addressed the dependence of ultrasound contrast agent concentration using two types of drug on the efficiency of transdermal drug delivery. Two types of experiment were designed to quantitatively evaluate the efficiency of transdermal drug delivery according to ultrasound contrast agent concentration. First, an experiment of optical clearing using a tissue optical clearing agent was designed to assess the efficiency of sonophoresis with ultrasound contrast agents. Second, a Franz diffusion cell with ferulic acid was used to quantitatively determine the amount of drug delivered to the skin sample by sonophoresis with ultrasound contrast agents. The maximum enhancement ratio of sonophoresis with a concentration of 1:1,000 was approximately 3.1 times greater than that in the ultrasound group without ultrasound contrast agent and approximately 7.5 times greater than that in the control group. These results support our hypothesis that sonophoresis becomes more effective in transdermal drug delivery due to the presence of engineered bubbles, and that the efficiency of transdermal drug delivery using sonophoresis with microbubbles depends on the

  16. Cumulative phase delay imaging for contrast-enhanced ultrasound tomography

    NASA Astrophysics Data System (ADS)

    Demi, Libertario; van Sloun, Ruud J. G.; Wijkstra, Hessel; Mischi, Massimo

    2015-11-01

    Standard dynamic-contrast enhanced ultrasound (DCE-US) imaging detects and estimates ultrasound-contrast-agent (UCA) concentration based on the amplitude of the nonlinear (harmonic) components generated during ultrasound (US) propagation through UCAs. However, harmonic components generation is not specific to UCAs, as it also occurs for US propagating through tissue. Moreover, nonlinear artifacts affect standard DCE-US imaging, causing contrast to tissue ratio reduction, and resulting in possible misclassification of tissue and misinterpretation of UCA concentration. Furthermore, no contrast-specific modality exists for DCE-US tomography; in particular speed-of-sound changes due to UCAs are well within those caused by different tissue types. Recently, a new marker for UCAs has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental component is in fact observable for US propagating through UCAs, and is absent in tissue. In this paper, tomographic US images based on CPD are for the first time presented and compared to speed-of-sound US tomography. Results show the applicability of this marker for contrast specific US imaging, with cumulative phase delay imaging (CPDI) showing superior capabilities in detecting and localizing UCA, as compared to speed-of-sound US tomography. Cavities (filled with UCA) which were down to 1 mm in diameter were clearly detectable. Moreover, CPDI is free of the above mentioned nonlinear artifacts. These results open important possibilities to DCE-US tomography, with potential applications to breast imaging for cancer localization.

  17. A comparison of AIUM/NEMA thermal indices with calculated temperature rises for a simple third-trimester pregnancy tissue model. American Institute of Ultrasound in Medicine/National Electrical Manufacturers Association.

    PubMed

    Jago, J R; Henderson, J; Whittingham, T A; Mitchell, G

    1999-05-01

    Temperature rises due to diagnostic ultrasound exposures have been calculated for a simple third-trimester pregnancy tissue model. This consisted of a layer of soft tissue representing the abdominal/uterine wall, a layer of liquid and a layer of fetal bone. The ultrasound field parameter used in the calculations was the temporal average of the square of the acoustic pressure (p2TA), measured in water but corrected for attenuation in the tissue model. The three-dimensional (3-D) distribution of p2TA was measured for five probes operating in B-mode, and four probes operating in pulsed Doppler and color flow imaging modes. The calculated temperature rises were compared to the AIUM/NEMA-defined thermal indices appropriate to third-trimester scanning. In B-mode, the ratio of calculated temperature rise to thermal index varied between 0.62 and 1.25, with calculated temperature rises as high as 1.4 degrees C. In color-flow imaging mode, this ratio varied between 1.26 and 2.45 and, in pulsed Doppler mode, between 1.46 and 2.92, with calculated temperature rises as high as 1.8 degrees C and 5.8 degrees C, respectively. These results indicate that, for scanning situations where bone is insonated through an overlying low attenuation liquid layer, the thermal index may substantially underestimate the maximum temperature rise that could occur.

  18. Using real-time ultrasound and carcass measurements to estimate total internal fat in beef cattle over different breed types and managements.

    PubMed

    Ribeiro, F R B; Tedeschi, L O

    2012-09-01

    The objective of this study was to re-evaluate our previously published technique of estimating total physically separable internal fat (IFAT) in beef cattle using real-time ultrasound (RTU) and carcass measurements from live animals by including more breed types and genders under different management scenarios. We expanded the original database and performed additional analyses. The database was gathered from 4 studies and contained 110 animals (16 bulls, 16 heifers, and 78 steers), being Angus (n = 56), Angus× 5/8 Angus × 3/8 Nellore (n = 18), and Angus crossbreds (n = 36). Ultrasound measurements were obtained 7 d before slaughter, including the 12th to 13th rib fat thickness (uBF) and ultrasound kidney fat depth (uKFd). The uKFd was measured in a cross-sectional image collected between the first lumbar and 13th rib as previously published. Carcass data were collected 48 h post-mortem and consisted of backfat thickness (cBF), kidney fat depth (cKFd) and KPH weight, live BW, and HCW. Whole gastrointestinal tracts were removed and dissected to obtain IFAT weights. Weight of IFAT was highly correlated with KPH weight (0.88) and cKFd (0.81) and moderately correlated with uKFd (0.71). Prediction equations were developed for estimating IFAT, KPH weight, and cKFd with the PROC REG of SAS using the stepwise statement. The best predictors of IFAT were KPH weight or cKFd and cBF (r(2) = 0.84 and 0.83 and root mean square errors (RMSE) of 4.23 and 4.33 kg, respectively). Ultrasound measurements of uKFd and uBF had an r(2) of 0.65 and RMSE of 6.07 kg when both were used to predict IFAT. The results of cross-validation analyses indicated that equations developed either with KPH weight or cKFd weight and cBF had greater precision than the equation developed with uKFd and uBF. Most of the errors associated with the mean square error of prediction were due to random, uncontrolled variation. These results were consistent with previously published evaluation of this technique

  19. Hot topics in biomedical ultrasound: ultrasound therapy and its integration with ultrasonic imaging

    NASA Astrophysics Data System (ADS)

    Everbach, E. Carr

    2005-09-01

    Since the development of biomedical ultrasound imaging from sonar after WWII, there has been a clear divide between ultrasonic imaging and ultrasound therapy. While imaging techniques are designed to cause as little change as possible in the tissues through which ultrasound propagates, ultrasound therapy typically relies upon heating or acoustic cavitation to produce a desirable therapeutic effect. Concerns over the increasingly high acoustic outputs of diagnostic ultrasound scanners prompted the adoption of the Mechanical Index (MI) and Thermal Index (TI) in the early 1990s. Therapeutic applications of ultrasound, meanwhile, have evolved from deep tissue heating in sports medicine to include targeted drug delivery, tumor and plaque ablation, cauterization via high intensity focused ultrasound (HIFU), and accelerated dissolution of blood clots. The integration of ultrasonic imaging and therapy in one device is just beginning, but the promise of improved patient outcomes is balanced by regulatory and practical impediments.

  20. Ultrasound-Guided Injection of Botulinum Toxin Type A for Piriformis Muscle Syndrome: A Case Report and Review of the Literature

    PubMed Central

    Santamato, Andrea; Micello, Maria Francesca; Valeno, Giovanni; Beatrice, Raffaele; Cinone, Nicoletta; Baricich, Alessio; Picelli, Alessandro; Panza, Francesco; Logroscino, Giancarlo; Fiore, Pietro; Ranieri, Maurizio

    2015-01-01

    Piriformis muscle syndrome (PMS) is caused by prolonged or excessive contraction of the piriformis muscle associated with pain in the buttocks, hips, and lower limbs because of the close proximity to the sciatic nerve. Botulinum toxin type A (BoNT-A) reduces muscle hypertonia as well as muscle contracture and pain inhibiting substance P release and other inflammatory factors. BoNT-A injection technique is important considering the difficult access of the needle for deep location, the small size of the muscle, and the proximity to neurovascular structures. Ultrasound guidance is easy to use and painless and several studies describe its use during BoNT-A administration in PMS. In the present review article, we briefly updated current knowledge regarding the BoNT therapy of PMS, describing also a case report in which this syndrome was treated with an ultrasound-guided injection of incobotulinumtoxin A. Pain reduction with an increase of hip articular range of motion in this patient with PMS confirmed the effectiveness of BoNT-A injection for the management of this syndrome. PMID:26266421

  1. Scanning Ultrasound (SUS) Causes No Changes to Neuronal Excitability and Prevents Age-Related Reductions in Hippocampal CA1 Dendritic Structure in Wild-Type Mice

    PubMed Central

    Hatch, Robert John; Leinenga, Gerhard

    2016-01-01

    Scanning ultrasound (SUS) is a noninvasive approach that has recently been shown to ameliorate histopathological changes and restore memory functions in an Alzheimer's disease mouse model. Although no overt neuronal damage was reported, the short- and long-term effects of SUS on neuronal excitability and dendritic tree morphology had not been investigated. To address this, we performed patch-clamp recordings from hippocampal CA1 pyramidal neurons in wild-type mice 2 and 24 hours after a single SUS treatment, and one week and 3 months after six weekly SUS treatments, including sham treatments as controls. In both treatment regimes, no changes in CA1 neuronal excitability were observed in SUS-treated neurons when compared to sham-treated neurons at any time-point. For the multiple treatment groups, we also determined the dendritic morphology and spine densities of the neurons from which we had recorded. The apical trees of sham-treated neurons were reduced at the 3 month time-point when compared to one week; however, surprisingly, no longitudinal change was detected in the apical dendritic trees of SUS-treated neurons. In contrast, the length and complexity of the basal dendritic trees were not affected by SUS treatment at either time-point. The apical dendritic spine densities were reduced, independent of the treatment group, at 3 months compared to one week. Collectively, these data suggest that ultrasound can be employed to prevent an age-associated loss of dendritic structure without impairing neuronal excitability. PMID:27727310

  2. Benign breast lesions: Ultrasound

    PubMed Central

    Masciadri, N.; Ferranti, C.

    2011-01-01

    Benign breast diseases constitute a heterogeneous group of lesions arising in the mammary epithelium or in other mammary tissues, and they may also be linked to vascular, inflammatory or traumatic pathologies. Most lesions found in women consulting a physician are benign. Ultrasound (US) diagnostic criteria indicating a benign lesion are described as well as US findings in the most frequent benign breast lesions. PMID:23396888

  3. Ultrasound - Breast

    MedlinePlus

    ... discharge) and to characterize potential abnormalities seen on mammography or breast magnetic resonance imaging (MRI). Ultrasound imaging ... supply in breast lesions . Supplemental Breast Cancer Screening Mammography is the only screening tool for breast cancer ...

  4. Thyroid ultrasound

    MedlinePlus

    ... Performed Ultrasound is a painless method that uses sound waves to create images of the inside of the ... neck to help with the transmission of the sound waves. Next, the technician moves a wand, called a ...

  5. Abdominal Ultrasound

    MedlinePlus

    ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

  6. Obstetrical Ultrasound

    MedlinePlus

    ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

  7. Resveratrol attenuates visfatin and vaspin genes expression in adipose tissue of rats with type 2 diabetes

    PubMed Central

    Asadi, Soheila; Goodarzi, Mohammad Taghi; Saidijam, Massoud; Karimi, Jamshid; Azari, Reza Yadgar; Farimani, Azam Rezaei; Salehi, Iraj

    2015-01-01

    Objective(s): Visfatin and vaspin are secreted by adipose tissue and play key roles in glucose homeostasis and subsequently are potential targets for diabetes treatment. Resveratrol (RVS) corrects insulin secretion and improves insulin sensitivity. We investigated the RVS effects on serum antioxidants, insulin and glucose levels, also visfatin and vaspin genes expression in adipose tissue of streptozotocin-nicotinamide (STZ-NA) induced type 2 diabetic rats. Materials and Methods: Diabetes was induced in Wistar rats (n=32) using STZ (60 mg/kg body weight) and NA (120 mg/kg body weight); rats were divided into 4 groups (n=8). Eight untreated normal rats were used as control group; four diabetic rat groups (2–5) were treated with 0, 1, 5 and 10 mg/kg body weight of RVS, respectively for 30 days. After treatment blood and adipose tissue were prepared from all animals. Serum glucose, insulin, HOMA index, total antioxidant capacity (TAC), and malondialdehyde (MDA) were measured. Visfatin and vaspin genes expression in adipose tissue were evaluated using real-time PCR. Results: RVS reduced blood glucose significantly and increased insulin level, resulting in insulin sensitivity improvement. Furthermore RVS increased weight and TAC, while reducing serum MDA in the diabetic groups. Visfatin gene expression increased in the diabetic group, and RVS treatment reduced it. Vaspin gene expression was reduced in RVS receiving diabetic groups. Conclusion: The results indicated that RVS has potential hypoglycemic effect, probably by increasing insulin level and changing gene expression of visfatin and vaspin. Moreover RVS showed antioxidant effects through reduction in peroxidiation products and augmented antioxidant capacity. PMID:26221476

  8. Blunted response of pituitary type 1 and brown adipose tissue type 2 deiodinases to swimming training in ovariectomized rats.

    PubMed

    Ignacio, D L; Fortunato, R S; Neto, R A L; da Silva Silvestre, D H; Nigro, M; Frankenfeld, T G P; Werneck-de-Castro, J P S; Carvalho, D P

    2012-10-01

    Ovariectomy leads to significant increase in body weight, but the possible peripheral mechanisms involved in weight gain are still unknown. Since exercise and thyroid hormones modulate energy balance, we aimed to study the effect of swimming training on body weight gain and brown adipose tissue (BAT) type 2 iodothyronine deiodinase responses in ovariectomized (Ox) or sham-operated (Sh) rats. Rats were submitted to a period of 8-week training, 5 days per week with progressive higher duration of exercise protocol. Swimming training program did not totally prevent the higher body mass gain that follows ovariectomy in rats (16.5% decrease in body mass gain in Ox trained rats compared to 22% decrease in sham operated trained animals, in relation to the respective sedentary groups), but training of Ox animals impaired the accumulation of subcutaneous fat pads. Interestingly, swimming training upregulates pituitary type 1 (p<0.001 vs. all groups) and BAT type 2 iodothyronine deiodinases (p<0.05 vs. ShS and OxS) in sham operated but not in Ox rats, indicating an impaired pituitary and peripheral response to exercise in Ox rats. However, BAT mitochondrial O2 consumption significantly increased by swimming training in both sham and Ox groups, indicating that Ox BAT mitochondria responds normally to exercise stimulus, but does not result in a significant reduction of body weight. In conclusion, increased body mass gain produced by Ox is not completely impaired by 8 weeks of high intensity physical training, showing that these animals sustain higher rate of body mass gain independent of being submitted to higher energy expenditure. PMID:22815055

  9. Identification of cell types, tissues and pathways affected by risk loci in psoriasis.

    PubMed

    Lin, Yan; Zhao, Pan; Shen, Changbing; Shen, Songke; Zheng, Xiaodong; Zuo, Xianbo; Yang, Sen; Zhang, Xuejun; Yin, Xianyong

    2016-04-01

    Many common variants have been found associated with the risk of psoriasis, but the underlying mechanism is still largely unknown, mostly owing to the difficulty in dissecting the mechanism of each variant using representative cell type and tissue in biological experiments. We applied an integrative method SNPsea which has been developed by investigators in Broad, to identify the most relevant cell types, tissues, and pathways to psoriasis by assessing the condition specificity affected by psoriasis genome-wide association studies-implicated genes. We employed this software on 89 single-nucleotide polymorphisms with genome-wide significance in Han Chinese and Caucasian populations. We found significant evidence for peripheral blood CD56 + NK cells (P = 1.30 × 10(-7)), Langerhans cells (P = 4.96 × 10(-6)) and CD14+ monocytes (P < 4.80 × 10(-5)) in psoriasis. We suggested that the DNase I hypersensitivity sites in CD14+ cells were active in psoriasis (P = 2.20 × 10(-16)). In addition, we discovered that biotic stimulus response, cytokine production and NF-κB pathways were significantly activated in psoriasis (P < 1.00 × 10(-5)). In conclusion, we found several innate immune cells and immune pathways in psoriasis that will help guide biological experiments for psoriasis risk variants in future.

  10. Identification of cell types, tissues and pathways affected by risk loci in psoriasis.

    PubMed

    Lin, Yan; Zhao, Pan; Shen, Changbing; Shen, Songke; Zheng, Xiaodong; Zuo, Xianbo; Yang, Sen; Zhang, Xuejun; Yin, Xianyong

    2016-04-01

    Many common variants have been found associated with the risk of psoriasis, but the underlying mechanism is still largely unknown, mostly owing to the difficulty in dissecting the mechanism of each variant using representative cell type and tissue in biological experiments. We applied an integrative method SNPsea which has been developed by investigators in Broad, to identify the most relevant cell types, tissues, and pathways to psoriasis by assessing the condition specificity affected by psoriasis genome-wide association studies-implicated genes. We employed this software on 89 single-nucleotide polymorphisms with genome-wide significance in Han Chinese and Caucasian populations. We found significant evidence for peripheral blood CD56 + NK cells (P = 1.30 × 10(-7)), Langerhans cells (P = 4.96 × 10(-6)) and CD14+ monocytes (P < 4.80 × 10(-5)) in psoriasis. We suggested that the DNase I hypersensitivity sites in CD14+ cells were active in psoriasis (P = 2.20 × 10(-16)). In addition, we discovered that biotic stimulus response, cytokine production and NF-κB pathways were significantly activated in psoriasis (P < 1.00 × 10(-5)). In conclusion, we found several innate immune cells and immune pathways in psoriasis that will help guide biological experiments for psoriasis risk variants in future. PMID:26563434

  11. Ultrasound for neuraxial blockade.

    PubMed

    Srinivasan, Karthikeyan Kallidaikurichi; Lee, Peter John; Iohom, Gabriella

    2014-12-01

    Neuraxial blockade is still largely performed as a blind procedure. Despite of developments in the type of needles used and drugs administered, the process of locating the epidural or intra-thecal space is still limited to identification of landmarks by palpation and reliance on tactile feedback of the operator. Ultrasound has provided the long needed "eye" to the procedure and has already shown promise of improving the safety and efficacy or neuraxial blocks. This review focuses on understanding the sonoanatomy of the neuraxial space, performing a systematic pre-procedural ultrasound scan, and reviewing the available evidence. PMID:25463890

  12. [The activity of redox-regulatory systems in the tumor and its surrounding tissues in various histological types of tumor].

    PubMed

    Surikova, E I; Goroshinskaja, I A; Nerodo, G A; Frantsiyants, E M; Malejko, M L; Shalashnaja, E V; Kachesova, P; Nemashkalova, L A; Leonova, A V

    2016-01-01

    According to modern concepts cancer is a complex dynamic system having multiple relationships with both the immediate environment and with remote nonmalignant tissues and organs. Changes in the redox balance in them can result in disruption of the normal tissue control. Understanding of the biology of redox processes in a particular tumor and its surroundings, and of their functioning mechanisms is necessary for the development of new anti-cancer strategies based on the effects on the redox state of the tumor and surrounding tissue. Thus the aim of this work was to investigate activity of enzymatic systems influencing the redox state in the tumor tissue, peritumoral area and nonmalignant tissue (taken along the line of resection) for different histological types of tumors. The data obtained showed a similar level of reduced glutathione (GSH) in tumor tissues of gastric adenocarcinoma and vulvar squamous cell carcinoma, but its dynamics in the tissues surrounding the tumor was different. In contrast to the gastric adenocarcinoma the carcinoma of the vulva had a significant level of GSH and higher activity of glutathione dependent enzymes in the tumor tissue and its peritumoral area compared with the surrounding nonmalignant tissue. The results indicate that there are differences in the functioning of the redox regulatory systems in the tumor tissue and its surrounding tissues of various histological origin and localization, possibly due to different mechanisms involved in maintenance of the redox balance in the originally nonmalignant tissue. PMID:27143378

  13. [The activity of redox-regulatory systems in the tumor and its surrounding tissues in various histological types of tumor].

    PubMed

    Surikova, E I; Goroshinskaja, I A; Nerodo, G A; Frantsiyants, E M; Malejko, M L; Shalashnaja, E V; Kachesova, P; Nemashkalova, L A; Leonova, A V

    2016-01-01

    According to modern concepts cancer is a complex dynamic system having multiple relationships with both the immediate environment and with remote nonmalignant tissues and organs. Changes in the redox balance in them can result in disruption of the normal tissue control. Understanding of the biology of redox processes in a particular tumor and its surroundings, and of their functioning mechanisms is necessary for the development of new anti-cancer strategies based on the effects on the redox state of the tumor and surrounding tissue. Thus the aim of this work was to investigate activity of enzymatic systems influencing the redox state in the tumor tissue, peritumoral area and nonmalignant tissue (taken along the line of resection) for different histological types of tumors. The data obtained showed a similar level of reduced glutathione (GSH) in tumor tissues of gastric adenocarcinoma and vulvar squamous cell carcinoma, but its dynamics in the tissues surrounding the tumor was different. In contrast to the gastric adenocarcinoma the carcinoma of the vulva had a significant level of GSH and higher activity of glutathione dependent enzymes in the tumor tissue and its peritumoral area compared with the surrounding nonmalignant tissue. The results indicate that there are differences in the functioning of the redox regulatory systems in the tumor tissue and its surrounding tissues of various histological origin and localization, possibly due to different mechanisms involved in maintenance of the redox balance in the originally nonmalignant tissue.

  14. [Interventional ultrasound].

    PubMed

    Blázquez Sánchez, N; Fernández Canedo, I; Valdés Vilches, L; de Troya Martín, M

    2015-11-01

    High-frequency ultrasound has become increasingly used in dermatology. This technique is accessible, non-invasive, and rapid and provides information in real time. Consequently, it has become of great diagnostic value in dermatology. However, high-frequency ultrasound also has a promising future as a complementary technique in interventional diagnostic procedures, even though its application in this field has been little studied by dermatologists. PMID:26895944

  15. Patterns of peripheral steroid metabolism vary with sex, season, and tissue type in blotched blue-tongued lizards (Tiliqua nigrolutea).

    PubMed

    Edwards, Ashley; Jones, Susan M; Davies, Noel W

    2005-01-01

    We examined sexual and seasonal variation in the ability of reproductively relevant tissues (liver, skin, adrenal gland, cloaca, kidney, renal sexual segment, epididymis, oviduct, muscle, testis, and ovary) to metabolise a primary steroid [testosterone (T) or estradiol (E2)] in the scincid lizard, Tiliqua nigrolutea. We observed considerable variation between sexes and across seasons in the patterns of conjugation and derivatisation of the primary steroids by these tissues. All tissues demonstrated the ability to conjugate the relevant primary steroid. Other general trends included increased conjugation by all tissues of gestating females, reduced metabolism of E2 by female tissues during late vitellogenesis, and reduced metabolism of T by males during early spermatogenesis. 5alpha-Dihydrotestosterone was the most commonly detected derivative in males, and production varied with season and tissue type. We suggest that seasonal variation in the ability of reproductively relevant tissues may be important in the physiological regulation of reproduction in this species.

  16. Trauma Ultrasound.

    PubMed

    Wongwaisayawan, Sirote; Suwannanon, Ruedeekorn; Prachanukool, Thidathit; Sricharoen, Pungkava; Saksobhavivat, Nitima; Kaewlai, Rathachai

    2015-10-01

    Ultrasound plays a pivotal role in the evaluation of acute trauma patients through the use of multi-site scanning encompassing abdominal, cardiothoracic, vascular and skeletal scans. In a high-speed polytrauma setting, because exsanguinations are the primary cause of trauma morbidity and mortality, ultrasound is used for quick and accurate detection of hemorrhages in the pericardial, pleural, and peritoneal cavities during the primary Advanced Trauma Life Support (ATLS) survey. Volume status can be assessed non-invasively with ultrasound of the inferior vena cava (IVC), which is a useful tool in the initial phase and follow-up evaluations. Pneumothorax can also be quickly detected with ultrasound. During the secondary survey and in patients sustaining low-speed or localized trauma, ultrasound can be used to help detect abdominal organ injuries. This is particularly helpful in patients in whom hemoperitoneum is not identified on an initial scan because findings of organ injuries will expedite the next test, often computed tomography (CT). Moreover, ultrasound can assist in detection of fractures easily obscured on radiography, such as rib and sternal fractures.

  17. The effects of twisting and type of aspiration needle on the efficiency of transvaginal ultrasound-guided ovum pick-up in cattle.

    PubMed

    Sasamoto, Yoshihiko; Sakaguchi, Minoru; Katagiri, Seiji; Yamada, Yutaka; Takahashi, Yoshiyuki

    2003-10-01

    The effects of twisting and type (single- or double-lumen) of aspiration needle on the efficiency of transvaginal ultrasound-guided ovum pick-up (US-guided OPU) were investigated in cattle. The first study using slaughterhouse ovaries revealed that twisting of the needle during follicle aspiration improved the oocyte recovery rate without deleterious effects on the attachment of cumulus layers. Vacuum pressure affected the oocyte recovery and cumulus attachment, regardless of the needle type. The needle type did not affect the oocyte recovery or cumulus attachment with an optimized vacuum pressure. In the second study, US-guided OPU was performed in live cows using two types of needles with a vacuum pressure of 75 mmHg. The needle type did not affect the oocyte recovery or cumulus attachment of the recovered oocytes. The results revealed that twisting of the needle is effective in follicle aspiration, and suggested that a single-lumen needle is as useful as a double-lumen needle for US-guided OPU in cattle.

  18. 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.

  19. Propolis Modifies Collagen Types I and III Accumulation in the Matrix of Burnt Tissue

    PubMed Central

    Olczyk, Pawel; Wisowski, Grzegorz; Komosinska-Vassev, Katarzyna; Stojko, Jerzy; Klimek, Katarzyna; Olczyk, Monika; Kozma, Ewa M.

    2013-01-01

    Wound healing represents an interactive process which requires highly organized activity of various cells, synthesizing cytokines, growth factors, and collagen. Collagen types I and III, serving as structural and regulatory molecules, play pivotal roles during wound healing. The aim of this study was to compare the propolis and silver sulfadiazine therapeutic efficacy throughout the quantitative and qualitative assessment of collagen types I and III accumulation in the matrix of burnt tissues. Burn wounds were inflicted on pigs, chosen for the evaluation of wound repair because of many similarities between pig and human skin. Isolated collagen types I and III were estimated by the surface plasmon resonance method with a subsequent collagenous quantification using electrophoretic and densitometric analyses. Propolis burn treatment led to enhanced collagens and its components expression, especially during the initial stage of the study. Less expressed changes were observed after silver sulfadiazine (AgSD) application. AgSD and, with a smaller intensity, propolis stimulated accumulation of collagenous degradation products. The assessed propolis therapeutic efficacy, throughout quantitatively and qualitatively analyses of collagen types I and III expression and degradation in wounds matrix, may indicate that apitherapeutic agent can generate favorable biochemical environment supporting reepithelization. PMID:23781260

  20. Propolis Modifies Collagen Types I and III Accumulation in the Matrix of Burnt Tissue.

    PubMed

    Olczyk, Pawel; Wisowski, Grzegorz; Komosinska-Vassev, Katarzyna; Stojko, Jerzy; Klimek, Katarzyna; Olczyk, Monika; Kozma, Ewa M

    2013-01-01

    Wound healing represents an interactive process which requires highly organized activity of various cells, synthesizing cytokines, growth factors, and collagen. Collagen types I and III, serving as structural and regulatory molecules, play pivotal roles during wound healing. The aim of this study was to compare the propolis and silver sulfadiazine therapeutic efficacy throughout the quantitative and qualitative assessment of collagen types I and III accumulation in the matrix of burnt tissues. Burn wounds were inflicted on pigs, chosen for the evaluation of wound repair because of many similarities between pig and human skin. Isolated collagen types I and III were estimated by the surface plasmon resonance method with a subsequent collagenous quantification using electrophoretic and densitometric analyses. Propolis burn treatment led to enhanced collagens and its components expression, especially during the initial stage of the study. Less expressed changes were observed after silver sulfadiazine (AgSD) application. AgSD and, with a smaller intensity, propolis stimulated accumulation of collagenous degradation products. The assessed propolis therapeutic efficacy, throughout quantitatively and qualitatively analyses of collagen types I and III expression and degradation in wounds matrix, may indicate that apitherapeutic agent can generate favorable biochemical environment supporting reepithelization.

  1. Differential biological significance of tissue-type and urokinase-type plasminogen activator in human breast cancer.

    PubMed Central

    Yamashita, J.; Ogawa, M.; Yamashita, S.; Nakashima, Y.; Saishoji, T.; Nomura, K.; Inada, K.; Kawano, I.

    1993-01-01

    Plasminogen activator (PA) is a serine protease existing in two forms known as tissue-type (t-PA) and urokinase-type (u-PA). To examine whether PA is related to the postoperative clinical course of human breast cancer, total PA activity, t-PA activity, u-PA activity, and immunoreactive t-PA were determined in tissue extracts from 144 breast cancer specimens. The patients were initially divided into four groups according to the postoperative clinical course: Group I (83 patients who are disease-free), Group II (20 patients whose first metastases were found only in bone), Group III (19 patients whose first metastases were found in both bone and lung), and Group IV (22 patients whose first metastases were found only in lung). Total PA activity was significantly lower in Groups, II, III and IV than in Group I. Both t-PA activity and t-PA antigen levels were also significantly lower in Groups II, III and IV than in Group I, while no significant difference was found in u-PA activity among these groups, indicating that low activity of total PA in Groups II, III and IV was due to a decrease in t-PA but not in u-PA. In the multivariate analyses, t-PA activity was found to be an independent prognostic factor for relapse-free survival. When four groups of patients were further analysed in terms of nodal status, both t-PA activity and antigen levels were markedly decreased in the node-negative Group II compared with the node-negative Groups III and IV or with the node-positive Groups II, III and IV. Of additional interest, u-PA activity was significantly higher in node-positive patients than in node-negative patients with any group. The clinico-pathologic analyses of the patients in this series showed that node involvement and lymphatic invasion were more frequently positive in Groups III and IV than in Groups I and II. When 144 breast cancers were categorised in terms of combinations of oestrogen receptor (ER) and progesterone receptor (PgR) status, breast cancers which were

  2. Type I Interferon Counters or Promotes Coxiella burnetii Replication Dependent on Tissue.

    PubMed

    Hedges, Jodi F; Robison, Amanda; Kimmel, Emily; Christensen, Kelly; Lucas, Erin; Ramstead, Andrew; Jutila, Mark A

    2016-06-01

    Coxiella burnetii is an intracellular pathogen and the cause of Q fever. Gamma interferon (IFN-γ) is critical for host protection from infection, but a role for type I IFN in C. burnetii infection has not been determined. Type I IFN supports host protection from a related pathogen, Legionella pneumophila, and we hypothesized that it would be similarly protective in C. burnetii infection. In contrast to our prediction, IFN-α receptor-deficient (IFNAR(-/-)) mice were protected from C. burnetii-induced infection. Therefore, the role of type I IFN in C. burnetii infection was distinct from that in L. pneumophila Mice treated with a double-stranded-RNA mimetic were protected from C. burnetii-induced weight loss through an IFNAR-independent pathway. We next treated mice with recombinant IFN-α (rIFN-α). When rIFN-α was injected by the intraperitoneal route during infection, disease-induced weight loss was exacerbated. Mice that received rIFN-α by this route had dampened interleukin 1β (IL-1β) expression in bronchoalveolar lavage fluids. However, when rIFN-α was delivered to the lung, bacterial replication was decreased in all tissues. Thus, the presence of type I IFN in the lung protected from infection, but when delivered to the periphery, type I IFN enhanced disease, potentially by dampening inflammatory cytokines. To better characterize the capacity for type I IFN induction by C. burnetii, we assessed expression of IFN-β transcripts by human macrophages following stimulation with lipopolysaccharide (LPS) from C. burnetii Understanding innate responses in C. burnetii infection will support the discovery of novel therapies that may be alternative or complementary to the current antibiotic treatment. PMID:27068091

  3. 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

  4. Connective tissue reflex massage for type 2 diabetic patients with peripheral arterial disease: randomized controlled trial.

    PubMed

    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

  5. Cranial Ultrasound/Head Ultrasound

    MedlinePlus

    ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

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

    PubMed

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

    2012-01-01

    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.

  7. 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.

  8. Replication of type 2 herpes simplex virus in human endocervical tissue in organ culture.

    PubMed Central

    Birch, J.; Fink, C. G.; Skinner, G. R.; Thomas, G. H.; Jordan, J. A.

    1976-01-01

    The replication of type 2 herpes simplex virus in human endocervical tissue in organ culture was investigated. The temporal profile of virus replication was related to the initial virus inoculum; high input inocula induced a rapid increase in virus titre while lower multiplicities induced a more slow-rising increase in virus titre. Our evidence suggested that explants were capable of initiating and supporting virus replication for at least 2 weeks following establishment of the culture. Virus yields were optimal when explants were cultured at 37 degrees and in serum-supplemented medium. Explants also supported the replication of type 1 herpes simplex virus and a "non-human" herpes simplex virus (pseudo-rabies virus). The optimal conditions for replication of type 2 herpes simplex virus in human endocervical explants have been established and will provide a model permitting precise investigation of lytic or other virus-cervical cell interactions and their possible relationship to herpes virus-induced pre-invasive carcinoma of this organ. Images Fig. 1 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 PMID:183806

  9. An update on the constitutive relation of ligament tissues with the effects of collagen types.

    PubMed

    Wan, Chao; Hao, Zhixiu; Tong, Lingying; Lin, Jianhao; Li, Zhichang; Wen, Shizhu

    2015-10-01

    The musculoskeletal ligament is a kind of multiscale composite material with collagen fibers embedded in a ground matrix. As the major constituent in ligaments to bear external loads, collagens are composed mainly of two collagen contents with different mechanical properties, i.e., types I and III collagen. The constitutive relation of ligaments plays a critical role in the stability and normal function of human joints. However, collagen types have not been distinguished in the previous constitutive relations. In this paper a constitutive relation for ligament tissues was modified based on the previous constitutive relation by considering the effects of collagen types. Both the collagen contents and the mechanical properties of sixteen ligament specimens from four cadaveric human knee joints were measured for determining their material coefficients in the constitutive relation. The mechanical behaviors of ligaments were obtained from both the uniaxial tensile and simple shear tests. A linear regression between joint kinematic results from in vitro and in silico experiments was made to validate the accuracy of this constitutive relation. The high correlation coefficient (R(2)=0.93) and significance (P<0.0001) of the regression equation revealed that this modified constitutive relation of ligaments was accurate to be used in studying joint biomechanics. Another finite element analysis with collagen contents changing demonstrated that the effect of variations in collagen ratios on both joint kinematics and ligament biomechanics could be simulated by this constitutive relation.

  10. Molecular Cloning and Characterization of a New C-type Lysozyme Gene from Yak Mammary Tissue.

    PubMed

    Jiang, Ming Feng; Hu, Ming Jun; Ren, Hong Hui; Wang, Li

    2015-12-01

    Milk lysozyme is the ubiquitous enzyme in milk of mammals. In this study, the cDNA sequence of a new chicken-type (c-type) milk lysozyme gene (YML), was cloned from yak mammary gland tissue. A 444 bp open reading frames, which encodes 148 amino acids (16.54 kDa) with a signal peptide of 18 amino acids, was sequenced. Further analysis indicated that the nucleic acid and amino acid sequences identities between yak and cow milk lysozyme were 89.04% and 80.41%, respectively. Recombinant yak milk lysozyme (rYML) was produced by Escherichia coli BL21 and Pichia pastoris X33. The highest lysozyme activity was detected for heterologous protein rYML5 (M = 1,864.24 U/mg, SD = 25.75) which was expressed in P. pastoris with expression vector pPICZαA and it clearly inhibited growth of Staphylococcus aureus. Result of the YML gene expression using quantitative polymerase chain reaction showed that the YML gene was up-regulated to maximum at 30 day postpartum, that is, comparatively high YML can be found in initial milk production. The phylogenetic tree indicated that the amino acid sequence was similar to cow kidney lysozyme, which implied that the YML may have diverged from a different ancestor gene such as cow mammary glands. In our study, we suggest that YML be a new c-type lysozyme expressed in yak mammary glands that plays a role as host immunity.

  11. Tissue-type-specific transcriptome analysis identifies developing xylem-specific promoters in poplar.

    PubMed

    Ko, Jae-Heung; Kim, Hyun-Tae; Hwang, Ildoo; Han, Kyung-Hwan

    2012-06-01

    Plant biotechnology offers a means to create novel phenotypes. However, commercial application of biotechnology in crop improvement programmes is severely hindered by the lack of utility promoters (or freedom to operate the existing ones) that can drive gene expression in a tissue-specific or temporally controlled manner. Woody biomass is gaining popularity as a source of fermentable sugars for liquid fuel production. To improve the quantity and quality of woody biomass, developing xylem (DX)-specific modification of the feedstock is highly desirable. To develop utility promoters that can drive transgene expression in a DX-specific manner, we used the Affymetrix Poplar Genome Arrays to obtain tissue-type-specific transcriptomes from poplar stems. Subsequent bioinformatics analysis identified 37 transcripts that are specifically or strongly expressed in DX cells of poplar. After further confirmation of their DX-specific expression using semi-quantitative PCR, we selected four genes (DX5, DX8, DX11 and DX15) for in vivo confirmation of their tissue-specific expression in transgenic poplars. The promoter regions of the selected DX genes were isolated and fused to a β-glucuronidase (GUS)-reported gene in a binary vector. This construct was used to produce transgenic poplars via Agrobacterium-mediated transformation. The GUS expression patterns of the resulting transgenic plants showed that these promoters were active in the xylem cells at early seedling growth and had strongest expression in the developing xylem cells at later growth stages of poplar. We conclude that these DX promoters can be used as a utility promoter for DX-specific biomass engineering.

  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. )

    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. Massively parallel single cell RNA-Seq for marker-free decomposition of tissues into cell types

    PubMed Central

    Jaitin, Diego Adhemar; Kenigsberg, Ephraim; Keren-Shaul, Hadas; Elefant, Naama; Paul, Franziska; Zaretsky, Irina; Mildner, Alexander; Cohen, Nadav; Jung, Steffen; Tanay, Amos; Amit, Ido

    2015-01-01

    In multi-cellular organisms, biological function emerges when heterogeneous cell types form complex organs. Nevertheless dissection of tissues into mixtures of cellular subpopulations is currently challenging. We introduce an automated massively parallel single-cell RNA sequencing approach for analyzing in vivo transcriptional states in thousands of single cells. Combined with unsupervised classification algorithms, this facilitates ab initio cell type characterization of splenic tissues. Modeling single-cell transcriptional states in dendritic cells and additional hematopoietic cell types uncovers rich cell-type heterogeneity and gene-modules activity in steady-state and after pathogen activation. Cellular diversity is thereby approached through inference of variable and dynamic pathway activity rather than a fixed pre-programmed cell-type hierarchy. These data demonstrate single-cell RNA-Seq as an effective tool for comprehensive cellular decomposition of complex tissues. PMID:24531970

  14. MERAV: a tool for comparing gene expression across human tissues and cell types.

    PubMed

    Shaul, Yoav D; Yuan, Bingbing; Thiru, Prathapan; Nutter-Upham, Andy; McCallum, Scott; Lanzkron, Carolyn; Bell, George W; Sabatini, David M

    2016-01-01

    The oncogenic transformation of normal cells into malignant, rapidly proliferating cells requires major alterations in cell physiology. For example, the transformed cells remodel their metabolic processes to supply the additional demand for cellular building blocks. We have recently demonstrated essential metabolic processes in tumor progression through the development of a methodological analysis of gene expression. Here, we present the Metabolic gEne RApid Visualizer (MERAV, http://merav.wi.mit.edu), a web-based tool that can query a database comprising ∼4300 microarrays, representing human gene expression in normal tissues, cancer cell lines and primary tumors. MERAV has been designed as a powerful tool for whole genome analysis which offers multiple advantages: one can search many genes in parallel; compare gene expression among different tissue types as well as between normal and cancer cells; download raw data; and generate heatmaps; and finally, use its internal statistical tool. Most importantly, MERAV has been designed as a unique tool for analyzing metabolic processes as it includes matrixes specifically focused on metabolic genes and is linked to the Kyoto Encyclopedia of Genes and Genomes pathway search.

  15. Tissue sorbitol concentration can be altered by changing the type of dietary carbohydrate or copper status

    SciTech Connect

    Beal, T.; Lewis, C.G.; Fields, M. )

    1989-02-09

    This study was designed to determine whether rehabilitation of tissue sorbitol concentration occurs when rats consuming a high-fructose, low-copper diet are changed to diets containing starch or copper. Weanling male rats were provided with a diet which contained 62.7% fructose and 0.6 or 6.0 {mu}g Cu/g (F-Cu) for 4 weeks and then changed to either a fructose diet which contained 6.0 {mu}g Cu/g or a starch diet which contained either 0.6 or 6.0 {mu}g Cu/g for 2 weeks. Hepatic copper concentration of rats eating copper-deficient diets was about 30% of copper adequate rats regardless of the type of dietary carbohydrate. Pancreatic fructose, glucose and sorbitol concentrations were significantly lowered in rats changed to a starch diet. Kidney fructose and sorbitol concentrations were significantly lowered in rats changed to a starch diet. For all dietary groups, pancreatic and kidney sorbitol concentrations returned to normal after removal of rats from the F-Cu diet. In general, changing rats from a high-fructose, low-copper diet to a fructose diet with copper or a starch diet with or without copper improved the copper deficiency symptoms which changed in concert with tissue sorbitol levels.

  16. [Comparative studies on the breaking strength of tissue adhesives of the butylcyanoacrylate type].

    PubMed

    Gitt, H A; Hlubna-Daum, E; Zennig, S

    1977-07-01

    Four tissue adhesives of the butylcyano-acrylate type were tested for breaking strength. The addition of dyes and stabilizers results in an increase in breaking strength. Adhesives coloured with an anthraquinone dye and stabilized with SO2 significantly surpass in breaking strength adhesives that are only coloured or stabilized. Fiomed II (coloured, stabilized with SO2) yields significantly (at P=0.001) better values than Histoacryl blue. Addition of the dye alone seems to exert a better effect on breaking strength than addition of the stabilizer alone. As evidenced by our results, the breaking strength is in the order: 1. Fiomed II (coloured, stabilized with SO2), 2. Histoacryl blue, 3. Fiomed III (coloured, without SO2), 4. Fiomed I (without dye, stabilized with SO2).

  17. Characterization of tissue plasminogen activator binding proteins isolated from endothelial cells and other cell types

    SciTech Connect

    Beebe, D.P.; Wood, L.L.; Moos, M. )

    1990-07-15

    Human tissue plasminogen activator (t-PA) was shown to bind specifically to human osteosarcoma cells (HOS), and human epidermoid carcinoma cells (A-431 cells). Crosslinking studies with DTSSP demonstrated high molecular weight complexes (130,000) between {sup 125}I-t-PA and cell membrane protein on human umbilical vein endothelial cells (HUVEC), HOS, and A-431 cells. A 48-65,000 molecular weight complex was demonstrated after crosslinking t-PA peptide (res. 7-20) to cells. Ligand blotting of cell lysates which had been passed over a t-PA affinity column revealed binding of t-PA to 54,000 and 95,000 molecular weight proteins. Several t-PA binding proteins were identified in immunopurified cell lysates, including tubulin beta chain, plasminogen activator inhibitor type 1 and single chain urokinase.

  18. Enhanced ROS production and oxidative damage in subcutaneous white adipose tissue mitochondria in obese and type 2 diabetes subjects.

    PubMed

    Chattopadhyay, Mrittika; Khemka, Vineet Kumar; Chatterjee, Gargi; Ganguly, Anirban; Mukhopadhyay, Satinath; Chakrabarti, Sasanka

    2015-01-01

    Oxidative stress in the insulin target tissues has been implicated in the pathophysiology of type 2 diabetes. The study has examined the oxidative stress parameters in the mitochondria of subcutaneous white adipose tissue from obese and non-obese subjects with or without type 2 diabetes. An accumulation of protein carbonyls, fluorescent lipid peroxidation products, and malondialdehyde occurs in the adipose tissue mitochondria of obese type 2 diabetic, non-diabetic obese, and non-obese diabetic subjects with the maximum increase noticed in the obese type 2 diabetes patients and the minimum in non-obese type 2 diabetics. The mitochondria from obese type 2 diabetics, non-diabetic obese, and non-obese type 2 diabetics also produce significantly more reactive oxygen species (ROS) in vitro compared to those of controls, and apparently the mitochondrial ROS production rate in each group is proportional to the respective load of oxidative damage markers. Likewise, the mitochondrial antioxidant enzymes like superoxide dismutase and glutathione peroxidase show decreased activities most markedly in obese type 2 diabetes subjects and to a lesser degree in non-obese type 2 diabetes or non-diabetic obese subjects in comparison to control. The results imply that mitochondrial dysfunction with enhanced ROS production may contribute to the metabolic abnormality of adipose tissue in obesity and diabetes.

  19. Nonlinear effects in ultrasound fields of diagnostic-type transducers used for kidney stone propulsion: Characterization in water

    SciTech Connect

    Karzova, M.; Cunitz, B.; Kreider, W.; Bailey, M.; Yuldashev, P.; Andriyakhina, Y.; Sapozhnikov, O.; Khokhlova, V.

    2015-10-28

    Newer imaging and therapeutic ultrasound technologies require higher in situ pressure levels compared to conventional diagnostic values. One example is the recently developed use of focused ultrasonic radiation force to move kidney stones and residual fragments out of the urinary collecting system. A commercial diagnostic 2.3 MHz C5-2 array probe is used to deliver the acoustic pushing pulses. The probe comprises 128 elements equally spaced at the 55 mm long convex cylindrical surface with 38 mm radius of curvature. The efficacy of the treatment can be increased by using higher intensity at the focus to provide stronger pushing force; however, nonlinear acoustic saturation can be a limiting factor. In this work nonlinear propagation effects were analyzed for the C5-2 transducer using a combined measurement and modeling approach. Simulations were based on the 3D Westervelt equation; the boundary condition was set to match the focal geometry of the beam as measured at a low power output. Focal waveforms simulated for increased output power levels were compared with the fiber-optic hydrophone measurements and were found in good agreement. It was shown that saturation effects do limit the acoustic pressure in the focal region of the transducer. This work has application to standard diagnostic probes and imaging.

  20. Efficacy of transdermal magnesium ascorbyl phosphate delivery after ultrasound treatment with microbubbles in gel-type surrounding medium in mice.

    PubMed

    Liao, Ai-Ho; Lu, Ying-Jui; Hung, Chi-Ray; Yang, Meng-Yu

    2016-04-01

    Liquid microemulsions appropriate for topical application were obtained by increasing their viscosity through the addition of thickening agents. The present study first assessed the usefulness of ultrasound (US) plus US contrast agent, microbubbles (MBs), in agarose gel for enhancing transdermal drug delivery. The effect of US plus MBs in agarose gel on the penetration of the skin by magnesium ascorbyl phosphate (MAP) was explored both in vitro and in vivo. In the in vitro experiments, the stability of MBs was investigated by examining the penetration of MAP by the model drug, Evans blue, in two media: an agarose phantom and pig skin. The penetration depth in the agarose phantom and pig skin increased by 40% and 195%, respectively, when treated with US plus MBs in 0.1% agarose solution combined with MAP (UMB1), and by 48% and 206%, respectively, when treated with US plus MBs in 0.15% agarose solution and MAP (UMB2). The skin-whitening effects in C57BL/6J mice in the UMB1 and UMB2 groups over a 4-week experimental period were significantly increased by 63% and 70%, respectively, in the fourth week. The findings of this study suggest that the survival of MBs with US is affected by the viscosity of the surrounding medium, and that in mice, treatment with US plus MBs in a suitable agarose gel can increase skin permeability and enhance transdermal MAP delivery. PMID:26838887

  1. Nonlinear effects in ultrasound fields of diagnostic-type transducers used for kidney stone propulsion: Characterization in water

    NASA Astrophysics Data System (ADS)

    Karzova, M.; Cunitz, B.; Yuldashev, P.; Andriyakhina, Y.; Kreider, W.; Sapozhnikov, O.; Bailey, M.; Khokhlova, V.

    2015-10-01

    Newer imaging and therapeutic ultrasound technologies require higher in situ pressure levels compared to conventional diagnostic values. One example is the recently developed use of focused ultrasonic radiation force to move kidney stones and residual fragments out of the urinary collecting system. A commercial diagnostic 2.3 MHz C5-2 array probe is used to deliver the acoustic pushing pulses. The probe comprises 128 elements equally spaced at the 55 mm long convex cylindrical surface with 38 mm radius of curvature. The efficacy of the treatment can be increased by using higher intensity at the focus to provide stronger pushing force; however, nonlinear acoustic saturation can be a limiting factor. In this work nonlinear propagation effects were analyzed for the C5-2 transducer using a combined measurement and modeling approach. Simulations were based on the 3D Westervelt equation; the boundary condition was set to match the focal geometry of the beam as measured at a low power output. Focal waveforms simulated for increased output power levels were compared with the fiber-optic hydrophone measurements and were found in good agreement. It was shown that saturation effects do limit the acoustic pressure in the focal region of the transducer. This work has application to standard diagnostic probes and imaging.

  2. Nonlinear Effects in Ultrasound Fields of Diagnostic-type Transducers Used for Kidney Stone Propulsion: Characterization in Water

    PubMed Central

    Karzova, M.; Cunitz, B.; Yuldashev, P.; Andriyakhina, Y.; Kreider, W.; Sapozhnikov, O.; Bailey, M.; Khokhlova, V.

    2016-01-01

    Newer imaging and therapeutic ultrasound technologies require higher in situ pressure levels compared to conventional diagnostic values. One example is the recently developed use of focused ultrasonic radiation force to move kidney stones and residual fragments out of the urinary collecting system. A commercial diagnostic 2.3 MHz C5-2 array probe is used to deliver the acoustic pushing pulses. The probe comprises 128 elements equally spaced at the 55 mm long convex cylindrical surface with 38 mm radius of curvature. The efficacy of the treatment can be increased by using higher transducer output to provide stronger pushing force; however, nonlinear acoustic saturation effect can be a limiting factor. In this work nonlinear propagation effects were analyzed for the C5-2 transducer using a combined measurement and modeling approach. Simulations were based on the 3D Westervelt equation; the boundary condition was set to match low power pressure beam scans. Focal waveforms simulated for increased output power levels were compared with the fiber-optic hydrophone measurements and were found in good agreement. It was shown that saturation effects do limit the acoustic pressure in the focal region of the transducer. This work has application to standard diagnostic probes and imaging. PMID:27087711

  3. 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

  4. 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.

  5. Therapeutic potential of ultrasound microbubbles in gastrointestinal oncology: recent advances and future prospects

    PubMed Central

    Khokhlova, Tatiana D.; Haider, Yasser; Hwang, Joo Ha

    2015-01-01

    Microbubbles were initially invented as contrast agents for ultrasound imaging. However, lately more and more therapeutic applications of microbubbles are emerging, mostly related to drug and gene delivery. Ultrasound is a safe and noninvasive therapeutic modality which has the unique ability to interact with microbubbles and release their payload in situ in addition to permeabilizing the target tissues. The combination of drug-loaded microbubbles and ultrasound has been used in preclinical studies on blood–brain barrier opening, drug and gene delivery to solid tumors, and ablation of blood vessels. This review covers the basic principles of ultrasound–microbubble interaction, the types of microbubbles and the effect they have on tissue, and the preclinical and clinical experience with this approach to date in the field of gastrointestinal oncology. PMID:26557894

  6. In vitro effects of low-intensity pulsed ultrasound stimulation on the osteogenic differentiation of human alveolar bone-derived mesenchymal stem cells for tooth tissue engineering.

    PubMed

    Lim, Kitaek; Kim, Jangho; Seonwoo, Hoon; Park, Soo Hyun; Choung, Pill-Hoon; Chung, Jong Hoon

    2013-01-01

    Ultrasound stimulation produces significant multifunctional effects that are directly relevant to alveolar bone formation, which is necessary for periodontal healing and regeneration. We focused to find out effects of specific duty cycles and the percentage of time that ultrasound is being generated over one on/off pulse period, under ultrasound stimulation. Low-intensity pulsed ultrasound ((LIPUS) 1 MHz) with duty cycles of 20% and 50% was used in this study, and human alveolar bone-derived mesenchymal stem cells (hABMSCs) were treated with an intensity of 50 mW/cm(2) and exposure time of 10 min/day. hABMSCs exposed at duty cycles of 20% and 50% had similar cell viability (O.D.), which was higher (*P < 0.05) than that of control cells. The alkaline phosphatase (ALP) was significantly enhanced at 1 week with LIPUS treatment in osteogenic cultures as compared to control. Gene expressions showed significantly higher expression levels of CD29, CD44, COL1, and OCN in the hABMSCs under LIPUS treatment when compared to control after two weeks of treatment. The effects were partially controlled by LIPUS treatment, indicating that modulation of osteogenesis in hABMSCs was related to the specific stimulation. Furthermore, mineralized nodule formation was markedly increased after LIPUS treatment than that seen in untreated cells. Through simple staining methods such as Alizarin red and von Kossa staining, calcium deposits generated their highest levels at about 3 weeks. These results suggest that LIPUS could enhance the cell viability and osteogenic differentiation of hABMSCs, and could be part of effective treatment methods for clinical applications.

  7. The influence of breeding strategy, reproductive stage, and tissue type on transcript variability in fish.

    PubMed

    Dreier, David A; Loughery, Jennifer R; Denslow, Nancy D; Martyniuk, Christopher J

    2016-09-01

    Characterizing factors that contribute to transcript variability is necessary before molecular endpoints are widely adopted as biomarkers for environmental monitoring programs and risk assessment. Here, we employed a meta-analysis approach to understand how reproductive stage, breeding strategy, and tissue type influence transcript variability in multiple fish species. Transcript abundance from the scientific literature was examined by method of quantification (qPCR or microarray), and the extracted data were used to calculate the coefficient of variation (CoV) for each transcript. Based on qPCR data, variability in the abundance of estrogen receptor 1 and hydroxysteroid dehydrogenase 3b was dependent upon reproductive stage and/or breeding strategy in the female ovaries. The variability of other transcripts in the steroid biosynthesis pathway as well as other steroid receptors did not depend upon sex, breeding strategy, or reproductive stage. Variability estimates were used to determine sample size requirements for detecting specific critical effects in molecular endpoints. It was estimated that only 37.8% of published studies used in the qPCR meta-analysis had sufficient experimental power (0.8) to detect a 2-fold expression difference in a transcript. To build upon these analyses, microarray data were used to measure overall variability of the transcriptome, and it was determined that the vitellogenic reproductive stage had the lowest transcriptomic variability compared to other reproductive stages. This variability was lower in a single-spawning species (largemouth bass) compared to a multiple-spawner (fathead minnow). Following this, a meta-analysis of 777 microarrays for multiple fish species was performed to determine the influence of breeding strategy and tissue type on transcriptomic variability. In this analysis, single-spawning fish showed lower gonadal and hepatic transcriptome variability compared to multiple-spawning species. Thus, these species may

  8. Individual-specific muscle maximum force estimation using ultrasound for ankle joint torque prediction using an EMG-driven Hill-type model.

    PubMed

    de Oliveira, Liliam Fernandes; Menegaldo, Luciano Luporini

    2010-10-19

    EMG-driven models can be used to estimate muscle force in biomechanical systems. Collected and processed EMG readings are used as the input of a dynamic system, which is integrated numerically. This approach requires the definition of a reasonably large set of parameters. Some of these vary widely among subjects, and slight inaccuracies in such parameters can lead to large model output errors. One of these parameters is the maximum voluntary contraction force (F(om)). This paper proposes an approach to find F(om) by estimating muscle physiological cross-sectional area (PCSA) using ultrasound (US), which is multiplied by a realistic value of maximum muscle specific tension. Ultrasound is used to measure muscle thickness, which allows for the determination of muscle volume through regression equations. Soleus, gastrocnemius medialis and gastrocnemius lateralis PCSAs are estimated using published volume proportions among leg muscles, which also requires measurements of muscle fiber length and pennation angle by US. F(om) obtained by this approach and from data widely cited in the literature was used to comparatively test a Hill-type EMG-driven model of the ankle joint. The model uses 3 EMGs (Soleus, gastrocnemius medialis and gastrocnemius lateralis) as inputs with joint torque as the output. The EMG signals were obtained in a series of experiments carried out with 8 adult male subjects, who performed an isometric contraction protocol consisting of 10s step contractions at 20% and 60% of the maximum voluntary contraction level. Isometric torque was simultaneously collected using a dynamometer. A statistically significant reduction in the root mean square error was observed when US-obtained F(om) was used, as compared to F(om) from the literature.

  9. 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.

  10. Caloric Restriction Leads to Browning of White Adipose Tissue through Type 2 Immune Signaling.

    PubMed

    Fabbiano, Salvatore; Suárez-Zamorano, Nicolas; Rigo, Dorothée; Veyrat-Durebex, Christelle; Stevanovic Dokic, Ana; Colin, Didier J; Trajkovski, Mirko

    2016-09-13

    Caloric restriction (CR) extends lifespan from yeast to mammals, delays onset of age-associated diseases, and improves metabolic health. We show that CR stimulates development of functional beige fat within the subcutaneous and visceral adipose tissue, contributing to decreased white fat and adipocyte size in lean C57BL/6 and BALB/c mice kept at room temperature or at thermoneutrality and in obese leptin-deficient mice. These metabolic changes are mediated by increased eosinophil infiltration, type 2 cytokine signaling, and M2 macrophage polarization in fat of CR animals. Suppression of the type 2 signaling, using Il4ra(-/-), Stat6(-/-), or mice transplanted with Stat6(-/-) bone marrow-derived hematopoietic cells, prevents the CR-induced browning and abrogates the subcutaneous fat loss and the metabolic improvements induced by CR. These results provide insights into the overall energy homeostasis during CR, and they suggest beige fat development as a common feature in conditions of negative energy balance. PMID:27568549

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

    PubMed

    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

    2015-01-20

    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.

  12. 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

  13. Tissue-type plasminogen activator is a neuroprotectant in the mouse hippocampus.

    PubMed

    Echeverry, Ramiro; Wu, Jialing; Haile, Woldeab B; Guzman, Johanna; Yepes, Manuel

    2010-06-01

    The best-known function of the serine protease tissue-type plasminogen activator (tPA) is as a thrombolytic enzyme. However, it is also found in structures of the brain that are highly vulnerable to hypoxia-induced cell death, where its association with neuronal survival is poorly understood. Here, we have demonstrated that hippocampal areas of the mouse brain lacking tPA activity are more vulnerable to neuronal death following an ischemic insult. We found that sublethal hypoxia, which elicits tolerance to subsequent lethal hypoxic/ischemic injury in a natural process known as ischemic preconditioning (IPC), induced a rapid release of neuronal tPA. Treatment of hippocampal neurons with tPA induced tolerance against a lethal hypoxic insult applied either immediately following insult (early IPC) or 24 hours later (delayed IPC). tPA-induced early IPC was independent of the proteolytic activity of tPA and required the engagement of a member of the LDL receptor family. In contrast, tPA-induced delayed IPC required the proteolytic activity of tPA and was mediated by plasmin, the NMDA receptor, and PKB phosphorylation. We also found that IPC in vivo increased tPA activity in the cornu ammonis area 1 (CA1) layer and Akt phosphorylation in the hippocampus, as well as ischemic tolerance in wild-type but not tPA- or plasminogen-deficient mice. These data show that tPA can act as an endogenous neuroprotectant in the murine hippocampus.

  14. Impacts of tissue-type plasminogen activator (tPA) on neuronal survival

    PubMed Central

    Chevilley, Arnaud; Lesept, Flavie; Lenoir, Sophie; Ali, Carine; Parcq, Jérôme; Vivien, Denis

    2015-01-01

    Tissue-type plasminogen activator (tPA) a serine protease is constituted of five functional domains through which it interacts with different substrates, binding proteins, and receptors. In the last years, great interest has been given to the clinical relevance of targeting tPA in different diseases of the central nervous system, in particular stroke. Among its reported functions in the central nervous system, tPA displays both neurotrophic and neurotoxic effects. How can the protease mediate such opposite functions remain unclear but several hypotheses have been proposed. These include an influence of the degree of maturity and/or the type of neurons, of the level of tPA, of its origin (endogenous or exogenous) or of its form (single chain tPA versus two chain tPA). In this review, we will provide a synthetic snapshot of our current knowledge regarding the natural history of tPA and discuss how it sustains its pleiotropic functions with focus on excitotoxic/ischemic neuronal death and neuronal survival. PMID:26528141

  15. Tissue-type plasminogen activator is not required for kainate-induced motoneuron death in vitro.

    PubMed

    Vandenberghe, W; Van Den Bosch, L; Robberecht, W

    1998-08-24

    Spinal motoneurons are highly vulnerable to kainate both in vivo and in vitro. Tissue-type plasminogen activator (tPA) and plasmin have recently been shown to mediate kainate-induced neuronal death in the mouse hippocampus in vivo. The aim of the present study was to determine whether tPA also mediates the kainate-induced death of motoneurons in vitro. A motoneuron-enriched neuronal population was isolated from the ventral spinal cord of wild-type (WT) and tPA-deficient (tPA-/-) mouse embryos. WT and tPA-/- neurons were cultured on WT and tPA-/- spinal glial feeder layers, respectively. WT and tPA-/- co-cultures were morphologically indistinguishable. Expression of tPA in WT co-cultures was demonstrated using RT-PCR. WT and tPA-/- co-cultures were exposed to kainate for 24 h. The neurotoxic effect of kainate did not differ significantly between WT and tPA-/- cultures. The plasmin inhibitor alpha2-antiplasmin did not protect WT neurons against kainate-induced injury. These results indicate that the plasmin system is not a universal mediator of kainate-induced excitotoxicity.

  16. [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

  17. [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.

  18. Ultrasound Based Method and Apparatus for Stone Detection and to Facilitate Clearance Thereof

    NASA Technical Reports Server (NTRS)

    Bailey, Michael (Inventor); Kucewicz, John (Inventor); Lu, Wei (Inventor); Sapozhnikov, Oleg (Inventor); Illian, Paul (Inventor); Shah, Anup (Inventor); Dunmire, Barbrina (Inventor); Owen, Neil (Inventor); Cunitz, Bryan (Inventor); Kaczkowski, Peter (Inventor)

    2015-01-01

    Described herein are methods and apparatus for detecting stones by ultrasound, in which the ultrasound reflections from a stone are preferentially selected and accentuated relative to the ultrasound reflections from blood or tissue. Also described herein are methods and apparatus for applying pushing ultrasound to in vivo stones or other objects, to facilitate the removal of such in vivo objects.

  19. 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

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

    SciTech Connect

    Sadeghi-Naini, Ali; Falou, Omar; Czarnota, Gregory J.; Papanicolau, Naum; Tadayyon, Hadi; Lee, Justin; Zubovits, Judit; Sadeghian, Alireza; Karshafian, Raffi; Al-Mahrouki, Azza; Giles, Anoja; Kolios, Michael C.

    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

  1. Phenotypical heterogeneity linked to adipose tissue dysfunction in patients with Type 2 diabetes.

    PubMed

    Barchetta, Ilaria; Angelico, Francesco; Del Ben, Maria; Di Martino, Michele; Cimini, Flavia Agata; Bertoccini, Laura; Polimeni, Licia; Catalano, Carlo; Fraioli, Antonio; Del Vescovo, Riccardo; Morini, Sergio; Baroni, Marco Giorgio; Cavallo, Maria Gisella

    2016-10-01

    Adipose tissue (AT) inflammation leads to increased free fatty acid (FFA) efflux and ectopic fat deposition, but whether AT dysfunction drives selective fat accumulation in specific sites remains unknown. The aim of the present study was to investigate the correlation between AT dysfunction, hepatic/pancreatic fat fraction (HFF, PFF) and the associated metabolic phenotype in patients with Type 2 diabetes (T2D). Sixty-five consecutive T2D patients were recruited at the Diabetes Centre of Sapienza University, Rome, Italy. The study population underwent clinical examination and blood sampling for routine biochemistry and calculation of insulin secretion [homoeostasis model assessment of insulin secretion (HOMA-β%)] and insulin-resistance [homoeostasis model assessment of insulin resistance (HOMA-IR) and adipose tissue insulin resistance (ADIPO-IR)] indexes. Subcutaneous (SAT) and visceral (VAT) AT area, HFF and PFF were determined by magnetic resonance. Some 55.4% of T2D patients had non-alcoholic fatty liver disease (NAFLD); they were significantly younger and more insulin-resistant than non-NAFLD subjects. ADIPO-IR was the main determinant of HFF independently of age, sex, HOMA-IR, VAT, SAT and predicted severe NAFLD with the area under the receiver operating characteristic curve (AUROC)=0.796 (95% confidence interval: 0.65-0.94, P=0.001). PFF was independently associated with increased total adiposity but did not correlate with AT dysfunction, insulin resistance and secretion or NAFLD. The ADIPO-IR index was capable of predicting NAFLD independently of all confounders, whereas it did not seem to be related to intrapancreatic fat deposition; unlike HFF, higher PFF was not associated with relevant alterations in the metabolic profile. In conclusion, the presence and severity of AT dysfunction may drive ectopic fat accumulation towards specific targets, such as VAT and liver, therefore evaluation of AT dysfunction may contribute to the identification of different

  2. Cellular localization of type 1 plasminogen activator inhibitor messenger RNA and protein in murine renal tissue.

    PubMed Central

    Keeton, M.; Eguchi, Y.; Sawdey, M.; Ahn, C.; Loskutoff, D. J.

    1993-01-01

    Type 1 plasminogen activator inhibitor (PAI-1) may be markedly increased in the plasma of patients with endotoxemia and/or renal disease. To investigate renal PAI-1 production during acute endotoxemia, a murine model system was used. Mice were injected with either saline alone or saline containing 50 micrograms endotoxin, and sacrificed 3 hours later and their tissues analyzed for PAI-1 messenger RNA (mRNA) and antigen. Northern blot analysis confirmed that the level of renal PAI-1 mRNA was greatly increased in the endotoxemic mice relative to the saline controls. In situ hybridization was then performed to determine the cellular localization of PAI-1 mRNA within the renal tissues. In the control kidneys, low levels of PAI-1 mRNA were detected in the renal papilla and in the muscular walls of renal arteries. However, in the endotoxemic mice, an intense hybridization signal for PAI-1 mRNA was observed in glomerular and peritubular cells. These cells also stained positively for von Willebrand factor antigen, an endothelial cell-specific marker. The PAI-1 mRNA hybridization signal could further be observed in peritubular endothelial cells in the medulla and in endothelial cells of veins and arteries throughout the kidney. Immunochemical analysis revealed that PAI-1 antigen co-localized to the cytoplasm of cells expressing PAI-1 mRNA. This study provides the first direct evidence that PAI-1 is induced in endothelial cells of the kidney during endotoxemia in vivo and suggests a role for PAI-1 in the pathogenesis of renal disease. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:8424466

  3. Exercise training does not improve myocardial diastolic tissue velocities in Type 2 diabetes

    PubMed Central

    Loimaala, Antti; Groundstroem, Kaj; Rinne, Marjo; Nenonen, Arja; Huhtala, Heini; Vuori, Ilkka

    2007-01-01

    Background Myocardial diastolic tissue velocities are reduced already in newly onset Type 2 diabetes mellitus (T2D). Poor disease control may lead to left ventricular (LV) systolic dysfunction and heart failure. The aim of this study was to assess the effects of exercise training on myocardial diastolic function in T2D patients without ischemic heart disease. Methods 48 men (52.3 ± 5.6 yrs) with T2D were randomized to supervised training four times a week and standard therapy (E), or standard treatment alone (C) for 12 months. Glycated hemoglobin (HbA1c), oxygen consumption (VO2max), and muscle strength (Sit-up) were measured. Tissue Doppler Imaging (TDI) was used to determine the average maximal mitral annular early (Ea) and late (Aa) diastolic as well as systolic (Sa) velocities, systolic strain (ε) and strain rate (έ) from the septum, and an estimation of left ventricular end diastolic pressure (E/Ea). Results Exercise capacity (VO2max, E 32.0 to 34.7 vs. C 32.6 to 31.5 ml/kg/min, p = .001), muscle strength (E 12.7 to 18.3 times vs. C 14.6 to 14.7 times, p < .001), and HbA1c (E 8.2 to 7.5% vs. C 8.0 to 8.4%, p = .006) improved significantly in the exercise group compared to the controls (ANOVA). Systolic blood pressure decreased in the E group (E 144 to 138 mmHg vs. C 146 to 144 mmHg, p = .04). Contrary to risk factor changes diastolic long axis relaxation did not improve significantly, early diastolic velocity Ea from 8.1 to 7.9 cm/s for the E group vs. C 7.4 to 7.8 cm/s (p = .85, ANOVA). Likewise, after 12 months the mitral annular systolic velocity, systolic strain and strain rate, as well as E/Ea were unchanged. Conclusion Exercise training improves endurance and muscle fitness in T2D, resulting in better glycemic control and reduced blood pressure. However, myocardial diastolic tissue velocities did not change significantly. Our data suggest that a much longer exercise intervention may be needed in order to reverse diastolic impairment in diabetics, if

  4. Dynamic culture induces a cell type-dependent response impacting on the thickness of engineered connective tissues.

    PubMed

    Fortier, Guillaume Marceau; Gauvin, Robert; Proulx, Maryse; Vallée, Maud; Fradette, Julie

    2013-04-01

    Mesenchymal cells are central to connective tissue homeostasis and are widely used for tissue-engineering applications. Dermal fibroblasts and adipose-derived stromal cells (ASCs) allow successful tissue reconstruction by the self-assembly approach of tissue engineering. This method leads to the production of multilayered tissues, devoid of exogenous biomaterials, that can be used as stromal compartments for skin or vesical reconstruction. These tissues are formed by combining cell sheets, generated through cell stimulation with ascorbic acid, which favours the cell-derived production/organization of matrix components. Since media motion can impact on cell behaviour, we investigated the effect of dynamic culture on mesenchymal cells during tissue reconstruction, using the self-assembly method. Tissues produced using ASCs in the presence of a wave-like movement were nearly twice thicker than under standard conditions, while no difference was observed for tissues produced from dermal fibroblasts. The increased matrix deposition was not correlated with an increased proliferation of ASCs, or by higher transcript levels of fibronectin or collagens I and III. A 30% increase of type V collagen mRNA was observed. Interestingly, tissues engineered from dermal fibroblasts featured a four-fold higher level of MMP-1 transcripts under dynamic conditions. Mechanical properties were similar for tissues reconstructed using dynamic or static conditions. Finally, cell sheets produced using ASCs under dynamic conditions could readily be manipulated, resulting in a 2 week reduction of the production time (from 5 to 3 weeks). Our results describe a distinctive property of ASCs' response to media motion, indicating that their culture under dynamic conditions leads to optimized tissue engineering.

  5. Stimulation of Bone Repair with Ultrasound.

    PubMed

    Padilla, Frédéric; Puts, Regina; Vico, Laurence; Guignandon, Alain; Raum, Kay

    2016-01-01

    This chapter reviews the different options available for the use of ultrasound in the enhancement of fracture healing or in the reactivation of a failed healing process: LIPUS, shock waves and ultrasound-mediated delivery of bioactive molecules, such as growth factors or plasmids. The main emphasis is on LIPUS, or Low Intensity Pulsed Ultrasound, the most widespread and studied technique. LIPUS has pronounced bioeffects on tissue regeneration, while employing intensities within a diagnostic range. The biological response to LIPUS is complex as the response of numerous cell types to this stimulus involves several pathways. Known to-date mechanotransduction pathways involved in cell responses include MAPK and other kinases signaling pathways, gap-junctional intercellular communication, up-regulation and clustering of integrins, involvement of the COX-2/PGE2 and iNOS/NO pathways, and activation of the ATI mechanoreceptor. Mechanisms at the origin of LIPUS biological effects remain intriguing, and analysis is hampered by the diversity of experimental systems used in-vitro. Data point to clear evidence that bioeffects can be modulated by direct and indirect mechanical effects, like acoustic radiation force, acoustic streaming, propagation of surface waves, heat, fluid-flow induced circulation and redistribution of nutrients, oxygen and signaling molecules. One of the future engineering challenge is therefore the design of dedicated experimental set-ups allowing control of these different mechanical phenomena, and to relate them to biological responses. Then, the derivation of an 'acoustic dose' and the cross-calibration of the different experimental systems will be possible. Despite this imperfect knowledge of LIPUS biophysics, the clinical evidence, although most often of low quality, speaks in favor of the clinical use of LIPUS, when the economics of nonunion and the absence of toxicity of this ultrasound technology are taken into account. PMID:26486349

  6. [Therapies by focused ultrasound].

    PubMed

    Grenier, N; Trillaud, H; Palussière, J; Mougenot, C; Quesson, B; Denis De Senneville, B; Moonen, C

    2007-11-01

    Many techniques of thermotherapy have emerged over the last several years in the field of oncology using different types of physical agents, including ultrasound. Only ultrasound can target deep seated lesions non-invasively without need for percutaneous probe insertion. Depending on their utilization, it is possible to select either thermal effects, in a continuous mode, at low temperature (allowing thermo-induced biological effects) or at high temperature (allowing thermoablation), or mechanical effects, in a pulsed mode, at low energy level (allowing biological effects) or at high energy levels (histotripsy). Thermoablation by focused ultrasound is now developing fast for applications in many organs. It gained a well defined role for the treatment of prostatic cancer and uterine leiomyoma but needs to be better evaluated in other organs such as the breast. Treatment of abdominal tumors must still be considered as experimental as long as problems related to acoustic interfaces (produced by ribs and gas) and movement correction are not resolved. Biological applications of focused ultrasound are currently being explored and have a great long term potential.

  7. Evaluation of DNA typing as a positive identification method for soft and hard tissues immersed in strong acids.

    PubMed

    Robino, C; Pazzi, M; Di Vella, G; Martinelli, D; Mazzola, L; Ricci, U; Testi, R; Vincenti, M

    2015-11-01

    Identification of human remains can be hindered by several factors (e.g., traumatic mutilation, carbonization or decomposition). Moreover, in some criminal cases, offenders may purposely adopt various expedients to thwart the victim's identification, including the dissolution of body tissues by the use of corrosive reagents, as repeatedly reported in the past for Mafia-related murders. By means of an animal model, namely porcine samples, we evaluated standard DNA typing as a method for identifying soft (muscle) and hard (bone and teeth) tissues immersed in strong acids (hydrochloric, nitric and sulfuric acid) or in mixtures of acids (aqua regia). Samples were tested at different time intervals, ranging between 2 and 6h (soft tissues) and 2-28 days (hard tissues). It was shown that, in every type of acid, complete degradation of the DNA extracted from soft tissues preceded tissue dissolution and could be observed within 4h of immersion. Conversely, high molecular weight DNA amenable to STR analysis could be isolated from hard tissues as long as cortical bone fragments were still present (28 days for sulfuric acid, 7 days for nitric acid, 2 days for hydrochloric acid and aqua regia), or the integrity of the dental pulp chamber was preserved (7 days, in sulfuric acid only). The results indicate that DNA profiling of acid-treated body parts (in particular, cortical bone) is still feasible at advanced stages of corrosion, even when the morphological methods used in forensic anthropology and odontology can no longer be applied for identification purposes.

  8. Characterization of the interaction in vivo of tissue-type plasminogen activator with liver cells

    SciTech Connect

    Kuiper, J.; Otter, M.; Rijken, D.C.; van Berkel, T.J.

    1988-12-05

    The interaction in vivo of 125I-labeled tissue-type plasminogen activator (t-PA) with the rat liver and the various liver cell types was characterized. Intravenously injected 125I-t-PA was rapidly cleared from the plasma (t1/2 = 1 min), and 80% of the injected dose associated with the liver. After uptake, t-PA was rapidly degraded in the lysosomes. The interaction of 125I-t-PA with the liver could be inhibited by preinjection of the rats with ovalbumin or unlabeled t-PA. The intrahepatic recognition site(s) for t-PA were determined by subfractionation of the liver in parenchymal, endothelial, and Kupffer cells. It can be calculated that parenchymal cells are responsible for 54.5% of the interaction of t-PA with the liver, endothelial cells for 39.5%, and Kupffer cells for only 6%. The association of t-PA with parenchymal cells was not mediated by a carbohydrate-specific receptor and could only be inhibited by an excess of unlabeled t-PA, indicating involvement of a specific t-PA recognition site. The association of t-PA with endothelial cells could be inhibited 80% by the mannose-terminated glycoprotein ovalbumin, suggesting that the mannose receptor plays a major role in the recognition of t-PA by endothelial liver cells. An excess of unlabeled t-PA inhibited the association of 125I-t-PA to endothelial liver cells 95%, indicating that an additional specific t-PA recognition site may be responsible for 15% of the high affinity interaction of t-PA with this liver cell type. It is concluded that the uptake of t-PA by the liver is mainly mediated by two recognition systems: a specific t-PA site on parenchymal cells and the mannose receptor on endothelial liver cells. It is suggested that for the development of strategies to prolong the half-life of t-PA in the blood, the presence of both types of recognition systems has to be taken into account.

  9. An unusual presentation of gastric mucosa-associated lymphoid tissue (MALT)-type lymphoma

    PubMed Central

    Shrestha, Bikram; Kim, Bernard; Huffstetler, Alison

    2016-01-01

    Mucosa-associated lymphoid tissue (MALT)-type lymphoma is a relatively rare disease; nevertheless, it is the third most common lymphoma type, accounting for 5–7% of all non-Hodgkin lymphomas. Case series and retrospective analysis published in the literature have suggested that extra gastrointestinal (GI) MALT-type lymphoma can occur simultaneously with MALT-type lymphoma involving the GI tract. We report the case of a healthy, 64-year-old Caucasian male who presented with progressive fatigue, non-productive cough, and worsening exertional shortness of breath for 3 months who was subsequently diagnosed with gastric extra-nodal marginal zone B-cell lymphoma or MALToma with simultaneous metastasis to the lung (bronchi) based on biopsy reports. Case presentation A 64-year-old Caucasian male presented to the emergency room complaining of progressive fatigue for 3 months which had progressed to the point of hindering his usual activities of daily living (ADL). He had recently visited his primary care provider for evaluation of a non-productive cough and exertional shortness of breath. A chest radiography obtained at the time showed bilateral infiltrates. He was then treated for atypical pneumonia but his symptoms unfortunately did not improve. Initial investigations in the emergency room revealed severe anemia and a positive stool guaiac test. Imaging showed bilateral pulmonary infiltrates and an irregular gastric mass. Gastric and transbronchial biopsies were suggestive of extra-nodal marginal zone B-cell lymphoma with simultaneous metastasis to the bronchi. He was treated symptomatically with transfusion of packed red blood cells (PRBC) and intravenous iron followed by radiotherapy. Helicobacter pylori infection was ruled out eliminating the possibility of treating him with eradication therapy. Conclusion Although the stomach is the most common and most extensively studied site of involvement of MALT lymphomas, they can also emerge in many other locations. MALT

  10. Evaluation of transfection efficiency in skeletal muscle using nano/microbubbles and ultrasound.

    PubMed

    Kodama, Tetsuya; Aoi, Atsuko; Watanabe, Yukiko; Horie, Sachiko; Kodama, Mizuho; Li, Li; Chen, Rui; Teramoto, Noriyoshi; Morikawa, Hidehiro; Mori, Shiro; Fukumoto, Manabu

    2010-07-01

    Recent studies have revealed that ultrasound contrast agents with low-intensity ultrasound, namely, sonoporation, can noninvasively deliver therapeutic molecules into target sites. However, the efficiency of molecular delivery is relatively low and the methodology requires optimization. Here, we investigated three types of nano/microbubbles (NMBs)-human albumin shell bubbles, lipid bubbles and acoustic liposomes-to evaluate the efficiency of gene expression in skeletal muscle as a function of their physicochemical properties and the number of bubbles in solution. We found that acoustic liposomes showed the highest transfection and gene expression efficiency among the three types of NMBs under ultrasound-optimized conditions. Liposome transfection efficiency increased with bubble volume concentration; however, neither bubble volume concentration nor their physicochemical properties were related to the tissue damage detected in the skeletal muscle, which was primarily caused by needle injection.

  11. Focused Ultrasound and Lithotripsy.

    PubMed

    Ikeda, Teiichiro; Yoshizawa, Shin; Koizumi, Norihiro; Mitsuishi, Mamoru; Matsumoto, Yoichiro

    2016-01-01

    Shock wave lithotripsy has generally been a first choice for kidney stone removal. The shock wave lithotripter uses an order of microsecond pulse durations and up to a 100 MPa pressure spike triggered at approximately 0.5-2 Hz to fragment kidney stones through mechanical mechanisms. One important mechanism is cavitation. We proposed an alternative type of lithotripsy method that maximizes cavitation activity to disintegrate kidney stones using high-intensity focused ultrasound (HIFU). Here we outline the method according to the previously published literature (Matsumoto et al., Dynamics of bubble cloud in focused ultrasound. Proceedings of the second international symposium on therapeutic ultrasound, pp 290-299, 2002; Ikeda et al., Ultrasound Med Biol 32:1383-1397, 2006; Yoshizawa et al., Med Biol Eng Comput 47:851-860, 2009; Koizumi et al., A control framework for the non-invasive ultrasound the ragnostic system. Proceedings of 2009 IEEE/RSJ International Conference on Intelligent Robotics and Systems (IROS), pp 4511-4516, 2009; Koizumi et al., IEEE Trans Robot 25:522-538, 2009). Cavitation activity is highly unpredictable; thus, a precise control system is needed. The proposed method comprises three steps of control in kidney stone treatment. The first step is control of localized high pressure fluctuation on the stone. The second step is monitoring of cavitation activity and giving feedback on the optimized ultrasound conditions. The third step is stone tracking and precise ultrasound focusing on the stone. For the high pressure control we designed a two-frequency wave (cavitation control (C-C) waveform); a high frequency ultrasound pulse (1-4 MHz) to create a cavitation cloud, and a low frequency trailing pulse (0.5 MHz) following the high frequency pulse to force the cloud into collapse. High speed photography showed cavitation collapse on a kidney stone and shock wave emission from the cloud. We also conducted in-vitro erosion tests of model and natural

  12. Focused Ultrasound and Lithotripsy.

    PubMed

    Ikeda, Teiichiro; Yoshizawa, Shin; Koizumi, Norihiro; Mitsuishi, Mamoru; Matsumoto, Yoichiro

    2016-01-01

    Shock wave lithotripsy has generally been a first choice for kidney stone removal. The shock wave lithotripter uses an order of microsecond pulse durations and up to a 100 MPa pressure spike triggered at approximately 0.5-2 Hz to fragment kidney stones through mechanical mechanisms. One important mechanism is cavitation. We proposed an alternative type of lithotripsy method that maximizes cavitation activity to disintegrate kidney stones using high-intensity focused ultrasound (HIFU). Here we outline the method according to the previously published literature (Matsumoto et al., Dynamics of bubble cloud in focused ultrasound. Proceedings of the second international symposium on therapeutic ultrasound, pp 290-299, 2002; Ikeda et al., Ultrasound Med Biol 32:1383-1397, 2006; Yoshizawa et al., Med Biol Eng Comput 47:851-860, 2009; Koizumi et al., A control framework for the non-invasive ultrasound the ragnostic system. Proceedings of 2009 IEEE/RSJ International Conference on Intelligent Robotics and Systems (IROS), pp 4511-4516, 2009; Koizumi et al., IEEE Trans Robot 25:522-538, 2009). Cavitation activity is highly unpredictable; thus, a precise control system is needed. The proposed method comprises three steps of control in kidney stone treatment. The first step is control of localized high pressure fluctuation on the stone. The second step is monitoring of cavitation activity and giving feedback on the optimized ultrasound conditions. The third step is stone tracking and precise ultrasound focusing on the stone. For the high pressure control we designed a two-frequency wave (cavitation control (C-C) waveform); a high frequency ultrasound pulse (1-4 MHz) to create a cavitation cloud, and a low frequency trailing pulse (0.5 MHz) following the high frequency pulse to force the cloud into collapse. High speed photography showed cavitation collapse on a kidney stone and shock wave emission from the cloud. We also conducted in-vitro erosion tests of model and natural

  13. Early intracardiac thrombosis in preterm infants and thrombolysis with recombinant tissue type plasminogen activator

    PubMed Central

    Ferrari, F; Vagnarelli, F; Gargano, G; Roversi, M; Biagioni, O; Ranzi, A; Cavazzuti, G

    2001-01-01

    OBJECTIVES—To determine the incidence of catheter related thrombosis and to test the efficacy of recombinant tissue type plasminogen activator (rt-PA) in preterm infants.
STUDY DESIGN—From January 1995 to December 1998, echocardiography was performed in the first few days of life in 76 very low birthweight (⩽ 1500 g) infants out of a total of 147 having an umbilical catheter placed. When intracardiac thrombosis was diagnosed, rt-PA infusion was performed.
RESULTS—Four infants (5%) developed an intracardiac thrombosis during the first few days of life. In three of them, rt-PA at a dose of 0.4-0.5 mg/kg in a 20-30 minute bolus led to dissolution of the clot. One patient received a three hour infusion after the bolus, at a dose of 0.1 mg/kg/h, with resolution of the thrombus. No systemic effects were observed after rt-PA infusion.
CONCLUSIONS—Early thrombosis may occur as a complication of umbilical catheterisation in preterm infants; early echocardiographic detection of this disorder allows complete, safe, and rapid lysis with rt-PA.

 PMID:11420328

  14. Stage IV intramucosal gastric marginal zone B cell lymphoma of mucosa-associated lymphoid tissue type.

    PubMed

    Ohtaka, Masahiko; Sato, Tadashi; Kobayashi, Shouji; Sueki, Ryouta; Yamaguchi, Tatsuya; Uetake, Tomoyoshi; Ohtsuka, Hiroyuki; Iwao, Noriaki; Kirito, Keita; Enomoto, Nobuyuki

    2013-04-01

    A 45-year-old woman with no symptoms underwent upper gastrointestinal endoscopy. A discolored area was noted at the greater curvature of the gastric upper body. Endoscopic ultrasonography demonstrated thickening of the second sonographic layer indicating that the depth of invasion was confined to the mucosa. A urea breath test and anti-Helicobacter pylori antibody test were negative. A computed tomography scan showed a consolidation at the right lung. Gastric biopsy and transbronchial lung biopsy (TBLB) demonstrated a monotonous proliferation of atypical small lymphocytes. A diagnosis of gastric marginal zone B cell lymphoma of mucosa-associated lymphoid tissue type (MALT lymphoma) was made. The clinical stage was stage IV. A genetic analysis showed rearrangement of the joining region of the immunoglobulin heavy chain gene and identical clones in both lesions. An API2-MALT1 fusion gene was detected in the gastric lesion. After H. pylori eradication treatment, combination treatment with rituximab plus CHOP (R-CHOP) was performed; 6 months later an endoscopy revealed complete disappearance of the lesion. Multiple gastric biopsies showed no infiltrating atypical lymphocytes. Similarly, the lesion in the lung showed complete remission (CR) on CT and TBLB. This report shows that a gastric MALT lymphoma located in the mucosa and disseminated to the lung maintained CR by R-CHOP. PMID:26181449

  15. Systemic Low-Frequency Oscillations in BOLD Signal Vary with Tissue Type

    PubMed Central

    Tong, Yunjie; Hocke, Lia M.; Lindsey, Kimberly P.; Erdoğan, Sinem B.; Vitaliano, Gordana; Caine, Carolyn E.; Frederick, Blaise deB.

    2016-01-01

    Blood-oxygen-level dependent (BOLD) signals are widely used in functional magnetic resonance imaging (fMRI) as a proxy measure of brain activation. However, because these signals are blood-related, they are also influenced by other physiological processes. This is especially true in resting state fMRI, during which no experimental stimulation occurs. Previous studies have found that the amplitude of resting state BOLD is closely related to regional vascular density. In this study, we investigated how some of the temporal fluctuations of the BOLD signal also possibly relate to regional vascular density. We began by identifying the blood-bound systemic low-frequency oscillation (sLFO). We then assessed the distribution of all voxels based on their correlations with this sLFO. We found that sLFO signals are widely present in resting state BOLD signals and that the proportion of these sLFOs in each voxel correlates with different tissue types, which vary significantly in underlying vascular density. These results deepen our understanding of the BOLD signal and suggest new imaging biomarkers based on fMRI data, such as amplitude of low-frequency fluctuation (ALFF) and sLFO, a combination of both, for assessing vascular density. PMID:27445680

  16. Systemic Low-Frequency Oscillations in BOLD Signal Vary with Tissue Type.

    PubMed

    Tong, Yunjie; Hocke, Lia M; Lindsey, Kimberly P; Erdoğan, Sinem B; Vitaliano, Gordana; Caine, Carolyn E; Frederick, Blaise deB

    2016-01-01

    Blood-oxygen-level dependent (BOLD) signals are widely used in functional magnetic resonance imaging (fMRI) as a proxy measure of brain activation. However, because these signals are blood-related, they are also influenced by other physiological processes. This is especially true in resting state fMRI, during which no experimental stimulation occurs. Previous studies have found that the amplitude of resting state BOLD is closely related to regional vascular density. In this study, we investigated how some of the temporal fluctuations of the BOLD signal also possibly relate to regional vascular density. We began by identifying the blood-bound systemic low-frequency oscillation (sLFO). We then assessed the distribution of all voxels based on their correlations with this sLFO. We found that sLFO signals are widely present in resting state BOLD signals and that the proportion of these sLFOs in each voxel correlates with different tissue types, which vary significantly in underlying vascular density. These results deepen our understanding of the BOLD signal and suggest new imaging biomarkers based on fMRI data, such as amplitude of low-frequency fluctuation (ALFF) and sLFO, a combination of both, for assessing vascular density.

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

    PubMed

    de Jesus, L A; Carvalho, S D; Ribeiro, M O; Schneider, M; Kim, S W; Harney, J W; Larsen, P R; Bianco, A C

    2001-11-01

    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 O(2) 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 beta (TR beta) while the normal sympathetic response of brown adipocytes requires TR alpha. Intracellularly generated T3 may be required to saturate the TR alpha, which has an approximately fourfold lower T3-binding affinity than does TR beta. Thus, D2 is an essential component in the thyroid-sympathetic synergism required for thermal homeostasis in small mammals. PMID:11696583

  18. Successful Emergency Carotid Endarterectomy after Thrombolysis with Intravenous Recombinant Tissue-Type Plasminogen Activator.

    PubMed

    Yamamoto, Yoko; Okazaki, Toshiyuki; Yoda, Keishi; Tada, Yoshiteru; Nagahiro, Shinji

    2016-01-01

    Acute internal carotid artery (ICA) occlusion may result in severe disability or death. Revascularization by carotid artery stenting after treatment with intravenous (iv) recombinant tissue-type plasminogen activator (rt-PA) has been documented. However, there are few reports on emergency carotid endarterectomy (CEA) within 24 hours after the iv administration of rt-PA. We treated a 58-year-old man with right ICA occlusion with iv rt-PA. Although partial recanalization of the ICA was obtained, severe stenosis at the origin of the ICA persisted and he developed fluctuating neurological deficits. To prevent progressive stroke he underwent CEA 10.5 hours after rt-PA treatment. Thereafter his blood pressure was strictly controlled under sedation. During and after CEA there were no hemorrhagic complications. Our findings suggest that emergency CEA may be an option to address symptomatic severe residual ICA stenosis even after iv rt-PA therapy delivered in the acute stage. J. Med. Invest. 63: 300-304, August, 2016. PMID:27644576

  19. Tissue-type plasminogen activator is a neuroprotectant in the central nervous system

    PubMed Central

    Yepes, Manuel

    2015-01-01

    Tissue-type plasminogen activator (tPA) is a serine proteinase found not only in the intravascular space but also in a well-defined sub-set of neurons in the brain. tPA is rapidly released from neurons after either exposure to hypoxia or hypoglycemia in vitro, or the induction of cerebral ischemia in vivo. It has been proposed that tPA has a neurotoxic effect in the ischemic brain. However, recent evidence indicate that once released into the synaptic cleft tPA activates specific cell signaling pathways that promote the detection and adaptation to metabolic stress. More specifically, the non-proteolytic interaction of tPA with N-methyl-D-aspartate receptors (NMDARs) and a member of the low-density lipoprotein receptor (LDLR) family in dendritic spines activates the mammalian target of rapamycin (mTOR) pathway that adapts cellular processes to the availability of energy and metabolic resources. TPA-induced mTOR activation in neurons leads to hypoxia-inducible factor 1α (HIF-1α) accumulation, HIF-1α-induced expression and membrane recruitment of the neuronal transporter of glucose GLUT3, and GLUT3-mediated uptake of glucose. These and other data discussed in this Review suggest that the postulated neurotoxic effect of tPA needs to be reconsidered and instead indicate the emergence of a new paradigm: that tPA is an endogenous neuroprotectant in the central nervous system (CNS). PMID:26347605

  20. 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.

  1. Ultrasonic detection of photothermal interaction of lasers with tissue using a pulsed Doppler system

    NASA Astrophysics Data System (ADS)

    Ying, Hao; Azeemi, Aamer; Hartley, Craig J.; Motamedi, Massoud; Bell, Brent A.; Rastegar, Sohi; Sheppard, L. C.

    1995-05-01

    Thermal therapy using various heating sources such as lasers or microwaves to destroy benign and malignant lesions has recently gained widespread acceptance. However, the accurate prediction of thermal damage in tissue according to theoretical or computer modeling is difficult and unreliable due to target variability with respect to physical properties, geometry, and blood perfusion. Thus, one of the major obstacles to application of thermal therapies has been the lack of a noninvasive, real-time method that could determine the extent and geometry of treated tissue. To evaluate the effects of laser heating on tissue, we have developed an analog-digital hybrid Doppler ultrasound system to measure the phase and amplitude of ultrasonic echoes returned from the heated tissue. The system consists of an eight-gate pulsed Doppler detector, a 16-channel 12-bit A/D converter, and a signal analysis and visualization software package. In vitro studies using canine liver showed two distinct types of modulation of the echoes along the ultrasound beam path during laser irradiation using an 810 nm diode laser. Type 1 signals showed a small and slow variation in amplitude and phase, and were attributed to tissue coagulation. Type 1 signals showed a small and slow variation in amplitude and phase, and were attributed to tissue coagulation. Type 2 signals showed large and rapid variations in amplitude and phase which usually appeared after tissue surface explosion and were indicative of tissue ablation. We hypothesize that the observed phase changes in type 1 signals are due to thermal effects within the tissue consistent with tissue expansion and contraction while the phase changes in type 2 signals are likely due to formation and motion of gas bubbles in the tissue. A further development of the Doppler ultrasound technique could lead to the generation of feedback information needed for monitoring and automatic control of thermal treatment using various heating modalities such as

  2. Endobronchial ultrasound elastography

    PubMed Central

    Dietrich, Christoph F.; Jenssen, Christian; Herth, Felix J. F.

    2016-01-01

    Elastographic techniques have recently become available as advanced diagnostic tools for tissue characterization. Strain elastography is a real-time technique used with transcutaneous ultrasound (US) and endoscopic US. Convincing evidence is available demonstrating a significant value of strain elastography for the discrimination of benign and malignant lymph nodes (LNs). This paper reviews preliminary data demonstrating the feasibility of performing real-time elastography during endobronchial US (EBUS) and a potential application of this technique for selection of LNs for EBUS-guided transbronchial needle aspiration in patients with lung cancer and extrathoracic malignancies. PMID:27503154

  3. 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.

  4. Attenuation mapping for monitoring thermal therapy using ultrasound transmission imaging.

    PubMed

    Parmar, N; Kolios, M C

    2004-01-01

    The use of an ultrasound (US) transmission imaging system to monitor attenuation changes during tissue heating was investigated. This work presents preliminary results of images obtained from an acoustic camera before, during and after heating tissue phantoms using a heated needle. Two types of tissue-mimicking phantoms were used, agar and polyacrylamide-based. Regions of interests were chosen in images obtained from the real-time imaging system, and the pixel intensity values before, during and after heating were compared. In both phantoms, a decrease in image intensities was observed during heating, indicating an increase in tissue attenuation. Additionally, an irreversible change in image intensity was observed in regions close to the heat source. The reversibility of the intensity change was shown to be a function of the distance from the heating needle to the selected region. Initial results indicate that US transmission imaging can be used to monitor thermal therapy. PMID:17271937

  5. 5α-Reductase Type 3 Expression in Human Benign and Malignant Tissues: A Comparative Analysis During Prostate Cancer Progression

    PubMed Central

    Godoy, Alejandro; Kawinski, Elzbieta; Li, Yun; Oka, Daizo; Alexiev, Borislav; Azzouni, Faris; Titus, Mark A.; Mohler, James L.

    2015-01-01

    BACKGROUND A third isozyme of human 5α-steroid reductase, 5α-reductase-3, was identified in prostate tissue at the mRNA level. However, the levels of 5α-reductase-3 protein expression and its cellular localization in human tissues remain unknown. METHODS A specific monoclonal antibody was developed, validated, and used to characterize for the first time the expression of 5α-reductase-3 protein in 18 benign and 26 malignant human tissue types using immunostaining analyses. RESULTS AND CONCLUSIONS In benign tissues, 5α-reductase-3 immunostaining was high in conventional androgen-regulated human tissues, such as skeletal muscle and prostate. However, high levels of expression also were observed in non-conventional androgen-regulated tissues, which suggest either multiples target tissues for androgens or different functions of 5α-reductase-3 among human tissues. In malignant tissues, 5α-reductase-3 immunostaining was ubiquitous but particularly over-expressed in some cancers compared to their benign counterparts, which suggests a potential role for 5α-reductase-3 as a biomarker of malignancy. In benign prostate, 5α-reductase-3 immunostaining was localized to basal epithelial cells, with no immunostaining observed in secretory/luminal epithelial cells. In high-grade prostatic intraepithelial neoplasia (HGPIN), 5α-reductase-3 immunostaining was localized in both basal epithelial cells and neoplastic epithelial cells characteristic of HGPIN. In androgen-stimulated and castration-recurrent prostate cancer (CaP), 5α-reductase-3 immunostaining was present in most epithelial cells and at similar levels, and at levels higher than observed in benign prostate. Analyses of expression and functionality of 5α-reductase-3 in human tissues may prove useful for development of treatment for benign prostatic enlargement and prevention and treatment of CaP. PMID:21557268

  6. Herpes Simplex Virus Type 2 Seroprevalence and Ultrasound-Diagnosed Uterine Fibroids in a Large Population of Young African-American Women.

    PubMed

    Moore, Kristen R; Smith, Jennifer S; Cole, Stephen R; Schoenbach, Victor J; Schlusser, Katherine; Gaydos, Charlotte A; Baird, Donna D

    2016-06-01

    For decades reproductive tract infections (RTIs) have been hypothesized to play a role in uterine fibroid development. The few previous studies conducted used self-reported history of RTIs and had inconsistent findings. We investigated this hypothesis further using serological analysis, an immunological measure of past exposure. We focused on herpes simplex virus type 2 (HSV-2) because prior published data have suggested a possible association with fibroids, and serology for HSV-2 is much more sensitive than self-report. We used cross-sectional enrollment data from African-American women enrolled in a prospective study of fibroid incidence and growth (recruited 2010-2012) in the Detroit, Michigan, area. The women were aged 23-34 years and were screened for fibroids using a standardized ultrasound examination at their enrollment. Age- and multivariable-adjusted logistic regression models were used to estimate odds ratios. Of 1,696 participants, 1,658 had blood samples and HSV-2 serology results; 22% of participants with serology results had fibroids. There was no significant association between HSV-2 seropositivity and the presence of fibroids (multivariable-adjusted odds ratio = 0.94, 95% confidence interval: 0.73, 1.20), nor were there any associations with size of the largest fibroid, number of fibroids, or total fibroid volume. Our data provide no evidence for an influence of HSV-2 exposure on fibroid risk in young African-American women. Further study of other serologically measured RTIs is warranted. PMID:27188945

  7. Herpes Simplex Virus Type 2 Seroprevalence and Ultrasound-Diagnosed Uterine Fibroids in a Large Population of Young African-American Women.

    PubMed

    Moore, Kristen R; Smith, Jennifer S; Cole, Stephen R; Schoenbach, Victor J; Schlusser, Katherine; Gaydos, Charlotte A; Baird, Donna D

    2016-06-01

    For decades reproductive tract infections (RTIs) have been hypothesized to play a role in uterine fibroid development. The few previous studies conducted used self-reported history of RTIs and had inconsistent findings. We investigated this hypothesis further using serological analysis, an immunological measure of past exposure. We focused on herpes simplex virus type 2 (HSV-2) because prior published data have suggested a possible association with fibroids, and serology for HSV-2 is much more sensitive than self-report. We used cross-sectional enrollment data from African-American women enrolled in a prospective study of fibroid incidence and growth (recruited 2010-2012) in the Detroit, Michigan, area. The women were aged 23-34 years and were screened for fibroids using a standardized ultrasound examination at their enrollment. Age- and multivariable-adjusted logistic regression models were used to estimate odds ratios. Of 1,696 participants, 1,658 had blood samples and HSV-2 serology results; 22% of participants with serology results had fibroids. There was no significant association between HSV-2 seropositivity and the presence of fibroids (multivariable-adjusted odds ratio = 0.94, 95% confidence interval: 0.73, 1.20), nor were there any associations with size of the largest fibroid, number of fibroids, or total fibroid volume. Our data provide no evidence for an influence of HSV-2 exposure on fibroid risk in young African-American women. Further study of other serologically measured RTIs is warranted.

  8. Differential localization of type I and type III procollagen messenger ribonucleic acids in inflamed periodontal and periapical connective tissues by in situ hybridization.

    PubMed

    Larjava, H; Sandberg, M; Happonen, R P; Vuorio, E

    1990-01-01

    Inflammatory lesions of periodontal and periapical connective tissue were studied by in situ hybridization to detect cells responsible for type I and type III collagen production. Formalin-fixed and paraffin-embedded tissue specimens from patients with oral lesions of various stages of inflammation were hybridized with cDNA probes specific for human pro alpha 1(I) and pro alpha 1(III) collagen mRNAs, and with bacteriophage lambda DNA as a control probe. This technique permitted us to localize fibroblasts active in type I collagen synthesis in the vicinity of inflammatory infiltrates in all the samples studied. Cells containing high levels of type III collagen mRNA were seen in early abscess formation and they were particularly abundant in pyogenic granuloma and irritation fibroma. Type I collagen mRNA was prominent in gingival fibrosis. In the infrabony lesions with active inflammatory infiltrations the production of collagen was confined mostly to the periphery of the lesions. These findings give indirect evidence that cytokines liberated during the early stages of the inflammatory process stimulate expression of the type III collagen gene by fibroblasts. In chronic lesions a gradual switch from type III to type I collagen gene expression occurs. The change in collagen types appears to underlie the observed isolation of the inflammation by a collagenous capsule. In all the samples studied fibroblasts exhibited marked variation in their levels of procollagen mRNAs, supporting previous views about their heterogeneity in connective tissues. The approach presented here offers new possibilities to study cellular interactions and metabolic activities in inflammatory lesions. PMID:2296161

  9. Venous Ultrasound (Extremities)

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  10. Metabolic inflexibility of white and brown adipose tissues in abnormal fatty acid partitioning of type 2 diabetes.

    PubMed

    Grenier-Larouche, T; Labbé, S M; Noll, C; Richard, D; Carpentier, A C

    2012-12-01

    Type 2 diabetes (T2D) is characterized by a general dysregulation of postprandial energy substrate partitioning. Although classically described in regard to glucose metabolism, it is now evident that metabolic inflexibility of plasma lipid fluxes is also present in T2D. The organ that is most importantly involved in the latter metabolic defect is the white adipose tissue (WAT). Both catecholamine-induced nonesterified fatty acid mobilization and insulin-stimulated storage of meal fatty acids are impaired in many WAT depots of insulin-resistant individuals. Novel molecular imaging techniques now demonstrate that these defects are linked to increased dietary fatty acid fluxes toward lean organs and myocardial dysfunction in humans. Recent findings also demonstrate functional abnormalities of brown adipose tissues in T2D, thus suggesting that a generalized adipose tissue dysregulation of energy storage and dissipation may be at play in the development of lean tissue energy overload and lipotoxicity. PMID:27152152