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Sample records for doppler tissue imaging

  1. Tissue Doppler imaging reproducibility during exercise.

    Science.gov (United States)

    Bougault, V; Nottin, S; Noltin, S; Doucende, G; Obert, P

    2008-05-01

    Tissue Doppler imaging (TDI) is an echocardiographic technique used during exercising to improve the accuracy of a cardiovascular diagnostic. The validity of TDI requires its reproducibility, which has never been challenged during moderate to maximal intensity exercising. The present study was specifically designed to assess the transmitral Doppler and pulsed TDI reproducibility in 19 healthy men, who had undergone two identical semi-supine maximal exercise tests on a cycle ergometer. Systolic (S') and diastolic (E') tissue velocities at the septal and lateral walls as well as early transmitral velocities (E) were assessed during exercise up to maximal effort. The data were compared between the two tests at 40 %, 60 %, 80 % and 100 % of maximal aerobic power. Despite upper body movements and hyperventilation, good quality echocardiographic images were obtained in each case. Regardless of exercise intensity, no differences were noticed between the two tests for all measurements. The variation coefficients for Doppler variables ranged from 3 % to 9 % over the transition from rest to maximal exercise. The random measurement error was, on average, 5.8 cm/s for E' and 4.4 cm/s for S'. Overall, the reproducibility of TDI was acceptable. Tissue Doppler imaging can be used to accurately evaluate LV diastolic and/or systolic function for this range of exercise intensity.

  2. Cardiac Time Intervals by Tissue Doppler Imaging M-Mode

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Mogelvang, Rasmus; de Knegt, Martina Chantal;

    2016-01-01

    PURPOSE: To define normal values of the cardiac time intervals obtained by tissue Doppler imaging (TDI) M-mode through the mitral valve (MV). Furthermore, to evaluate the association of the myocardial performance index (MPI) obtained by TDI M-mode (MPITDI) and the conventional method of obtaining...... MPI (MPIConv), with established echocardiographic and invasive measures of systolic and diastolic function. METHODS: In a large community based population study (n = 974), where all are free of any cardiovascular disease and cardiovascular risk factors, cardiac time intervals, including isovolumic...... the MPITDI and MPIConv measured. RESULTS: IVRT, IVRT/ET and MPI all increased significantly with increasing age in both genders (pcardiac function. MPITDI...

  3. Hypercholesterolemia and Myocardial function evaluated via Tissue Doppler Imaging

    Directory of Open Access Journals (Sweden)

    Kotaru Pavan

    2009-11-01

    Full Text Available Abstract Objective To establish a link between hypercholesterolemia and myocardial dysfunction. Background Heart failure is a complex disease involving changes in systolic and diastolic function. Newer echocardiographic imaging modalities may be able to detect discreet changes in myocardial function associated with hypercholesterolemia. Therefore we sought to establish a link between hypercholesterolemia and myocardial dysfunction with tissue Doppler imaging (TDI. Methods Twenty-seven rabbits were studied: 7 were fed normal chow (group 1 and 20 a high cholesterol diet (10 with ezetimibe, 1 mg/kg/day; group 2 and 10 without, group 3. Echocardiographic images were obtained under general anesthesia. Serum cholesterol levels were obtained at baseline, 3 and 6 months and myocardial cholesterol levels measured following euthanasia. Results Doppler measurements, including E/A, E'/A' and S' were significantly lower in group 3 compared to both groups 1 and 2 but no significant differences were noted in chamber sizes or ejection fraction among the groups. Average serum cholesterol was higher in group 3 compared to groups 1 and 2 respectively (495 ± 305 mg/dl vs. 114 ± 95 mg/dl and 87 ± 37 mg/dl; p 2 = 0.17 p = 0.04, r2 = 0.37 p = 0.001 and r2 = 0.24 p = 0.01. Conclusion Cholesterol load in the serum and myocardium was significantly associated with decreased systolic and diastolic function by TDI. Moreover, lipid lowering was protective.

  4. Cardiac conductive system excitation maps using intracardiac tissue Doppler imaging

    Institute of Scientific and Technical Information of China (English)

    尹立雪; 郑昌琼; 蔡力; 郑翊; 李春梅; 邓燕; 罗芸; 李德玉; 赵树魁

    2003-01-01

    Objective To precisely visualize cardiac anatomic structures and simultaneously depict ele ctro-mechanical events for the purpose of precise underblood intervention. Methods Intracardiac high-resolution tissue Doppler imaging was used to map realt imemyocardial contractions in response to electrical activation within the anat omic structure of the cardiac conductive system using a canine open-chest model . Results The detailed inner anatomic structure of the cardiac conductive system at differ entsites (i.e., sino-atrial, atrial wall, atrial-ventricular node and ventr icular wall) with the inside onset and propagation of myocardial velocity and ac celeration induced by electrical activation was clearly visualized and quan titatively evaluated.Conclusion The simultaneous single modality visualization of the anatomy, function and electrical events of the cardiac conductive system will foster target pacing and pre cision ablation.

  5. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H.; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue ...

  6. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been......Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue...... vectors. This review briefly introduces the principles behind colour Doppler imaging and describes some clinical applications. It then describes the basic components of conventional colour Doppler systems and the methods used to derive velocity information from the ultrasound signal. Next, a number of new...

  7. Doppler imaging

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    Piskunov, N [Department of Physics and Astronomy, Uppsala University, Box 515, S-75120 Uppsala (Sweden)], E-mail: piskunov@fysast.uu.se

    2008-12-15

    In this paper, I present a short review of the history and modern status of Doppler imaging techniques, highlighting their dependence on the knowledge of the fundamental stellar parameters, the quality of stellar atmospheric models and the accuracy of spectral synthesis.

  8. Heart wall motion analysis by dynamic 3D strain rate imaging from tissue Doppler echocardiography

    Science.gov (United States)

    Hastenteufel, Mark; Wolf, Ivo; de Simone, Raffaele; Mottl-Link, Sibylle; Meinzer, Hans-Peter

    2002-04-01

    The knowledge about the complex three-dimensional (3D) heart wall motion pattern, particular in the left ventricle, provides valuable information about potential malfunctions, e.g., myocardial ischemia. Nowadays, echocardiography (cardiac ultrasound) is the predominant technique for evaluation of cardiac function. Beside morphology, tissue velocities can be obtained by Doppler techniques (tissue Doppler imaging, TDI). Strain rate imaging (SRI) is a new technique to diagnose heart vitality. It provides information about the contraction ability of the myocardium. Two-dimensional color Doppler echocardiography is still the most important clinical method for estimation of morphology and function. Two-dimensional methods leads to a lack of information due to the three-dimensional overall nature of the heart movement. Due to this complex three-dimensional motion pattern of the heart, the knowledge about velocity and strain rate distribution over the whole ventricle can provide more valuable diagnostic information about motion disorders. For the assessment of intracardiac blood flow three-dimensional color Doppler has already shown its clinical utility. We have developed methods to produce strain rate images by means of 3D tissue Doppler echocardiography. The tissue Doppler and strain rate images can be visualized and quantified by different methods. The methods are integrated into an interactively usable software environment, making them available in clinical everyday life. Our software provides the physician with a valuable tool for diagnosis of heart wall motion.

  9. Assessment of cardiac functions using tissue Doppler imaging in children with familial Mediterranean fever.

    Science.gov (United States)

    Ozdemir, Osman; Agras, Pinar Isik; Aydin, Yusuf; Abaci, Ayhan; Hizli, Samil; Akkus, Halil Ibrahim; Fidan, Cihan

    2012-04-01

    Familial Mediterranean fever may carry a potential for cardiovascular disorders because of sustained inflammation during its course; however, there has been a limited number of studies investigating the cardiac functions in children. The aim of this study was to assess both ventricular diastolic functions using conventional echocardiography and tissue Doppler imaging in children with familial Mediterranean fever. The study population included 25 patients with familial Mediterranean fever - mean age was 11.8 plus or minus 5.30 years - and 23 healthy patients as controls - mean age was 9.88 plus or minus 3.69 years. Both ventricular functions were measured using echocardiography comprising standard M-mode and conventional Doppler and tissue Doppler imaging during an attack-free period. The conventional echocardiographic parameters with myocardial performance index were in normal ranges and similar in patients with familial Mediterranean fever and controls, with a p-value more than 0.05. However, right ventricular diastolic dysfunction was observed in patients with familial Mediterranean fever documented by tissue Doppler imaging, with a p-value less than 0.05 for E't and A't wave ratio. Using tissue Doppler imaging, we have demonstrated that although left ventricular functions were comparable in the patients and healthy children, right ventricular diastolic function indices were impaired in patients with familial Mediterranean fever during childhood. Impaired right ventricular diastolic function may be an early manifestation of cardiac involvement in children with familial Mediterranean fever.

  10. Left ventricular function in professional football players evaluated by tissue Doppler imaging and strain imaging.

    Science.gov (United States)

    Tümüklü, Mustafa Murat; Etikan, Ilker; Cinar, Cahide Soydaş

    2008-01-01

    Long-term regular exercise is associated with physiologic and morphologic cardiac alterations. Tissue Doppler Imaging(TDI) and Strain Myocardial Imaging(SI) are new tools in the evaluation systolic and diastolic myocardial function. We sought to compare TDI and SI findings in professional football players and age adjusted sedentary controls to assess the effect of regular athletic training on myocardial function. Transthoracic echocardiography, M-mode, 2-D measurements, Doppler derived mitral-tricuspid annular velocities, reconstructed spectral pulsed wave tissue Doppler velocities, strain and strain rate imaging of seven different myocardial regions were obtained from 24 professional football players and age, sex and weight adjusted 20 controls. Age, body surface area, blood pressure and heart rate were comparable between 2 groups. Football players had significantly increased LV mass, mass index (due to both higher wall thickness and end-diastolic diameter), end-systolic and end-diastolic volume, left atrial diameter and decreased transmitral diastolic late velocity. In athletes TDI analysis showed significantly increased mitral annulus septal TDI peak early diastolic(e) velocity(0.22 +/- 0.04 vs. 0.19 +/- 0.04 m/s, P velocity (0.19 +/- 0.03 vs. 0.16 +/- 0.02 m/s, P football playing is associated with morphologic alteration in left ventricle and left atrium and improvement in left ventricle diastolic function which can be detected by TDI. Strain rate imaging may be a new tool to define subtle change in systolic left ventricular function in "athletes heart" which cannot be determined in standard echocardiographic parameters.

  11. Predicting Paroxysmal Atrial Fibrillation in Cerebrovascular Ischemia Using Tissue Doppler Imaging and Speckle Tracking Echocardiography

    DEFF Research Database (Denmark)

    Olsen, Flemming Javier; Jørgensen, Peter Godsk; Møgelvang, Rasmus

    2016-01-01

    , tissue Doppler imaging (TDI), and speckle tracking. TDI was performed to acquire myocardial peak velocities during systole/ventricular contraction (global s'), early diastole/ventricular filling (global e'), and late diastole/atrial contraction (global a'). Speckle tracking was performed for myocardial...

  12. Laser Doppler flowmetry imaging

    Science.gov (United States)

    Nilsson, Gert E.; Wardell, Karin

    1994-02-01

    A laser Doppler perfusion imager has been developed that makes possible mapping of tissue blood flow over surfaces with extensions up to about 12 cm X 12 cm. The He-Ne laser beam scans the tissue under study throughout 4096 measurement sites. A fraction of the backscattered and Doppler broadened light is detected by a photo diode positioned about 20 cm above the tissue surface. After processing, a signal that scales linearly with perfusion is stored in a computer and a color coded image of the spatial tissue perfusion is shown on a monitor. A full format scan is completed in about 4.5 minutes. Algorithms for calculating perfusion profiles and averages as well as substraction of one image from another, form an integral part of the system data analysis software. The perfusion images can also be exported to other software packages for further processing and analysis.

  13. Development of heart failure assessed by tissue Doppler imaging in hypertensive Dahl rats

    OpenAIRE

    宮田, 聖子||ミヤタ, セイコ||Miyata, Seiko; 山田, 亜紀||ヤマダ, アキ||Yamada, Aki||Iwami Yamada, Aki; 橋本, 克徳||ハシモト, カツノリ||Hashimoto, Katsunori; 黒木, 祥子||クロキ, ショウコ||Kuroki, Shoko; 岩本, 隆司||イワモト, タカシ||Iwamoto, Takashi; 野田, 明子||ノダ, アキコ||Noda, Akiko

    2014-01-01

    Objective: Tissue Doppler imaging (TDI) has been recognized as a useful tool to assess regional myocardial function. The purpose of this study was to evaluate the development of heart failure in hypertensive Dahl rats using echocardiography with TDI. Methods: Dahl salt-sensitive (DS) rats were placed on 8% NaCl diet from 7 weeks old. As an age-matched control, DS rats were consistently placed on normal diet. In these rats, echocardiography was performed successively. We evaluated interventric...

  14. ASSESSMENT OF DIASTOLIC FUNCTION IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY BY DOPPLER TISSUE IMAGING

    Institute of Scientific and Technical Information of China (English)

    Jing Li; Yan-ling Liu; Hao Wang; Xiu-zhang Lü; Hong-chang Yang; Fu-jian Duan; Zhen-hui Zhu

    2004-01-01

    Objective To determine the clinical application of pulsed Doppler tissue imaging in assessing the left ventricular diastolic function and in discriminating between normal subjects and patients with hypertrophic cardiomyopathy with various stages of diastolic dysfunction.Methods We measured the peak diastolic velocities of mitral annulus in 81 patients with hypertrophic cardiomyopathy with various stages of diastolic dysfunction and 50 normal volunteers by Doppler tissue imaging using the apical window at 2-chamber and long apical views, respectively. The myocardial velocities were determined with use of variance F statistical analysis.Results Early diastolic myocardial velocities ofmitral annulus were higher in normal subjects than in patients with hypertrophic cardiomyopathy with either delayed relaxation, pseudonormal filling, or restrictive filling. However, peak myocardial velocities of mitral annulus during atrial contraction were similar in normal subjects and patients with hypertrophic cardiomyopathy.Conclusion Doppler tissue imaging can directly reflect upon left diastolic ventricular function. Early phase of diastole was the best discriminator between control subjects and patients with hypertrophic cardiomyopathy.

  15. Biodynamic Doppler imaging of subcellular motion inside 3D living tissue culture and biopsies (Conference Presentation)

    Science.gov (United States)

    Nolte, David D.

    2016-03-01

    Biodynamic imaging is an emerging 3D optical imaging technology that probes up to 1 mm deep inside three-dimensional living tissue using short-coherence dynamic light scattering to measure the intracellular motions of cells inside their natural microenvironments. Biodynamic imaging is label-free and non-invasive. The information content of biodynamic imaging is captured through tissue dynamics spectroscopy that displays the changes in the Doppler signatures from intracellular constituents in response to applied compounds. The affected dynamic intracellular mechanisms include organelle transport, membrane undulations, cytoskeletal restructuring, strain at cellular adhesions, cytokinesis, mitosis, exo- and endo-cytosis among others. The development of 3D high-content assays such as biodynamic profiling can become a critical new tool for assessing efficacy of drugs and the suitability of specific types of tissue growth for drug discovery and development. The use of biodynamic profiling to predict clinical outcome of living biopsies to cancer therapeutics can be developed into a phenotypic companion diagnostic, as well as a new tool for therapy selection in personalized medicine. This invited talk will present an overview of the optical, physical and physiological processes involved in biodynamic imaging. Several different biodynamic imaging modalities include motility contrast imaging (MCI), tissue-dynamics spectroscopy (TDS) and tissue-dynamics imaging (TDI). A wide range of potential applications will be described that include process monitoring for 3D tissue culture, drug discovery and development, cancer therapy selection, embryo assessment for in-vitro fertilization and artificial reproductive technologies, among others.

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

    Science.gov (United States)

    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. Shear Wave Imaging of Breast Tissue by Color Doppler Shear Wave Elastography.

    Science.gov (United States)

    Yamakoshi, Yoshiki; Nakajima, Takahito; Kasahara, Toshihiro; Yamazaki, Mayuko; Koda, Ren; Sunaguchi, Naoki

    2017-02-01

    Shear wave elastography is a distinctive method to access the viscoelastic characteristic of the soft tissue that is difficult to obtain by other imaging modalities. This paper proposes a novel shear wave elastography [color Doppler shear wave imaging (CD SWI)] for breast tissue. Continuous shear wave is produced by a small lightweight actuator, which is attached to the tissue surface. Shear wave wavefront that propagates in tissue is reconstructed as a binary pattern that consists of zero and the maximum flow velocities on color flow image (CFI). Neither any modifications of the ultrasound color flow imaging instrument nor a high frame rate ultrasound imaging instrument is required to obtain the shear wave wavefront map. However, two conditions of shear wave displacement amplitude and shear wave frequency are needed to obtain the map. However, these conditions are not severe restrictions in breast imaging. This is because the minimum displacement amplitude is [Formula: see text] for an ultrasonic wave frequency of 12 MHz and the shear wave frequency is available from several frequencies suited for breast imaging. Fourier analysis along time axis suppresses clutter noise in CFI. A directional filter extracts shear wave, which propagates in the forward direction. Several maps, such as shear wave phase, velocity, and propagation maps, are reconstructed by CD SWI. The accuracy of shear wave velocity measurement is evaluated for homogeneous agar gel phantom by comparing with the acoustic radiation force impulse method. The experimental results for breast tissue are shown for a shear wave frequency of 296.6 Hz.

  18. Left ventricular dysfunction measured by tissue Doppler imaging and strain rate imaging in hypertensive adolescents

    Directory of Open Access Journals (Sweden)

    Hye Mi Ahn

    2010-01-01

    Full Text Available Purpose : Left ventricular (LV hypertrophy and impaired diastolic function may occur early in systemic hypertension. Diastolic dysfunction is associated with increased cardiovascular risk. Tissue Doppler imaging (TDI-derived tissue velocity and strain rate are new parameters for assessing diastolic dysfunction. The aim of this study is to determine whether TDI and strain rate imaging (SRI would improve the ability to recognize early impaired diastolic and systolic functions compared with conventional echocardiography in hypertensive adolescents. Methods : We included 38 hypertensive patients with systolic blood pressure above 140 mmHg or diastolic blood pressure above 90 mmHg. Ejection fraction and myocardial performance index (MPI were estimated by conventional echocardiography. Peak systolic myocardial velocity, early diastolic myocardial velocity (Em, and peak late diastolic myocardial velocity (Am were obtained by using TDI and SRI. Results : In the hypertensive group, interventricular septal thickness was significantly increased on M-mode echocardiography. Em/Am was significantly decreased at the mitral valve annulus. Among hypertensive subjects, the E strain rate at basal, mid, and apex was significantly decreased. Systolic strain was significantly decreased at the septum in the hypertensive group. Conclusion : Strain rate might be a useful new parameter for the quantification of both regional and global LV functions and could be used in long-term follow up in hypertensive patients. Early identification by SRI of subjects at risk for hypertensive and ventricular dysfunction may help to stratify risk and guide therapy. Further studies, including serial assessment of LV structure and function in a larger number of adolescents with hypertension, is necessary.

  19. Total average diastolic longitudinal displacement by colour tissue doppler imaging as an assessment of diastolic function

    DEFF Research Database (Denmark)

    de Knegt, Martina Chantal; Biering-Sørensen, Tor; Søgaard, Peter;

    2016-01-01

    BACKGROUND: The current method for a non-invasive assessment of diastolic dysfunction is complex with the use of algorithms of many different echocardiographic parameters. Total average diastolic longitudinal displacement (LD), determined by colour tissue Doppler imaging (TDI) via the measurement...... by TDI, and the degree of diastolic dysfunction, based on current guidelines. Of these 206 patients, 157 had cardiac anomalies that could potentially affect diastolic LD such as severe systolic heart failure (n = 45), LV hypertrophy (n = 49), left ventricular (LV) dilation (n = 30), and mitral...

  20. Cardiac time intervals by tissue Doppler imaging M-mode echocardiography

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor

    2016-01-01

    BACKGROUND: The preservation of normal cardiac time intervals is intimately related to normal cardiac physiology and function. In the ailing myocardium, the cardiac time intervals will change during disease progression. As left ventricular (LV) systolic function deteriorates, the time it takes...... of whether the LV is suffering from impaired systolic or diastolic function. A novel method of evaluating the cardiac time intervals has recently evolved. Using tissue Doppler imaging (TDI) M-mode through the mitral valve (MV) to estimate the cardiac time intervals may be an improved method reflecting global...

  1. Total average diastolic longitudinal displacement by colour tissue doppler imaging as an assessment of diastolic function

    DEFF Research Database (Denmark)

    de Knegt, Martina Chantal; Biering-Sørensen, Tor; Søgaard, Peter

    2016-01-01

    BACKGROUND: The current method for a non-invasive assessment of diastolic dysfunction is complex with the use of algorithms of many different echocardiographic parameters. Total average diastolic longitudinal displacement (LD), determined by colour tissue Doppler imaging (TDI) via the measurement...... for the general discrimination of patients with or without diastolic dysfunction. Using linear regression, total average diastolic LD was estimated to fall by 2.4 mm for every increase in graded severity of diastolic dysfunction (β = -0.61, p-value preserved total average...

  2. Full-field laser Doppler imaging and its physiological significance for tissue blood perfusion

    Science.gov (United States)

    Binzoni, T.; Van DeVille, D.

    2008-12-01

    Using Monte Carlo simulations for a semi-infinite medium representing a skeletal muscle tissue, it is demonstrated that the zero- and first-order moments of the power spectrum for a representative pixel of a full-field laser-Doppler imager behave differently from classical laser-Doppler flowmetry. In particular, the zero-order moment has a very low sensitivity to tissue blood volume changes, and it becomes completely insensitive if the probability for a photon to interact with a moving red blood cell is above 0.05. It is shown that the loss in sensitivity is due to the strong forward scatter of the propagating photons in biological tissues (i.e., anisotropy factor g = 0.9). The first-order moment is linearly related to the root mean square of the red blood cell velocity (the Brownian component), and there is also a positive relationship with tissue blood volume. The most common physiological interpretation of the first-order moment is as tissue blood volume times expectation of the blood velocity (in probabilistic terms). In this sense, the use of the first-order moment appears to be a reasonable approach for qualitative real-time blood flow monitoring, but it does not allow us to obtain information on blood velocity or volume independently. Finally, it is shown that the spatial and temporal resolution trade-off imposed by the CMOS detectors, used in full-field laser-Doppler hardware, may lead to measurements that vary oppositely with the underlying physiological quantities. Further improvements on detectors' sampling rate will overcome this limitation.

  3. Full-field laser-Doppler imaging and its physiological significance for tissue blood perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Binzoni, T [Departement des Neurosciences Fondamentales, University of Geneva (Switzerland); Ville, D van de [Biomedical Imaging Group, Ecole Polytechnique Federale de Lausanne (EPFL) (Switzerland)], E-mail: Tiziano.Binzoni@medecine.unige.ch

    2008-12-07

    Using Monte Carlo simulations for a semi-infinite medium representing a skeletal muscle tissue, it is demonstrated that the zero- and first-order moments of the power spectrum for a representative pixel of a full-field laser-Doppler imager behave differently from classical laser-Doppler flowmetry. In particular, the zero-order moment has a very low sensitivity to tissue blood volume changes, and it becomes completely insensitive if the probability for a photon to interact with a moving red blood cell is above 0.05. It is shown that the loss in sensitivity is due to the strong forward scatter of the propagating photons in biological tissues (i.e., anisotropy factor g = 0.9). The first-order moment is linearly related to the root mean square of the red blood cell velocity (the Brownian component), and there is also a positive relationship with tissue blood volume. The most common physiological interpretation of the first-order moment is as tissue blood volume times expectation of the blood velocity (in probabilistic terms). In this sense, the use of the first-order moment appears to be a reasonable approach for qualitative real-time blood flow monitoring, but it does not allow us to obtain information on blood velocity or volume independently. Finally, it is shown that the spatial and temporal resolution trade-off imposed by the CMOS detectors, used in full-field laser-Doppler hardware, may lead to measurements that vary oppositely with the underlying physiological quantities. Further improvements on detectors' sampling rate will overcome this limitation.

  4. Contrast biases the autocorrelation phase shift estimation in Doppler tissue imaging.

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    Ressner, Marcus; Jansson, Tomas; Cedefamn, Jonny; Ask, Per; Janerot-Sjoberg, Birgitta

    2009-03-01

    Quantitative assessment of regional myocardial function at rest and during stress with Doppler tissue imaging (DTI) plays an important role in daily routine echocardiography. However, reliable visual analysis is largely dependent on image quality and adequate border delineation, which still remains a challenge in a significant number of patients. In this respect, an ultrasound contrast agent (UCA) is often used to improve visualization in patients with suboptimal image quality. The knowledge of how DTI measurements will be affected by UCA present in the tissue is therefore of significant importance for an accurate interpretation of local myocardial motion. The aim of this paper was to investigate how signal contribution from UCA and nonlinear wave propagation influence the performance of the autocorrelation phase shift estimator used for DTI applications. Our results are based on model experiments with a clinical 2-D grayscale scanner and computational simulations of the DTI velocity estimator for synthetically-derived pulses, simulated bubble echoes and experimentally-sampled RF data of transmitted pulses and backscattered contrast echoes. The results show that destruction of UCA present in the tissue will give rise to an apparent bidirectional velocity bias of individual velocity estimates, but that spatial averaging of individual velocity measurements within a region-of-interest will result in a negative bias (away from the transducer) of the estimated mean or mean peak velocity. The UCA destruction will also have a significant impact on the measured integrated mean velocity over time, i.e., displacement. To achieve improved visualization with UCA during DTI-examinations, we either recommend that it is performed at low acoustic powers, mechanical index Doppler pulse package is preceded by a destruction burst similar to "Flash imaging" to clear the target area of contrast microbubbles.

  5. Assessment of left ventricular function by tissue Doppler imaging in patients with ankylosing spondylitis

    Directory of Open Access Journals (Sweden)

    Osman Kuloglu

    2012-05-01

    Full Text Available Ankylosing spondylitis (ASpis a chronic, inflammatory and systemic disease affecting pericardium, myocardium and the conduction system of the heart. In this study, we aimed to analyse left ventricular systolic and diastolic functions using tissue Doppler imaging (TDI. 30 patients with ASp and 30 healthy volunteers having the similar demographic characteristics were included. Left ventricular systolic and diastolic functions were assessed by using two dimensional (2D echocardiography, M-mode, pulsed-wave (PW and tissue Doppler echocardiography. The peak systolic velocity (Sm, early diastolic myocardial peak velocity (m, late diastolic myocardial peak velocity (Am, isovolumic acceleration (IVA, myocardial precontraction time (PCTm, myocardial contraction time (CTm, myocardial relaxation time (RTm, and myocardial performance index (MPI were measured at septal and lateral mitral annulus. In conventional echocardiography, end-diastolic interventricular septum and posterior wall diameters were higher in patients with ASp than the control group. The ratio of E/A was significantly lower and deceleration time was significantly prolonged in patients with ASp, but mitral E and A velocities, isovolumic relaxation time and MPI were similar in patient and control group (P>0.05. Left ventricular lateral and septal wall tissue Doppler echocardiography showed that Em, Em/Am ratio and CTm were significantly lower, IVRTm was longer and MPI was higher in patients with ASp. No significant differences were detected between the groups for IVA, Sm, Am, PCTm, PCTm/CTm ratio (P>0.05. We have demonstrated that in patients with ASp, diastolic functions were impaired but systolic functions were preserved by using TDI.

  6. Clinical utility of tissue Doppler imaging in patients with acute myocardial infarction complicated by cardiogenic shock

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    Zieroth Shelley

    2008-03-01

    Full Text Available Abstract Background Echocardiography is widely used in the management of patients with cardiogenic shock (CS. Left ventricular ejection fraction (EF has been shown to be an independent predictor of survival in CS. Tissue Doppler Imaging (TDI is a sensitive echocardiographic technique that allows for the early quantitative assessment of regional left ventricular dysfunction. TDI derived indices, including systolic velocity (S', early (E' and late (A' diastolic velocities of the lateral mitral annulus, are reduced in heart failure patients (EF Objective To characterize TDI derived indices in CS patients as compared to patients with chronic CHF. Methods Between 2006 and 2007, 100 patients were retrospectively evaluated who underwent echocardiography for assessment of LV systolic function. This population included: Group I 50 patients (30 males, 57 ± 13 years with chronic CHF as controls; and Group II 50 patients (29 males, 58 ± 10 years with CS. Spectral Doppler indices including peak early (E and late (A transmitral velocities, E/A ratio, and E-wave deceleration time were determined. Tissue Doppler indices including S', E' and A' velocities of the lateral annulus were measured. Results Of the entire cohort, the mean LVEF was 25 ± 5%. Cardiogenic shock patients demonstrated significantly lower lateral S', E' and a higher E/E' ratio (p Conclusion Despite similar reduction in LV systolic function, CS patients have reduced myocardial velocities and higher filling pressures using TDI, as compared to CHF patients. Whether TDI could be a reliable tool to determine CS patients with the best chance of recovery following revascularization is yet to be determined.

  7. Tissue Doppler Imaging as Part of Assessing the Diastolic Functions of the Left Ventricular Myocardium in Athletes

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    Alina Yu. Tatarinova

    2013-12-01

    Full Text Available The article presents the results of assessing the morphofunctional condition of the left ventricular myocardium within 231 athletes who specialise in various sports. All of them underwent a transthoracic echocardiogram that included colour and tissue Doppler imaging. There are no significant differences in the diastolic function indicators of the left ventricular myocardium between different types of sports. Athletes that exhibit slight hypertrophy of the left ventricular myocardium do not exhibit signs of diastolic dysfunction. Tissue Doppler imaging helps identify signs of diastolic dysfunction in athletes who have a formally normal transmitral flow.

  8. Prognostic value of tissue Doppler imaging for predicting ventricular arrhythmias and cardiovascular mortality in ischaemic cardiomyopathy

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Olsen, Flemming Javier; Storm, Katrine;

    2016-01-01

    AIMS: Only 30% of patients receiving an implantable cardioverter defibrillator (ICD) for primary prevention receive appropriately therapy. We sought to investigate the value of tissue Doppler imaging (TDI) to predict ventricular tachycardia (VT), ventricular fibrillation (VF), and cardiovascular...... mortality (CVD) in patients with primary prevention ICD. METHODS AND RESULTS: In total, 151 ICD patients meeting primary prevention criteria and with no history of ventricular arrhythmias were included. All participants were examined by conventional 2D echocardiography and TDI echocardiography. Longitudinal...... systolic (s'), early diastolic (e'), and late diastolic (a') myocardial velocities were measured using TDI at six mitral annular sites and averaged to provide global estimates. Forty patients experienced the combined endpoint of VT, VF, or CVD during a median follow-up of 2.3 years. Left ventricular...

  9. Cardiac dysfunction assessed by echocardiographic tissue Doppler imaging is an independent predictor of mortality in the general population

    DEFF Research Database (Denmark)

    Mogelvang, Rasmus; Sogaard, Peter; Pedersen, Sune A

    2009-01-01

    BACKGROUND: Tissue Doppler imaging (TDI) detects left ventricular dysfunction in patients with heart failure and normal ejection fraction, but the prognostic significance of left ventricular dysfunction by TDI in the general population is unknown. METHODS AND RESULTS: Within the Copenhagen City...

  10. The Value of Conventional Echocardiographic and Tissue Doppler Imaging in the Diagnosis of Cardiac Amyloidosis

    Institute of Scientific and Technical Information of China (English)

    Li ZHANG; Mingxing XIE; Xinfang WANG; Yali YANG; Junhong HUANG; Ming CHENG; Feixiang XIANG; Qing LU

    2008-01-01

    Transthoracic echocardiographic characteristics of 17 cases of cardiac amyloidosis (CA),a rare disease in China, were analyzed in order to improve the understanding of the disease. Seventeen cases of biopsy-proven CA, admitted to Wuhan Union Hospital from June 1994 to September 2008 were retrospectively reviewed. Twenty normal volunteers served as control group. Left atrial and ventricular functions and mitral inflow velocity were measured by two-dimensional, and Doppler echocardiography, and tissue Doppler imaging (TDI)-derived peak systolic wall motion velocities (Sv), peak early diastolic wall motion velocities (Ev), and peak late diastolic wall motion (Av) were measured at the septunm. Lateral, inferior and anterior comers of mitral annulus from the apical 4- and 2 chamber views. Compared with the control group, the interventricular septal thickness (IVSd), the left ventricular posterior wall (LVPWd), right ventricular transverse diameter (RVTDd) near the end of diastole and the interauricular septum thickness (IASs), left atrial anteroposterior diameter (LAADs), right atrial transverse diameter (RATDs) near the end of systole were increased significantly (all P<0.05) and left ventricular ejection fraction (LVEF) decreased (P<0.05) in the CA group.Compared with the control group, Sv, Ev at each wall and Av at almost all walls were significantly decreased in the CA group. In the CA group, Myocardial echoes of interventricular septum and free wall of left ventricle were enhanced evidently and distributed unevenly. The echoes presented as ground glass-like images, with some spotty hyper echoes. Both atria were enlarged, and LVEF decreased, with diastolic function impaired, and mild-moderate hydropericardium found in the CA group. It was concluded that echocardiography was a relatively sensitive and highly specific non-invasive method for the diagnosis of CA.

  11. Age-related intramyocardial patterns in healthy subjects evaluated with Doppler tissue imaging.

    Science.gov (United States)

    Pérez-David, Esther; García-Fernández, Miguel A; Ledesma, Maria Jesús; Malpica, Norberto; López Fernández, Teresa; Santos, Andrés; Moreno, Mar; Antoranz, José C; Bermejo, Javier; Desco, Manuel

    2005-06-01

    The aim of this study is to analyse spatial distribution of myocardial velocities (MV) and myocardial velocity gradient (MVG) with color M-mode Doppler tissue imaging (DTI) and to analyse the influence of age in such parameters. A prospective study including 66 healthy volunteers was carried out with color M-mode DTI. Postprocessing of images was performed using proprietary software allowing the division of the myocardial wall into subendocardium, mesocardium and subepicardium. MV corresponding to the three layers and MVG time curves were obtained and systolic, early diastolic and late diastolic peak values were identified. MV were highest in subendocardium in systole, protodiastole and telediastole compared to external layers. Protodiastolic peak MV decreased in all layers with age, but with a higher impact in the subendocardium (r = 0.72, b = 0.136 (IC 95% 0.107-0.164), p = 0.0005). Older age resulted in larger telediastolic peak MV, without significant differences among layers. Linear correlation between protodiastolic peak mitral flow and peak protodiastolic velocity was higher in endocardium than in other layers (r = 0.79, p = 0.0005). Color M-mode DTI multilayer analysis showed that endocardium is more susceptible to age-related changes involving diastolic function. This dependency on age should be considered when assessing MV in other clinical settings.

  12. Echocardiographic Assessment of Left Ventricle Torsion by Tissue Doppler and Velocity Vector Imaging

    Directory of Open Access Journals (Sweden)

    Zahra Ojaghi-Haghighi

    2014-08-01

    Full Text Available Introduction Left ventricular (LV twist is believed to store potential energy and plays an important role in generating diastolic suction. Recent advances in echocardiography techniques have allowed quantification of LV twist. The aim of the present study was to compare LV twist and torsion in healthy human subjects determined by velocity vector imaging (VVI and tissue Doppler imaging (TDI at rest. Materials and Methods All volunteers (72 healthy subjects underwent complete echocardiographic study and LV torsional parameters were assessed using VVI or TDI methods. LV rotation at apical and basal short-axis levels was calculated throughout cardiac cycle and LV twist was defined as net difference between rotation angles of the two levels. The LV torsion was calculated as the LV twist divided by the LV end-diastolic length. Results Twist degree was significantly lower in the VVI group than the TDI group (11.4±2.4º vs.14.1±3.0º, p

  13. High-resolution tissue Doppler imaging of the zebrafish heart during its regeneration.

    Science.gov (United States)

    Huang, Chih-Chung; Su, Ta-Han; Shih, Cho-Chiang

    2015-02-01

    The human heart cannot regenerate after injury, whereas the adult zebrafish can fully regenerate its heart even after 20% of the ventricle is amputated. Many studies have begun to reveal the cellular and molecular mechanisms underlying this regenerative process, which have exciting implications for human cardiac diseases. However, the dynamic functions of the zebrafish heart during regeneration are not yet understood. This study established a high-resolution echocardiography for tissue Doppler imaging (TDI) of the zebrafish heart to explore the cardiac functions during different regeneration phases. Experiments were performed on AB-line adult zebrafish (n=40) in which 15% of the ventricle was surgically removed. An 80-MHz ultrasound TDI based on color M-mode imaging technology was employed. The cardiac flow velocities and patterns from both the ventricular chamber and myocardium were measured at different regeneration phases relative to the day of amputation. The peak velocities of early diastolic inflow, early diastolic myocardial motion, late diastolic myocardial motion, early diastolic deceleration slope, and heart rate were increased at 3 days after the myocardium amputation, but these parameters gradually returned to close to their baseline values for the normal heart at 7 days after amputation. The peak velocities of late diastolic inflow, ventricular systolic outflow, and systolic myocardial motion did not significantly differ during the heart regeneration.

  14. What Is the Meaning of Increased Myocardial Injury Enzymes during Hemodialysis? A Tissue Doppler Imaging Study.

    Science.gov (United States)

    Yildiz, Gürsel; Kayataş, Mansur; Candan, Ferhan; Yilmaz, Mehmet Birhan; Zorlu, Ali; Sarikaya, Savaş

    2013-07-01

    Cardiovascular death is decreasing in the general population; however, it appears in still higher rates and even increases gradually in hemodialysis (HD) patients. This situation has led to a debate about cardiovascular adverse effects of HD which lead to significant changes in cardiac and hemodynamic events. It is known that troponins are often elevated in HD patients, and high levels of troponin are associated with increased mortality. Therefore, it is difficult to interpret the value of elevations in chronic kidney disease patients. Echocardiographic and biochemical parameters of 41 patients treated with HD were evaluated before and after a HD session. HD led to an increased heart rate, and tissue Doppler imaging parameters such as early diastolic mitral peak velocity (E)/early diastolic myocardial peak velocity (é) and septal é decreased significantly after HD. HD caused an increase in troponin I, myoglobin and cardiac creatine kinase (CK MB) levels (p = 0.019, p increased levels of cardiac damage markers (group 2) compared to those without increased levels of cardiac damage markers (group 1) in HD. A decrease in LV S' velocity was found to be an independent predictor of an increase of myocardial injury enzymes in HD (odds ratio = 1.099; p = 0.039). We concluded that HD may lead to significant acute stress upon the myocardium.

  15. Experimental Study of Assessment on Ventricular Activation Origin and Contraction Sequence by Doppler Tissue Imaging

    Institute of Scientific and Technical Information of China (English)

    冀瑞平; 王新房; 郑宗锷; 刘望彭; 李治安; 刘俐

    2002-01-01

    To evaluate the possibility and accuracy of Doppler tissue image (DTI) on assessment of normal and abnormal ventricular activation and contraction sequence, 9 open chest canine hearts were analyzed by acceleration mode, M-mode, and spectrum mode DTI. Our results showed that: (1) Acceleration mode DTI could show the origin of activation and conduction sequence on line; (2) Mmode DTI revealed that the activation in mid-interventricular septum was earlier than that in mid-left ventricular posterior wall at sinus activation; (3) Spectrum DTI showed the ventricular endocardium was activated earlier than the ventricular epicardium in all segments at sinus rhythm. The earliest site of activation of the normal ventricular wall was at middle interventricular septum; the latest site was at basal-posterior wall; the contraction sequence was different at the different walls; (4) During abnormal ventricular activation, mid-left ventricular posterior wall was activated earliest in accordance with the pacing sites. Abnormal ventricular activation was slower than sinus activation, and the contraction sequence varied at different sites of ventricular wall. It is concluded that DTI can be used to localize the origin of normal or abnormal myocardial activation and to assess the contraction sequence conveniently, accurately and non-invasively.

  16. Acute Effects of Hemodialysis on Left and Right Ventricular Function: A Doppler Tissue Imaging Study

    Directory of Open Access Journals (Sweden)

    Tansel Erol

    2012-08-01

    Full Text Available Purpose: Doppler tissue imaging (DTI allows noninvasive assessment of both left ventricular (LV and right ventricular (RV function. The aim of this study was to evaluate the effect of hemodialysis (HD on LV and RV function using DTI. Method: Our study group included 30 patients on chronic HD program (mean age 45 15 years. Myocardial (Sm, Em, Am and annular velocities (Ea, Aa were measured in several cardiac territories before and after HD. Results: After HD, Ea significantly reduced from 10.8 3.4 cm/s to 9.6 2.4 cm/s (p = 0.029. Patients exhibited a lower Em following HD in all measured territories. Em/Am ratio was also reduced for each LV wall investigated after HD in all measured territories. At the RV segments, Sm, Em, and Am decreased significantly in all measured territories. Em of the anterior wall was positively related to ultrafiltration volume (r = 0.25, p = 0.006, whereas the decrease of Sm of RV basal segment correlated with a decrease of diastolic blood pressure (r = 0.23, p < 0.01. Conclusion: Our data indicate that a single HD session is associated with acute changes of systolic and diastolic parameters of LV and RV. [Cukurova Med J 2012; 37(4.000: 215-222

  17. Doppler Tissue Imaging: A Non-Invasive Technique for Estimation of Left Ventricular End Diastolic Pressure in Severe Mitral Regurgitation

    Directory of Open Access Journals (Sweden)

    Mojtaba Salarifar

    2010-08-01

    Full Text Available Background: Conventional Doppler measurements, including mitral inflow and pulmonary venous flow, are used to estimate left ventricular end diastolic pressure (LVEDP. However, these parameters have limitations in predicting LVEDP among patients with mitral regurgitation. This study sought to establish whether the correlation between measurements derived from tissue Doppler echocardiography and LVEDP remains valid in the setting of severe mitral regurgitation.Methods: Thirty patients (mean age: 57.37 ± 13.29 years with severe mitral regurgitation and a mean left ventricular ejection fraction (EF of 46.0 ± 14.95 were enrolled; 16 (53.4% patients were defined to have EF < 50% and 14 (46.6% patients had EF ≥ 50%. Doppler signals from the mitral inflow, pulmonary venous flow, and Doppler tissue imaging indices were obtained, and LVEDP was measured invasively through cardiac catheterization.Results: The majority of the standard Doppler and Doppler tissue imaging indices were not significantly correlated with LVEDP in the univariate analysis. In the multiple linear regression, however, early (E transmitral velocity to annular E' (E/E' ratio (ß = 1.09, p value < 0.01, E wave velocity to propagation velocity (E/Vp ratio (ß = 7.87, p value < 0.01, and isovolumic relaxation time (ß = 0.21, p value = 0.01 were shown as independent predictors of LVEDP (R2 = 91.7%.Conclusion: The ratio of E/Vp and E/E' ratio and also the isovolumic relaxation time could be applied properly to estimate LVEDP in mitral regurgitation patients even in the setting of severe mitral regurgitation.

  18. Diagnostic Value of Strain Rate Imaging by Tissue Doppler in Patients with Suspected Coronary Artery Disease

    Directory of Open Access Journals (Sweden)

    Hasan Mahfood

    2016-12-01

    Full Text Available Background: Strain Rate Imaging (SRI is a new diagnostic technique. Objectives: The present study aimed to determine the diagnostic value of SRI in detection and localization of coronary lesions in patients with chest pain, but without apparent wall motion abnormalities. Patients and Methods: This study was conducted on 91 patients with suspicion of stable angina or unstable angina selected through simple random sampling. SRI was done using Tissue Doppler Imaging (TDI prior to coronary angiography. All the patients had normal electrocardiograms and normal wall motion in echocardiography. Longitudinal strain was obtained for 18 segments in the Left Ventricle (LV. Then, peak longitudinal systolic strain (εsys, post systolic shortening, and its characteristics were assessed in normal and abnormal segments. Significant coronary lesion was considered if stenosis was above 70%. Results: The results showed that 40 patients with heterogeneous strains and 2 patients with constant strains had significant coronary stenosis. Besides, 31 patients with constant strains and 18 ones with heterogeneous strains had normal or minimal coronary lesions. Moreover, εsys was lower in ischemic than in normal segments (P < 0.001. Receiver Operator Characteristic (ROC analysis for εsys yielded the following results: Area Under Curve (AUC = 0.86 [95% CI (0.84 - 0.88]. Additionally, the cutoff point of -11.4 had the highest sensitivity and specificity (69.55% and 87.23%, respectively. The gold standard for ROC analysis was the catheter result. Furthermore, post systolic shortening was found more in ischemic compared to normal segments (64.5% vs. 22.6%, P < 0.001. The magnitudes of εpss, εpss/εsys (PSI, and εpss/εmax were significantly larger (P < 0.001 and T εpss was longer (P < 0.001 in ischemic segments. Conclusions: SRI is a new non-invasive diagnostic tool that could be used for detecting coronary stenosis in patients with chest pain, but without apparent wall

  19. Pulsed Doppler Tissue Imaging for Assessment of Left Ventricular Systolic and Diastolic Synchronicity in Normal Subjects

    Institute of Scientific and Technical Information of China (English)

    Yang Li; Wu Wei; Wang Jingfeng; Zhang Xiaoling

    2006-01-01

    Objectives To quantitatively analyze the longitudinal myocardial systolic and diastolic velocities and time intervals of the left ventricle in normal subjects, and to explore the value of pulsed Doppler tissue imaging (DTI) for the assessment of left ventricular systolic and diastolic synchronicity.Methods Twenty and six healthy subjects were studied by pulsed DTI. The septal and lateral, anterior and inferior walls of the left ventricle were displayed respectively, and basal and middle segments of each wall were selected for myocardial motion spectrum sampling. DTI parameters were: peak systolic myocardial velocity (s), regional pre-ejection period (PEP), time to the peak of s wave (Ts), regional ejection time (ET); peak early diastolic velocity (e),peak late diastolic velocity (a), e/a ratio, time to the beginning of e wave (QE), time to the peak of e wave (Te) and regional isovolumic relaxation time (IVRT).Results The e and e/a were significantly different among basal segments, and s and e/a were significantly different among middle segments, with the highest value in lateral segments and the lowest value in septal segments. The s, e and a were all significantly higher in basal segments than middle segments. None of the systolic time intervals (PEP, Ts and ET) and diastolic time intervals (QE, Te and IVRT) were significantly different among basal segments and middle segments,neither were they when basal segment was compared with middle segment. Conclusions In normal subjects, the longitudinal myocardial systolic and diastolic velocities of the left ventricle are not homogeneous, but the contraction and relaxation are highly synchronized. Pulsed DTI can be used to quantitatively analyze the systolic and diastolic synchronicity of the heart.

  20. The role of tissue harmonic imaging ultrasound combined with power Doppler ultrasound in the diagnosis of childhood febrile urinary tract infections

    National Research Council Canada - National Science Library

    İlarslan, Nisa Eda Çullas; Fitöz, Ömer Suat; Öztuna, Derya Gökmen; Küçük, Nuriye Özlem; Yalçınkaya, Fatma Fatoş

    2015-01-01

    This study assessed the ability of tissue harmonic imaging ultrasound combined with power Doppler ultrasound in the detection of childhood febrile urinary tract infections in comparison with the gold...

  1. Influence of oxygen tension on myocardial performance. Evaluation by tissue Doppler imaging

    Directory of Open Access Journals (Sweden)

    Poulsen Steen

    2004-11-01

    Full Text Available Abstract Background Low O2 tension dilates coronary arteries and high O2 tension is a coronary vasoconstrictor but reports on O2-dependent effects on ventricular performance diverge. Yet oxygen supplementation remains first line treatment in cardiovascular disease. We hypothesized that hypoxia improves and hyperoxia worsens myocardial performance. Methods Seven male volunteers (mean age 38 ± 3 years were examined with echocardiography at respiratory equilibrium during: 1 normoxia (≈21% O2, 79% N2, 2 while inhaling a hypoxic gas mixture (≈11% O2, 89% N2, and 3 while inhaling 100% O2. Tissue Doppler recordings were acquired in the apical 4-chamber, 2-chamber, and long-axis views. Strain rate and tissue tracking displacement analyses were carried out in each segment of the 16-segment left ventricular model and in the basal, middle and apical portions of the right ventricle. Results Heart rate increased with hypoxia (68 ± 4 bpm at normoxia vs. 79 ± 5 bpm, P Conclusion Hypoxia improves and hyperoxia worsens systolic myocardial performance in healthy male volunteers. Tissue Doppler measures of diastolic function are unaffected by hypoxia/hyperoxia which support that the changes in myocardial performance are secondary to changes in vascular tone. It remains to be settled whether oxygen therapy to patients with heart disease is a consistent rational treatment.

  2. The detailed assessment of left and right ventricular functions by tissue Doppler imaging in patients with familial Mediterranean fever.

    Science.gov (United States)

    Tavil, Yusuf; Ureten, Kemal; Oztürk, Mehmet Akif; Sen, Nihat; Kaya, Mehmet Güngör; Cemri, Mustafa; Cengel, Atiye

    2008-02-01

    In the contrary to other rheumatologic disorders, there have been limited numbers of studies investigating the cardiac involvement in patients with familial Mediterranean fever (FMF), although the disease may carry a potential for cardiovascular disorders because of sustained inflammation during its course. In the present study, we used high usefulness tissue Doppler echocardiography for detailed analysis of cardiac changes in FMF patients. The study population included 30 patients with FMF (11 men, 19 women; mean age, 35 +/- 7 years, mean disease duration, 15.4 +/- 7.6 years) and 30 healthy subjects as controls (12 men, 18 women; mean age, 33 +/- 7 years). The diagnosis of FMF was established according to the Tell-Hashomer criteria. Left and right ventricular functions were measured using echocardiography comprising standard two-dimensional, M-mode, and conventional Doppler as well as tissue Doppler imaging. The conventional echocardiographic paratemeters were similar apart from left ventricular relaxation time was longer (107 +/- 25 vs 85 +/- 10 ms, p < 0.001, respectively) in patients with FMF. According to the tissue Doppler measurements, while systolic velocities of both ventricles were not different, diastolic filling velocities of left ventricle including E'(m) (12.6 +/- 3.4 vs 14.7 +/- 3.3 cm/s, p = 0.04), A'(m) (10.1 +/- 2.6 vs 8.6 +/- 2.0 cm/s, p = 0.015), and E'(m)/ A'(m) (1.24 +/- 0.4 vs 1.71 +/- 0.5 cm/s, p = 0.012) values were statistically different between the groups. Left ventricular myocardial performance indices and right ventricular diastolic functions were found similar between two groups. In addition, there were no significant correlations between the disease duration, clinical features, and echocardiographic parameters. In conclusion, we have demonstrated that although systolic functions were comparable in the patients and controls, left ventricular diastolic function indices were impaired in FMF patients by using tissue Doppler analysis.

  3. Comparison of right ventricular functions by tissue Doppler imaging in patients with obstructive sleep apnea syndrome with or without hypertension.

    Science.gov (United States)

    Tavil, Yusuf; Kanbay, Asiye; Sen, Nihat; Ciftçi, Tansu Ulukavak; Abaci, Adnan; Yalçin, M Ridvan; Köktürk, Oğuz; Cengel, Atiye

    2007-08-01

    To evaluate the right ventricular function in patients with obstructive sleep apnea syndrome (OSAS) independent from systemic hypertension (HT) and to determine the association between OSAS severity and right ventricular dysfunction. The study population included 77 consecutive subjects; 20 of these patients had OSAS, 20 of them had HT, but did not have OSAS, 16 patients, who constituted the study group, had both disorders, and 21 subjects without any of these two disorders represented the control group. Right ventricular function was assessed by echocardiography: standard two-dimensional, M-Mode, and conventional Doppler as well as tissue Doppler imaging. None of the patients had a previous history of cardiac disease. The diagnosis of OSAS was based on an apnea- hipopnea index of 5 or higher in polysomnography. Tricuspid inflow velocities and tissue Doppler derived tricuspid annular diastolic velocities were significantly different in the patient groups (OSAS, HT, OSAS + HT) compared to the control group. Tricuspid annular plane systolic excursion (TAPSE) (18.3 +/- 3.2, 18.4 +/- 2.5, 20.1 +/- 2.1, and 20.7 +/- 2.5 mm, respectively, P = 0.024) and peak systolic myocardial velocity at tricuspid lateral annulus (S-vel) (12.2 +/- 1.5, 10.9 +/- 0.9, 11.2 +/- 1.1, and 13.1 +/- 2.1 cm/s, respectively, P < 0.001) were significantly lower in patient groups compared to those of the study group. Tissue Doppler derived myocardial performance index (MPI) of the right ventricle was significantly impaired in the patient groups compared to the control group (0.34 +/- 0.06, 0.44 +/- 0.06, 0.45 +/- 0.07, and 0.41 +/- 0.06, respectively, P < 0.001). With regard to these right ventricular functional parameters, there was no significant difference between OSAS and the other patient groups (HT and OSAS + HT). There were significant correlations both between OSAS severity and the right ventricular functions, and between diastolic and systolic parameters of the right ventricle (r = -0

  4. The role of tissue harmonic imaging ultrasound combined with power Doppler ultrasound in the diagnosis of childhood febrile urinary tract infections.

    Science.gov (United States)

    İlarslan, Nisa Eda Çullas; Fitöz, Ömer Suat; Öztuna, Derya Gökmen; Küçük, Nuriye Özlem; Yalçınkaya, Fatma Fatoş

    2015-06-01

    This study assessed the ability of tissue harmonic imaging ultrasound combined with power Doppler ultrasound in the detection of childhood febrile urinary tract infections in comparison with the gold standard reference method: Tc-99m dimercaptosuccinicacid renal cortical scintigraphy. This prospective study included 60 patients who were hospitalized with a first episode of febrile urinary tract infections. All children were examined with dimercaptosuccinicacid scan and tissue harmonic imaging ultrasound combined with power Doppler ultrasound within the first 3 days of admission. Signs indicative of acute infection were observed in 29 patients according to the results of tissue harmonic imaging ultrasound combined with power Doppler ultrasound while dimercaptosuccinicacid scan revealed abnormal findings in 33 patients. The sensitivity, specificity, positive predictive value and negative predictive value of tissue harmonic imaging combined with power Doppler ultrasound using dimercaptosuccinicacid scintigraphy as the reference method in patients diagnosed with first episode febrile urinary tract infections were calculated as 57.58% (95% confidence interval: 40.81%-72.76%); 62.96% (95% confidence interval: 44.23%-78.47%); 65.52% (95% confidence interval: 52.04%-77%); 54.84% (95% confidence interval: 41.54%-67.52%); respectively. Although current results exhibit inadequate success of power Doppler ultrasound, this practical and radiation-free method may soon be comprise a part of the routine ultrasonographic evaluation of febrile urinary tract infections of childhood if patients are evaluated early and under appropriate sedation.

  5. Prognostic value of cardiac time intervals measured by tissue Doppler imaging M-mode in the general population

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Mogelvang, Rasmus; Jensen, Jan Skov

    2015-01-01

    OBJECTIVE: Tissue Doppler imaging (TDI) M-mode through the mitral leaflet is an easy and precise method to estimate the cardiac time intervals. The aim was to evaluate the usability of the cardiac time intervals in predicting major cardiovascular events (MACE) in the general population. METHODS......: In a large prospective community-based study, cardiac function was evaluated in 1915 participants by both conventional echocardiography and TDI. The cardiac time intervals, including the isovolumic relaxation time (IVRT), isovolumic contraction time (IVCT) and ejection time (ET), were obtained by TDI M...... echocardiographic parameters resulted in a significant increase in the c-statistics (0.76 vs 0.75 ptime intervals that include...

  6. Doppler Tissue Imaging Assessment of Left Ventricular Systolic Dyssynchrony in Severe Heart Failure Patients With a Normal QRS Duration

    Institute of Scientific and Technical Information of China (English)

    Xiaozhu Chen; Jieting Wang; Suyun Song; Juan Fu; Xinxia Zhang

    2008-01-01

    Objectives To assess the prevalence of systolic dyssynchrony of the left ventricular(LV)wails in patients of heart failure(HF)with a normal QRS duration by Doppler tissue imaging(DTI).Methods 20 patients of HF with a normal QRS duration and 20 healthy individuals were investigated with DTI to quantitatively analyze their pulsed-wave Doppler spectrum of basal and middle segments in six walls of left ventricle.The time between the onset of the QRS complex of the surface ECG and the onset of the systolic wave of pulsed-wave Doppler spectrum was measured(TS).LV systolic synchronization was assessed by the maximal difference(MD)in time of TS,the standard deviation(SD)and the coefficient of variation(CV)of TS in the all 12 LV segments.Results When a TS-MD of TS>53.08 ms,a TS-SD of TS>18.08 ms and a TS-CV of TS>0.91(+1.65 SD of normal controls) was used to define significant systolic dyssynchrony,the prevalence of systolic dyssynchrony was 55.0%,55.0% and 55.0%,respectively,in the HF patients group,significantly gher than those in the normai control and the locations of delayed contraction of these patients were different.Conclusions LV systolic dyssynchrony could be commonly demonstrated by DTI in HF patients with a normal QRS duration.This finding will support the view about the possibility that more HF patients could benefit from cardiac resynchronization therapy.

  7. Spectral pulsed-wave tissue Doppler imaging lateral-to-septal delay fails to predict clinical or echocardiographic outcome after cardiac resynchronization therapy

    NARCIS (Netherlands)

    O.I.I. Soliman (Osama Ibrahim Ibrahim); D.A.M.J. Theuns (Dominic); M.L. Geleijnse (Marcel); A. Nemes (Attila); K. Caliskan (Kadir); W.B. Vletter (Wim); L.J.L.M. Jordaens (Luc); F.J. ten Cate (Folkert)

    2007-01-01

    textabstractAims: The current study sought to assess if pre-implantation lateral-to-septal delay (LSD) ≥60 ms assessed by spectral pulsed-wave myocardial tissue Doppler imaging (PW-TDI) could predict successful long-term outcome after cardiac resynchronization therapy (CRT). Methods and results Sixt

  8. Spectral pulsed-wave tissue Doppler imaging lateral-to-septal delay fails to predict clinical or echocardiographic outcome after cardiac resynchronization therapy

    NARCIS (Netherlands)

    O.I.I. Soliman (Osama Ibrahim Ibrahim); D.A.M.J. Theuns (Dominic); M.L. Geleijnse (Marcel); A. Nemes (Attila); K. Caliskan (Kadir); W.B. Vletter (Wim); L.J.L.M. Jordaens (Luc); F.J. ten Cate (Folkert)

    2007-01-01

    textabstractAims: The current study sought to assess if pre-implantation lateral-to-septal delay (LSD) ≥60 ms assessed by spectral pulsed-wave myocardial tissue Doppler imaging (PW-TDI) could predict successful long-term outcome after cardiac resynchronization therapy (CRT). Methods and results

  9. Spectral pulsed-wave tissue Doppler imaging lateral-to-septal delay fails to predict clinical or echocardiographic outcome after cardiac resynchronization therapy

    NARCIS (Netherlands)

    O.I.I. Soliman (Osama Ibrahim Ibrahim); D.A.M.J. Theuns (Dominic); M.L. Geleijnse (Marcel); A. Nemes (Attila); K. Caliskan (Kadir); W.B. Vletter (Wim); L.J.L.M. Jordaens (Luc); F.J. ten Cate (Folkert)

    2007-01-01

    textabstractAims: The current study sought to assess if pre-implantation lateral-to-septal delay (LSD) ≥60 ms assessed by spectral pulsed-wave myocardial tissue Doppler imaging (PW-TDI) could predict successful long-term outcome after cardiac resynchronization therapy (CRT). Methods and results Sixt

  10. Assessment of Subclinical Left Ventricular Dysfunction in Patients with Chronic Mitral Regurgitation Using Torsional Parameters Described by Tissue Doppler Imaging

    Directory of Open Access Journals (Sweden)

    Zahra Ojaghi-Haghighi

    2015-10-01

    Full Text Available Background: Left ventricular (LV twist is due to oppositely directed apical and basal rotation and has been proposed as a sensitive marker of LV function. We sought to assess the impact of chronic pure mitral regurgitation (MR on the torsional mechanics of the left human ventricle using tissue Doppler imaging.Methods: Nineteen severe MR patients with a normal LV ejection fraction and 16 non-MR controls underwent conventional echocardiography and apical and basal short-axis color Doppler myocardial imaging (CDMI. LV rotation at the apical and basal short-axis levels was calculated from the averaged tangential velocities of the septal and lateral regions, corrected for the LV radius over time. LV twist was defined as the difference in LV rotation between the two levels, and the LV twist and twisting/untwisting rate profiles were analyzed throughout the cardiac cycle.Results: LV twist and LV torsion were significantly lower in the MR group than in the non-MR group (10.38˚ ± 4.04˚ vs.13.95˚ ± 4.27˚; p value = 0.020; and 1.29 ± 0.54 ˚/cm vs. 1.76 ± 0.56 ˚/cm; p value = 0.021, respectively, both suggesting incipient LV dysfunction in the MR group. Similarly, the untwisting rate was lower in the MR group (-79.74 ± 35.97 ˚/s vs.-110.96 ± 34.65 ˚/s; p value = 0.020, but there was statistically no significant difference in the LV twist rate.Conclusion: The evaluation of LV torsional parameters in MR patients with a normal LV ejection fraction suggests the potential role of these sensitive variables in assessing the early signs of ventricular dysfunction in asymptomatic patients

  11. Pulsed-wave tissue Doppler imaging of the myocardium of cats with induced thyrotoxicosis Doppler tecidual pulsado do miocárdio de gatos com tirotoxicose induzida

    Directory of Open Access Journals (Sweden)

    Daniel Capucho de Oliveira

    2011-06-01

    Full Text Available Left ventricular myocardial motion was quantified using pulsed-wave tissue Doppler imaging (PW-TDI in nine adult cats before and after thyrotoxicosis induction. In order to induce thyrotoxicosis, all cats were given 150µg kg-1 of levothyroxine sodium as a single oral dose each day for 10 weeks. PW-TDI examinations were performed immediately before the induction and by the end of the experimental protocol. An increase in myocardial motion velocity was documented at the interventricular septum level, demonstrated by an elevation in systolic (Sa, and early (Ea and late (Aa diastolic waves (PA velocidade de movimentação miocárdica do ventrículo esquerdo foi quantificada por meio de exames ecocardiográficos com Doppler tecidual pulsado (PW-TDI em nove gatos adultos antes e após indução à tirotoxicose. Para indução da tirotoxicose, todos os gatos receberam doses diárias de 150mg kg-1 de levotiroxina sódica, por via oral, durante 10 semanas. Os exames de PW-TDI foram realizados imediatamente antes da indução e ao final do protocolo experimental. Uma elevação na velocidade de movimentação miocárdica foi documentada ao nível do septo interventricular, demonstrado por um aumento das ondas sistólica (Sa e diastólicas (Ea e Aa; P<0,05. No entanto, nenhuma alteração nos valores de Sa, Ea e Aa foi encontrada ao nível da parede livre do ventrículo esquerdo. A frequência cardíaca aumentou significativamente entre os momentos experimentais, sendo que três animais apresentaram fusão das ondas Aa e Ea ao final do experimento. O protocolo experimental utilizado neste estudo causou alterações na velocidade de movimentação do miocárdio ventricular esquerdo, mas sem causar danos à função diastólica do ventrículo esquerdo.

  12. Tissue Doppler Imaging Combined with Advanced 12-Lead ECG Analysis Might Improve Early Diagnosis of Hypertrophic Cardiomyopathy in Childhood

    Science.gov (United States)

    Femlund, E.; Schlegel, T.; Liuba, P.

    2011-01-01

    Optimization of early diagnosis of childhood hypertrophic cardiomyopathy (HCM) is essential in lowering the risk of HCM complications. Standard echocardiography (ECHO) has shown to be less sensitive in this regard. In this study, we sought to assess whether spatial QRS-T angle deviation, which has shown to predict HCM in adults with high sensitivity, and myocardial Tissue Doppler Imaging (TDI) could be additional tools in early diagnosis of HCM in childhood. Methods: Children and adolescents with familial HCM (n=10, median age 16, range 5-27 years), and without obvious hypertrophy but with heredity for HCM (n=12, median age 16, range 4-25 years, HCM or sudden death with autopsy-verified HCM in greater than or equal to 1 first-degree relative, HCM-risk) were additionally investigated with TDI and advanced 12-lead ECG analysis using Cardiax(Registered trademark) (IMED Co Ltd, Budapest, Hungary and Houston). Spatial QRS-T angle (SA) was derived from Kors regression-related transformation. Healthy age-matched controls (n=21) were also studied. All participants underwent thorough clinical examination. Results: Spatial QRS-T angle (Figure/ Panel A) and septal E/Ea ratio (Figure/Panel B) were most increased in HCM group as compared to the HCM-risk and control groups (p less than 0.05). Of note, these 2 variables showed a trend toward higher levels in HCM-risk group than in control group (p=0.05 for E/Ea and 0.06 for QRS/T by ANOVA). In a logistic regression model, increased SA and septal E/Ea ratio appeared to significantly predict both the disease (Chi-square in HCM group: 9 and 5, respectively, p less than 0.05 for both) and the risk for HCM (Chi-square in HCM-risk group: 5 and 4 respectively, p less than 0.05 for both), with further increased predictability level when these 2 variables were combined (Chi-square 10 in HCM group, and 7 in HCM-risk group, p less than 0.01 for both). Conclusions: In this small material, Tissue Doppler Imaging and spatial mean QRS-T angle

  13. Laser Doppler Imaging of Microflow

    CERN Document Server

    Gross, Michel; Leng, Jacques

    2013-01-01

    We report a pilot study with a wide-field laser Doppler detection scheme used to perform laser Doppler anemometry and imaging of particle seeded microflow. The optical field carrying the local scatterers (particles) dynamic state, as a consequence of momentum transfer at each scattering event, is analyzed in the temporal frequencies domain. The setup is based on heterodyne digital holography, which is used to map the scattered field in the object plane at a tunable frequency with a multipixel detector. We show that wide-field heterodyne laser Doppler imaging can be used for quantitative microflow diagnosis; in the presented study, maps of the first-order moment of the Doppler frequency shift are used as a quantitative and directional estimator of the Doppler signature of particles velocity.

  14. Doppler tecidual do miocárdio de gatos submetidos à anestesia dissociativa Tissue Doppler imaging of the myocardium in cats submitted to dissociative anesthesia

    Directory of Open Access Journals (Sweden)

    Daniel Cometti Borlini

    2009-11-01

    Full Text Available O Doppler tecidual é uma técnica recente que permite avaliar a velocidade de movimentação do miocárdio durante as fases do ciclo cardíaco, fornecendo informações importantes da função cardíaca. Na medicina veterinária, estudos têm sido realizados para a caracterização de disfunções da contratilidade cardíaca e o estabelecimento de padrões de normalidade. O presente trabalho objetivou avaliar a velocidade de contração do miocárdio pela técnica de Doppler tecidual em gatos submetidos à anestesia dissociativa. Para tanto, foram utilizados nove gatos adultos, hígidos, sem distinção de sexo ou raça. Foram medidos os valores de Ea (velocidade máxima longitudinal no início da diástole, Aa (velocidade máxima longitudinal na sístole atrial e Sa (velocidade máxima longitudinal na sístole ventricular nas bordas lateral e septal do anel mitral. Os valores médios observados para Ea septal e Sa septal foram de 7,2±2,5cm s-1 e 6,3±1,7cm s-1, respectivamente. O valor médio obtido para Ea lateral foi de 12,0±4,1cm s-1, enquanto que o valor médio de Sa lateral foi de 8,3±1,6cm s-1. Foi obtido um valor médio de 7,0±3,1cm s-1 para Aa lateral e 4,7±1,5cm s-1 para Aa septal. A padronização dos valores médios da velocidade de contração do miocárdio na espécie felina é de grande importância, podendo auxiliar no diagnóstico precoce de alterações da função contrátil do coração. Em razão da escassez de estudos com a técnica de Doppler tecidual em gatos, os valores obtidos neste trabalho permitem a realização de estudos comparativos, auxiliando a aplicação dessa técnica em protocolos experimentais e no diagnóstico precoce de cardiopatias na espécie felina.The tissue Doppler imaging (TDI is a recent technique that allows the evaluation of the myocardium movement velocity during the cardiac cycle phases, providing important informations of the cardiac function. In veterinary medicine, studies have been

  15. TISSUE DOPPLER IMAGING OF LONGITUDINAL MOVEMENT OF A FIBROUS RING OF MITRAL VALVE DURING ISOVOLUMIC PERIODS IN LEFT VENTRICULAR HYPERTROPHY

    Directory of Open Access Journals (Sweden)

    B. Amarjagal

    2015-12-01

    Full Text Available Aim. To study change of rate and duration indicators of longitudinal movement of a fibrous ring of mitral valve (MFR during isovolumic contraction (IVC and relaxation (IVR in hypertensive patients with various degree of a left ventricular hypertrophy (LVH.Material and methods. 80 hypertensive patients with moderate LVH (n=40 and severe LVH (n=40 are examined. The control group was presented by 30 healthy volunteers. Transthoracic echocardiography and Tissue Doppler imaging has been performed with ultrasonic tomograph “HDI 5000” (Philips.Results. Increase in LVH (Smm and Е/Еmm associates with reduction in systolic velocity of movement of medial MFR (Smm. There is direct relation with duration of IVC-negative and IVR-positive components and myocardium mass index. Maximal velocity of IVC-positive component increases and maximal velocity of IVR-negative component decreases when LVH is growing.Conclusion. Velocities curves of IVC and IVR were bi-phase both in healthy persons and in hypertensive patients with LVH. Velocity and duration of positive and negative components of IVC and IVR depended on LVH degree.

  16. TISSUE DOPPLER IMAGING OF LONGITUDINAL MOVEMENT OF A FIBROUS RING OF MITRAL VALVE DURING ISOVOLUMIC PERIODS IN LEFT VENTRICULAR HYPERTROPHY

    Directory of Open Access Journals (Sweden)

    B. Amarjagal

    2007-01-01

    Full Text Available Aim. To study change of rate and duration indicators of longitudinal movement of a fibrous ring of mitral valve (MFR during isovolumic contraction (IVC and relaxation (IVR in hypertensive patients with various degree of a left ventricular hypertrophy (LVH.Material and methods. 80 hypertensive patients with moderate LVH (n=40 and severe LVH (n=40 are examined. The control group was presented by 30 healthy volunteers. Transthoracic echocardiography and Tissue Doppler imaging has been performed with ultrasonic tomograph “HDI 5000” (Philips.Results. Increase in LVH (Smm and Е/Еmm associates with reduction in systolic velocity of movement of medial MFR (Smm. There is direct relation with duration of IVC-negative and IVR-positive components and myocardium mass index. Maximal velocity of IVC-positive component increases and maximal velocity of IVR-negative component decreases when LVH is growing.Conclusion. Velocities curves of IVC and IVR were bi-phase both in healthy persons and in hypertensive patients with LVH. Velocity and duration of positive and negative components of IVC and IVR depended on LVH degree.

  17. Effect of sample volume size and sampling method on feline longitudinal myocardial velocity profiles from color tissue Doppler imaging.

    Science.gov (United States)

    Granström, Sara; Pipper, Christian Bressen; Møgelvang, Rasmus; Sogaard, Peter; Willesen, Jakob Lundgren; Koch, Jørgen

    2012-12-01

    The aims of this study were to compare the effect of sample volume (SV) size settings and sampling method on measurement variability and peak systolic (s'), and early (e') and late (a') diastolic longitudinal myocardial velocities using color tissue Doppler imaging (cTDI) in cats. Twenty cats with normal echocardiograms and 20 cats with hypertrophic cardiomyopathy. We quantified and compared empirical variance and average absolute values of s', e' and a' for three cardiac cycles using eight different SV settings (length 1,2,3 and 5 mm; width 1 and 2 mm) and three methods of sampling (end-diastolic sampling with manual tracking of the SV, end-systolic sampling without tracking, and random-frame sampling without tracking). No significant difference in empirical variance could be demonstrated between most of the tested SVs. However, the two settings with a length of 1 mm resulted in a significantly higher variance compared with all settings where the SV length exceeded 2 mm (p sampling method on the variability of measurements (p = 0.003) and manual tracking obtained the lowest variance. No difference in average values of s', e' or a' could be found between any of the SV settings or sampling methods. Within the tested range of SV settings, an SV length of 1 mm resulted in higher measurement variability compared with an SV length of 3 and 5 mm, and should therefore be avoided. Manual tracking of the sample volume is recommended. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Pig model of chronic myocardial ischemia and its investigation by ultrasonic integrated backscatter and Doppler tissue imaging

    Institute of Scientific and Technical Information of China (English)

    XU Jing; ZHAO Bao-zhen; WANG Zhong; GU Jun-yan; LU Shi-ping

    2004-01-01

    Objective: To construct an animal model of chronic ischemic myocardium, and evaluate it by ultrasonic integrated backscatter (IBS) and Doppler tissue imaging (DTI). Methods: An Ameroid constrictor was placed around the porcine left circumflex coronary artery (LCX). The calibrated average image intensity ( % AII), cyclic variation of IBS(CVIB), transmural gradient index (TGI) of CVIB in lateral- posterior wall (LPW), and DTI spectrum of LPW in left ventricular papillary muscle level short axis view (LVPM-SAM) and apical four chamber view (AP-4CV) at normal state, 2, 4,6 and 8 weeks postoperatively were measured. Results: Normal %AII, CVIB and TGI were 2.29 ± 0.32, 9.69 ± 2.22dB and 0.22 ± 0.08, respectively. The % AII increased gradually postoperatively. The CVIB decreased also gradually, and the decrease was higher in subepicardium than in subendocardium. Most of TGI decrease occurred from 2 to 4 weeks postoperatively and became zero at 8 weeks (P < O. 01 ); Normal Vs (peak systolic velocity) of AP-4CV was higher than that of LVPM-SAM ( P < 0.01 ). VE (peak early diastolic velocity) of AP-4CV was lower than that of LVPM-SAM ( P < 0.05). Vs and VE were all decreased after operation ( P < 0.01 ). The decrease of Vs in AP-4CV was greater than that in LVPM-SAM.Conclusion: The pathological changes of the myocardium in human ischemic heart disease (IHD) are similar to that of Ameriod model. IBS and DTI can detect echo changes and ventricular wall motion in chronic ischemic myocardium, and provide more information for clinical investigation and treatment of IHD.

  19. Detection of unstable carotid plaque by tissue Doppler imaging and contrast-enhanced ultrasound in a patient with recurrent amaurosis fugax.

    Science.gov (United States)

    Kunte, Hagen; Rückert, Ralph-Ingo; Schmidt, Charlotte; Harms, Lutz; Kasper, Antje-Susanne; Hellweg, Rainer; Grigoryev, Maria; Fischer, Thomas; Kronenberg, Golo

    2013-01-01

    Ultrasound (US) is one of the most important diagnostic tools available for the detection and evaluation of carotid stenosis. The case of a 70-year-old woman with recurrent right-sided amaurosis fugax presented here highlights the way in which tissue Doppler imaging (TDI) and contrast-enhanced US (CEUS) may aid in the diagnosis of carotid plaque vulnerability. Furthermore, the novel inverse fly-through technique was used for the three-dimensional visualization of the carotid stenosis.

  20. The impact of total bile acid levels on fetal cardiac function in intrahepatic cholestasis of pregnancy using fetal echocardiography: a tissue Doppler imaging study.

    Science.gov (United States)

    Ataalla, Walid M; Ziada, Dina H; Gaber, Rania; Ossman, Ahmed; Bayomy, Suzan; Elemary, Berihan R

    2016-01-01

    The aim of this study was to assess total bile acid (TBA) levels and its impact on systolic and diastolic functions in fetuses of mothers with intrahepatic cholestasis of pregnancy (ICP) using tissue Doppler imaging (TDI), and to explore the correlation between TBA levels and fetal cardiac function. The study employed 98 pregnant women with ICP who were divided into two groups according to their bile acid levels. Fifty pregnant women without ICP represented the control group. Significant differences in the myocardial tissue velocities of both mitral and tricuspid valves were found between the fetuses of mothers with ICP and TBA levels of 40 mmol/L. There was a significant increase in neonatal respiratory distress, meconium staining and neonatal TBAs in group II compared to the control group and group I. There was a correlation between maternal TBA levels and preterm delivery, APGAR scores and neonatal TBA levels at birth. There was also a positive correlation between maternal TBA and fetal myocardial tissue velocities of both mitral and tricuspid, and fetal diastolic myocardial tissue Doppler velocities. ICP is a very serious condition especially when maternal TBA levels are >40 mmol/L. Fetal echocardiography with tissue Doppler is a useful tool for fetal assessment in patients with ICP. It could be an indication of induction of labor in cases of ICP and bile acid levels ≥40 mol/L. Neonatal echocardiography is mandatory for follow-up and management of these neonates.

  1. Left ventricular diastolic dyssynchrony assessed with phase analysis of gated myocardial perfusion SPECT: a comparison with tissue Doppler imaging

    Energy Technology Data Exchange (ETDEWEB)

    Boogers, Mark J.; Veltman, Caroline E. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Interuniversity Cardiology Institute of the Netherlands, Utrecht (Netherlands); Chen, Ji; Garcia, Ernest V. [Emory University School of Medicine, Department of Radiology, Atlanta, GA (United States); Bommel, Rutger J. van; Mooyaart, Eline A.Q.; Wall, Ernst E. van der; Schalij, Martin J.; Bax, Jeroen J.; Delgado, Victoria [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Younis, Imad Al; Hiel, Bernies van der; Dibbets-Schneider, Petra [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands)

    2011-11-15

    The aim of the current study was to evaluate the feasibility of phase analysis on gated myocardial perfusion SPECT (GMPS) for the assessment of left ventricular (LV) diastolic dyssynchrony in a head-to-head comparison with tissue Doppler imaging (TDI). The population consisted of patients with end-stage heart failure of New York Heart Association functional class III or IV with a reduced LV ejection fraction of {<=}35%. LV diastolic dyssynchrony was calculated using TDI as the maximal time delay between early peak diastolic velocities of two opposing left ventricle walls (diastolic mechanical delay). Significant LV diastolic dyssynchrony was defined as a diastolic mechanical delay of >55 ms on TDI. Furthermore, phase analysis on GMPS was performed to evaluate LV diastolic dyssynchrony; diastolic phase standard deviation (SD) and histogram bandwidth (HBW) were used as markers of LV diastolic dyssynchrony. A total of 150 patients (114 men, mean age 66.0 {+-} 10.4 years) with end-stage heart failure were enrolled. Both diastolic phase SD (r = 0.81, p < 0.01) and diastolic HBW (r = 0.75, p < 0.01) showed good correlations with LV diastolic dyssynchrony on TDI. Additionally, patients with LV diastolic dyssynchrony on TDI (>55 ms) showed significantly larger diastolic phase SD (68.1 {+-} 13.4 vs. 40.7 {+-} 14.0 , p < 0.01) and diastolic HBW (230.6 {+-} 54.3 vs. 129.0 {+-} 55.6 , p < 0.01) as compared to patients without LV diastolic dyssynchrony on TDI ({<=}55 ms). Finally, phase analysis on GMPS showed a good intra- and interobserver reproducibility for the determination of diastolic phase SD (ICC 0.97 and 0.88) and diastolic HBW (ICC 0.98 and 0.93). Phase analysis on GMPS showed good correlations with TDI for the assessment of LV diastolic dyssynchrony. (orig.)

  2. Study of the Myocardial Contraction and Relaxation Velocities through Doppler Tissue Imaging Echocardiography: A New Alternative in the Assessment of the Segmental Ventricular Function

    Directory of Open Access Journals (Sweden)

    Silva Carlos Eduardo Suaide

    2002-01-01

    Full Text Available OBJECTIVE: Doppler tissue imaging (DTI enables the study of the velocity of contraction and relaxation of myocardial segments. We established standards for the peak velocity of the different myocardial segments of the left ventricle in systole and diastole, and correlated them with the electrocardiogram. METHODS: We studied 35 healthy individuals (27 were male with ages ranging from 12 to 59 years (32.9 ± 10.6. Systolic and diastolic peak velocities were assessed by Doppler tissue imaging in 12 segments of the left ventricle, establishing their mean values and the temporal correlation with the cardiac cycle. RESULTS: The means (and standard deviation of the peak velocities in the basal, medial, and apical regions (of the septal, anterior, lateral, and posterior left ventricle walls were respectively, in cm/s, 7.35(1.64, 5.26(1.88, and 3.33(1.58 in systole and 10.56(2.34, 7.92(2.37, and 3.98(1.64 in diastole. The mean time in which systolic peak velocity was recorded was 131.59ms (±19.12ms, and diastolic was 459.18ms (±18.13ms based on the peak of the R wave of the electrocardiogram. CONCLUSION: In healthy individuals, maximum left ventricle segment velocities decreased from the bases to the ventricular apex, with certain proportionality between contraction and relaxation (P<0.05. The use of Doppler tissue imaging may be very helpful in detecting early alterations in ventricular contraction and relaxation.

  3. Detection of Unstable Carotid Plaque by Tissue Doppler Imaging and Contrast-Enhanced Ultrasound in a Patient with Recurrent Amaurosis Fugax

    Directory of Open Access Journals (Sweden)

    Hagen Kunte

    2013-01-01

    Full Text Available Ultrasound (US is one of the most important diagnostic tools available for the detection and evaluation of carotid stenosis. The case of a 70-year-old woman with recurrent right-sided amaurosis fugax presented here highlights the way in which tissue Doppler imaging (TDI and contrast-enhanced US (CEUS may aid in the diagnosis of carotid plaque vulnerability. Furthermore, the novel inverse fly-through technique was used for the three-dimensional visualization of the carotid stenosis.

  4. Preclinical systolic and diastolic dysfunction assessed by tissue Doppler imaging is associated with elevated plasma pro-B-type natriuretic peptide concentrations

    DEFF Research Database (Denmark)

    Møgelvang, Rasmus; Goetze, Jens P; Pedersen, Sune A

    2009-01-01

    BACKGROUND: Heart failure is a major public health problem. To improve its grave prognosis, early identification of cardiac dysfunction is mandatory. Conventional echocardiography is not suitable for this. Tissue Doppler imaging (TDI), however, could be so. METHODS AND RESULTS: Within a large......') velocities from 6 mitral annular sites were used. TDI was furthermore quantified by a combined index (eas-index) of diastolic and systolic performance: e'/(a' x s'). Compared with controls, persons with elevated plasma proBNP concentrations (n = 100) displayed lower systolic and diastolic performance by TDI...

  5. Planetary Doppler Imaging

    Science.gov (United States)

    Murphy, N.; Jefferies, S.; Hart, M.; Hubbard, W. B.; Showman, A. P.; Hernandez, G.; Rudd, L.

    2014-12-01

    Determining the internal structure of the solar system's gas and ice giant planets is key to understanding their formation and evolution (Hubbard et al., 1999, 2002, Guillot 2005), and in turn the formation and evolution of the solar system. While internal structure can be constrained theoretically, measurements of internal density distributions are needed to uncover the details of the deep interior where significant ambiguities exist. To date the interiors of giant planets have been probed by measuring gravitational moments using spacecraft passing close to, or in orbit around the planet. Gravity measurements are effective in determining structure in the outer envelope of a planet, and also probing dynamics (e.g. the Cassini and Juno missions), but are less effective in probing deep structure or the presence of discrete boundaries. A promising technique for overcoming this limitation is planetary seismology (analogous to helioseismology in the solar case), postulated by Vorontsov, 1976. Using trapped pressure waves to probe giant planet interiors allows insight into the density and temperature distribution (via the sound speed) down to the planetary core, and is also sensitive to sharp boundaries, for example at the molecular to metallic hydrogen transition or at the core-envelope interface. Detecting such boundaries is not only important in understanding the overall structure of the planet, but also has implications for our understanding of the basic properties of matter at extreme pressures. Recent Doppler measurements of Jupiter by Gaulme et al (2011) claimed a promising detection of trapped oscillations, while Hedman and Nicholson (2013) have shown that trapped waves in Saturn cause detectable perturbations in Saturn's C ring. Both these papers have fueled interest in using seismology as a tool for studying the solar system's giant planets. To fully exploit planetary seismology as a tool for understanding giant planet structure, measurements need to be made

  6. Left ventricular dyssynchrony assessed by two three-dimensional imaging modalities: phase analysis of gated myocardial perfusion SPECT and tri-plane tissue Doppler imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ajmone Marsan, Nina [Leiden University Medical Center, Department of Cardiology, Albinusdreef 2, ZA, Leiden (Netherlands); Policlinico S. Matteo, Department of Cardiology, Pavia (Italy); Henneman, Maureen M.; Ypenburg, Claudia; Bleeker, Gabe B.; Bax, Jeroen J. [Leiden University Medical Center, Department of Cardiology, Albinusdreef 2, ZA, Leiden (Netherlands); Chen, Ji; Garcia, Ernest V. [Emory University School of Medicine, Department of Radiology, Atlanta, Georgia (United States); Dibbets, Petra; Stokkel, Marcel P. [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands); Ghio, Stefano; Tavazzi, Luigi [Policlinico S. Matteo, Department of Cardiology, Pavia (Italy); Wall, Ernst E. van der [Leiden University Medical Center, Department of Cardiology, Albinusdreef 2, ZA, Leiden (Netherlands); The Interuniversity Cardiology Institute of the Netherlands, Utrecht (Netherlands)

    2008-01-15

    To compare left ventricular (LV) dyssynchrony assessment by phase analysis from gated myocardial perfusion SPECT (GMPS) with LV dyssynchrony assessment by tri-plane tissue Doppler imaging (TDI). Baseline LV dyssynchrony assessed with standard deviation (SD) of time-to-peak systolic velocity of 12 LV segments (Ts-SD) with TDI has proven to be a powerful predictor of response to CRT. Information on LV dyssynchrony can also be provided by GMPS with phase analysis of regional LV maximal count changes throughout the cardiac cycle. Forty heart failure patients, referred for evaluation of potential eligibility for CRT, underwent both 3D echocardiography, with tri-plane TDI, and resting GMPS. From tri-plane TDI, Ts-SD was used as a validated parameter of LV dyssynchrony and compared with different indices (histogram bandwidth, phase SD, histogram skewness and kurtosis) derived from phase analysis of GMPS. Histogram bandwidth and phase SD showed good correlation with Ts-SD (r=0.77 and r=0.74, p<0.0001, respectively). Patients with substantial LV dyssynchrony assessed with tri-plane TDI (Ts-SD {>=}33 ms) had also significantly higher values of histogram bandwidth and phase SD. The results of this study support the use of phase analysis by GMPS to evaluate LV dyssynchrony. Histogram bandwidth and phase SD showed the best correlation with Ts-SD assessed with tri-plane TDI and appeared the most optimal variables for assessment of LV dyssynchrony with GMPS. (orig.)

  7. Speckles in laser doppler perfusion imaging

    NARCIS (Netherlands)

    Rajan, Vinayakrishnan

    2007-01-01

    Laser Doppler Flowmetry (LDF) is a noninvasive diagnostic method to measure blood flow in tissue [1]. The technique is based on measuring the Doppler shift induced by moving red blood cells to the illuminating coherent light. A laser Doppler instrument often gives output signals related to the flux,

  8. Left ventricular dyssynchrony assessed by two three-dimensional imaging modalities: phase analysis of gated myocardial perfusion SPECT and tri-plane tissue Doppler imaging

    Science.gov (United States)

    Ajmone Marsan, Nina; Henneman, Maureen M.; Chen, Ji; Ypenburg, Claudia; Dibbets, Petra; Ghio, Stefano; Bleeker, Gabe B.; Stokkel, Marcel P.; van der Wall, Ernst E.; Tavazzi, Luigi; Garcia, Ernest V.

    2007-01-01

    Purpose To compare left ventricular (LV) dyssynchrony assessment by phase analysis from gated myocardial perfusion SPECT (GMPS) with LV dyssynchrony assessment by tri-plane tissue Doppler imaging (TDI). Baseline LV dyssynchrony assessed with standard deviation (SD) of time-to-peak systolic velocity of 12 LV segments (Ts-SD) with TDI has proven to be a powerful predictor of response to CRT. Information on LV dyssynchrony can also be provided by GMPS with phase analysis of regional LV maximal count changes throughout the cardiac cycle. Methods Forty heart failure patients, referred for evaluation of potential eligibility for CRT, underwent both 3D echocardiography, with tri-plane TDI, and resting GMPS. From tri-plane TDI, Ts-SD was used as a validated parameter of LV dyssynchrony and compared with different indices (histogram bandwidth, phase SD, histogram skewness and kurtosis) derived from phase analysis of GMPS. Results Histogram bandwidth and phase SD showed good correlation with Ts-SD (r=0.77 and r=0.74, p<0.0001, respectively). Patients with substantial LV dyssynchrony assessed with tri-plane TDI (Ts-SD ≥33 ms) had also significantly higher values of histogram bandwidth and phase SD. Conclusions The results of this study support the use of phase analysis by GMPS to evaluate LV dyssynchrony. Histogram bandwidth and phase SD showed the best correlation with Ts-SD assessed with tri-plane TDI and appeared the most optimal variables for assessment of LV dyssynchrony with GMPS. PMID:17874098

  9. Doppler Tissue Imaging Is an Independent Predictor of Outcome in Patients with ST-Segment Elevation Myocardial Infarction Treated with Primary Percutaneous Coronary Intervention

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Jensen, Jan Skov; Pedersen, Sune

    2014-01-01

    BACKGROUND: Doppler tissue imaging (DTI) detects early signs of left ventricular (LV) dysfunction; however, the prognostic significance of DTI after ST-segment elevation myocardial infarction (STEMI) is unknown. The aim of this study was to evaluate the prognostic value of DTI after STEMI...... in patients treated with primary percutaneous coronary intervention. METHOD: In total, 391 patients who were admitted with STEMIs and treated with primary percutaneous coronary intervention were prospectively included. All participants were examined by echocardiography 2 days (interquartile range, 1-3 days......) after STEMI. Longitudinal systolic (s'), early diastolic (e'), and late diastolic (a') myocardial velocities were measured using color DTI at six mitral annular sites and averaged to provide global estimates. RESULTS: The median follow-up period was 25 months (interquartile range, 19-32 months...

  10. Longitudinal left ventricular myocardial dysfunction assessed by 2D colour tissue Doppler imaging in a dog with systemic hypertension and severe arteriosclerosis.

    Science.gov (United States)

    Nicolle, A P; Carlos Sampedrano, C; Fontaine, J J; Tessier-Vetzel, D; Goumi, V; Pelligand, L; Pouchelon, J-L; Chetboul, V

    2005-03-01

    A 12-year-old sexually intact male Vendee Griffon Basset was presented for acute pulmonary oedema. Severe systemic systolic arterial hypertension (SAH) was diagnosed (290 mmHg). Despite blood and abdominal ultrasound tests, the underlying cause of the systemic hypertension could not be determined, and primary SAH was therefore suspected. Conventional echocardiography showed eccentric left ventricular hypertrophy with normal fractional shortening. Despite this apparent normal systolic function, 2D colour tissue Doppler imaging (TDI) identified a marked longitudinal systolic left ventricular myocardial alteration, whereas radial function was still preserved. Three months later, the dog underwent euthanasia because of an acute episode of distal aortic thromboembolism. Necropsy revealed severe aortic and iliac arteriosclerosis. SAH related to arteriosclerosis is a common finding in humans, but has not been previously described in dogs. Moreover, its consequence on longitudinal myocardial function using TDI has never been documented before in this species.

  11. Relation of tricuspid annular displacement and tissue Doppler imaging velocities with duration of weaning in mechanically ventilated patients with acute pulmonary edema

    Directory of Open Access Journals (Sweden)

    Dragoumanis Christos K

    2010-05-01

    Full Text Available Abstract Background Liberation from the ventilator is a difficult task, whereas early echocardiographic indices of weaning readiness are still lacking. The aim of this study was to test whether tricuspid annular plane systolic excursion (TAPSE and right ventricular (RV systolic (Sm and diastolic (Em & Am tissue Doppler imaging (TDI velocities are related with duration of weaning in mechanically ventilated patients with acute respiratory failure due to acute pulmonary edema (APE. Methods Detailed quantification of left and right ventricular systolic and diastolic function was performed at admission to the Intensive Care Unit by Doppler echocardiography, in a cohort of 32 mechanically ventilated patients with APE. TAPSE and RV TDI velocities were compared between patients with and without prolonged weaning (≥ or Results Patients with prolonged weaning (n = 12 had decreased TAPSE (14.59 ± 1.56 vs 19.13 ± 2.59 mm, Sm (8.68 ± 0.94 vs 11.62 ± 1.77 cm/sec and Em/Am ratio (0.98 ± 0.80 vs 2.62 ± 0.67, p 2 = 0.53, beta slope = 0.76, p 2 = 0.52, beta = 0.75, p 2 = 0.57, beta = 0.32, p Conclusions We suggest that in mechanically ventilated patients with APE, low TAPSE and RV TDI velocities upon admission are associated with delayed liberation from mechanical ventilation, probably due to more severe LV heart failure.

  12. Tissue Doppler assessment of right ventricular function in female patients with limited form of systemic sclerosis

    Directory of Open Access Journals (Sweden)

    Ayman Ahmed Abdelaziz

    2013-09-01

    Conclusions: Patients with limited form of SSc present with pulsed-tissue Doppler imaging indices indicative of right ventricle dysfunction, which had significant correlations with disease duration. Tissue Doppler is a valuable non-invasive tool for detecting RV myocardial involvement in patients with limited SSc.

  13. Assessment of Regional Myocardial Displacement via Spectral Tissue Doppler Compared with Color Tissue Tracking

    Directory of Open Access Journals (Sweden)

    Zahra Ojaghi-Haghighi

    2008-12-01

    Full Text Available Background: The recent developments in tissue Doppler imaging (TDI now more than ever permit the quantification of the myocardial function. In the current systems, tissue tracking or displacement curves are generated from color tissue Doppler data through the instantaneous temporal integral of velocity-time curves. Methods: The purpose of the present study was to assess regional myocardial displacement via spectral TDI. Maximum myocardial velocities were extracted from spectral pulsed tissue Doppler images using a developed computer program and were integrated throughout the cardiac cycle. Spectral tissue Doppler echocardiography was performed to evaluate longitudinal and radial functions in 20 healthy men, and the calculated end-systolic displacements were subsequently compared with the displacements measured from the same areas via color tissue tracking. Results: According to the Bland-Altman analysis between spectral tissue tracking and color tissue tracking, the significant arithmetic mean was 7.34 mm with SD mean differences of ±2.24 mm in all of the evaluated segments. Despite significant differences (p<0.001, there was a good significant correlation between the two methods (r=0.79, p<0.001. Conclusion: A verification study showed that the proposed approach had the ability to assess regional myocardial displacement using spectral TDI, which can be used in a wider range of equipment than is currently possible.

  14. Statin therapy blunts inflammatory activation and improves prognosis and left ventricular performance assessed by Tissue Doppler Imaging in subjects with chronic ischemic heart failure: results from the Daunia Heart Failure Registry

    Directory of Open Access Journals (Sweden)

    Michele Correale

    2011-01-01

    Full Text Available BACKGROUND: A limited number of studies have used Tissue Doppler Imaging (TDI to evaluate the effect of statin therapy on left ventricular dysfunction in patients with chronic heart failure. In this work, we aimed to determine whether statin administration influenced prognosis, inflammatory activation and myocardial performance evaluated by Tissue Doppler Imaging in subjects enrolled in the Daunia Heart Failure Registry, a local registry of patients with chronic heart failure. METHODS: This study retrospectively analyzed 353 consecutive outpatients with chronic heart failure (mean follow-up 384 days, based on whether statin therapy was used. In all patients, several Tissue Doppler Imaging parameters were measured; circulating levels of interleukin (IL-6, IL-10 and C-reactive protein were also assayed. RESULTS: Statin administration in 128 subjects with ischemic heart disease was associated with a lower incidence of adverse events (rehospitalization for HF 15% vs. 46%, p<0.001; ventricular arrhythmias 5% vs. 21%, p<0.01; cardiac death 1% vs. 8%, p<0.05, lower circulating levels of IL-6 (p<0.05 and IL-10 (p<0.01, lower rates of chronic heart failure (p<0.001 and better Tissue Doppler Imaging performance (E/E' ratio 12.82 + 5.42 vs. 19.85 + 9.14, p<0.001; ET: 260.62+ 44.16 vs. 227.11 +37.58 ms, p<0.05; TP: 176.79 + 49.93 vs. 136.7 + 37.78 ms, p<0.05 and St: 352.35 + 43.17 vs. 310.67 + 66.46 + 37.78 ms, p<0.05. CONCLUSIONS: Chronic ischemic heart failure outpatients undergoing statin treatment had fewer readmissions for adverse events, blunted inflammatory activation and improved left ventricular performance assessed by Tissue Doppler Imaging.

  15. Alterations in left ventricular structure and diastolic function in professional football players: assessment by tissue Doppler imaging and left ventricular flow propagation velocity.

    Science.gov (United States)

    Tumuklu, M Murat; Ildizli, Muge; Ceyhan, Koksal; Cinar, Cahide Soydas

    2007-02-01

    Long-term regular exercise is associated with physiologic and morphologic cardiac alterations. Tissue Doppler imaging (TDI) and ventricular early flow propagation velocity (Vp) are new tolls in the evaluation of myocardial function. We sought to compare TDI and Vp findings in professional football players and age-adjusted sedentary controls to assess the effect of regular athletic training on myocardial function. Twenty-four professional football players and age-, sex-, and weight-adjusted 20 control subjects underwent standard Doppler echocardiography pulsed TDI, performed parasternal four-chamber views by placing sample volume septal and lateral side of mitral annulus and lateral tricuspid annulus. Vp values were obtained by measuring the slope delineated by first aliasing velocity from the mitral tips toward the apex by using apical four-chamber color M-mode Doppler images. Age, body surface area, blood pressure, and heart rate were comparable between two groups. Football players had significantly increased LV mass, mass index (due to both higher wall thickness and end-diastolic diameter), end-systolic and end-diastolic volume, left atrial diameter, and decreased transmitral diastolic late velocity. In athletes TDI analysis showed significantly increased mitral annulus septal DTI peak early diastolic (e) velocity (0.22 +/- 0.04 vs 0.19 +/- 0.04, P velocity (0.19 +/- 0.03 vs 0.16 +/- 0.02, P velocity ratio (1.96 +/- 0.41 and 1.66 +/- 0.23, P velocity (E) to e in both lateral (4.72 +/- 1.20 vs 5.95 +/- 1.38, P = 0.007) and septal (3.90 +/- 0.80 vs 5.25 +/- 1.50, P = 0.002) side of mitral annulus were significantly lower in athletes. In Vp evaluation, we found higher Vp values (60.52 +/- 6.95 in athletes and 56.56 +/- 4.24 in controls, P = 0.03) in football players. Professional football playing is associated with morphologic alteration in left ventricle and left atrium and improvement in left ventricle diastolic function that can be detected by TDI and Vp. These

  16. with Ultrasound Color Doppler Imaging

    Directory of Open Access Journals (Sweden)

    Shin Takayama

    2012-01-01

    Full Text Available Color Doppler imaging (CDI can be used to noninvasively create images of human blood vessels and quantitatively evaluate blood flow in real-time. The purpose of this study was to assess the effects of acupuncture on the blood flow of the peripheral, mesenteric, and retrobulbar arteries by CDI. Statistical significance was defined as P values less than 0.05. Blood flow in the radial and brachial arteries was significantly lower during needle stimulation on LR3 than before in healthy volunteers, but was significantly higher after needle stimulation than before. LR3 stimulation also resulted in a significant decrease in the vascular resistance of the short posterior ciliary artery and no significant change of blood flow through the superior mesenteric artery (SMA during acupuncture. In contrast, ST36 stimulation resulted in a significant increase in blood flow through the SMA and no significant change in the vascular resistance of the retrobulbar arteries. Additionally, acupuncture at previously determined acupoints in patients with open-angle glaucoma led to a significant reduction in the vascular resistance of the central retinal artery and short posterior ciliary artery. Our results suggest that acupuncture can affect blood flow of the peripheral, mesenteric, and retrobulbar arteries, and CDI can be useful to evaluate hemodynamic changes by acupuncture.

  17. Tissue Doppler Findings in Patients with Pulmonary Arterial Hypertension

    Directory of Open Access Journals (Sweden)

    Firoozeh Abtahi

    2016-09-01

    Full Text Available In conclusion, our results suggested that increasing degrees of pulmonary artery systolic pressure affected timing of some tissue Doppler-derived intervals within the cardiac cycle, including IVC time, time to peak systolic myocardial velocity (Sm, and time to peak strain. Therefore, tissue Doppler imaging could be used in assessment of patients with suspected pulmonary arterial hypertension. Background: Pulmonary hypertension is an untreatable condition with poor prognosis and factors such as more elevated pulmonary arterial systolic pressure and right ventricular dysfunction are associated with a worse outcome. Objectives: Considering the limitations of the current modalities, this study aimed to find the relationship between tissue Doppler-derived systolic and diastolic parameters and elevated pulmonary arterial pressure in order to assess the routine application of tissue Doppler imaging in evaluation of pulmonary arterial hypertension. Patients and Methods: This study was conducted on 100 inpatient and outpatient individuals referred to the Department of Echocardiography in Shahid Faghihi hospital, Shiraz, Iran from July 2012 to March 2013. The individuals who had preserved right ventricular function in the presence of pulmonary arterial hypertension were included in the case group. On the other hand, the patients who did not have echocardiographic signs of pulmonary arterial hypertension were enrolled into the control group. All the patients underwent a complete transthoracic echocardiogram including 2-dimensional, color flow, and spectral Doppler as well as tissue Doppler imaging using a vivid E9 system, and the desired systolic and diastolic parameters were recorded. The relationship among these parameters was evaluated by independent sample t-test using the SPSS statistical software, version 16. Besides, P < 0.05 was considered to be statistically significant. Results: The mean time to peak strain was significantly longer in the case

  18. Tissue Doppler imaging for detection of radial and longitudinal myocardial dysfunction in a family of cats affected by dystrophin-deficient hypertrophic muscular dystrophy.

    Science.gov (United States)

    Chetboul, Valérie; Blot, Stephane; Sampedrano, Carolina Carlos; Thibaud, Jean-Laurent; Granger, Nicolas; Tissier, Renaud; Bruneval, Patrick; Gaschen, Frederic; Gouni, Vassiliki; Nicolle, Audrey P; Pouchelon, Jean-Louis

    2006-01-01

    Diagnosis of feline hypertrophic cardiomyopathy currently is based on the presence of myocardial hypertrophy detected using conventional echocardiography. The accuracy of tissue Doppler imaging (TDI) for earlier detection of the disease has never been described. The objective of this sudy was to quantify left ventricular free wall (LVFW) velocities in cats with hypertrophic muscular dystrophy (HFMD) during preclinical cardiomyopathy using TDI. The study animals included 22 healthy controls and 7 cats belonging to a family of cats with HFMD (2 affected adult males, 2 heterozygous adult females, one 2.5-month-old affected male kitten, and 2 phenotypically normal female kittens from the same litter). All cats were examined via conventional echocardiography and 2-dimensional color TDI. No LVFW hypertrophy was detected in the 2 carriers or in the affected kitten when using conventional echocardiography and histologic examination, respectively. The LVFW also was normal for 1 affected male and at the upper limit of normal for the 2nd male. Conversely, LVFW dysfunction was detected in all affected and carrier cats with HFMD when using TDI. TDI consistently detects LVFW dysfunction in cats with HFMD despite the absence of myocardial hypertrophy. Therefore, TDI appears more sensitive than conventional echocardiography in detecting regional myocardial abnormalities.

  19. Prognostic Value of Cardiac Time Intervals by Tissue Doppler Imaging M-Mode in Patients With Acute ST-Segment-Elevation Myocardial Infarction Treated With Primary Percutaneous Coronary Intervention

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Mogelvang, Rasmus; Søgaard, Peter;

    2013-01-01

    Background- Color tissue Doppler imaging M-mode through the mitral leaflet is an easy and precise method to estimate all cardiac time intervals from 1 cardiac cycle and thereby obtain the myocardial performance index (MPI). However, the prognostic value of the cardiac time intervals and the MPI...... assessed by color tissue Doppler imaging M-mode through the mitral leaflet in patients with ST-segment-elevation myocardial infarction (MI) is unknown. Methods and Results- In total, 391 patients were admitted with an ST-segment-elevation MI, treated with primary percutaneous coronary intervention......, and examined by echocardiography a median of 2 days after the ST-segment-elevation MI. Outcome was assessed according to death (n=33), hospitalization with heart failure (n=53), or new MI (n=25). Follow-up time was a median of 25 months. The population was stratified according to tertiles of the MPI. The risk...

  20. Holographic laser Doppler imaging of microvascular blood flow

    CERN Document Server

    Magnain, C; Boucneau, T; Simonutti, M; Ferezou, I; Rancillac, A; Vitalis, T; Sahel, J A; Paques, M; Atlan, M

    2014-01-01

    We report on local superficial blood flow monitoring in biological tissue from laser Doppler holographic imaging. In time averaging recording conditions, holography acts as a narrowband bandpass filter, which, combined with a frequency shifted reference beam, permits frequency selective imaging in the radiofrequency range. These Doppler images are acquired with an off axis Mach Zehnder interferometer. Microvascular hemodynamic components mapping is performed in the cerebral cortex of the mouse and the eye fundus of the rat with near-infrared laser light without any exogenous marker. These measures are made from a basic inverse method analysis of local first order optical fluctuation spectra at low radiofrequencies, from 0 Hz to 100 kHz. Local quadratic velocity is derived from Doppler broadenings induced by fluid flows, with elementary diffusing wave spectroscopy formalism in backscattering configuration. We demonstrate quadratic mean velocity assessment in the 0.1 to 10 millimeters per second range in vitro ...

  1. Magnetic Doppler Imaging of Active Stars

    CERN Document Server

    Kochukhov, O

    2007-01-01

    We present a new implementation of the magnetic Doppler imaging technique, which aims at self-consistent temperature and magnetic mapping of the surface structures in cool active stars. Our magnetic imaging procedure is unique in its capability to model individual spectral features in all four Stokes parameters. We discuss performance and intrinsic limitations of the new magnetic Doppler imaging method. A special emphasis is given to the simultaneous modelling of the magnetically sensitive lines in the optical and infrared regions and to combining information from both atomic and molecular spectral features. These two techniques may, for the first time, give us a tool to study magnetic fields in the starspot interiors.

  2. Cardiac functions assessment in children with celiac disease and its correlation with the degree of mucosal injury: Doppler tissue imaging study

    Directory of Open Access Journals (Sweden)

    Abeer Fathy

    2016-01-01

    Full Text Available Background/Aims: Celiac disease (CD-associated cardiologic disorders is a growing concern. However, data regarding cardiac affection in children with CD are few. This study aimed at assessing the subclinical impact of CD on the global myocardial performance in Saudi children with CD using Doppler tissue imaging (DTI. Patients and Methods: Conventional two-dimensional echocardiography was performed among 20 Saudi children with CDas well as 20 age and sex-matched healthy controls. DTI were used to determine right ventricular (RV and left ventricular (LV Tei indexes. These findings were correlated with the Modified Marsh Classification of the histologic findings in CD. Results: LV and RV Tei indexes were significantly higher in children with CD than the control group (mean ± standard deviation: 0.47 ± 0.05 vs. 0.31 ± 0.18; P< 0.0005 and 0.51 ± 0.04 vs. 0.32 ± 0.05; P< 0.0001, respectively. RV Tei index was found to be positively correlated with the Modified Marsh Classification of CD (r = 0.7753, P< 0.0001. LV Tei index tended to be more affected in patients with more severe histologic findings, however, such relation did not reach statistical significance (r = 0.2479, P = 0.292. Fractional shortening did not correlate with the Modified Marsh Classification of histologic findings in CD patients (r= −0.11, P = 0.641. Conclusions: Subclinical myocardial dysfunction of both ventricles occurs in children with CD. The DTI method appears to be more sensitive than conventional two-dimensional echocardiography in the early detection of myocardial dysfunction in children with CD.

  3. Cardiac Time Intervals by Tissue Doppler Imaging M-Mode: Normal Values and Association with Established Echocardiographic and Invasive Measures of Systolic and Diastolic Function.

    Directory of Open Access Journals (Sweden)

    Tor Biering-Sørensen

    Full Text Available To define normal values of the cardiac time intervals obtained by tissue Doppler imaging (TDI M-mode through the mitral valve (MV. Furthermore, to evaluate the association of the myocardial performance index (MPI obtained by TDI M-mode (MPITDI and the conventional method of obtaining MPI (MPIConv, with established echocardiographic and invasive measures of systolic and diastolic function.In a large community based population study (n = 974, where all are free of any cardiovascular disease and cardiovascular risk factors, cardiac time intervals, including isovolumic relaxation time (IVRT, isovolumic contraction time (IVCT, and ejection time (ET were obtained by TDI M-mode through the MV. IVCT/ET, IVRT/ET and the MPI ((IVRT+IVCT/ET were calculated. We also included a validation population (n = 44 of patients who underwent left heart catheterization and had the MPITDI and MPIConv measured.IVRT, IVRT/ET and MPI all increased significantly with increasing age in both genders (p<0.001 for all. IVCT, ET, IVRT/ET, and MPI differed significantly between males and females, displaying that women, in general exhibit better cardiac function. MPITDI was significantly associated with invasive (dP/dt max and echocardiographic measures of systolic (LVEF, global longitudinal strain and global strainrate s and diastolic function (e', global strainrate e(p<0.05 for all, whereas MPIConv was significantly associated with LVEF, e' and global strainrate e (p<0.05 for all.Normal values of cardiac time intervals differed between genders and deteriorated with increasing age. The MPITDI (but not MPIConv is associated with most invasive and established echocardiographic measures of systolic and diastolic function.

  4. Relation Between Capillary Wedge Pressure Measured by Echocardiography Through Tissue Doppler Imaging (TDI Method and Catheterism in Patients with Mitral Valve Stenosis

    Directory of Open Access Journals (Sweden)

    Mashallah Dehghani

    2006-07-01

    Full Text Available Background: Considering suggested formula in the references and PCWP measured by catheterism, in the present study the relation between pulmonary capillary wedge pressure (PCWP measured the flow velocity of mitral valve and mitral annulus motion through tissue doppler imaging is evaluated Methods: 52 cases of severe MS were admitted for Balloon Mitral Valvolotomy (BMV are included in this study. Mean age was 35±5 years consisting of 40 females and 12 males. Valve area, Pulmonary artery systolic pressure (PAP, E (Maximum Velocity of mitral valve at the beginning of diastole & Em (Maximum rate of mitral annular motion at the beginning of diastole which is recorded through septal or lateral wall annulus site velocity and left atrial (LA size were also measured by echocardiography and PCWP & PAP through catheterism. All patients had normal ejection fraction (EF and coronary arteries; there was no other valvular diseases and shunts. Results: There was a significant correlation between PAP in echocardiography and catheterism. Mean PAP was 53±19 mmHg in echocardiography and 53.9±17.8mmHg in catheterism. There wasn't any correlation between PCWP in echocardiography and catheterism (P=0.33 and also no relation between PCWP and mitral valve area (MVA or LA size (P=0.2. E/Em ratio increased in severe MS cases.Conclusion: E/Em ratio and suggested formula would overestimate the wedge pressure so echocardiography is not a reliable method for measuring PCWP in severe MS. Em velocity and E/Em ratio may be used for estimating MS severity.

  5. Laser Doppler perfusion monitoring and imaging of blood microcirculation

    Science.gov (United States)

    Nilsson, Gert E.; Wardell, Karin

    1994-07-01

    Laser Doppler perfusion monitoring is a method of assessing tissue perfusion based on measurements performed using Doppler broadening of monochromatic light scattered in moving blood cells. Ever since laser Doppler perfusion monitors became available about 15 years ago they have been used in numerous applications in both clinical and laboratory settings. The high spatial resolution has in practice manifested itself as one of the main limitations of the method. The reason for this is the difficulty in attaining reproducible values at successive measurement sites because most skin tissue possesses a substantial variation in blood flow even at adjacent measurement sites. In order to overcome this difficulty the laser Doppler perfusion imager was developed. In this camera-like device, the laser beam successively scans the tissue and the Doppler components of the backscattered light are detected by a remote photodiode. After a scanning procedure is complete, a color-coded perfusion map showing the spatial variation of skin blood flow is displayed on a monitor. The operating principle and early applications of this emerging technology are addressed in further detail.

  6. Wide Angle Michelson Doppler Imaging Interferometer (WAMDII)

    Science.gov (United States)

    Roberts, B.

    1986-01-01

    The wide angle Michelson Doppler imaging interferometer (WAMDII) is a specialized type of optical Michelson interferometer working at sufficiently long path difference to measure Doppler shifts and to infer Doppler line widths of naturally occurring upper atmospheric Gaussian line emissions. The instrument is intended to measure vertical profiles of atmospheric winds and temperatures within the altitude range of 85 km to 300 km. The WAMDII consists of a Michelson interferometer followed by a camera lens and an 85 x 106 charge coupled device photodiode array. Narrow band filters in a filter wheel are used to isolate individual line emissions and the lens forms an image of the emitting region on the charge coupled device array.

  7. Intramyocardial analysis of regional systolic and diastolic function in ischemic heart disease with Doppler tissue imaging: role of the different myocardial layers.

    Science.gov (United States)

    Marcos-Alberca, Pedro; García-Fernández, Miguel A; Ledesma, María J; Malpica, Norberto; Santos, Andrés; Moreno, Mar; Bermejo, Javier; Antoranz, José C; Desco, Manuel

    2002-02-01

    Preliminary experimental data have shown a nonuniform distribution of myocardial velocities (MVs) across the myocardial wall in normal conditions. However, after ischemic damage to the myocardium, a different pattern of reduction in the myocardial layers has been reported. The aim of this study is to analyze the spatial distribution of MVs and the resultant myocardial velocity gradients (MVGs) during the systolic and diastolic time periods. Doppler tissue imaging (DTI) in color M-mode was used to evaluate 3 different myocardial layers (endocardium, mesocardium, and epicardium) and their changes as a result of ischemia. Thirty-two consecutive patients were studied with DTI color M-mode: 18 patients with a history of previous or ongoing myocardial infarction and 14 healthy subjects. Postprocessing of images was accomplished with proprietary software. MV and MVG values of all layers along both systolic and diastolic time were calculated. For temporal analysis, systole was subdivided in 3 equal periods. Early- and late-diastolic times were also identified. In ischemic patients, the mean MV and maximum MV throughout systole decreased significantly in the endocardium and mesocardium, whereas only slightly in the epicardium. The mean MVG was less in ischemic patients (0.66 +/- 0.11 vs 0.23 +/- 0.15, P <.03). Temporal analysis showed a decrease in the maximal MV and MVG in all layers over the 3 systolic periods. This decrease was the more consistent in mesocardium. In diastole, there was a decrease in maximal MV in all layers, being more pronounced in endocardium and mesocardium. Diastolic mean MVG was shown to be different between control and ischemic groups (-0.2 +/- 0.05 vs -0.10 +/- 0.04, P <.06). A significant decrease of the maximal MV in endocardium and mesocardium was reported in the temporal analysis during early diastole. No change was reported in the epicardium. The MVG value also showed a significant decrease (-2.69 +/- 0.29 vs -1.59 +/- 0.89, P <.02). In

  8. ISAR imaging using the instantaneous range instantaneous Doppler method

    CSIR Research Space (South Africa)

    Wazna, TM

    2015-10-01

    Full Text Available In Inverse Synthetic Aperture Radar (ISAR) imaging, the Range Instantaneous Doppler (RID) method is used to compensate for the nonuniform rotational motion of the target that degrades the Doppler resolution of the ISAR image. The Instantaneous Range...

  9. Fish embryo multimodal imaging by laser Doppler digital holography

    CERN Document Server

    Verrier, Nicolas; Picart, Pascal; Gross, Michel

    2015-01-01

    A laser Doppler imaging scheme combined to an upright microscope is proposed. Quantitative Doppler imaging in both velocity norm and direction, as well as amplitude contrast of either zebrafish flesh or vasculature is demonstrated.

  10. Tissue Doppler imaging is a sensitive echocardiographic technique to detect subclinical systolic and diastolic dysfunction of both ventricles in type 1 diabetes mellitus.

    Science.gov (United States)

    Suran, David; Sinkovic, Andreja; Naji, Franjo

    2016-04-22

    Subclinical left (LV) and right ventricular (RV) dysfunction has been demonstrated in type 2 diabetes mellitus and evidence indicates impaired LV diastolic function in type 1 diabetes mellitus (T1DM) as well. The aim of our study was to evaluate the role of tissue Doppler imaging (TDI) in assessment of global LV and RV function in T1DM patients. A detailed two-dimensional, pulsed wave Doppler and pulsed wave TDI analysis was performed in 53 normotensive middle-aged T1DM patients and compared to healthy controls. In T1DM patients TDI analysis revealed reduced mean mitral septal and lateral E' velocities as well as reduced mean tricuspid E˙t velocity compared to healthy controls (E'sept 8.89 ± 1.89 cm/s vs. 11.50 ± 2.41 cm/s, p < 0.001; E'lat 12.29 ± 2.58 cm/s vs.15.30 ± 2.95 cm/s, p < 0,001; E't 13.56 ± 2.91 cm/s vs. 15.60 ± 2.99 cm/s, p = 0.001). Mean ratios E/E'sept, E/E'lat and E/E't were significantly higher in diabetics with cutoff value of 7.4 for E/E'sept and 3.4 for E/E't, differentiating diabetics with LV and RV diastolic impairement from matched healthy controls (sensitivity 76.5 %, specificity 73.8 % for E/E'sept and sensitivity 72.1 %, specificity 66.7 % for E/E't). Myocardial acceleration during isovolumetric contraction (IVA) measured at the septal mitral (LV IVA) and lateral tricuspid annulus (RV IVA) was the only parameter indicating reduced contractility of both ventricles in diabetics compared to controls (LV IVA 230.70 ± 61.26 cm/s(2) vs. 283.32 ± 59.74 cm/s(2), p < 0,001; RV IVA 275.48 ± 68.08 cm/s(2) vs. 316.86 ± 80.95 cm/s(2), p = 0.011). LV IVA had better diagnostic accuracy than RV IVA to predict early contractile impairement in T1DM patients (area under the curve 0.758, p < 0.001 for LV IVA and 0.648, p = 0.017 for RV IVA). TDI is essential to detect subclinical diastolic deterioration of both ventricles in T1DM patients. TDI-derived IVA might be useful to assess early systolic alterations of both ventricles in T1DM patients.

  11. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultrasonic pulsed doppler imaging system. 892.1550... system. (a) Identification. An ultrasonic pulsed doppler imaging system is a device that combines the features of continuous wave doppler-effect technology with pulsed-echo effect technology and is intended...

  12. Optical Doppler tomography and spectral Doppler imaging of localized ischemic stroke in a mouse model

    Science.gov (United States)

    Yu, Lingfeng; Nguyen, Elaine; Liu, Gangjun; Rao, Bin; Choi, Bernard; Chen, Zhongping

    2010-02-01

    We present a combined optical Doppler tomography/spectral Doppler imaging modality to quantitatively evaluate the dynamic blood circulation and the artery blockage before and after a localized ischemic stroke in a mouse model. Optical Doppler Tomography (ODT) combines the Doppler principle with optical coherence tomography for noninvasive localization and measurement of particle flow velocity in highly scattering media with micrometer scale spatial resolution. Spectral Doppler imaging (SDI) provides complementary temporal flow information to the spatially distributed flow information of Doppler imaging. Fast, repeated, ODT scans across an entire vessel were performed to record flow dynamic information with high temporal resolution of cardiac cycles. Spectral Doppler analysis of continuous Doppler images demonstrates how the velocity components and longitudinally projected flow-volume-rate change over time for scatters within the imaging volume using spectral Doppler waveforms. Furthermore, vascular conditions can be quantified with various Doppler-angle-independent flow indices. Non-invasive in-vivo mice experiments were performed to evaluate microvascular blood circulation of a localized ischemic stroke mouse model.

  13. Variações de parâmetros da função diastólica do ventrículo esquerdo de acordo com a idade através da ecocardiografia com Doppler tissular Changes in the parameters of left ventricular diastolic function according to age on tissue Doppler imaging

    Directory of Open Access Journals (Sweden)

    Márcia Duarte Pedone

    2004-12-01

    Full Text Available OBJETIVO: Determinar a correlação entre as velocidades diastólicas do Doppler tissular com a idade em amostra de adultos saudáveis, e correlacionar a idade com as velocidades do fluxo transmitral e de veias pulmonares. MÉTODOS: Estudados, através da ecocardiografia, 51 indivíduos saudáveis, com idades entre 21 e 69 anos e registradas as velocidades miocárdicas diastólicas ao Doppler tissular e determinadas as velocidades dos fluxos transmitral e venoso pulmonar. RESULTADOS: As velocidades miocárdicas diastólicas iniciais septal basal e lateral basal apresentaram correlação inversa com a idade, com r = - 0,40 (p = 0,004 e r = - 0,60 (p = 0,0001 respectivamente. As velocidades atriogênicas do Doppler tissular foram diretamente correlacionadas com a idade, sendo no segmento septal basal r = 0,56 (p = 0,0001 e no segmento lateral basal r = 0,50 (p = 0,0001. As velocidades do fluxo transmitral e do fluxo venoso pulmonar também mostraram correlação com a idade. CONCLUSÃO: Existe correlação entre a idade e as velocidades miocárdicas diastólicas do Doppler tissular e com as velocidades do fluxo transmitral e fluxo venoso pulmonar, demonstrando em indivíduos saudáveis uma variação de parâmetros da função diastólica do ventrículo esquerdo com a evolução natural da idade.OBJECTIVE: To determine the correlation between diastolic velocities on tissue Doppler imaging and age in a sample of healthy adults and to correlate age with the velocities of transmitral and pulmonary vein flows. METHODS: Echocardiographic assessment of 51 healthy individuals, whose ages ranged from 21 to 69 years. The diastolic myocardial velocities were recorded on tissue Doppler imaging. The velocities of the transmitral and pulmonary vein flows were also determined. RESULTS: The initial basal septal and basal lateral diastolic myocardial velocities showed an inverse correlation with age [r = - 0.40 (P = 0.004, and r = - 0.60 (P = 0.0001, respectively

  14. Range-instantaneous Doppler imaging of inverse synthetic aperture sonar

    Institute of Scientific and Technical Information of China (English)

    XU Jia; JIANG Xingzhou; TANG Jingsong

    2003-01-01

    Because the existing range-Doppler algorithm in inverse synthetic aperture sonar (ISAS) is based on target model of uniform motion, it may be invalidated for maneuvering targets due to the time-varying changes of both individual scatter′s Doppler and imaging projection plane. To resolve the problem, a new range-instantaneous Doppler imaging method is proposed for imaging maneuvering targets based on time-frequency analysis. The proposed approach is verified using real underwater acoustic data.

  15. EUV Doppler Imaging for CubeSat Platforms Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mature the design and fabricate the Flare Initiation Doppler Imager (FIDI) instrument to demonstrate low-spacecraft-resource EUV technology (most notably,...

  16. Color M-mode and pulsed wave tissue Doppler echocardiography

    DEFF Research Database (Denmark)

    Møller, J E; Søndergaard, E; Poulsen, S H;

    2001-01-01

    To assess the association between color M-mode flow propagation velocity and the early diastolic mitral annular velocity (E(m)) obtained with tissue Doppler echocardiography and to assess the prognostic implications of the indexes, echocardiography was performed on days 1 and 5, and 1 and 3 months...

  17. Combined perfusion and doppler imaging using plane-wave nonlinear detection and microbubble contrast agents.

    Science.gov (United States)

    Tremblay-Darveau, Charles; Williams, Ross; Milot, Laurent; Bruce, Matthew; Burns, Peter N

    2014-12-01

    Plane-wave imaging offers image acquisition rates at the pulse repetition frequency, effectively increasing the imaging frame rates by up to two orders of magnitude over conventional line-by-line imaging. This form of acquisition can be used to achieve very long ensemble lengths in nonlinear modes such as pulse inversion Doppler, which enables new imaging trade-offs that were previously unattainable. We first demonstrate in this paper that the coherence of microbubble signals under repeated exposure to acoustic pulses of low mechanical index can be as high as 204 ± 5 pulses, which is long enough to allow an accurate power Doppler measurement. We then show that external factors, such as tissue acceleration, restrict the detection of perfusion at the capillary level with linear Doppler, even if long Doppler ensembles are considered. Hence, perfusion at the capillary level can only be detected with ultrasound through combined microbubbles and Doppler imaging. Finally, plane-wave contrast-enhanced power and color Doppler are performed on a rabbit kidney in vivo as a proof of principle. We establish that long pulse-inversion Doppler sequences and conventional wall-filters can create an image that simultaneously resolves both the vascular morphology of veins and arteries, and perfusion at the capillary level with frame rates above 100 Hz.

  18. Resonant Doppler imaging with Fourier domain optical coherence tomography

    Science.gov (United States)

    Leitgeb, Rainer A.; Szklumowska, Anna; Pircher, Michael; Gotzinger, Erich; Fercher, Adolf F.

    2005-04-01

    Fourier Domain Optical Coherene Tomography (FD OCT) is a high speed imaging modality with increased sensitivity as compared to standard time domain (TD) OCT. The higher sensitivity is especially important, if strongly scattering tissue such as blood is investigated. Recently it could be shown that retinal blood flow can be assessed in-vivo by high speed FD OCT. However the detection bandwidth of color Doppler (CD) FDOCT is strongly limited due to blurring of the detected interference fringes during exposure. This leads to a loss of sensitivity for detection of fast changes in tissue. Using a moving mirror as a reference one can effectively increase the detection bandwidth for CD FDOCT and perform perfusion sectioning. The modality is called resonant CD FDOCT imaging. The principle of the method is presented and experimentally verified.

  19. Doppler time-of-flight imaging

    KAUST Repository

    Heidrich, Wolfgang

    2017-02-16

    Systems and methods for imaging object velocity are provided. In an embodiment, at least one Time-of-Flight camera is used to capture a signal representative of an object in motion over an exposure time. Illumination and modulation frequency of the captured motion are coded within the exposure time. A change of illumination frequency is mapped to measured pixel intensities of the captured motion within the exposure time, and information about a Doppler shift in the illumination frequency is extracted to obtain a measurement of instantaneous per pixel velocity of the object in motion. The radial velocity information of the object in motion can be simultaneously captured for each pixel captured within the exposure time. In one or more aspects, the illumination frequency can be coded orthogonal to the modulation frequency of the captured motion. The change of illumination frequency can correspond to radial object velocity.

  20. Remote Electromagnetic Vibration of Steerable Needles for Imaging in Power Doppler Ultrasound.

    Science.gov (United States)

    Cabreros, Sarah S; Jimenez, Nina M; Greer, Joseph D; Adebar, Troy K; Okamura, Allison M

    2015-05-01

    Robotic needle steering systems for minimally invasive medical procedures require complementary medical imaging systems to track the needles in real time. Ultrasound is a promising imaging modality because it offers relatively low-cost, real-time imaging of the needle. Previous methods applied vibration to the base of the needle using a voice coil actuator, in order to make the needle visible in power Doppler ultrasound. We propose a new method for needle tip vibration, using electromagnetic actuation of small permanent magnets placed inside the needle to improve needle tip visibility in power Doppler imaging. Robotic needle insertion experiments using artificial tissue and ex vivo porcine liver showed that the electromagnetic tip vibration method can generate a stronger Doppler response compared to the previous base vibration method, resulting in better imaging at greater needle depth in tissue. It also eliminates previous issues with vibration damping along the shaft of the needle.

  1. Functional Doppler optical coherence tomography for cortical blood flow imaging

    Science.gov (United States)

    Yu, Lingfeng; Liu, Gangjun; Nguyen, Elaine; Choi, Bernard; Chen, Zhongping

    2010-02-01

    Optical methods have been widely used in basic neuroscience research to study the cerebral blood flow dynamics in order to overcome the low spatial resolution associated with magnetic resonance imaging and positron emission tomography. Although laser Doppler imaging and laser speckle imaging can map out en face cortical hemodynamics and columns, depth resolution is not available. Two-photon microscopy has been used for mapping cortical activity. However, flow measurement requires fluorescent dye injection, which can be problematic. The noninvasive and high resolution tomographic capabilities of optical coherence tomography make it a promising technique for mapping depth resolved cortical blood flow. Here, we present a functional Doppler optical coherence tomography (OCT) imaging modality for quantitative evaluation of cortical blood flow in a mouse model. Fast, repeated, Doppler OCT scans across a vessel of interest were performed to record flow dynamic information with a high temporal resolution of the cardiac cycles. Spectral Doppler analysis of continuous Doppler images demonstrates how the velocity components and longitudinally projected flow-volume-rate change over time, thereby providing complementary temporal flow information to the spatially distributed flow information of Doppler OCT. The proposed functional Doppler OCT imaging modality can be used to diagnose vessel stenosis/blockage or monitor blood flow changes due to pharmacological agents/neuronal activities. Non-invasive in-vivo mice experiments were performed to verify the capabilities of function Doppler OCT.

  2. Doppler time-of-flight imaging

    KAUST Repository

    Heide, Felix

    2015-07-30

    Over the last few years, depth cameras have become increasingly popular for a range of applications, including human-computer interaction and gaming, augmented reality, machine vision, and medical imaging. Many of the commercially-available devices use the time-of-flight principle, where active illumination is temporally coded and analyzed on the camera to estimate a per-pixel depth map of the scene. In this paper, we propose a fundamentally new imaging modality for all time-of-flight (ToF) cameras: per-pixel velocity measurement. The proposed technique exploits the Doppler effect of objects in motion, which shifts the temporal frequency of the illumination before it reaches the camera. Using carefully coded illumination and modulation frequencies of the ToF camera, object velocities directly map to measured pixel intensities. We show that a slight modification of our imaging system allows for color, depth, and velocity information to be captured simultaneously. Combining the optical flow computed on the RGB frames with the measured metric axial velocity allows us to further estimate the full 3D metric velocity field of the scene. We believe that the proposed technique has applications in many computer graphics and vision problems, for example motion tracking, segmentation, recognition, and motion deblurring.

  3. Use of ultrasound, color Doppler imaging and radiography to monitor periapical healing after endodontic surgery.

    Science.gov (United States)

    Tikku, Aseem P; Kumar, Sunil; Loomba, Kapil; Chandra, Anil; Verma, Promila; Aggarwal, Renu

    2010-09-01

    This study evaluated the effectiveness of ultrasound, color Doppler imaging and conventional radiography in monitoring the post-surgical healing of periapical lesions of endodontic origin. Fifteen patients who underwent periapical surgery for endodontic pathology were randomly selected. In all patients, periapical lesions were evaluated preoperatively using ultrasound, color Doppler imaging and conventional radiography, to analyze characteristics such as size, shape and dimensions. On radiographic evaluation, dimensions were measured in the superoinferior and mesiodistal direction using image-analysis software. Ultrasound evaluation was used to measure the changes in shape and dimensions on the anteroposterior, superoinferior, and mesiodistal planes. Color Doppler imaging was used to detect the blood-flow velocity. Postoperative healing was monitored in all patients at 1 week and 6 months by using ultrasound and color Doppler imaging, together with conventional radiography. The findings were then analyzed to evaluate the effectiveness of the 3 imaging techniques. At 6 months, ultrasound and color Doppler imaging were significantly better than conventional radiography in detecting changes in the healing of hard tissue at the surgical site (P < 0.004). This study demonstrates that ultrasound and color Doppler imaging have the potential to supplement conventional radiography in monitoring the post-surgical healing of periapical lesions of endodontic origin.

  4. Assessment of right ventricular systolic function by tissue Doppler echocardiography

    DEFF Research Database (Denmark)

    Kjærgaard, Jesper

    2012-01-01

    is a promising tool for improving our understanding of right ventricular hemodynamics, several aspects of the technology must be evaluated. The accuracy and reproducibility of the technology is evaluated in vitro, and normal values, impact of changes in loading of the right ventricle, response to exercise...... gained from other quantitative echocardiographic measures of LV and RV function and pressure [VI]. Changes in tissue Doppler based measures of RV systolic function can be used to monitor the effect of selective vasodilation by phosphodiestares-5 inhibition in hypoxic pulmonary hypertension and exercise...... in normal individuals. Phosphodiestares-5 inhibition by sildenafil may predominantly be effective during hypoxia in resting conditions, and may improve the blunted response in RV contractility seen with exercise in hypoxia [VII]. Reduced RV free wall deformation can be quantified by tissue Doppler...

  5. Assessment of right ventricular systolic function by tissue Doppler echocardiography

    DEFF Research Database (Denmark)

    Kjærgaard, Jesper

    2012-01-01

    myocardial velocities, but no changes in SR, strain or isovolumic acceleration could be observed [II and III]. Tissue Doppler echocardiography of the RV free wall in non-massive pulmonary embolism quantifies degree of RV dysfunction, and supports the existence of the McConnell sign of mid-ventricular RV...... structure including significant dilatation, but is well tolerated with only mild reduction in measures of global RV systolic function as estimated by 2D echocardiography in an experimental animal model. Regional RV myocardial function is also only mildly reduced. Also no differences in global or regional RV......This thesis summarizes a series of studies performed in order to assess the clinical usefulness of a novel echocardiographic technology that allows non-invasive assessment of regional right ventricular myocardial velocities and deformation: tissue Doppler echocardiography. While the technology...

  6. Ventricular synchronicity: observations comparing pulse flow and tissue Doppler assessment in a Chinese healthy adult cohort

    Institute of Scientific and Technical Information of China (English)

    QUAN Xin; ZHU Tian-gang; GUO Shi; MA Jian-xin; WANG Xin; GUO Ji-hong

    2012-01-01

    Background Mechanical asynchrony is an important parameter in predicting the response to cardiac resynchronization therapy,but detailed knowledge about cardiac timing in healthy persons is scarce.Therefore,in the current study,we sought to investigate the physiological status of interventricular synchronicity using pulse wave flow and tissue Doppler imaging in a healthy Chinese population.Methods Eighty-eight healthy volunteers underwent standard flow and tissue Doppler echocardiographic examinations.Ventricular inflow and outflow pulse wave flow Doppler patterns were recorded together with annulus pulse tissue Doppler imaging.Time intervals from the beginning of the QRS complex to the onset,peak and end of each wave were measured.Results The onsets of systole between left and right ventricles were highly synchronized by both imaging modalities.However,the left ventricle reached the peak flow ejection and peak mechanical contraction earlier than the right ventricle,(165.61±26.23) ms vs.(204.3±34.55) ms (P <0.01) and (133.62±26.19) ms vs.(191.25±38.47) ms (P <0.01).Time to peak early diastolic relaxation was earlier in the left ventricle than in the right heart,(500.23±56.52) me vs.(524.94±47.42) ms (P <0.01).Conclusions Left and right ventricles were well synchronized at the onsets of systole and diastole even though interventricular peak systolic and peak early diastolic dyssynchrony was observed in healthy people by pulse wave Doppler imaging.In addition,diastolic timing events were slightly affected by age and gender.

  7. Using rotation for steerable needle detection in 3D color-Doppler ultrasound images.

    Science.gov (United States)

    Mignon, Paul; Poignet, Philippe; Troccaz, Jocelyne

    2015-08-01

    This paper demonstrates a new way to detect needles in 3D color-Doppler volumes of biological tissues. It uses rotation to generate vibrations of a needle using an existing robotic brachytherapy system. The results of our detection for color-Doppler and B-Mode ultrasound are compared to a needle location reference given by robot odometry and robot ultrasound calibration. Average errors between detection and reference are 5.8 mm on needle tip for B-Mode images and 2.17 mm for color-Doppler images. These results show that color-Doppler imaging leads to more robust needle detection in noisy environment with poor needle visibility or when needle interacts with other objects.

  8. Measurement of depth of burns by laser Doppler perfusion imaging

    NARCIS (Netherlands)

    Droog, E.J.; Droog, E.J.; Steenbergen, Wiendelt; Sjöberg, F.

    2001-01-01

    Laser Doppler perfusion imaging (LDPI), is a further development in laser Doppler flowmetry (LDF). Its advantage is that it enables assessment of microvascular blood flow in a predefined skin area rather than, as for LDF, in one place. In many ways this method seems to be more promising than LDF in

  9. Measurement of depth of burns by laser Doppler perfusion imaging

    NARCIS (Netherlands)

    Droog, E.J.; Steenbergen, W.; Sjöberg, F.

    2001-01-01

    Laser Doppler perfusion imaging (LDPI), is a further development in laser Doppler flowmetry (LDF). Its advantage is that it enables assessment of microvascular blood flow in a predefined skin area rather than, as for LDF, in one place. In many ways this method seems to be more promising than LDF in

  10. Using doppler radar images to estimate aircraft navigational heading error

    Science.gov (United States)

    Doerry, Armin W [Albuquerque, NM; Jordan, Jay D [Albuquerque, NM; Kim, Theodore J [Albuquerque, NM

    2012-07-03

    A yaw angle error of a motion measurement system carried on an aircraft for navigation is estimated from Doppler radar images captured using the aircraft. At least two radar pulses aimed at respectively different physical locations in a targeted area are transmitted from a radar antenna carried on the aircraft. At least two Doppler radar images that respectively correspond to the at least two transmitted radar pulses are produced. These images are used to produce an estimate of the yaw angle error.

  11. Tissue Doppler echocardiography reveals impaired cardiac function in patients with reversible ischaemia

    DEFF Research Database (Denmark)

    Hoffmann, Søren; Mogelvang, Rasmus; Sogaard, Peter

    2011-01-01

    AIMS: To determine if echocardiographic tissue Doppler imaging (TDI) performed at rest detects reduced myocardial function in patients with reversible ischaemia. METHODS AND RESULTS: Eighty-four patients with angina pectoris, no previous history of ischaemic heart disease and normal left ventricu......AIMS: To determine if echocardiographic tissue Doppler imaging (TDI) performed at rest detects reduced myocardial function in patients with reversible ischaemia. METHODS AND RESULTS: Eighty-four patients with angina pectoris, no previous history of ischaemic heart disease and normal left...... velocities could be demonstrated in patients with a false-positive SPECT compared with controls. CONCLUSION: In patients with stable angina pectoris, preserved ejection fraction, and reversible ischaemia assessed by SPECT, echocardiographic colour TDI performed at rest reveals impaired cardiac function...

  12. Myocardial Strain and Strain Rate Imaging: Comparison between Doppler Derived Strain Imaging and Speckle Tracking Echocardiography

    Directory of Open Access Journals (Sweden)

    Anita Sadeghpour

    2013-05-01

    Full Text Available Regional myocardial function has been traditionally assessed by visual estimation (1. Echocardiographic strain imaging which is known as deformation imaging, has been emerged as a quantitative technique to accurately estimate regional myocardial function and contractility. Currently, strain imaging has been regarded as a research tool in the most echocardiography laboratories. However, in recent years, strain imaging has gain momentum in daily clinical practice (2. The following two techniques have dominated the research arena of echocardiography: (1 Doppler based tissue velocity measurements, frequently referred to tissue Doppler or myocardial Doppler, and (2 speckle tracking on the basis of displacement measurements (3. Over the past two decades, Tissue Doppler Imaging (TDI and Doppler –derived strain (S and strain rate (SR imaging were introduced to quantify regional myocardial function. However, Doppler–derived strain variables faced criticisms, with regard to the angle dependency, noise interference, and substantial intraobserver and interobserver variability. The angle dependency is the major weakness of Doppler based methodology; however, it has the advantage of online measurements of velocities and time intervals with excellent temporal resolution, which is essential for the assessment of ischemia (4. Speckle-tracking echocardiography (STE or Non Doppler 2D strain echocardiography is a relatively new, largely angle-independent technique that analyzes motion by tracking natural acoustic reflections and interference patterns within an ultrasonic window. The image-processing algorithm tracks elements with approximately 20 to 40 pixels containing stable patterns and are described as ‘‘speckles’’ or ‘‘fingerprints’’. The speckles seen in grayscale B-mode (2D images are tracked consecutively frame to frame (5, 6. Assessment of 2D strain by STE is a semiautomatic method that requires definition of the myocardium

  13. Estimation of diastolic filling pressure with cardiac CT in comparison with echocardiography using tissue doppler imaging: Determination of optimal CT reconstruction parameters

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ji Sun; Suh, Jon; Lee, Heon [Soonchunhyang University Hospital Bucheon, Bucheon (Korea, Republic of); Lee, Bora [Dept. of Biostatistics, Soonchunhyang University College of Medicine, Seoul (Korea, Republic of); Lee, Soo Jeong [Terarecon Korea, Seoul (Korea, Republic of); Jou, Sung Shick [Dept. of Radiology, Soonchunhyang University Hospital Cheonan, Cheonan (Korea, Republic of); Lim, Hyun Kyung [Dept. of Radiology, Soonchunhyang University Hospital Seoul, Seoul (Korea, Republic of)

    2017-08-01

    To determine the optimal CT image reconstruction parameters for the measurement of early transmitral peak velocity (E), early peak mitral septal tissue velocity (E′), and E / E′. Forty-six patients underwent simultaneous cardiac CT and echocardiography on the same day. Four CT datasets were reconstructed with a slice thickness/interval of 0.9/0.9 mm or 3/3 mm at 10 (10% RR-interval) or 20 (5% RR-interval) RR-intervals. The E was calculated by dividing the peak transmitral flow (mL/s) by the corresponding mitral valve area (cm{sup 2}). E′ was calculated from the changes in the left ventricular length per cardiac phase. E / E′ was then estimated and compared with that from echocardiography. For assessment of E / E′, CT and echocardiography were more strongly correlated (p < 0.05) with a slice thickness of 0.9 mm and 5% RR-interval (r = 0.77) than with 3 mm or 10% RR-interval. The diagnostic accuracy of predicting elevated filling pressure (E / E′ ≥ 13, n = 14) was better with a slice thickness of 0.9 mm and 5% RR-interval (87.0%) than with 0.9 mm and 10% RR-interval (71.7%) (p = 0.123) and significantly higher than that with a slice thickness of 3 mm with 5% (67.4%) and 10% RR-interval (63.0%), (p < 0.05), respectively. Data reconstruction with a slice thickness of 0.9 mm at 5% RR-interval is superior to that with a slice thickness of 3 mm or 10% RR-interval in terms of the correlation of E / E′ between CT and echocardiography. Thin slices and frequent sampling also allow for more accurate prediction of elevated filling pressure.

  14. A new technique for assessing arterial pressure wave forms and central pressure with tissue Doppler

    Science.gov (United States)

    Haluska, Brian A; Jeffriess, Leanne; Mottram, Phillip M; Carlier, Stephane G; Marwick, Thomas H

    2007-01-01

    Background Non-invasive assessment of arterial pressure wave forms using applanation tonometry of the radial or carotid arteries can be technically challenging and has not found wide clinical application. 2D imaging of the common carotid arteries is routinely used and we sought to determine whether arterial waveform measurements could be derived from tissue Doppler imaging (TDI) of the carotid artery. Methods We studied 91 subjects (52 men, age 52 ± 14 years) with and without cardiovascular disease. Tonometry was performed on the carotid artery simultaneously with pulsed wave Doppler of the LVOT and acquired digitally. Longitudinal 2D images of the common carotid artery with and without TDI were also acquired digitally and both TDI and tonometry were calibrated using mean and diastolic cuff pressure and analysed off line. Results Correlation between central pressure by TDI and tonometry was excellent for maximum pressure (r = 0.97, p < 0.0001). The mean differences between central pressures derived by TDI and tonometry were minimal (systolic 5.36 ± 5.5 mmHg; diastolic 1.2 ± 1.2 mmHg). Conclusion Imaging of the common carotid artery motion with tissue Doppler may permit acquisition of a waveform analogous to that from tonometry. This method may simplify estimation of central arterial pressure and calculation of total arterial compliance. PMID:17266772

  15. Twente Optical Perfusion Camera: system overview and performance for video rate laser Doppler perfusion imaging

    NARCIS (Netherlands)

    M. Draijer; E. Hondebrink; T. van Leeuwen; W. Steenbergen

    2009-01-01

    We present the Twente Optical Perfusion Camera (TOPCam), a novel laser Doppler Perfusion Imager based on CMOS technology. The tissue under investigation is illuminated and the resulting dynamic speckle pattern is recorded with a high speed CMOS camera. Based on an overall analysis of the signal-to-n

  16. Twente Optical Perfusion Camera: system overview and performance for video rate laser Doppler perfusion imaging

    NARCIS (Netherlands)

    Draijer, M.; Hondebrink, E.; van Leeuwen, T.; Steenbergen, W.

    2009-01-01

    We present the Twente Optical Perfusion Camera (TOPCam), a novel laser Doppler Perfusion Imager based on CMOS technology. The tissue under investigation is illuminated and the resulting dynamic speckle pattern is recorded with a high speed CMOS camera. Based on an overall analysis of the

  17. Sensitivity evaluation of DSA-based parametric imaging using Doppler ultrasound in neurovascular phantoms

    Science.gov (United States)

    Balasubramoniam, A.; Bednarek, D. R.; Rudin, S.; Ionita, C. N.

    2016-03-01

    An evaluation of the relation between parametric imaging results obtained from Digital Subtraction Angiography (DSA) images and blood-flow velocity measured using Doppler ultrasound in patient-specific neurovascular phantoms is provided. A silicone neurovascular phantom containing internal carotid artery, middle cerebral artery and anterior communicating artery was embedded in a tissue equivalent gel. The gel prevented movement of the vessels when blood mimicking fluid was pumped through it to obtain Colour Doppler images. The phantom was connected to a peristaltic pump, simulating physiological flow conditions. To obtain the parametric images, water was pumped through the phantom at various flow rates (100, 120 and 160 ml/min) and 10 ml contrast boluses were injected. DSA images were obtained at 10 frames/sec from the Toshiba C-arm and DSA image sequences were input into LabVIEW software to get parametric maps from time-density curves. The parametric maps were compared with velocities determined by Doppler ultrasound at the internal carotid artery. The velocities measured by the Doppler ultrasound were 38, 48 and 65 cm/s for flow rates of 100, 120 and 160 ml/min, respectively. For the 20% increase in flow rate, the percentage change of blood velocity measured by Doppler ultrasound was 26.3%. Correspondingly, there was a 20% decrease of Bolus Arrival Time (BAT) and 14.3% decrease of Mean Transit Time (MTT), showing strong inverse correlation with Doppler measured velocity. The parametric imaging parameters are quite sensitive to velocity changes and are well correlated to the velocities measured by Doppler ultrasound.

  18. Automatic extraction of disease-specific features from Doppler images

    Science.gov (United States)

    Negahdar, Mohammadreza; Moradi, Mehdi; Parajuli, Nripesh; Syeda-Mahmood, Tanveer

    2017-03-01

    Flow Doppler imaging is widely used by clinicians to detect diseases of the valves. In particular, continuous wave (CW) Doppler mode scan is routinely done during echocardiography and shows Doppler signal traces over multiple heart cycles. Traditionally, echocardiographers have manually traced such velocity envelopes to extract measurements such as decay time and pressure gradient which are then matched to normal and abnormal values based on clinical guidelines. In this paper, we present a fully automatic approach to deriving these measurements for aortic stenosis retrospectively from echocardiography videos. Comparison of our method with measurements made by echocardiographers shows large agreement as well as identification of new cases missed by echocardiographers.

  19. Doppler Fourier Domain Optical Coherence Tomography for Label-Free Tissue Angiography

    Science.gov (United States)

    Leitgeb, Rainer A.; Szkulmowski, Maciej; Blatter, Cedric; Wojtkowski, Maciej

    Information about tissue perfusion and the vascular structure is certainly most important for assessment of tissue state or personal health and the diagnosis of any pathological conditions. It is therefore of key medical interest to have tools available for both quantitative blood flow assessment as well as qualitative vascular imaging. The strength of optical techniques is the unprecedented level of detail even for small capillary structures or microaneurysms and the possibility to combine different techniques for additional tissue spectroscopy giving insight into tissue metabolism. There is an immediate diagnostic and pharmacological demand for high-resolution, label-free, tissue angiography and flow assessment that in addition allow for precise depth gating of flow information. The most promising candidate is Doppler optical coherence tomography (DOCT) being noncontact, label free, and without employing hazardous radiation. DOCT provides fully quantitative volumetric information about blood flow together with the vascular and structural anatomy. Besides flow quantification, analysis of OCT signal fluctuations allows to contrast moving scatterers in tissue such as red blood cells from static tissue. This allows for non-invasive optical angiography and yields high resolution even for smallest capillaries. Because of the huge potential of DOCT and lable-free optical angiography for diagnosis, the last years saw a rapid increase of publications in this field with many different approaches. The present chapter gives an overview over existing Doppler OCT approaches and angiography techniques. It furthermore discusses limitations and noise issues, and gives examples for angiography in the eye and the skin.

  20. [Left ventricular functions in patients with cardiac syndrome X: a tissue Doppler study].

    Science.gov (United States)

    Yazici, Hüseyin Uğur; Sen, Nihat; Tavil, Yusuf; Hizal, Fatma; Turfan, Murat; Poyraz, Fatih; Boyaci, Bülent; Cengel, Atiye

    2009-12-01

    The aim of the study was to compare diagnostic accuracy of tissue Doppler imaging (TDI) and conventional Doppler echocardiography in diagnosis of left ventricular diastolic dysfunction in patients with cardiac syndrome X. Our study was designed as cross-sectional study. In our study, we compared 35 patients with cardiac syndrome X (19 female, mean age 47.2+/- 7.3 years) with 33 healthy persons as control group (18 female, mean age 49.5+/- 7.1 years) with no coronary artery disease and having no ischemic complaints or findings at exercise test. Left ventricular systolic function was found by considering mean values of modified Simpson method for left ventricular ejection fraction and TDI assessment of systolic wave peak velocity. The diastolic function of left ventricle was assessed with conventional echocardiography and TDI. Unpaired t test for independent samples or Mann-Whitney U test were used for comparison of continuous variables, Chi square test - for comparison of categorical variables. To define the capability of predicting diastolic dysfunction for conventional Doppler echocardiography and tissue Doppler imaging ROC curve analysis was applied. Left ventricular ejection fraction and systolic wave peak velocity were similar for both groups. Conventional Doppler echocardiographic measurements for left ventricular diastolic functions delineated the more frequent presence of diastolic dysfunction in cardiac syndrome X group As compared with controls (48% vs 18%; p<0.01). When both methods used for assessing diastolic dysfunction, it was found more apparent (66% vs 24%; p<0.01). When ROC curve was drawn for conventional Doppler echocardiography the AUC was 0.623, the sensitivity and the specificity were 49% and 76%, respectively. When the same was done for TDI the values were AUC=0.669, the sensitivity - 66% and the specificity - 68%. Our study revealed the deterioration of left ventricular diastolic function in patients with cardiac syndrome X. We found TDI

  1. Accuracy of heart strain rate calculation derived from Doppler tissue velocity data

    Science.gov (United States)

    Santos, Andres; Ledesma-Carbayo, Maria J.; Malpica, Norberto; Desco, Manuel; Antoranz, Jose C.; Marcos-Alberca, Pedro; Garcia-Fernandez, Miguel A.

    2001-05-01

    Strain Rate (SR) Imaging is a recent imaging technique that provides information about regional myocardial deformation by measuring local compression and expansion rates. SR can be obtained by calculating the local in-plane velocity gradients along the ultrasound beam from Doppler Tissue velocity data. However, SR calculations are very dependent on the image noise and artifacts, and different calculation algorithms may provide inconsistent results. This paper compares techniques to calculate SR. 2D Doppler Tissue Images (DTI) are acquired with an Acuson Sequoia scanner. Noise was measured with the aid of a rotating phantom. Processing is performed on polar coordinates. For each image, after removal of black spot artifacts by a selective median filter, two different SR calculation methods have been implemented. In the first one, SR is computed as the discrete velocity derivative, and noise is reduced with a variable-width gaussian filter. In the second method a smoothing cubic spine is calculated for every scan line according to the noise level and the derivative is obtained from an analytical expression. Both methods have been tested with DTI data from synthetic phantoms and normal volunteers. Results show that noise characteristics, border effects and the adequate scale are critical to obtain meaningful results.

  2. Tissue-Doppler assessment of cardiac left ventricular function during short-term adjuvant epirubicin therapy for breast cancer

    DEFF Research Database (Denmark)

    Appel, Jon M; Sogaard, Peter; Mortensen, Christiane E;

    2011-01-01

    It has been hypothesized that the extent of acute anthracycline-induced cardiotoxicity reflects the risk for late development of heart failure. The aim of this study was to examine if short-term changes in cardiac function can be detected even after low-dose adjuvant epirubicin therapy for breast...... cancer when using Doppler tissue imaging of longitudinal left ventricular function....

  3. The assessment of cardiac functions by tissue Doppler-derived myocardial performance index in patients with Behcet's disease.

    Science.gov (United States)

    Tavil, Yusuf; Ozturk, Mehmet Akif; Sen, Nihat; Kaya, Mehmet Gungor; Hizal, Fatma; Poyraz, Fatih; Turfan, Murat; Onder, Meltem; Gurer, Mehmet Ali; Cengel, Atiye

    2008-03-01

    Vascular involvement is one of the major characteristics of Behcet's disease (BD). However, there are controversial findings regarding cardiac involvement in BD. Although early reports demonstrated that there is diastolic dysfunction in BD, conflicting results were found in the following trials. Hence, a new method for more objectively estimating the cardiac functions is needed. For this aim, we used high-usefulness tissue Doppler echocardiography for detailed analysis of cardiac changes in BD patients because this method was superior to other conventional echocardiographic techniques. The study population included 42 patients with BD (19 men, 23 women; mean age, 35 +/- 10 years, mean disease duration, 2.7 +/- 1.6 years) and 30 healthy subjects (14 men, 16 women; mean age, 38 +/- 7 years). Cardiac functions were determined using echocardiography, comprising standard two-dimensional and conventional Doppler and tissue Doppler imaging (TDI). Peak systolic myocardial velocity at mitral annulus, early diastolic mitral annular velocity (Em), late diastolic mitral annular velocity (Am), Em/Am, and myocardial performance index (MPI) were calculated by TDI. The conventional echocardiographic parameters and tissue Doppler measurements were similar between the groups. Tissue Doppler derived mitral relaxation time was longer (75 +/- 13 vs 63 +/- 16 msn, p = 0.021) in patients with BD. There was statistically significant difference between the two groups regarding left ventricular MPI (0.458 +/- 0.072 vs 0.416 +/- 0.068%, p = 0.016), which were calculated from tissue Doppler systolic time intervals. There was also significant correlation between the disease duration and MPI (r = 0.38, p = 0.017). We have demonstrated that tissue Doppler-derived myocardial left ventricular relaxation time and MPI were impaired in BD patients, although systolic and diastolic function parameters were comparable in the patients and controls.

  4. THE DIAGNOSTIC VALUE OF PULSED WAVE TISSUE DOPPLER IMAGING IN ASYMPTOMATIC BETA- THALASSEMIA MAJOR CHILDREN AND YOUNG ADULTS ; RELATION TO CHEMICAL BIOMARKERS OF LEFT VENTRICULAR FUNCTION AND IRON OVERLOAD .

    Directory of Open Access Journals (Sweden)

    Seham Ragab

    2015-08-01

    Full Text Available Background: Cardiac iron toxicity is the leading cause of death among  β-halassaemia major (TM  patients.  Once  heart failure becomes overt , it will be  difficult to reverse . Objectives: To investigate non overt cardiac dysfunctions  in TM patients using  pulsed wave Tissue Doppler  Imaging (TD I and its relation to the iron overload and brain natruritic peptide (BNP. Methods: Thorough  clinical , conventional echo and  pulsed  wave TDI  parameters were compared between  asymtomatic 25 β-TM  patients  and 20 age and gender matched individuals. Serum ferritin and plasma BNP  levels were assayed by  ELISA .  Results: TM patients had significant higher mitral inflow early diastolic (E wave and  non significant other conventional echo  parameters. Pulsed wave TDI revealed systolic and diastolic dysfunctions in the form of significant higher  isovolumetric contraction time (ICT , ejection time ( E T and  isovolumetric relaxation time (IRT with significantly lower  mitral annulus  early diastolic velocity E` (12.07 ±2.06 vs 15.04±2.65 ,P= 0.003  in patients compared to  controls. Plasma BNP was higher in patients compared to the controls.  Plasma BNP and serum ferritin had significant correlation with each other and with pulsed wave conventional and TDI indices of systolic and diastolic functions.  Patients with E/E` ≥ 8 had  significant higher  serum ferritin  and plasma BNP levels compared to those with E/E` ratio < 8 without difference in Hb levels .Conclusion:  Pulsed wave TDI  is an  important diagnostic tool for latent cardiac dysfunction in iron loaded TM patients and is related to iron overload and BNP .

  5. Using Rotation for Steerable Needle Detection in 3D Color-Doppler Ultrasound Images

    OpenAIRE

    Mignon, Paul; Poignet, Philippe; Troccaz, Jocelyne

    2015-01-01

    International audience; This paper demonstrates a new way to detect needles in 3D color-Doppler volumes of biological tissues. It uses rotation to generate vibrations of a needle using an existing robotic brachytherapy system. The results of our detection for color-Doppler and B-Mode ultrasound are compared to a needle location reference given by robot odometry and robot ultrasound calibration. Average errors between detection and reference are 5.8 mm on needle tip for B-Mode images and 2.17 ...

  6. 高频超声组织谐波技术及多普勒血流成像技术在四肢深度电烧伤诊断中的应用%The Application of High-frequency Ultrasound Tissue Harmonic Imaging and Doppler Vascular Imaging Techniques in the Diagnosis of Severe Electrical Burns in Extremities

    Institute of Scientific and Technical Information of China (English)

    郭瑜峰; 陈浩杰; 于新国; 朱维平; 陈国华; 王意达; 王怡

    2013-01-01

      目的:探讨高频超声组织谐波技术及多普勒血流成像技术在四肢深度电烧伤诊疗中的应用价值。方法:2008年12月-2010年8月笔者对本科收治的15例四肢深度电烧伤患者手术前后使用超声组织谐波成像技术及多普勒血流成像技术进行全面检查,观察软组织损伤情况及范围,测量血流相关参数,判断血管损伤程度。结果:共检测患肢28条,上肢19条,下肢 9条。组织谐波技术所得到的声像图能准确显示软组织受损程度及范围,判断肌组织坏死情况。彩色多普勒及频谱多普勒技术能对血管受损情况做出准确判断,检测出7例血栓形成病例。术前超声检查结果与手术中所见一致。术后超声检查可以动态追踪软组织恢复情况并检测血管内血流动力学参数,并据此评估疗效。结论:高频超声组织谐波技术及多普勒血流成像技术应用于重度电烧伤患肢可在手术前后实时、形象、直观地显示组织、血管损伤的形态学及功能学变化,具有很高的临床应用价值。%Objective:To evaluate the diagnosis value of high-frequency ultrasound tissue harmonic imaging and Doppler vascular imaging techniques in the treatment of severe electrical burns in limbs.Method:From December 2008 to August 2010,fifteen patients with severe electrical burns in limbs were admitted to author’s hospital. Ultrasound tissue harmonic imaging and Doppler vascular imaging techniques were applied in the thorough ultrasonogarphy examination of their limbs pre- and post-operatively,with the special attention to the extension and damage level of suffered soft tissue and vasculars.Result:Altogether,twenty-eight limbs,nineteen upper extremities and nine lower extremities,were examined.Sonograms acquired by tissue harmonic imaging technique could precisely show the extension and damage level of suffered soft and muscular tissues. Doppler vascular imaging

  7. Tissue Doppler echocardiography predicts acute myocardial infarction, heart failure, and cardiovascular death in the general population

    DEFF Research Database (Denmark)

    Mogelvang, Rasmus; Biering-Sørensen, Tor; Jensen, Jan Skov

    2015-01-01

    AIMS: To improve risk prediction of cardiovascular morbidity and mortality, we need sensitive markers of cardiac dysfunction; Echocardiographic Tissue Doppler Imaging (TDI) is feasible and harmless and may be ideal for this purpose. METHODS AND RESULTS: Within the community-based Copenhagen City...... by TDI was associated with increased risk of the combined end point, even in the subgroup of persons with a normal conventional echocardiographic examination [per 1 cm/s decrease: s': HR 1.32 (1.12-1.57), P ... in persons with a normal conventional echocardiographic examination....

  8. Burn imaging with a whole field laser Doppler perfusion imager based on a CMOS imaging array

    NARCIS (Netherlands)

    van Herpt, Heleen; Draijer, Matthijs; Hondebrink, Erwin; Nieuwenhuis, Marianne; Beerthuizen, Gerard; van Leeuwen, Ton; Steenbergen, Wiendelt

    2010-01-01

    Laser Doppler perfusion imaging (LDPI) has been proven to be a useful tool in predicting the burn wound outcome in an early stage. A major disadvantage of scanning beam LDPI devices is their slow scanning speed, leading to patient discomfort and imaging artifacts. We have developed the Twente Optica

  9. Burn imaging with a whole field laser Doppler perfusion imager based on a CMOS imaging array

    NARCIS (Netherlands)

    van Herpt, Heleen; Draijer, Matthijs; Hondebrink, Erwin; Nieuwenhuis, Marianne; Beerthuizen, Gerard; van Leeuwen, Ton; van Leeuwen, Ton; Steenbergen, Wiendelt

    2010-01-01

    Laser Doppler perfusion imaging (LDPI) has been proven to be a useful tool in predicting the burn wound outcome in an early stage. A major disadvantage of scanning beam LDPI devices is their slow scanning speed, leading to patient discomfort and imaging artifacts. We have developed the Twente

  10. 组织多普勒应变成像评价无心肌梗死的冠心病患者左心室收缩功能变化%Evaluation of Left Ventricular Function in Patients with Coronary Artery Diseases and without Myocardial Infarction by Strain Imaging Based on Tissue Doppler Imaging

    Institute of Scientific and Technical Information of China (English)

    李伟霞; 周宇

    2012-01-01

    Objective: To assess left ventricular function in patients with coronary artery diseases who had no myocardial infarc-tion history by strain imaging based on tissue Doppler imaging (TDD. Methods: Color-coded tissue Doppler echocardiography was performed in 25 healthy subjects and 26 patients with coronary artery diseases and without myocardial infarction. The short-axis views at basal,middle and apical levels were recorded. The mean peak values of strain were measured using Philips Q-Lab 7. 1 workshop. Results; The mean peak value in the group of coronary artery disease was significantly lower than that in the control group[(-42. 3 ± 9. 3) % vs. (-28. 8 ± 10. 3) %,P<0. 01],while other conventional echocardiographic parameters showed no significant difference. Conclusions: Strain imaging based on TDI can be used to assess myocardial function even when there is no obvious change in left ventricular ejection fraction in patients with coronary artery diseases.%目的:应用组织多普勒(tissue Doppler imaging,TDI)应变成像技术评价无心肌梗死史的冠心病患者左心室收缩功能的变化.方法:对既往均无心肌梗死史的25例健康志愿者(对照组)和26例经冠状动脉造影证实冠心痛的患者(冠心病组)进行TDI应变分析.分别得出每例研究对象的平均左心室应变峰值.结果:冠心病组和对照组的年龄、心率以及经常规超声心动图Simpson法测量的左室射血分数(left ventricular ejection fraction,LVEF)的差异均无统计意义(P>0.05),但冠心病组的平均左心室应变峰值显著低于对照组[(-42.3±9.3)%比(-28.8±10.3)%,P<0.01].结论:TDI应变峰值能敏感地反映左室功能不全的亚临床信息,有助于心血管疾病的早期诊断.

  11. The effectiveness of power Doppler vocal fremitus imaging in the diagnosis of breast hamartoma.

    Science.gov (United States)

    Yildiz, Seyma; Bakan, Ayse Ahsen; Aydın, Sinem; Kadıoglu, Huseiyn; Serter, Asli; Bilgin, Sennur; Alkan, Alpay

    2014-09-01

    To evaluate the usefulness of power Doppler vocal fremitus (PDVF) breast sonography for differentiation of hamartomas from other breast (malign or benign) masses. Two hundred and six breast masses in 180 women were evaluated. The breast lesions were scanned first by mammography (MG), then by ultrasonography (US) with PDVF imaging. Finally, biopsy was performed on lesions suspicious for malignancy (n=172). We used PDVF imaging to evaluate whether the Power acoustic Doppler artifact existed in all breast lesions. Pathology results of 172 biopsied lesions showed that 83 were malign and 89 masses were benign. Totally 39 breast hamartomas were diagnosed radiologically (n=25) or histopathologically (n=14). All hamartomas (n=39) produced the power acoustic Doppler artifact as the surrounding tissue at the same depth in PDVF imaging. On the other hand, none of the malign or benign lesions, apart from hamartomas, evidenced a similar vibrational artifact as the surrounding tissue at the same depth in the PDVF imaging. PDVF imaging during breast sonography is an invaluable technique in the identification of breast hamartomas from other benign or malign breast masses.

  12. Quantification of colour Doppler activity in the wrist in patients with rheumatoid arthritis--the reliability of different methods for image selection and evaluation

    DEFF Research Database (Denmark)

    Ellegaard, K; Torp-Pedersen, S; Lund, Hans;

    2008-01-01

    PURPOSE: The amount of colour Doppler activity in the inflamed synovium is used to quantify inflammatory activity. The measurements may vary due to image selection, quantification method, and point in cardiac cycle. This study investigated the test-retest reliability of ultrasound colour Doppler...... by the anatomical position only or by the anatomical position with maximum colour Doppler activity. Subsequently, the amount of colour Doppler was measured in an area defined by either the synovial tissue or by specific anatomical structures surrounding the synovial tissue. RESULTS: The best test-retest reliability...... test-retest reliability was found if the images were selected by anatomical position only and the quantification was done in an area defined by the synovial tissue (ICC [2.1] = 0.48 and SW = 0.049). CONCLUSION: The study showed that colour Doppler measurements are reliable if the images for analysis...

  13. Evaluation of tissue doppler imaging on preterm newborns' cardiac function with infant respiratory distress syndrome%组织多普勒对呼吸窘迫综合征早产儿心功能的评价

    Institute of Scientific and Technical Information of China (English)

    张华; 梁伟翔; 袁文琳; 张费通

    2014-01-01

    目的 利用组织多普勒(tissue doppler imaging,TDI)技术定量评价早产儿合并新生儿呼吸窘迫综合征(infant respiratory distress syndrome,IRDS)的心功能情况,为临床治疗提供依据.方法 选取我院出生且诊断为新生儿呼吸窘迫综合征的早产儿30例,并选取健康足月儿30例为对照组,抽血检验血清CK-MB,并进行心脏组织多普勒超声检查.测定左室射血分数(LVEF),测量二、三尖瓣环收缩期峰值速度(Sm)、舒张早期峰值速度(Em)及舒张晚期峰值速度(Am),并计算Em/Am.测定等容收缩期(ICT)与等容舒张期(IRT)时间之和及射血期时间(ET),计算左右室Tei指数.结果 IRDS早产儿组中27例(90.0%)合并心肌损害,肺动脉收缩压、血清CK-MB及左、右室Tei指数均明显高于对照组(P <0.05),而且右室Tei指数偏高于左室.血清CK-MB值与肺动脉压力升高呈正相关关系(r=0.375,P=0.003).左室Tei指数随着肺动脉压力升高而显著升高(r=0.254,P=0.050).结论 早产儿合并新生儿呼吸窘迫综合征易伴有心肌损害.组织多普勒Tei指数对心功能的评估相对传统射血分数具有更高的敏感性,为临床提供一种更快速准确的评价方法.

  14. Tissue types (image)

    Science.gov (United States)

    There are 4 basic types of tissue: connective tissue, epithelial tissue, muscle tissue, and nervous tissue. Connective tissue ... and binds them together (bone, blood, and lymph tissues). Epithelial tissue provides a covering (skin, the linings of ...

  15. Features of remodeling of right heart chambers according to tissue Doppler and its correlation with cardiac rhythm disturbance in patients with COPD 2-3 severity

    Directory of Open Access Journals (Sweden)

    O. A. Zhuk

    2014-01-01

    Full Text Available The article presents the study of early sings of dysfunction of right and left chambers of heart in patients with COPD 2 - 3 severity, correlation between structural and electrical remodeling of heart according to the stages of pulmonary hypertension. Standard tissue Doppler echocardiographic parameters and modes were used for the diagnosing. We examined 35 patients with COPD 2 - 3 severity; the control group consisted of 15 patients. The ECG Holter monitoring was made for all patients to identify cardiac rhythm disturbance and correlation with the COPD severity. Standard method of the ECG with modes of tissue Doppler (pulsed wave Tissue Doppler Imaging - PW TDI, color tissue Doppler imaging -TDI, tissue myocardial Doppler - TMD, tissue Tracking - TT, Doppler for evaluation of myocardial strain and myocardial strain rate were made to identify the stage of dysfunction. The results of the study concluded that according to the TDI the dysfunction of right ventricle was more apparent in patients with COPD 3 severity. Pathological arrhythmias were significantly detected in group of patients with COPD 3 severity. In compliance with our observations, the reduce of rapid myocardial strain rates and its inverse proportion with the severity in accordance to the evaluation of longitudinal strain and rate of movement of fibrous ring in tricuspid valve were observed in patients with COPD. Thus the application of the TDI modes for evaluating of early signs of cardiac remodeling in patients with COPD and potential adequate jugulation for preventing chronic cor pulmonale is expedient.

  16. In-vivo imaging of blood flow in human retinal vessels using color Doppler optical coherence tomography

    Science.gov (United States)

    Yazdanfar, Siavash; Rollins, Andrew M.; Izatt, Joseph A.

    1999-04-01

    Quantification of retinal blood flow may lead to a better understanding of the progression and treatment of several ocular disorders, including diabetic retinopathy, age- related macular degeneration, and glaucoma. Current techniques, such as fluorescein angiography and laser Doppler velocimetry are limited, failing to provide sufficient information to the clinician. Color Doppler optical coherence tomography (CDOCT) is a novel technique using coherent heterodyne detection for simultaneous cross- sectional imaging of tissue microstructure and blood flow. This technique is capable of high spatial and velocity resolution imaging in highly scattering media. We implemented CDOCT for retinal blood flow mapping in human subjects. No dilation of the pupil was necessary. CDOCT is demonstrated for determining bidirectional flow in sub- 100micrometers diameter vessels in the retina. Additionally, we calculated Doppler broadening using the variance of depth- resolved spectra to identify regions with large velocity gradients within the Xenopus heart. This technique may be useful in quantifying local tissue perfusion in highly vascular retinal tissue.

  17. Adaptive clutter rejection for ultrasound color Doppler imaging

    Science.gov (United States)

    Yoo, Yang Mo; Managuli, Ravi; Kim, Yongmin

    2005-04-01

    We have developed a new adaptive clutter rejection technique where an optimum clutter filter is dynamically selected according to the varying clutter characteristics in ultrasound color Doppler imaging. The selection criteria have been established based on the underlying clutter characteristics (i.e., the maximum instantaneous clutter velocity and the clutter power) and the properties of various candidate clutter filters (e.g., projection-initialized infinite impulse response and polynomial regression). We obtained an average improvement of 3.97 dB and 3.27 dB in flow signal-to-clutter-ratio (SCR) compared to the conventional and down-mixing methods, respectively. These preliminary results indicate that the proposed adaptive clutter rejection method could improve the sensitivity and accuracy in flow velocity estimation for ultrasound color Doppler imaging. For a 192 x 256 color Doppler image with an ensemble size of 10, the proposed method takes only 57.2 ms, which is less than the acquisition time. Thus, the proposed method could be implemented in modern ultrasound systems, while providing improved clutter rejection and more accurate velocity estimation in real time.

  18. Myocardial tissue Doppler velocities in fetuses with hypoplastic left heart syndrome

    Directory of Open Access Journals (Sweden)

    Himesh V Vyas

    2011-01-01

    Full Text Available Background : Tissue Doppler Imaging (TDI is a sensitive index of myocardial function. Its role in the fetus has not been extensively evaluated. Objective: To compare myocardial tissue Doppler velocities in fetuses with hypoplastic left heart syndrome (HLHS to those of normal fetuses (matched for gestational age. Methods: Cross-sectional retrospective study conducted at 2 large perinatal centers (2003-2007. Fetuses with HLHS ( n = 13 were compared with normal fetuses ( n = 207 in 5 gestational age groups. TDI data included peak systolic (s′, peak early (e′, and late diastolic velocities (a′. Linear regression was used to compare TDI parameters in fetuses with HLHS to normal fetuses matched for gestational age. Results: Fetuses with HLHS had significantly reduced lateral tricuspid annular e′ as compared to normal fetuses. Both normal fetuses and those with HLHS had linear increase in TDI velocities with advancing gestational age. Conclusions: TDI velocities are abnormal in fetuses with HLHS. TDI can be useful in serial follow-up of cardiac function in fetuses with HLHS.

  19. Tissue Doppler echocardiography reveals distinct patterns of impaired myocardial velocities in different degrees of coronary artery disease

    DEFF Research Database (Denmark)

    Hoffmann, Soren; Mogelvang, Rasmus; Olsen, Niels Thue

    2010-01-01

    Aim To determine how the left ventricular wall motion assessed by echocardiographic Tissue Doppler Imaging (TDI) is affected by increasing severity of coronary artery disease (CAD) among patients with stable angina pectoris and preserved ejection fraction. METHODS AND RESULTS: This study comprises.......86 +/- 0.24 vs. 1.00 +/- 0.28, P preserved ejection fraction reveals both diastolic and systolic dysfunction and the nature...

  20. Evaluation of Pulsed Doppler-Versus Tissue Doppler-Derived Tei Index of Right and Left Ventricle in Fetuses

    Directory of Open Access Journals (Sweden)

    Hamid Amoozgar

    2011-12-01

    Full Text Available Background: The myocardial performance index (MPI, also known as the Tei index, was introduced by Tei et al. to evaluate cardiac function in adults with dilated cardiomyopathy. This index is defined as the sum of isovolumic contraction time (ICT and isovolumic relaxation time (IRT, divided by ejection time (ET. Objectives: To determine the correlation between pulsed Doppler (PD- and tissue Doppler imaging (TDI-derived Tei indices in fetuses. Patients and Methods: Right and left ventricle PD and TDI echocardiographic data were obtained from 59 fetuses (11 pregnant women who were positive for anti-SSA-Ro or anti-SSB-La antibodies, 18 women who were referred due to dysrhythmia, and 30 women who had normal clinical findings. Results: Mean fetal gestational age was 27 ± 6.4 weeks. Mean PD Tei index of the mitral and tricuspid valve was 0.58 ± 0.05 and 0.53 ± 0.08, respectively. Mean TDI indices for the mitral and tricuspid valve were 0.56 ± 0.09 and 0.55 ± 0.08, respectively. There were no significant differences between mitral and tricuspid PD- and TDI-derived Tei indices (P = 0.87, P= 0.21, but the Bland-Altman diagrams showed no fine agreement between the indices (the mean difference ± 1 standard deviation of the right ventricular PD- and TDI-derived Tei indices was 0.24 ± 0.02 and 0.29 ± 0.04 for the left ventricle. There were no significant differences in PD- and TDI-derived Tei indexes between groups of evaluated fetuses (Mitral valve: PD-Tei P=0.69, TDI-Tei P=0.49; Tricuspid valve: PD-Tei P=0.41, TDI-Tei P=0.36. Conclusions: Although the mean values of the two indices did not differ significantly, the TDI-derived and PD-derived Tei indices did not have fine agreement.

  1. Doppler OCT imaging of cytoplasm shuttle flow in Physarum polycephalum.

    Science.gov (United States)

    Bykov, Alexander V; Priezzhev, Alexander V; Lauri, Janne; Myllylä, Risto

    2009-09-01

    The Doppler optical coherence tomography technique was applied to image the oscillatory dynamics of protoplasm in the strands of the plasmodium of slime mould Physarum polycephalum. Radial contractions of the gel-like walls of the strands and the velocity distributions in the sol-like endoplasm streaming along the plasmodial strands are imaged. The motility inhibitor effect of carbon dioxide on the cytoplasm shuttle flow and strand-wall contraction is shown. The optical attenuation coefficient of cytoplasm is estimated. 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  2. Holographic laser Doppler imaging of pulsatile blood flow

    CERN Document Server

    Bencteux, Jeffrey; Kostas, Thomas; Bayat, Sam; Atlan, Michael

    2015-01-01

    We report on wide-field imaging of pulsatile motion induced by blood flow using heterodyne holographic interferometry on the thumb of a healthy volunteer, in real-time. Optical Doppler images were measured with green laser light by a frequency-shifted Mach-Zehnder interferometer in off-axis configuration. The recorded optical signal was linked to local instantaneous out-of-plane motion of the skin at velocities of a few hundreds of microns per second, and compared to blood pulse monitored by plethysmoraphy during an occlusion-reperfusion experiment.

  3. Tissue Doppler echocardiography and biventricular pacing in heart failure: Patient selection, procedural guidance, follow-up, quantification of success

    Directory of Open Access Journals (Sweden)

    Baumann Gert

    2004-09-01

    Full Text Available Abstract Asynchronous myocardial contraction in heart failure is associated with poor prognosis. Resynchronization can be achieved by biventricular pacing (BVP, which leads to clinical improvement and reverse remodeling. However, there is a substantial subset of patients with wide QRS complexes in the electrocardiogram that does not improve despite BVP. QRS width does not predict benefit of BVP and only correlates weakly with echocardiographically determined myocardial asynchrony. Determination of asynchrony by Tissue Doppler echocardiography seems to be the best predictor for improvement after BVP, although no consensus on the optimal method to assess asynchrony has been achieved yet. Our own preliminary results show the usefulness of Tissue Doppler Imaging and Tissue Synchronization Imaging to document acute and sustained improvement after BVP. To date, all studies evaluating Tissue Doppler in BVP were performed retrospectively and no prospective studies with patient selection for BVP according to echocardiographic criteria of asynchrony were published yet. We believe that these new echocardiographic tools will help to prospectively select patients for BVP, help to guide implantation and to optimize device programming.

  4. High Frequency Color Doppler Image of Choroidal Detachment

    Institute of Scientific and Technical Information of China (English)

    Jinghong Wu; Lijuan Zou; Zhongyao Wu; Lixun Cheng

    2000-01-01

    Purpose: To study the Color Doppler Image (CDI) characteristics of choroidal detachment and the applied value of CDI.Methods: Seventy-two cases (74 eyes) of choroidal detachment were studied retrospectively.Results: The typical ultragraph of chroridal detachment displayed one or several smooth hemispherical or lobuler circular thick bands, with convex side toward vitreous cavity. Most of the choroidal detachments were located before the equator, a few of them were beyond the equator. CDI displayed blood flow singnal in the band. Pulse Doppler showed the frequency spectrum features of retinal detachment band were similar to those of central retinal vessels, whereas the frequency spectum features of choroidal detachment bend resembled those of ciliary artery in some cases of retinal detachment (RD) accompanied by choroidal detachment.Conclusion: CDI could make a correct and precise diagnosis of choroidal detachment.Eye Science 2000; 16. 61 ~ 64.

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

    Directory of Open Access Journals (Sweden)

    Nagano Satoshi

    2015-06-01

    Full Text Available Background. The utility of ultrasound imaging in the screening of soft-part tumours (SPTs has been reported. We classified SPTs according to their blood flow pattern on Doppler ultrasound and re-evaluated the efficacy of this imaging modality as a screening method. Additionally, we combined Doppler ultrasound with several values to improve the diagnostic efficacy and to establish a new diagnostic tool.

  6. Doppler imaging of myocardium tissue from aged hypertensive patients with increased differential pulse pressure%老年脉压差增大高血压患者心肌多普勒成像改变

    Institute of Scientific and Technical Information of China (English)

    王新明; 孙红

    2012-01-01

    Objective To assess the effect of increased differential pulse pressure on myocardium function in aged patients by tissue Doppler imaging(TDI). Medthods One hundred and one aged patients were divided into normal pressure group with their differential pulse pressure ≤40 mm Hg(n = 45) and hypertension group with their differential pulse >40 mm Hg(n = 56). The inner diameter and interventricular septal thickness of ascending aorta,thickness of lefet ventricle posterior wall,inner diameter of left ventricle at late diastolic phase,maximum blood flow speed through mitral vlve at early diastolic phase were measured to detect the peak blood flow speed at diastolic phase,early diastolic phase and late diastolic phase. Results The peak blood flow speed at diastolic phase,early diastolic phase and late diastolic phase was higher in hypertension group than in normal pressure group. Conclusion TDI is a reliable new procedure for the diagnosis of abnormal systolic and diastolic function of myocardium due to increased differential pulse pressure in aged patients with hypertension. The mitral valve ring in left ventricular septum is sensitive to TDI in measuring systolic pressure.%目的 应用组织多普勒超声成像评价老年脉压差增大对心肌收缩和舒张功能的影响.方法 应用常规超声心动图及组织多普勒等方法检测左心室射血分数>50%的老年男性高血压患者共101例,其中血压正常、脉压差≤40 mm Hg(1 mm Hg=0.133 kPa)45例(正常组),高血压、且脉压差>40 mm Hg 56例(异常组),测量升主动脉内径、室间隔厚度、左心室后壁厚度、左心室舒张末内径、左心室舒张早期二尖瓣血流最大速度和左心室舒张晚期二尖瓣血流最大速度(A)值,获取舒张期室间隔基底部组织多普勒收缩期峰值速度(s)、舒张早期峰值速度、舒张晚期峰值速度(a).结果 异常组A值、a峰、s峰明显高于正常组,差异有统计学意义(P<0.05,P<0.01).

  7. Tissue Doppler echocardiography improves the diagnosis of coronary artery stenosis in stable angina pectoris

    DEFF Research Database (Denmark)

    Hoffmann, Soren; Jensen, Jan Skov; Iversen, Allan Zeeberg

    2012-01-01

    by colour TDI at six mitral annular sites and averaged to provide global estimates. Duke score (DS), including ST depression, chest pain, and exercise capacity, was used as the outcome of the exercise ECG. Patients with an area stenosis of ≥70% in at least one epicardial coronary artery were categorized......Aim To determine if colour tissue Doppler imaging (TDI) performed at rest in patients with suspected stable angina pectoris (SAP) is able to predict the presence of significant coronary artery disease (CAD). METHODS AND RESULTS: This study comprises 296 consecutive patients with clinically...... suspected SAP, no previous cardiac history, and a normal ejection fraction. All patients were examined by colour TDI, exercise electrocardiogram (ECG), and coronary angiography (CAG). Regional longitudinal systolic (s'), early diastolic (e'), and late diastolic (a') myocardial velocities were measured...

  8. First Magnetic Doppler Images of a roAp star

    Science.gov (United States)

    Lüftinger, T.; Kochukhov, O.; Ryabchikova, T.; Weiss, W. W.; Ilyin, I.

    2007-06-01

    We present the first analysis of the magnetic field geometry and elemental abundance distributions on the surface of a rapidly oscillating Ap (roAp) star, using an elaborate magnetic Doppler Imaging (MDI) code (Piskunov et al. 2002, Kochukhov et al. 2002), inv, which allows to reconstruct simultaneously and consistently the magnetic field geometry and abundance distributions on a stellar surface without any a priori assumptions. We analysed Stokes I and V time series obtained with the SOFIN polarimeter and recovered the magnetic field and surface abundance structures of Fe and Nd (among others). These two elements are found to be anticorrelated.

  9. Laser Doppler Blood Flow Imaging Using a CMOS Imaging Sensor with On-Chip Signal Processing

    Directory of Open Access Journals (Sweden)

    Cally Gill

    2013-09-01

    Full Text Available The first fully integrated 2D CMOS imaging sensor with on-chip signal processing for applications in laser Doppler blood flow (LDBF imaging has been designed and tested. To obtain a space efficient design over 64 × 64 pixels means that standard processing electronics used off-chip cannot be implemented. Therefore the analog signal processing at each pixel is a tailored design for LDBF signals with balanced optimization for signal-to-noise ratio and silicon area. This custom made sensor offers key advantages over conventional sensors, viz. the analog signal processing at the pixel level carries out signal normalization; the AC amplification in combination with an anti-aliasing filter allows analog-to-digital conversion with a low number of bits; low resource implementation of the digital processor enables on-chip processing and the data bottleneck that exists between the detector and processing electronics has been overcome. The sensor demonstrates good agreement with simulation at each design stage. The measured optical performance of the sensor is demonstrated using modulated light signals and in vivo blood flow experiments. Images showing blood flow changes with arterial occlusion and an inflammatory response to a histamine skin-prick demonstrate that the sensor array is capable of detecting blood flow signals from tissue.

  10. Laser doppler blood flow imaging using a CMOS imaging sensor with on-chip signal processing.

    Science.gov (United States)

    He, Diwei; Nguyen, Hoang C; Hayes-Gill, Barrie R; Zhu, Yiqun; Crowe, John A; Gill, Cally; Clough, Geraldine F; Morgan, Stephen P

    2013-09-18

    The first fully integrated 2D CMOS imaging sensor with on-chip signal processing for applications in laser Doppler blood flow (LDBF) imaging has been designed and tested. To obtain a space efficient design over 64 × 64 pixels means that standard processing electronics used off-chip cannot be implemented. Therefore the analog signal processing at each pixel is a tailored design for LDBF signals with balanced optimization for signal-to-noise ratio and silicon area. This custom made sensor offers key advantages over conventional sensors, viz. the analog signal processing at the pixel level carries out signal normalization; the AC amplification in combination with an anti-aliasing filter allows analog-to-digital conversion with a low number of bits; low resource implementation of the digital processor enables on-chip processing and the data bottleneck that exists between the detector and processing electronics has been overcome. The sensor demonstrates good agreement with simulation at each design stage. The measured optical performance of the sensor is demonstrated using modulated light signals and in vivo blood flow experiments. Images showing blood flow changes with arterial occlusion and an inflammatory response to a histamine skin-prick demonstrate that the sensor array is capable of detecting blood flow signals from tissue.

  11. Laser Doppler Blood Flow Imaging Using a CMOS Imaging Sensor with On-Chip Signal Processing

    Science.gov (United States)

    He, Diwei; Nguyen, Hoang C.; Hayes-Gill, Barrie R.; Zhu, Yiqun; Crowe, John A.; Gill, Cally; Clough, Geraldine F.; Morgan, Stephen P.

    2013-01-01

    The first fully integrated 2D CMOS imaging sensor with on-chip signal processing for applications in laser Doppler blood flow (LDBF) imaging has been designed and tested. To obtain a space efficient design over 64 × 64 pixels means that standard processing electronics used off-chip cannot be implemented. Therefore the analog signal processing at each pixel is a tailored design for LDBF signals with balanced optimization for signal-to-noise ratio and silicon area. This custom made sensor offers key advantages over conventional sensors, viz. the analog signal processing at the pixel level carries out signal normalization; the AC amplification in combination with an anti-aliasing filter allows analog-to-digital conversion with a low number of bits; low resource implementation of the digital processor enables on-chip processing and the data bottleneck that exists between the detector and processing electronics has been overcome. The sensor demonstrates good agreement with simulation at each design stage. The measured optical performance of the sensor is demonstrated using modulated light signals and in vivo blood flow experiments. Images showing blood flow changes with arterial occlusion and an inflammatory response to a histamine skin-prick demonstrate that the sensor array is capable of detecting blood flow signals from tissue. PMID:24051525

  12. Magnetic Doppler imaging of the chemically peculiar star HD 125248

    CERN Document Server

    Rusomarov, N; Ryabchikova, T; Ilyin, I

    2016-01-01

    Intermediate-mass, chemically peculiar stars with strong magnetic fields give us an excellent opportunity to study the topology of their surface magnetic fields and the interplay between magnetic geometries and abundance inhomogeneities in their atmospheres. We reconstruct detailed maps of the surface magnetic field and abundance distributions for the magnetic Ap star HD 125248. We performed the analysis based on phase-resolved, four Stokes parameter spectropolarimetric observations obtained with the HARPSpol instrument. These data were interpreted with the magnetic Doppler imaging technique. We improved the atmospheric parameters of the star, T_eff = 9850K +/- 250K and logg = 4.05 +/- 0.10. We performed detailed abundance analysis and discovered vertical stratification effects for the FeII and CrII ions. We computed LSD Stokes profiles and studied their behavior with rotational phase. We improved the rotational period of the star P_rot = 9.29558(6)d. Magnetic Doppler imaging of HD 125248 showed that its magn...

  13. The first Doppler images of the eclipsing binary SZ Piscium

    CERN Document Server

    Xiang, Yue; Cameron, A Collier; Barnes, J R; Zhang, Liyun

    2015-01-01

    We present the first Doppler images of the active eclipsing binary system SZ Psc, based on the high-resolution spectral data sets obtained in 2004 November and 2006 September--December. The least-squares deconvolution technique was applied to derive high signal-to-noise profiles from the observed spectra of SZ Psc. Absorption features contributed by a third component of the system were detected in the LSD profiles at all observed phases. We estimated the mass and period of the third component to be about $0.9 M_{\\odot}$ and $1283 \\pm 10$ d, respectively. After removing the contribution of the third body from the LSD profiles, we derived the surface maps of SZ Psc. The resulting Doppler images indicate significant starspot activities on the surface of the K subgiant component. The distributions of starspots are more complex than that revealed by previous photometric studies. The cooler K component exhibited pronounced high-latitude spots as well as numerous low- and intermediate-latitude spot groups during the...

  14. The first Doppler images of the eclipsing binary SZ Piscium

    Science.gov (United States)

    Xiang, Yue; Gu, Shenghong; Cameron, A. Collier; Barnes, J. R.; Zhang, Liyun

    2016-02-01

    We present the first Doppler images of the active eclipsing binary system SZ Psc, based on the high-resolution spectral data sets obtained in 2004 November and 2006 September-December. The least-squares deconvolution technique was applied to derive high signal-to-noise profiles from the observed spectra of SZ Psc. Absorption features contributed by a third component of the system were detected in the LSD profiles at all observed phases. We estimated the mass and period of the third component to be about 0.9 M⊙ and 1283 ± 10 d, respectively. After removing the contribution of the third body from the least-squares deconvolved profiles, we derived the surface maps of SZ Psc. The resulting Doppler images indicate significant star-spot activities on the surface of the K subgiant component. The distributions of star-spots are more complex than that revealed by previous photometric studies. The cooler K component exhibited pronounced high-latitude spots as well as numerous low- and intermediate-latitude spot groups during the entire observing seasons, but did not show any large, stable polar cap, different from many other active RS CVn-type binaries.

  15. The association between brain natriuretic peptide and tissue Doppler parameters in children with hypertrophic cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Taliha Öner

    2016-01-01

    Full Text Available In this study, we investigated the association between brain natriuretic peptide (BNP levels and tissue Doppler imaging measurements and also screening for deadly mutations in patients with hypertrophic cardiomyopathy (HCM. We enrolled 20 patients diagnosed with HCM (age:10.7±5 years (1-17, 85% male, weight:42.25±23.10 kg, height:141.80±32.45 cm and 20 age, gender and body weight-matched control subjects. We performed electrocardiography, transthoracic echocardiography, and tissue Doppler echocardiography in each group, as well as genetic tests (for Arg403Gln, Arg453Cys, Arg719Trp and Arg719Gln mutations in MYH7 Exons 13, 14, 19 and BNP in the patients. The patients were divided into two groups according to the presence (Group 1 or absence (Group 2 of left ventricular (LV outflow tract obstruction. QTc dispersion and the LV ejection fraction and left atrial (LA volume index were increased in Group 1. The LA volume index and the mitral and septal E/Ea ratio and septum Z-score were increased while the mitral lateral annulus and septal annulus Ea wave velocities and the mitral and tricuspid E/A ratio were decreased in patients with high levels of BNP compared to those with normal BNP levels. There were no mutations that are associated with increased risk of sudden death found in patients included in this study. In the light of our data, we conclude that such parameters BNP levels above the 98 pg/mL, septal thickness Z-score ˃6, and higher mitral and septal E/Ea ratios can be used for management of patients with HCM according to life-threatening conditions.

  16. Soft tissue tumours: imaging strategy

    Energy Technology Data Exchange (ETDEWEB)

    Brisse, Herve J. [Institute Curie, Department of Radiology, Paris (France); Orbach, Daniel [Institute Curie, Department of Paediatric Oncology, Paris (France); Klijanienko, Jerzy [Institute Curie, Department of Pathology, Paris (France)

    2010-06-15

    Vascular tumours and malformations, fibrous and fibrohistiocytic tumours and pseudotumours are the most common benign soft-tissue masses observed in children, and can be treated conservatively. Rhabdomyosarcomas are the most frequent malignant tumours, accounting for about half of soft tissue sarcomas. A child referred for a soft-tissue mass should ideally be managed by a multidisciplinary team and primary excision should be proscribed until a definite diagnosis has been established. Clinical examination, conventional radiography and US with Doppler represent the first-line examinations and are sometimes sufficient to make a diagnosis. In all other situations, MRI is mandatory to establish the aggressiveness and extension of the tumour. This technique provides the relevant data to guide the decision regarding tissue sampling. (orig.)

  17. Mechanical dyssynchrony evaluated by tissue Doppler cross-correlation analysis is associated with long-term survival in patients after cardiac resynchronization therapy

    DEFF Research Database (Denmark)

    Risum, Niels; Williams, Eric S; Khouri, Michel G

    2013-01-01

    Aims Pre-implant assessment of longitudinal mechanical dyssynchrony using cross-correlation analysis (XCA) was tested for association with long-term survival and compared with other tissue Doppler imaging (TDI)-derived indices. Methods and results In 131 patients referred for cardiac resynchroniz...

  18. Fabrication of Two Flow Phantoms for Doppler Ultrasound Imaging.

    Science.gov (United States)

    Zhou, Xiaowei; Kenwright, David A; Wang, Shiying; Hossack, John A; Hoskins, Peter R

    2017-01-01

    Flow phantoms are widely used in studies associated with Doppler ultrasound measurements, acting as an effective experimental validation system in cardiovascular-related research and in new algorithm/instrumentation development. The development of materials that match the acoustic and mechanical properties of the vascular system is of great interest while designing flow phantoms. Although recipes that meet the flow phantom standard defined by the International Electrotechnical Commission 61685 are already available in the literature, the standard procedure for material preparations and phantom fabrications has not been well established. In this paper, two types of flow phantoms, with and without blood vessel mimic, are described in detail in terms of the material preparation and phantom fabrication. The phantom materials chosen for the two phantoms are from published phantom studies, and their physical properties have been investigated previously. Both the flow phantoms have been scanned by ultrasound scanners and images from different modes are presented. These phantoms may be used in the validation and characterization of Doppler ultrasound measurements in blood vessels with a diameter above 1 mm.

  19. Acoustic micro-Doppler radar for human gait imaging.

    Science.gov (United States)

    Zhang, Zhaonian; Pouliquen, Philippe O; Waxman, Allen; Andreou, Andreas G

    2007-03-01

    A portable acoustic micro-Doppler radar system for the acquisition of human gait signatures in indoor and outdoor environments is reported. Signals from an accelerometer attached to the leg support the identification of the components in the measured micro-Doppler signature. The acoustic micro-Doppler system described in this paper is simpler and offers advantages over the widely used electromagnetic wave micro-Doppler radars.

  20. Magnetic Doppler imaging of the chemically peculiar star HD 125248

    Science.gov (United States)

    Rusomarov, N.; Kochukhov, O.; Ryabchikova, T.; Ilyin, I.

    2016-04-01

    Context. Intermediate-mass, chemically peculiar stars with strong magnetic fields provide an excellent opportunity to study the topology of their surface magnetic fields and the interplay between magnetic geometries and abundance inhomogeneities in the atmospheres of these stars. Aims: We reconstruct detailed maps of the surface magnetic field and abundance distributions for the magnetic Ap star HD 125248. Methods: We performed the analysis based on phase-resolved, four Stokes parameter spectropolarimetric observations obtained with the HARPSpol instrument. These data were interpreted with the help of magnetic Doppler imaging techniques and model atmospheres taking the effects of strong magnetic fields and nonsolar chemical composition into account. Results: We improved the atmospheric parameters of the star, Teff = 9850 ± 250 K and log g = 4.05 ± 0.10. We performed detailed abundance analysis, which confirmed that HD 125248 has abundances typical of other Ap stars, and discovered significant vertical stratification effects for the Fe ii and Cr ii ions. We computed LSD Stokes profiles using several line masks corresponding to Fe-peak and rare earth elements, and studied their behavior with rotational phase. Combining previous longitudinal field measurements with our own observations, we improved the rotational period of the star Prot = 9.29558 ± 0.00006 d. Magnetic Doppler imaging of HD 125248 showed that its magnetic field is mostly poloidal and quasi-dipolar with two large spots of different polarity and field strength. The chemical maps of Fe, Cr, Ce, Nd, Gd, and Ti show abundance contrasts of 0.9-3.5 dex. Among these elements, the Fe abundance map does not show high-contrast features. Cr is overabundant around the negative magnetic pole and has 3.5 dex abundance range. The rare earth elements and Ti are overabundant near the positive magnetic pole. Conclusions: The magnetic field of HD 125248 has strong deviations from the classical oblique dipole field

  1. Acute effects of lateral thigh foam rolling on arterial tissue perfusion determined by spectral Doppler and Power Doppler ultrasound.

    Science.gov (United States)

    T, Hotfiel; B, Swoboda; S, Krinner; C, Grim; M, Engelhardt; M, Uder; R, Hei

    2016-09-23

    Foam rolling has been developed as a popular intervention in training and rehabilitation. However, evidence on its effects on the cellular and physiological level is lacking. The aim of this study was to assess the effect of foam rolling on arterial blood flow of the lateral thigh. Twenty-one healthy participants (age 25 ± 2 years, height 177 ± 9 cm, body weight 74 ± 9 kg) were recruited from the medical and sports faculty. Arterial tissue perfusion was determined by spectral Doppler and power Doppler ultrasound, represented as peak flow (Vmax), time average velocity maximum (TAMx), time average velocity mean (TAMn), and resistive index (RI), and with semiquantitative grading that was assessed by four blind-folded investigators. Measurement values were assessed under resting conditions and twice after foam rolling exercises of the lateral thigh (0 min and 30 min post intervention). The trochanteric region, mid portion, and distal tibial insertion of the lateral thigh were representative for data analysis. Arterial blood flow of the lateral thigh increased significantly following foam rolling exercises compared to baseline (p<0.05). We detected a relative increase in Vmax of 73.6% (0 min) and 52.7 % (30 min) (p<0.001), in TAMx of 53.2% (p<0.001) and 38.3 % (p=0.002), and in TAMn of 84.4% (p<0.001) and 68.2 % (p<0.001). Semiquantitative Power Doppler scores at all portions revealed increased average grading of 1.96 after intervention and 2.04 after 30 min compared to 0.75 at baseline. Our results may contribute to the understanding of local physiological reactions to self-myofascial release.

  2. Value of tissue Doppler-derived Tei index and two-dimensional speckle tracking imaging derived longitudinal strain on predicting outcome of patients with light-chain cardiac amyloidosis.

    Science.gov (United States)

    Liu, Dan; Hu, Kai; Herrmann, Sebastian; Cikes, Maja; Ertl, Georg; Weidemann, Frank; Störk, Stefan; Nordbeck, Peter

    2017-06-01

    Prognosis of patients with light-chain cardiac amyloidosis (AL-CA) is poor. Speckle tracking imaging (STI) derived longitudinal deformation parameters and Doppler-derived left ventricular (LV) Tei index are valuable predictors of outcome in patients with AL-CA. We estimated the prognostic utility of Tei index and deformation parameters in 58 comprehensively phenotyped patients with AL-CA after a median follow-up of 365 days (quartiles 121, 365 days). The primary end point was all-cause mortality. 19 (33%) patients died during follow-up. Tei index (0.89 ± 0.29 vs. 0.61 ± 0.16, p < 0.001) and E to global early diastolic strain rate ratio (E/GLSRdias) were higher while global longitudinal systolic strain (GLSsys) was lower in non-survivors than in survivors (all p < 0.05). Tei index, NYHA functional class, GLSsys and E/GLSRdias were independent predictors of all-cause mortality risk, and Tei index ≥0.9 (HR 7.01, 95% CI 2.43-20.21, p < 0.001) was the best predictor of poor outcome. Combining Tei index and GLSsys yielded the best results on predicting death within 1 year (100% with Tei index ≥0.9 and GLSsys ≤13%) or survival (95% with Tei index ≤0.9 and GLSsys ≥13%). We conclude that 1-year mortality risk in AL-CA patients can be reliably predicted using Tei index or deformation parameters, with combined analysis offering best performance.

  3. Assessment of left ventricular systolic and diastolic function by tissue Doppler analysis in patients with hypertension with or without hyperuricemia.

    Science.gov (United States)

    Tavil, Yusuf; Kaya, Mehmet Gungor; Sen, Nihat; Tacoy, Gulten; Okyay, Kaan; Yazici, Huseyin Ugur; Yalcin, Mehmet Ridvan; Cengel, Atiye

    2008-04-01

    Hyperuricemia (HU) is a well-recognized risk factor for cardiovascular diseases. The independence of this association from other confounding factors has remained controversial. The possible contributory effect of HU to myocardial impairment produced by hypertension (HT), however, has not been clarified yet. The study was designed to assess the left ventricular (LV) systolic and diastolic function in patients with HT with or without HU. Tissue Doppler imaging (TDI) was used for detailed analysis as this method was superior to other conventional echocardiographic techniques. The study participants consisted of 27 patients (men 56%, mean age+/-SD; 55+/-10 years) with HT without HU, and 27 patients with HT with HU (men 62%, mean age+/-SD; 56+/-9 years), and 27 age-matched healthy control participants (men 57%, mean age+/-SD; 53+/-11 years). Cardiac functions were determined using echocardiography, comprising standard two-dimensional and conventional Doppler and TDI. Peak systolic myocardial velocity at mitral annulus (Sm), mitral inflow velocities and early diastolic mitral annular velocity (Em), late diastolic mitral annular velocity (Am), peak systolic mitral annular velocity, Em/Am, and myocardial performance index were calculated by TDI. Mitral inflow velocities and tissue Doppler-derived mitral annular diastolic velocities were significantly different in the patient groups (HT without HU and HT with HU) compared with the control cases. Tissue Doppler-derived myocardial performance index (LV-MPI) was significantly impaired in the patient groups compared with those of the control's (0.48+/-0.09, 0.53+/-0.07, and 0.39+/-0.07, respectively, P<0.001). Significant differences were also observed between the patients who had HT without HU and the patients who had HT with HU regarding LV-MPI. Significant correlations were observed between the serum uric acid levels and LV function parameters.

  4. Zeeman-Doppler Imaging : Old Problems and New Methods

    CERN Document Server

    Carroll, T A; Strassmeier, K G; Ilyin, I

    2009-01-01

    Zeeman-Doppler Imaging (ZDI) is a powerful inversion method to reconstruct stellar magnetic surface fields. The reconstruction process is usually solved by translating the inverse problem into a regularized least-square or optimization problem. In this contribution we will emphasize that ZDI is an inherent non-linear problem and the corresponding regularized optimization is, like many non-linear problems, potentially prone to local minima. We show how this problem will be exacerbated by using an inadequate forward model. To facilitate a more consistent full radiative transfer driven approach to ZDI we describe a two-stage strategy that consist of a principal component analysis (PCA) based line profile reconstruction and a fast approximate polarized radiative transfer method to synthesize local Stokes profiles. Moreover, we introduce a novel statistical inversion method based on artificial neural networks (ANN) which provide a fast calculation of a first guess model and allows to incorporate better physical co...

  5. Zeeman-Doppler imaging: old problems and new methods

    Science.gov (United States)

    Carroll, Thorsten A.; Kopf, Markus; Strassmeier, Klaus G.; Ilyin, Ilya

    2009-04-01

    Zeeman-Doppler Imaging (ZDI) is a powerful inversion method to reconstruct stellar magnetic surface fields. The reconstruction process is usually solved by translating the inverse problem into a regularized least-square or optimization problem. In this contribution we will emphasize that ZDI is an inherent non-linear problem and the corresponding regularized optimization is, like many non-linear problems, potentially prone to local minima. We show how this problem will be exacerbated by using an inadequate forward model. To facilitate a more consistent full radiative transfer driven approach to ZDI we describe a two-stage strategy that consist of a principal component analysis (PCA) based line profile reconstruction and a fast approximate polarized radiative transfer method to synthesize local Stokes profiles. Moreover, we introduce a novel statistical inversion method based on artificial neural networks (ANN) which provide a fast calculation of a first guess model and allows to incorporate better physical constraints into the inversion process.

  6. Wide angle Michelson Doppler imaging interferometer. [measuring atmospheric emissions

    Science.gov (United States)

    Shepherd, G. G.

    1980-01-01

    The optical system, stepping control, phase and modulation depth, array detector, and directions sensor are described for a specialized type of Michelson interferometer which works at sufficiently high resolution to measure the line widths and Doppler shifts of naturally occurring atmospheric emissions. With its imaging capability, the instrument can potentially supply this data independently for each element of the 100 x 100 detector array. The experiment seeks: (1) to obtain vertical profiles of atmospheric winds and temperatures as functions of latitude by observing near the limb; (2) to acquire exploratory wind and temperature data on smaller scale structures in airglow irregularities and in auroral forms; and (3) to collaborate with other Spacelab experiments, such as barium cloud releases, in providing wind and temperature data.

  7. WAMDII: The Wide Angle Michelson Doppler Imaging Interferometer

    Science.gov (United States)

    1992-01-01

    As part of an effort to learn more about the upper atmosphere and how it is linked to the weather experienced each day, NASA and NRCC are jointly sponsoring the Wide Angle Michelson Doppler Imaging Interferometer (WAMDII) Mission. WAMDII will measure atmospheric temperature and wind speed in the upper atmosphere. In addition to providing data on the upper atmosphere, the wind speed and temperature readings WAMDII takes will also be highly useful in developing and updating computer simulated models of the upper atmosphere. These models are used in the design and testing of equipment and software for Shuttles, satellites, and reentry vehicles. In making its wind speed and temperature measurements, WAMDII examines the Earth's airglow, a faint photochemical luminescence caused by the influx of solar ultraviolet energy into the upper atmosphere. During periods of high solar flare activity, the amount of this UV energy entering the upper atmosphere increases, and this increase may effect airglow emissions.

  8. Magnetic Doppler Imaging of He-strong star HD 184927

    CERN Document Server

    Yakunin, I; Bohlender, D; Kochukhov, O; Tsymbal, V

    2013-01-01

    We have employed an extensive new timeseries of Stokes I and V spectra obtained with the ESPaDOnS spectropolarimeter at the 3.6-m Canada-France-Hawaii Telescope to investigate the physical parameters, chemical abundance distributions and magnetic field topology of the slowly-rotating He-strong star HD 184927. We infer a rotation period of 9.53071+-0.00120 from H-alpha, H-beta, LSD magnetic measurements and EWs of helium lines. We used an extensive NLTE TLUSTY grid along with the SYNSPEC code to model the observed spectra and find a new value of luminosity. In this poster we present the derived physical parameters of the star and the results of Magnetic Doppler Imaging analysis of the Stokes I and V profiles. Wide wings of helium lines can be described only under the assumption of the presence of a large, very helium-rich spot.

  9. Tissue Doppler Septal Tei Index Indicates Severity of Illness in Pediatric Patients with Congestive Heart Failure

    Science.gov (United States)

    Mejia, Aura A Sanchez; Simpson, Kathleen E.; Hildebolt, Charles F; Pahl, Elfriede; Matthews, Kathleen L; Rainey, Cheryl A; Canter, Charles E; Jay, Patrick Y; Johnson, Mark C

    2013-01-01

    Background: The Doppler Tei index is an independent predictor of outcomes in adult heart failure. Tissue Doppler imaging (TDI) may be a superior method to measure the Tei index in children, as it is less affected by heart rate variability. We hypothesized that the TDI Tei index reflects severity of illness in pediatric heart failure. Methods: Twenty-five pediatric heart failure patients were prospectively enrolled. Listing for heart transplantation or death were the outcomes used to define severity of illness. Baseline demographics, brain natriuretic peptide (BNP), standard echocardiographic and TDI-derived parameters were analyzed to determine outcome indicators. Results: Ten of the 25 patients (40%) were listed for transplantation. There were no deaths. Multivariate analysis combining age, heart rate, standard echocardiographic parameters, and BNP, resulted in shortening fraction (p=0.002) as the best indicator of listing for transplantation (R2 = 0.32). A second multivariate analysis combining age, heart rate, TDI parameters and BNP, resulted in age (p = 0.03) and septal Tei index (p = 0.03) as the best predictive model (R2 = 0.36). The area under the receiver operating characteristic (ROC) curve for septal Tei index was 0.84 (0.64-0.96, 95% confidence interval) and it was comparable to the ROC curve for shortening fraction, p=0.76. Optimal values of sensitivity (100%) and specificity (60%) were obtained with septal Tei index values > 0.51. Conclusion: The TDI septal Tei index is an indicator of disease severity in pediatric heart failure patients and offers potential advantages in comparison with standard echocardiographic measures of left ventricular ejection. PMID:24061276

  10. Tissue Doppler echocardiographic quantification. Comparison to coronary angiography results in Acute Coronary Syndrome patients

    Directory of Open Access Journals (Sweden)

    Allal Joseph

    2005-04-01

    Full Text Available Abstract Background Multiples indices have been described using tissue Doppler imaging (DTI capabilities. The aim of this study was to assess the capability of one or several regional DTI parameters in separating control from ischemic myocardium. Methods Twenty-eight patients with acute myocardial infarction were imaged within 24-hour following an emergent coronary angioplasty. Seventeen controls without any coronary artery or myocardial disease were also explored. Global and regional left ventricular functions were assessed. High frame rate color DTI cineloop recordings were made in apical 4 and 2-chamber for subsequent analysis. Peak velocity during isovolumic contraction time (IVC, ejection time, isovolumic relaxation (IVR and filling time were measured at the mitral annulus and the basal, mid and apical segments of each of the walls studied as well as peak systolic displacement and peak of strain. Results DTI-analysis enabled us to discriminate between the 3 populations (controls, inferior and anterior AMI. Even in non-ischemic segments, velocities and displacements were reduced in the 2 AMI populations. Peak systolic displacement was the best parameter to discriminate controls from AMI groups (wall by wall, p was systematically Conclusion DTI-analysis appears to be valuable in ischemic heart disease assessment. Its clinical impact remains to be established. However this simple index might really help in intensive care unit routine practice.

  11. Tissue Harmonic Synthetic Aperture Imaging

    DEFF Research Database (Denmark)

    Rasmussen, Joachim

    The main purpose of this PhD project is to develop an ultrasonic method for tissue harmonic synthetic aperture imaging. The motivation is to advance the field of synthetic aperture imaging in ultrasound, which has shown great potentials in the clinic. Suggestions for synthetic aperture tissue...... system complexity compared to conventional synthetic aperture techniques. In this project, SASB is sought combined with a pulse inversion technique for 2nd harmonic tissue harmonic imaging. The advantages in tissue harmonic imaging (THI) are expected to further improve the image quality of SASB...... harmonic techniques have been made, but none of these methods have so far been applicable for in-vivo imaging. The basis of this project is a synthetic aperture technique known as synthetic aperture sequential beamforming (SASB). The technique utilizes a two step beamforming approach to drastically reduce...

  12. Evaluation of pulmonary arterial hypertension with simple congenital heart disease using tissue Doppler imaging%组织多普勒对单纯先天性心脏病相关肺动脉高压的再评估

    Institute of Scientific and Technical Information of China (English)

    杜佩; 杜国庆; 李海茹; 陈双; 吴言; 田家玮

    2014-01-01

    目的 探讨组织多普勒技术评估常见单纯先天性心脏病患者肺动脉压力、判断肺动脉高压(PAH)及分级的应用价值.方法 经手术或介入证实的单纯先天性心脏病(房间隔缺损、室间隔缺损及动脉导管未闭)患者104例,均行组织多普勒检查和右心导管测压.根据右心导管所测肺动脉平均压(mPAP)分为PAH组60例[mPAP≥25 mmHg(1 mmHg=0.133 kPa)且肺毛细血管楔压(PCWP)≤15mmHg]和非肺动脉高压(non-PAH)组44例(mPAP<25 mmHg).根据严重程度PAH组又分为轻度(25mmHg≤mPAP≤35 mmHg)、中度(36 mmHg≤mPAP≤50 mmHg)及重度(mPAP>50 mmHg)三个亚组.组织多普勒测量三尖瓣环运动速度,获得三尖瓣环收缩期峰值速度(TS')、舒张早期峰值速度(TE ')、舒张晚期峰值速度(TA')以及TE'/TA',并计算Tei指数,以上各参数均与右心导管所测肺动脉压力(sPAP、mPAP、dPAP)行相关性分析.结果 ①PAH组TS'和TE'较non-PAH组明显降低(P<0.05),Tei指数较non-PAH组明显升高(P<0.001),而TA'和TE'/TA'在两组间差异无统计学意义(P>0.05);②多因素相关分析:Tei指数与肺动脉压力呈正相关(P<0.001),TS'与肺动脉压力呈负相关(P<0.05),而TE'、TA'和TE'/TA'与肺动脉压力无相关性(P>0.05);③ROC曲线分析:Tei指数和TS'判断PAH的曲线下面积分别为0.893和0.699,Tei指数>0.49和TS'<16 cm/s提示PAH的敏感性分别为86.67%和80.00%,特异性分别为79.55%和45.45%;④中、重度PAH的Tei指数较轻度PAH明显增高(P<0.05),重度PAH的TS'和TE'较轻、中度PAH减低(P<0.05).Tei指数>0.55提示中-重度PAH的敏感性为95.24%,特异性为72.22%.结论 组织多普勒测得Tei指数和TS '在判断PAH及分级方面具有较高的临床应用价值;Tei指数>0.49可提示PAH,而Tei指数>0.55提示中重度PAH;TS'<16 cm/s提示PAH亦具有一定的参考价值.%Objective To evaluate the value of tissue Doppler imaging (TDI) in diagnosing

  13. Assessment of myocardial strain and strain rate by tissue doppler echocar-diography

    Directory of Open Access Journals (Sweden)

    Ekimova N.A.

    2013-03-01

    Full Text Available The objective of the article is to review the current data on the method of quantitative evaluation of cardiac mechanics — assessment of myocardial strain and strain rate according to the results of the tissue Doppler echocardiography and prospects of its clinical application.

  14. SELF-MIXING LASER-DOPPLER VELOCIMETRY OF LIQUID FLOW AND OF BLOOD PERFUSION IN TISSUE

    NARCIS (Netherlands)

    DEMUL, FFM; KOELINK, MH; WEIJERS, AL; GREVE, J; AARNOUDSE, JG; GRAAFF, R; DASSEL, ACM

    1992-01-01

    The velocimetry method of self-mixing, i.e., the feedback of Doppler-scattered light into the laser cavity, is used for the measurement of liquid flow and of blood perfusion in human tissue. The method is eIucidated by the registration of the blood perfusion of a finger under repeated occlusion of t

  15. Value of dobutamine stress tissue Doppler in evaluation of LV ...

    African Journals Online (AJOL)

    Shaimaa Ahmed Mostafa

    2014-12-12

    Dec 12, 2014 ... Prosthetic valve disease. Complicated PCI. LVEF less .... annulus moved toward the cardiac apex due to longitudinal contraction of the LV. ..... to fibrotic tissue is too high and also, improved the integrity of cardiac myocyte cell ...

  16. Experimental verification of color flow imaging based on wideband Doppler method.

    Science.gov (United States)

    Tanaka, Naohiko

    2014-01-01

    The purpose of this study is to eliminate the aliasing in color flow imaging. The wideband Doppler method is applied to generate a color flow image, and the validity of the method is experimentally confirmed. The single beam experiment is carried out to confirm the velocity estimation based on the wideband Doppler method. The echo data for the conventional pulsed Doppler method and the wideband Doppler method are obtained using a flow model, and the estimated velocity for each method is compared. The color flow images for each method are also generated using several types of flow model. The generated images are compared, and the characteristics of the imaging based on the wideband Doppler method are discussed. The high velocity beyond the Nyquist limit is successfully estimated by the wideband Doppler method, and the availability in low velocity estimation is also confirmed. The aliasing in color flow images is eliminated, and the generated images show the significance of the elimination of the aliasing in the flow imaging. The aliasing in color flow imaging can be eliminated by the wideband Doppler method. This technique is useful for the exact understanding of blood flow dynamics.

  17. Ventricular structure and function in children with sickle cell disease using conventional and tissue Doppler echocardiography.

    Science.gov (United States)

    Eddine, Ahmad Charaf; Alvarez, Ofelia; Lipshultz, Steven E; Kardon, Richard; Arheart, Kristopher; Swaminathan, Sethuraman

    2012-05-01

    Conventional 2-dimensional, M-mode, and spectral Doppler echocardiographic techniques have documented abnormal ventricular function in adults with sickle cell disease (SCD), but assessments in children are conflicting. Tissue Doppler echocardiography (TDE) provides additional information about myocardial function. Two-dimensional, M-mode, tricuspid regurgitation jet velocity (TRJV) data, and tissue Doppler echocardiographically derived myocardial velocity measurements of left ventricular (LV) and right ventricular function were taken from children with SCD compared to those of similar healthy historical controls and correlated with clinical characteristics and hemoglobin levels. Compared to 55 controls, 54 children with SCD (mean age 14.2 years, range 6 to 21) had a larger left ventricle, greater LV mass, and higher LV fractional shortening; 30% had increased pulmonary artery pressure (TRJV ≥2.5 m/s). Conventional echocardiographic measurements of LV systolic function and spectral Doppler measurements of LV and right ventricular diastolic function were essentially normal, but TDE indicated that 31% of SCD children had evidence of LV diastolic dysfunction (peak early diastolic velocity of LV inflow Doppler/peak early diastolic velocity at lateral mitral valve annulus >8), a finding that correlated with lower hemoglobin levels. Although decreasing hemoglobin levels in children with SCD correlated with LV hypertrophy, LV dilation, and LV diastolic dysfunction, long-term transfusion or hydroxyurea therapy did not affect these measurements. In conclusion, 1/3 of children with SCD had tissue Doppler echocardiographic evidence of LV diastolic dysfunction, which was correlated with hemoglobin levels. Adding serial assessments of ventricular function with TDE to conventional echocardiography may detect early cardiac changes, especially in children with severe anemia.

  18. Laser Doppler holographic microscopy in transmission: application to fish embryo imaging

    CERN Document Server

    Verrier, Nicolas; Gross, Michel

    2014-01-01

    We have extended Laser Doppler holographic microscopy to transmission geometry. The technique is validated with living fish embryos imaged by a modified upright bio-microcope. By varying the frequency of the holographic reference beam, and the combination of frames used to calculate the hologram, multimodal imaging has been performed. Doppler images of the blood vessels for different Doppler shifts, images where the flow direction is coded in RGB colors or movies showing blood cells individual motion have been obtained as well. The ability to select the Fourier space zone that is used to calculate the signal, makes the method quantitative.

  19. Doppler images of II Peg for 2004-2010

    CERN Document Server

    Hackman, Thomas; Lindborg, Marjaana; Ilyin, Ilya; Kochukhov, Oleg; Piskunov, Nikolai; Tuominen, Ilkka

    2011-01-01

    Aims. We study the spot activity of II Peg during the years 2004-2010 in order to determine long- and short-term changes in the magnetic activity. In a previous study, we detected a persistent active longitude, as well as major changes in the spot configuration occurring on a timescale of less than a year. The main objective of this study is to determine whether the same phenomena persist in the star during these six years of spectroscopic monitoring. Methods. The observations were collected with the high-resolution SOFIN spectrograph at the Nordic Optical Telescope. The temperature maps were calculated using a Doppler imaging code based on Tikhonov regularization. Results. We present 12 new temperature maps that show spots distributed mainly over high and intermediate latitudes. In each image 1-3 main active regions can be identified. The activity level of the star is clearly lower than during our previous study of 1994-2002. Contrary to the previous observations, we detect no clear drift of the active regio...

  20. Doppler Imaging of LQ Hya for 1998-2002

    CERN Document Server

    Cole, E M; Käpylä, M J; Ilyin, I; Kochukhov, O; Piskunov, N

    2015-01-01

    We study the spot distribution on the surface of LQ~Hya during the observing seasons October 1998 -- November 2002. We look for persistent active longitudes, trends in the level of spot activity and compare to photometric data, specifically to the derived time epochs of the lightcurve minima. We apply the Doppler Imaging technique on photospheric spectral lines using an inversion code to retrieve images of the surface temperature. We present new temperature maps using multiple spectral lines for a total of 7 seasons. We calculate spot coverage fractions from each map, and as a result we find a general trend that is interpreted to be an indication of a spot cycle. There is a minimum during the observing season of March 1999. After this the activity increases until November 2000, followed by a general decrease in activity again. We find no evidence for active longitudes persisting over multiple observing seasons. The spot activity appears to be concentrated to two latitude regions. The high latitude spots are p...

  1. Effects of Mitral Balloon Valvuloplasty on Left Ventricular Systolic Functions: Assessment with Color Tissue Doppler

    Directory of Open Access Journals (Sweden)

    Cevat Kırma

    2010-04-01

    Full Text Available Objective: Left ventricular (LV systolic functions are generally depressed in Mitral Stenosis (MS. Recovery of LV systolic functions demonstrated with 2D echocardiography in some patients by mitral balloon valvuloplasty (MBV. Systolic mitral annular velocity (S' by Tissue Doppler Imaging (TDI predicts LV systolic function. We aimed to evaluate early effects of MBV on LV systolic function by TDI.Methods: Forty-eight consecutive patients included to the study (39 female, 36±10 years. A full transthoracic echocardiographic study (TTE including left ventricular ejection fraction assessment by teicholz method and mitral annular color TDI assessment was performed 24 hours before and after MBV in all patients. MBV performed by Inoue technique under guidance of TTE. Analysis of mitral lateral annular S' wave velocity was performed immediately after echocardiographic examination. Results: MBV performed successfully in 43 patients (Group A, and severe mitral regurgitation developed in 5 patients(Group B. Mitral valve area, and S’ wave velocity increased, mean and maximum mitral gradient, and left atrial diameter, and systolic pulmonary artery pressure (PAP were reduced significantly by MBV in group A patients (p<0.01, =0.046, <0.01, <0.01, <0.01, <0.01, respectively. But, only mitral valve area increased significantly ingroup B patients (p<0.01. LVEF by teicholz did not change significantly in both groups. Conclusion: Improvements of LV systolic functions after successfull MBV can easily showed by color TDI where2D echocardiography could not indicate.

  2. Dispersed single-phase-step Michelson interferometer for Doppler imaging using sunlight.

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian

    2012-09-15

    A Michelson interferometer is dispersed with a fiber array-fed spectrograph, providing 59 Doppler sensing channels using sunlight in the 510-570 nm wavelength region. The interferometer operates at a single-phase-step mode, which is particularly advantageous in multiplexing and data processing compared to the phase-stepping mode of other interferometer spectrometer instruments. Spectral templates are prepared using a standard solar spectrum and simulated interferometer modulations, such that the correlation function with a measured 1D spectrum determines the Doppler shift. Doppler imaging of a rotating cylinder is demonstrated. The average Doppler sensitivity is ~12 m/s, with some channels reaching ~5 m/s.

  3. In vivo imaging of melanoma-implanted magnetic nanoparticles using contrast-enhanced magneto-motive optical Doppler tomography

    Science.gov (United States)

    Wijesinghe, Ruchire Eranga; Park, Kibeom; Kim, Dong-Hyeon; Jeon, Mansik; Kim, Jeehyun

    2016-06-01

    We conducted an initial feasibility study using real-time magneto-motive optical Doppler tomography (MM-ODT) with enhanced contrast to investigate the detection of superparamagnetic iron oxide (SPIO) magnetic nanoparticles implanted into in vivo melanoma tissue. The MM-ODT signals were detected owing to the phase shift of the implanted magnetic nanoparticles, which occurred due to the action of an applied magnetic field. An amplifier circuit-based solenoid was utilized for generating high-intensity oscillating magnetic fields. The MM-ODT system was confirmed as an effective in vivo imaging method for detecting melanoma tissue, with the performance comparable to those of conventional optical coherence tomography and optical Doppler tomography methods. Moreover, the optimal values of the SPIO nanoparticles concentration and solenoid voltage for obtaining the uppermost Doppler velocity were derived as well. To improve the signal processing speed for real-time imaging, we adopted multithread programming techniques and optimized the signal path. The results suggest that this imaging modality can be used as a powerful tool to identify the intracellular and extracellular SPIO nanoparticles in melanoma tissues in vivo.

  4. Seismic imaging in laboratory trough laser Doppler vibrometry

    Science.gov (United States)

    Brito, Daniel; Poydenot, Valier; Garambois, Stéphane; Diaz, Julien; Bordes, Clarisse; Rolando, Jean-Paul

    2016-04-01

    Mimic near-surface seismic field measurements at a small scale, in the laboratory, under a well-controlled environment, may lead to a better understanding of wave propagation in complex media such as in geological materials. Laboratory experiments can help in particular to constrain and refine theoretical and numerical modelling of physical phenomena occurring during seismic propagation, in order to make a better use of the complete set of measurements recorded in the field. We have developed a laser Doppler vibrometer (laser interferometry) platform designed to measure non-contact seismic displacements (or velocities) of a surface. This technology enables to measure displacements as small as a tenth of a nanometer on a wide range of frequencies, from a few tenths to a few megahertz. Our experimental set-up is particularly suited to provide high-density spatial and temporal records of displacements on the edge of any vibrating material. We will show in particular a study of MHz wave propagation (excited by piezoelectric transducers) in cylindrical cores of typical diameter size around 10 cm. The laser vibrometer measurements will be first validated in homogeneous materials cylinders by comparing the measurements to a direct numerical simulation. Special attention will be given to the comparison of experimental versus numerical amplitudes of displacements. In a second step, we will conduct the same type of study through heterogeneous carbonate cores, possibly fractured. Tomographic images of velocity in 2D slices of the carbonate core will be derived based upon on the time of first arrival. Preliminary attempts of tomographic attenuation maps will also be presented based on the amplitudes of first arrivals. Experimental records will be confronted to direct numerical simulations and tomographic images will be compared to x-ray scanner imaging of the cylindrical cores.

  5. Imaging and characterizing shear wave and shear modulus under orthogonal acoustic radiation force excitation using OCT Doppler variance method.

    Science.gov (United States)

    Zhu, Jiang; Qu, Yueqiao; Ma, Teng; Li, Rui; Du, Yongzhao; Huang, Shenghai; Shung, K Kirk; Zhou, Qifa; Chen, Zhongping

    2015-05-01

    We report on a novel acoustic radiation force orthogonal excitation optical coherence elastography (ARFOE-OCE) technique for imaging shear wave and quantifying shear modulus under orthogonal acoustic radiation force (ARF) excitation using the optical coherence tomography (OCT) Doppler variance method. The ARF perpendicular to the OCT beam is produced by a remote ultrasonic transducer. A shear wave induced by ARF excitation propagates parallel to the OCT beam. The OCT Doppler variance method, which is sensitive to the transverse vibration, is used to measure the ARF-induced vibration. For analysis of the shear modulus, the Doppler variance method is utilized to visualize shear wave propagation instead of Doppler OCT method, and the propagation velocity of the shear wave is measured at different depths of one location with the M scan. In order to quantify shear modulus beyond the OCT imaging depth, we move ARF to a deeper layer at a known step and measure the time delay of the shear wave propagating to the same OCT imaging depth. We also quantitatively map the shear modulus of a cross-section in a tissue-equivalent phantom after employing the B scan.

  6. The impacts of piezoelectric element's defects on color and power doppler images

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Sung [Dept. of Radiotechnology, Cheju Halla University, Cheju (Korea, Republic of)

    2015-12-15

    An ultrasound probe has a big impact on Doppler images even though it has very high risk of frequent function-breakdowns occurring in medical ultrasound scanners. This study experimentally analyses the impacts of an ultrasonic probe’s defected elements on power and color Doppler images. The results show that, the bigger the size of defected probe elements is, and the closer a group of action elements is to the center, the more the brightness of images and the velocity of Doppler diminish. When elements’ defects increase in color and power Doppler images, false images are formed to be mistaken for blood-vessel plaque in neighboring regions. Accordingly, whenever element defects are suspected, we need check-up process in B-mode. From this respective, it is advisable to have primary interest in a probe and carry out continuous probe QA for ultrasonography.

  7. New adaptive clutter rejection for ultrasound color Doppler imaging: in vivo study.

    Science.gov (United States)

    Yoo, Yang Mo; Kim, Yongmin

    2010-03-01

    Clutter rejection is essential for accurate flow estimation in ultrasound color Doppler imaging. In this article, we present a new adaptive clutter rejection (ACR) technique where an optimum filter is dynamically selected depending upon the underlying clutter characteristics (e.g., tissue acceleration and power). We compared the performance of the ACR method with other adaptive methods, i.e., down-mixing (DM) and adaptive clutter filtering (ACF), using in vivo data acquired from the kidney, liver and common carotid artery. With the kidney data, the ACR method provided an average improvement of 3.05 dB and 1.7 dB in flow signal-to-clutter ratio (SCR) compared with DM and ACF, respectively. With the liver data, SCR was improved by 2.75 dB and 1.8 dB over DM and ACF while no significant improvement with ACR was found in the common carotid artery data. Thus, the proposed adaptive method could provide more accurate flow estimation by improving clutter rejection in abdominal ultrasound color Doppler imaging pending validation.

  8. A gel-based skin and blood flow model for a Doppler optical coherence tomography (DOCT) imaging system

    Science.gov (United States)

    Lawlor, Kate; O'Connell, Marie-Louise; Jonathan, Enock; Leahy, Martin J.

    2010-02-01

    Since its discovery in 1842 by Christian Johann Doppler, the Doppler Effect has had many applications in the scientific world. In recent years, the phenomenon has been integrated with Optical Coherence Tomography (OCT) yielding Doppler Optical Coherence Tomography (DOCT), a technique that is useful for high-resolution imaging of the skin microcirculation. However, interpretation of DOCT images is rather challenging. Thus, our study aims to aid understanding of DOCT images with respect to parameters of microcirculation components such as blood vessel size, depth and angular position. To this end, we have constructed a gel-based tissue and blood-flow model for performing DOCT studies under well controlled conditions. We present results from a pilot study using a gel-based tissue and blood flow model. Human blood was pumped through the model at various velocities from a commercial calibrated syringe pump, serving as a standard reference point for all velocity measurements. The range of velocity values was chosen to coincide with that found in the human vasculature. Simultaneous DOCT imaging at different flow rates contributed to establishing the capabilities and limitations of the DOCT system under investigation. We present preliminary results as first step to developing a robust validation protocol with which to aid future research in this area.

  9. Zeeman-Doppler imaging of active young solar type stars

    CERN Document Server

    Hackman, Thomas; Rosén, Lisa; Kochukhov, Oleg; Käpylä, Maarit J

    2015-01-01

    By studying young magnetically active late-type stars, i.e. analogues to the young Sun, one can draw conclusions on the evolution of the solar dynamo. We determine the topology of the surface magnetic field and study the relation between the magnetic field and cool photospheric spots in three young late-type stars. High-resolution spectropolarimetry of the targets were obtained with the HARPSpol instrument mounted at the ESO 3.6 m telescope. The signal-to-noise ratio of the Stokes IV measurements were boosted by combining the signal from a large number of spectroscopic absorption lines through the least squares deconvolution technique. Surface brightness and magnetic field maps were calculated using the Zeeman-Doppler imaging technique. All the three targets show clear signs of both magnetic fields and cool spots. Only one of the targets, namely V1358 Ori, shows evidence of the dominance of non-axisymmetric modes. In two of the targets, the poloidal field is significantly stronger than the toroidal one, indic...

  10. High resolution Doppler imager on the Upper Atmosphere Research Satellite

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, W.R.; Hays, P.B.; Grassl, H.J.; Gell, D.A.; Burrage, M.D.; Marshall, A.R.; Ortland, D.A. [Univ. of Michigan, Ann Arbor, MI (United States)

    1994-12-31

    The High Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite has been providing measurements of the wind field in the stratosphere, mesosphere and lower thermosphere since November 1991. Examination of various calibration data indicates the instrument has remained remarkably stable since launch. The instrument has a thermal drift of about 30 m/s/{degree}C (slightly dependent on wavelength) and a long-term temporal drift that has amounted to about 80 m/s since launch. These effects are removed in the data processing leaving an uncertainty in the instrument stability of {minus}2 nVs. The temperature control of the instrument has improved significantly since launch as a new method was implemented. The initial temperature control held the instrument temperature at about {+-}1{degree}C. The improved method, which holds constant the temperature of the optical bench instead of the radiator, keeps the instrument temperature at about 0.2{degree}C. The calibrations indicate very little change in the sensitivity of the instrument. The detector response has shown no degradation and the optics have not changed their transmittance.

  11. Transcranial functional ultrasound imaging of the brain using microbubble-enhanced ultrasensitive Doppler.

    Science.gov (United States)

    Errico, Claudia; Osmanski, Bruno-Félix; Pezet, Sophie; Couture, Olivier; Lenkei, Zsolt; Tanter, Mickael

    2016-01-01

    Functional ultrasound (fUS) is a novel neuroimaging technique, based on high-sensitivity ultrafast Doppler imaging of cerebral blood volume, capable of measuring brain activation and connectivity in rodents with high spatiotemporal resolution (100μm, 1ms). However, the skull attenuates acoustic waves, so fUS in rats currently requires craniotomy or a thinned-skull window. Here we propose a non-invasive approach by enhancing the fUS signal with a contrast agent, inert gas microbubbles. Plane-wave illumination of the brain at high frame rate (500Hz compounded sequence with three tilted plane waves, PRF=1500Hz with a 128 element 15MHz linear transducer), yields highly-resolved neurovascular maps. We compared fUS imaging performance through the intact skull bone (transcranial fUS) versus a thinned-skull window in the same animal. First, we show that the vascular network of the adult rat brain can be imaged transcranially only after a bolus intravenous injection of microbubbles, which leads to a 9dB gain in the contrast-to-tissue ratio. Next, we demonstrate that functional increase in the blood volume of the primary sensory cortex after targeted electrical-evoked stimulations of the sciatic nerve is observable transcranially in presence of contrast agents, with high reproducibility (Pearson's coefficient ρ=0.7±0.1, p=0.85). Our work demonstrates that the combination of ultrafast Doppler imaging and injection of contrast agent allows non-invasive functional brain imaging through the intact skull bone in rats. These results should ease non-invasive longitudinal studies in rodents and open a promising perspective for the adoption of highly resolved fUS approaches for the adult human brain.

  12. Electroacoustic Tissue Imaging

    Science.gov (United States)

    2007-03-01

    cm−3 ◦C−1), I is the ultrasound intensity in W cm−2 and t is the application time (15 µs) (Herman and Harris 2002). The maximum intensity can be...elastic properties of tissue—a review Ultrasound Med. Biol. 22 959–77 Herman B A and Harris G R 2002 Models and regulatory considerations for... Alpert Medical School, Brown University, Providence, RI, USA, 02912 A Fresnel-Kirchhoff integral can be used to calculate x-ray phase contrast images

  13. FEASIBILITY STUDY OF AN ULTRASOUND CONTRAST AGENT (LEVOVIST) IN COLOR DOPPLER IMAGING OF LIVER NEOPLASMS

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    @@ The purpose of this study was to determine the efficacy of using an ultrasound contrast agent(levovist)to enhance the color Doppler imaging of liver neoplasms.Thirty patients with hepatic tumors were enrolled in this study.After intravenous administration of levovist,the color Doppler signals of normal hepatic vessels were enhanced.In various hepatic tumors,the different patterns of tumor vascularity were observed,which had not been demonstrated in conventional non-contrast color Doppler imaging.In 11 of 16 patients with hepatocarcinoma,additoal color Doppler signals were observed in the central part of the tumors.On the contrary,3 patients with metastatic liver lesions the enhanced color Doppler signal appear only at the peripheral of tumors.A typical rim-like color enhancement was seen in 2 of the 3 cases.In six patients with hpatic hemangiomas contrast-enhanced color Doppler imaging demonstrated the blood vessels at the margin of the neoplasms.Contrast-enhanced color Doppler imaging improves the visualization of the hepatic neoplasm vascularity.This technique holds great promise for detecting small liver tumors and differentiating hepatic neoplasms.

  14. Nonsearching Doppler parameter and velocity estimation method for synthetic aperture radar ground moving target imaging

    Science.gov (United States)

    Li, Zhongyu; Wu, Junjie; Huang, Yunlin; Yang, Haiguang; Yang, Jianyu

    2016-07-01

    For synthetic aperture radar (SAR), ground moving target (GMT) imaging necessitates the compensation of the additional azimuth modulation contributed by the unknown movement of the GMT. That is to say, it is necessary to estimate the Doppler parameters of the GMT without a priori knowledge of the GMT's motion parameters. This paper presents a Doppler parameter and velocity estimation method to refocus the GMT from its smeared response in SAR image. The main idea of this method is that an azimuth reference function is constructed to do the correlation integral with the azimuth signal of the GMT. And in general, the Doppler parameters of the presumed azimuth reference function are different from those of the GMT's azimuth signal since the velocity parameters of the GMT are unknown. Therefore, the correlation operation referred to here is actually mismatched, and the processing result of is shifted and defocused. The shifted and defocused result is utilized to get the real Doppler parameters and the velocity parameters of the GMT. One advantage of this method is that it is a nonsearching method. Another advantage is that both the Doppler centroid and the Doppler frequency rate of the GMT can be simultaneously estimated according to the relationships between the Doppler parameters and the smeared response of the GMT. In addition, the velocity of the GMT can also be obtained based on the estimated Doppler parameters. Numerical simulations and experimental data processing verify the validity of the method proposed.

  15. Noninvasive monitoring of cardiac function in a chronic ischemic heart failure model in the rat: Assessment with tissue Doppler and non-Doppler 2D strain echocardiography

    Directory of Open Access Journals (Sweden)

    Baumann Gert

    2011-05-01

    Full Text Available Abstract Objectives Feasibility of noninvasive monitoring of cardiac function after surgically induced ischemic cardiomyopathy with tissue Doppler and non-Doppler 2D strain echocardiography in rats. Background The optimal method for quantitative assessment of global and regional ventricular function in rats with chronic heart failure for research purposes remains unclear. Methods 20 rats underwent suture ligation of the left anterior descending coronary artery via a left thoracotomy to induce ischemic cardiomyopathy. Echocardiographic examination with estimation of left ventricular wall thickness, diameters, fractional shortening, ejection fraction, wall velocities as well as radial strain were performed before and 4 weeks after surgery. Results Mean LVEF decreased from 70 ± 6% to 40 ± 8% (p Conclusion It is feasible to assess dimensions, global function, and regional contractility with echocardiography in rats suffering from chronic heart failure after myocardial infarction. Particularly regional function can be exactly evaluated if tissue Doppler and 2D strain is used.

  16. PRELIMINARY APPLICATION OF COLOR DOPPLER FLOW IMAGING IN THE LOCALIZATION OF PARATHYROID ADENOMAS

    Institute of Scientific and Technical Information of China (English)

    张缙熙; 李建初

    1994-01-01

    From December 1991 to April 1993,we performed color Doppler flow imaging(CDFI) in 11 patients with parathyroid adenoma,and all cases were confirmed by toperation and pathology.In all the parathyroid adenomas,vessels were clearly revealed at the periphery of the upper pole and /or anterior periphery,where arterial signals were elicited.These arteries had branches into the adenomas and originated from inferior thyroid arteries on the same side in most cases.The internal flow signals were increased markedly as compared to normal thyroid,and high-velocity arterial signals were detected.Because of the thyroid's rich blood supply and landmark peripheral vessels.CDFI can distinguish parathyroid foci from thyroid nodules,lymph nodes,and normal tissues and provide a sound basis for the diagnosis of small parathyroid foci.

  17. High-frequency subharmonic pulsed-wave Doppler and color flow imaging of microbubble contrast agents.

    Science.gov (United States)

    Needles, A; Goertz, D E; Karshafian, R; Cherin, E; Brown, A S; Burns, P N; Foster, F S

    2008-07-01

    A recent study has shown the feasibility of subharmonic (SH) flow imaging at a transmit frequency of 20 MHz. This paper builds on these results by examining the performance of SH flow imaging as a function of transmit pressure. Further, we also investigate the feasibility of SH pulsed-wave Doppler (PWD) imaging. In vitro flow experiments were performed with a 1-mm-diameter wall-less vessel cryogel phantom using the ultrasound contrast agent Definity and an imaging frequency of 20 MHz. The phantom results show that there is an identifiable pressure range where accurate flow velocity and power estimates can be made with SH imaging at 10 MHz (SH10), above which velocity estimates are biased by radiation force effects and unstable bubble behavior, and below which velocity and power estimates are degraded by poor SNR. In vivo validation of SH PWD was performed in an arteriole of a rabbit ear, and blood velocity estimates compared well with fundamental (F20) mode PWD. The ability to suppress tissue signals using SH signals may enable the use of higher frame rates and improve sensitivity to microvascular flow or slow velocities near large vessel walls by reducing or eliminating the need for clutter filters.

  18. V-plane显像与组织多普勒技术评价扩张型心肌病患者左心室收缩同步性的一致性研究%Evaluation of consistency between V-plane imaging and tissue Doppler imaging for systolic synchronicity in patients with dilated cardiomyopathy

    Institute of Scientific and Technical Information of China (English)

    宋宏宁; 周青; 秦真英; 陈金玲; 郭瑞强

    2014-01-01

    目的 应用V-plane技术观察扩张型心肌病(DCM)患者左心室收缩不同步显像,并与临床常用的组织多普勒显像(TDI)技术进行对比,评价其相关性与一致性.方法 对20例DCM患者及20例健康对照者进行超声检查,获取二维图像、V-plane双平面图像和TDI图像,测量左室12个节段TDI脉冲频谱达峰时间,并计算其标准差(TDI_SD),测量V-plane显像中12节段收缩位移达峰时间,并计算其标准差(V-plane_SD).结果 与对照组相比,DCM组的TDI SD和V-plane_SD增大,TDI达峰时间延迟,V-plane达峰时间缩短,差异有统计学意义(P<0.01);DCM组与对照组12节段中各节段V-plane收缩达峰时间均显著高于TDI收缩达峰时间,差异有统计学意义(P<0.01);V-plane_SD与TDI_SD具有显著相关性(r=0.925,P<0.001),Bland-Ahman分析显示TDI SD与V-plane_SD比值的95%数据点在一致性界限内,其比值的一致性界限为(0.50,1.36).结论 在评价DCM患者左室收缩同步性时V-plane技术与TDI技术具有较高的相关性及一致性,V-plane能克服TDI不能在同一心动周期显示12节段的局限性.%Objective To evaluate left ventricular systolic synchronicity in patients with dilated cardiomyopathy by V-plane imaging and compare with clinical commonly used tissue Doppler imaging (TDI),evaluate the relevance and consistency between these two parameters.Methods 20 patients diagnosed with DCM and 20 healthy controls were enrolled,2D images,V-plane imaging and TDI waveform were acquired.Time to peak velocity of left ventricular 12 segments were measured by TDI and the standard deviation (TDI_SD) were calculated.Displacement time to peak were measured by V-plane and the standard deviation (V-plane_SD) were calculated.Results Compared with control group,TDI_SD and V-plane_SD increased significantly (P < 0.01),TDI time to peak increased and V-plane time to peak decreased significantly(P <0.01).In the two group,12 segment time to peak measured by V

  19. Time domain algorithm for accelerated determination of the first order moment of photo current fluctuations in high speed laser Doppler perfusion imaging

    NARCIS (Netherlands)

    Draijer, M.; Hondebrink, E.; van Leeuwen, T.; Steenbergen, W.

    2009-01-01

    Advances in optical array sensor technology allow for the real time acquisition of dynamic laser speckle patterns generated by tissue perfusion, which, in principle, allows for real time laser Doppler perfusion imaging (LDPI). Exploitation of these developments is enhanced with the introduction of f

  20. 组织多普勒技术定量评价陈旧性室间隔心肌梗死的右室功能%Right ventricular regional and global function in patients with old septal myocardial infarction by different techniques of tissue Doppler imaging

    Institute of Scientific and Technical Information of China (English)

    赵玉; 周晓彦; 蒋银花; 张民

    2012-01-01

    目的:采用不同组织多普勒技术定量研究陈旧性室间隔心肌梗死患者的右室局部和整体功能.方法:20例陈旧性室间隔心肌梗死患者,30例健康成人.采用应变率及组织速度成像获取右室侧壁各节段的组织速度、位移、应变及应变率曲线.测量收缩功能参数:收缩期峰值速度(Vs)、最大位移(D)、收缩期峰值应变(S)及应变率(SR);测量舒张功能参数:舒张早期充盈速度(Ve)、心房收缩期充盈速度(Va)、舒张早期充盈应变率( Esr)、心房收缩期充盈应变率(Asr).脉冲组织多普勒获取三尖瓣环运动频谱曲线,计算右室Tei指数.结果:陈旧性室间隔心肌梗死组右室侧壁基底段的S和D以及心尖段的SR和D均较正常组明显减低;基底段及中间段的Ve和Esr均较正常组明显减低;右室Tei指数明显高于正常组.结论:陈旧性室间隔心肌梗死患者右室侧壁多个节段的局部收缩和舒张功能明显受损,此外右室整体功能也明显受损.%Objective:To evaluate right ventricular (RV) regional and global function in patients with old septal myocar-dial infarction by different techniques of tissue Doppler imaging. Methods: The curves of RV lateral wall myocardial Doppler velocity, displacement, strain and strain rate were acquired by strain rate and tissue velocity imaging in 20 patients with old septal myocardial infarction and 30 healthy volunteers. Measured systolic function parameters were as fo Hows: the peak systolic velocity (Vs), displacement (D), strain (S) and strain rate (SR). Measured diastolic function parameters were listed below: the early diastolic velocity (Ve) , atrial systolic velocity (Va) , early diastolic strain rate (Esr) . At-rial systolic strain rate (Asr). Pulsed tissue Doppler sample volume was placed in tricuspid annulus and RV Tei index was calculated. Results: In old septal myocardial infarction groups, the S and D in basal segment and the SR and D in apical

  1. Left ventricular radial colour and longitudinal pulsed-wave tissue Doppler echocardiography in 39 healthy domestic pet rabbits.

    Science.gov (United States)

    Casamian-Sorrosal, Domingo; Saunders, Richard; Browne, William; Elliot, Sarah; Fonfara, Sonja

    2014-10-01

    This paper reports radial colour and longitudinal mitral annulus pulsed-wave tissue Doppler findings in a large cohort of healthy, adult pet rabbits. Thirty-nine rabbits (22 Dwarf Lops, 14 French Lops and three Alaskans) underwent conscious echocardiography. The median age of the rabbits was 22 months and the median weight was 2.8 kg (Dwarf Lop 2.4 kg/French Lop 6.0 kg). Adequate radial colour and longitudinal pulsed-wave tissue Doppler traces were obtained in 100% and 85% of cases, respectively. Most systolic tissue Doppler parameters were significantly higher in French Lops than in Dwarf Lops. Separation of mitral inflow diastolic waves was present in 40% of cases using conventional spectral Doppler and in >60% of cases using pulsed-wave tissue Doppler which could be beneficial when evaluating diastolic function in rabbits. This study can be used as a reference for normal echocardiographic tissue Doppler values for adult rabbits undergoing conscious echocardiography in clinical practice.

  2. An image-based approach for classification of human micro-doppler radar signatures

    Science.gov (United States)

    Tivive, Fok Hing Chi; Phung, Son Lam; Bouzerdoum, Abdesselam

    2013-05-01

    With the advances in radar technology, there is an increasing interest in automatic radar-based human gait identification. This is because radar signals can penetrate through most dielectric materials. In this paper, an image-based approach is proposed for classifying human micro-Doppler radar signatures. The time-varying radar signal is first converted into a time-frequency representation, which is then cast as a two-dimensional image. A descriptor is developed to extract micro-Doppler features from local time-frequency patches centered along the torso Doppler frequency. Experimental results based on real data collected from a 24-GHz Doppler radar showed that the proposed approach achieves promising classification performance.

  3. Two-dimensional multi-frequency imaging of a tumor inclusion in a homogeneous breast phantom using the harmonic motion Doppler imaging method

    Science.gov (United States)

    Kamali Tafreshi, Azadeh; Barış Top, Can; Güneri Gençer, Nevzat

    2017-06-01

    Harmonic motion microwave Doppler imaging (HMMDI) is a novel imaging modality for imaging the coupled electrical and mechanical properties of body tissues. In this paper, we used two experimental systems with different receiver configurations to obtain HMMDI images from tissue-mimicking phantoms at multiple vibration frequencies between 15 Hz and 35 Hz. In the first system, we used a spectrum analyzer to obtain the Doppler data in the frequency domain, while in the second one, we used a homodyne receiver that was designed to acquire time-domain data. The developed phantoms mimicked the elastic and dielectric properties of breast fat tissue, and included a 14~\\text{mm}× 9 mm cylindrical inclusion representing the tumor. A focused ultrasound probe was mechanically scanned in two lateral dimensions to obtain two-dimensional HMMDI images of the phantoms. The inclusions were resolved inside the fat phantom using both experimental setups. The image resolution increased with increasing vibration frequency. The designed receiver showed higher sensitivity than the spectrum analyzer measurements. The results also showed that time-domain data acquisition should be used to fully exploit the potential of the HMMDI method.

  4. Color Doppler Imaging in the Diagnosis and Follow-up of Carotid Cavernous Sinus Fistulas

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    This report describes color doppler imaging (CDI) in theevaluation and follow-up of nine patients with carotid cavernous sinusfistulas.The orbits and carotid arteries were examined with CDI.In allcases,the diagnosis was confirmed by angiography.CDI clearlydemonstrated the dilated superior ophthalmic veins (SOVs) with retrogradeflow and low resistance arterial doppler waveform in all nine patients (10eyes).After the study of quantitative hemodynamics,we found that directcarotid cavernous sinus fistulas s...

  5. Comparison of pulsed wave and color Doppler myocardial velocity imaging in healthy dogs.

    Science.gov (United States)

    Wess, G; Killich, M; Hartmann, K

    2010-01-01

    Tissue velocity imaging (TVI) is increasingly used in small animal cardiology. Tissue velocity of the myocardial wall can be measured by pulsed wave (PW) or color Doppler (CD) imaging methods. Currently, the same reference ranges are used for PW TVI and CD TVI methods. However, if and how both methods correlate, and whether they can be used interchangeably, have not been assessed in small animals. To compare the results of PW TVI and CD TVI measurements. Seventy-one healthy dogs. Longitudinal myocardial velocity profiles were recorded from the 4-chamber left apical view. Peak maximal systolic (S), early (E), and late diastolic (A) velocities were measured off-line in a blinded fashion in the septal and lateral left ventricular wall by PW TVI and CD TVI. Differences between peak PW TVI and CD TVI waves were analyzed by a paired t-test. Regression analysis and Bland-Altman difference plots also were used to assess agreement between methods. There was a significant correlation between PW TVI and CD TVI (P Theses differences are clinically relevant. These methods should not be used interchangeably, and different reference ranges for PW TVI and CD TVI should be used.

  6. Tissue Doppler echocardiography in persons with hypertension, diabetes, or ischaemic heart disease: the Copenhagen City Heart Study

    DEFF Research Database (Denmark)

    Mogelvang, Rasmus; Sogaard, Peter; Pedersen, Sune A

    2009-01-01

    AIMS: To test the hypothesis that echocardiographic tissue Doppler imaging (TDI) reveals reduced myocardial function in hypertension, diabetes, and ischaemic heart disease (IHD) in the general population. METHODS AND RESULTS: Within a large, community-based population study, cardiac function...... and diastolic cardiac function in hypertension [n = 345; LD 10.1 (+/-standard deviation, SD 2.0 mm), P diabetes [n = 65; LD 9.8 (+/-SD 2.2 mm), P ....001] compared with controls [n = 533; LD 11.4 (+/-SD 2.0 mm); E/e' 9.0 (x/SD 1.3)]. This pattern remained significant after adjusting for age, sex, body mass index, heart rate, and the results of conventional echocardiography. CONCLUSION: In the general population, persons with hypertension, diabetes, or IHD...

  7. Azimuth resolution improvement for spaceborne SAR images with quasi-non-overlapped Doppler bandwidth

    Institute of Scientific and Technical Information of China (English)

    Zheng Bao

    2014-01-01

    The azimuth resolution improvement problem is solved via a coherent combination of synthetic aperture radar (SAR) ima-ges with the quasi-non-overlapped Doppler bandwidth. Prior to the spectra combination, SAR images should be co-registered, while phase biases induced by topography, atmospheric propagation de-lays and baseline measurement errors should be calibrated. How-ever, the coregistration accuracy suffers from large Doppler decorrelation caused by the quasi-non-overlapped Doppler band-width. Furthermore, the method used to estimate phase biases from interferogram of azimuth pre-filtered SAR image pairs wil fail when there is no overlapped spectrum. The fringe simulation and maximum sharpness optimization are adopted to deal with the problems. Accordingly, a novel algorithm to coherently synthesize SAR images is presented. The experiment with the Terra SAR X-band (TerraSAR-X) satel ite data validates the performance of the presented method.

  8. Study on Left Ventricular Systolic Function in Patients with Dilated Cardiomyopathy Using Doppler Tissue Imaging%多普勒组织成像对扩张型心肌病患者左室收缩功能的研究

    Institute of Scientific and Technical Information of China (English)

    白文伟; 章克信; 陆映珠; 汪丽琼; 冯震霞

    2004-01-01

    目的探讨多普勒组织成像(Doppler tissue imaging,DTI)评价扩张型心肌病(dilated cardiomyopathy,DCM)患者左室收缩功能的应用价值.方法脉冲DTI测定左室长轴切面室间隔(IVS)左室面、右室面及左室后壁(LVPW)内膜下心肌、外膜下心肌的收缩期运动峰值速度(Peak-S).计算左室面与右室面,内膜下心肌与外膜下心肌间的速度差(△V=peakS1-peakS2);心尖四腔切面测定二尖瓣环外侧收缩期运动峰值速度(Sa峰值速度).结果 DCM患者室壁收缩期运动峰值速度(peak-S)、内外膜间峰值速度差(△V)及Sa峰值速度较正常人明显降低,(P<0.01),二尖瓣侧环Sa峰值速度与LVE F高度相关(r=0.79,P<0.01).结论 DTI可作为评价DCM患者左室局部及整体收缩功能的新方法.

  9. 心内组织多普勒超声显像标测心脏传导系统心肌兴奋心肌电和机械兴奋多参数显像%Cardiac conductive system excitation maps using intracardiac ultrasound catheter with tissue Doppler imaging:multiparametric imaging of electrical and mechanical activation

    Institute of Scientific and Technical Information of China (English)

    尹立雪; 蔡力; 李春梅; 邓燕; 罗芸; 郑昌琼; 李德舆; 赵树魁

    2001-01-01

    feasible tissue Doppler maps of myocardial contraction in response to electrical activation of cardiac conductive system using intracardiac ultrasound catheter with high resolution tissue Doppler imaging (TDI).Methods Open-chest model of five dogs were used. An intracardiac ultrasound catheter with TDI capabilities was introduced into SVC, right atria and ventricle. The stimulating electrode was placed within ventricular subepicardium and subendocardium. 2D gray-scale ultrasonic examination was performed to observe the anatomic structure of sino-atrial node (SAN), right Koch's triangle, IVS and free ventricular wall. M-mode and 2D TDI were obtained to map myocardial velocity and acceleration with normal sinus rhyme at different sites of cardiac conductive system described above. Mapping of ventricular myocardial velocity and acceleration was performed during pacing. The regional myocardial excitation on the 2D TDI images was analyzed using a dedicated method for quantification.Results The detail anatomic structure of SAN with a dramatic increase of velocity and acceleration of SAN was presented at the beginning of atrial electrical excitation. The changes of velocity and acceleration of SAN as a time sequence curve quantitatively demonstrated the process of SAN′s excitation. A high value distribution of velocity and acceleration within right Koch′s triangle progressed into upper IVS before the early ventricular electrical excitation. The ventricular onset of myocardial velocity and acceleration induced by electrical stimulation was exactly at the location of electrical stimulating sites with size less than 5 mm, and coextended as concentric circle within ventricular wall. The delay of myocardial contraction is less than 7 ms.Conclusions The onset and propagation of myocardial velocity and acceleration can be defined within cardiac conductive system using intracardiac ultrasonic catheter with TDI. This techniqne will provide a simultaneous single visualization of

  10. Ultrahigh field magnetic resonance and colour Doppler real-time fusion imaging of the orbit - a hybrid tool for assessment of choroidal melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Walter, Uwe [University of Rostock, Department of Neurology, Rostock (Germany); Niendorf, Thoralf; Rieger, Jan [Berlin Ultrahigh Field Facility, Max-Delbrueck-Center for Molecular Medicine, Berlin (Germany); MRI.TOOLS GmbH, Berlin (Germany); Graessl, Andreas [Berlin Ultrahigh Field Facility, Max-Delbrueck-Center for Molecular Medicine, Berlin (Germany); Krueger, Paul-Christian; Langner, Soenke [University of Greifswald, Institute for Diagnostic Radiology and Neuroradiology, Greifswald (Germany); Guthoff, Rudolf F.; Stachs, Oliver [University of Rostock, Department of Ophthalmology, Rostock (Germany)

    2014-05-15

    A combination of magnetic resonance images with real-time high-resolution ultrasound known as fusion imaging may improve ophthalmologic examination. This study was undertaken to evaluate the feasibility of orbital high-field magnetic resonance and real-time colour Doppler ultrasound image fusion and navigation. This case study, performed between April and June 2013, included one healthy man (age, 47 years) and two patients (one woman, 57 years; one man, 67 years) with choroidal melanomas. All cases underwent 7.0-T magnetic resonance imaging using a custom-made ocular imaging surface coil. The Digital Imaging and Communications in Medicine volume data set was then loaded into the ultrasound system for manual registration of the live ultrasound image and fusion imaging examination. Data registration, matching and then volume navigation were feasible in all cases. Fusion imaging provided real-time imaging capabilities and high tissue contrast of choroidal tumour and optic nerve. It also allowed adding a real-time colour Doppler signal on magnetic resonance images for assessment of vasculature of tumour and retrobulbar structures. The combination of orbital high-field magnetic resonance and colour Doppler ultrasound image fusion and navigation is feasible. Multimodal fusion imaging promises to foster assessment and monitoring of choroidal melanoma and optic nerve disorders. (orig.)

  11. Early right ventricular systolic dysfunction in patients with systemic sclerosis without pulmonary hypertension: a Doppler Tissue and Speckle Tracking echocardiography study

    Directory of Open Access Journals (Sweden)

    Baumann Gert

    2010-01-01

    Full Text Available Abstract Background Isovolumetric acceleration (IVA is a novel tissue Doppler parameter for the assessment of systolic function. The aim of this study was to evaluate IVA as an early parameter for the detection of right ventricular (RV systolic dysfunction in patients with systemic sclerosis (SSc without pulmonary hypertension. Methods 22 patients and 22 gender- and age-matched healthy subjects underwent standard echocardiography with tissue Doppler imaging (TDI and speckle tracking strain to assess RV function. Results Tricuspid annular plane systolic excursion (TAPSE (23.2 ± 4.1 mm vs. 26.5 ± 2.9 mm, p 2 vs. 4.1 ± 0.8 m/s2, p Conclusion IVA is a useful tool with high-predictive power to detect early right ventricular systolic impairment in patients with SSc and without pulmonary hypertension.

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

    Science.gov (United States)

    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.

  13. Longitudinal two dimensional strain rate imaging is superior to tissue Doppler imaging in predicting echocardiographic response in cardiac resynchronization therapy%二维斑点追踪显像技术预测心脏再同步治疗的疗效

    Institute of Scientific and Technical Information of China (English)

    史浩颖; 舒先红; 汪芳; 陈灏珠; 刘少稳

    2009-01-01

    Objective The aim of this study was to investigate the ability of longitudinal strain and strain rate imaging by two dimensional speckle tracking in predicting echocardiographic response under cardiac resynchronization therapy (CRT),in comparison with tissue Doppler imaging (TDI). Methods Fifty patients suffering from heart failure,who received CRT,were selected. TDI and two dimensional speckle tracking ima ging in addition to standard echocardiography were performed prior to CRT. The average value of peak longitu dinal strain in 12 left ventricular (LV) segments (Strain-12), the standard deviation of time to peak longitudinal strain in 12 LV segments (Tstrain-SD) and the standard deviation of time to the end of longitudinal systolic strain rate in 6 basal LV segments (Tsr-SD) were calculated. Patients were classified as echocardiographic re sponders if the LV end-systolic volume (LVESV) was reduced > 15% compared with baseline volumes. Re sults No significant difference was seen in baseline Ts-SD,Strain-12 and Tstrain-SD between nonresponders and responders. However, the Tsr-SD was much higher in responders than nonresponders[ (95. 9 ±33. 0)% vs (64. 8 ±39. 6)%,P15%或左心室射血分数(LVEF)绝对值增加>5%的患者.结果 CRT有效组起搏前左心室射血前时间显著长于无效组[(146.0±34.5)ms对(123.5±32.0)ms,P0.05),而CRT有效组的应变率结束时间标准差(Tsr-SD)显著高于无效组(P0.05),而CRT有效组的左心室12节段纵轴反向应变总和(Pstrain-12)显著高于无效组[(12.5±7.9)%对(7.1±8.4)%,P<0.05].将140.5 ms作为截点值,左心室射血前时间预测超声心动图有效的敏感性和特异性分别为63%和79%,将70.7 ms作为截点值,Tsr-SD预测CRT有效的敏感性和特异性分别为73%和65%.结论 常规超声心动图参数中仅左心室射血前时间能预测CRT疗效,二维斑点追踪显像技术的部分参数预测CRT疗效优于组织多普勒.

  14. Laparoscopic splenectomy: color Doppler flow imaging for preoperative evaluation

    Institute of Scientific and Technical Information of China (English)

    XU Wei-li; LI Suo-lin; WANG Yan; SHI Bao-jun; LI Meng; LI Ying-chao; ZHONG Zhi-yong; LI Zhen-dong

    2009-01-01

    Background Laparoscopic splenectomy (LS) is currently the standard approach for resection of a normal-sized spleen.However, this method becomes technical challenge in cases of splenomegaly due to intraoperative hemorrhage. A complete understanding of the splenic vessel anatomy is important to facilitate the difficult laparoscopic procedure. In this retrospective study, we examined the role of color Doppler flow imaging (CDFI) in splenic vessel anatomy and evaluated its value for LS.Methods Forty-eight patients who underwent splenectomy for various hematologic and autoimmune disorders from May 2004 to December 2007 were enrolled in this study. Twenty-three patients underwent preoperative CDFI examination that included examination of the anatomic type of splenic pedicle, the adjacent relationship between the splenic vessel and pancreas, and spleen size (CDFI group). In the remaining 25 patients, ultrasonic inspections of the splenic vessel were not performed (non-CDFI group). Laparoscopic splenectomies in the CDFI group were performed in accordance with the information provided by the preoperative CDFI in each patient. In the non-CDFI group, LS was performed according to the conventional method. In the CDFI group, the constituent ratios of the above-mentioned parameters by CDFI were compared with those recorded during LS using the chi square test. The effectiveness of the technique on surgery in both groups was compared with an independent sample Student's ttest.Results All laparoscopic splenectomies in both groups were performed successfully. However, 2 cases in the non-CDFI group were converted to LS with the assistance of micro-incision because the branches of the splenic vein were inadvertently torn. Two anatomic types of splenic pedicle and four different adjacent relationships between the splenic vessel and pancreas were detected by CDFI. About 80% of spleens fit the criteria of megalosplenia. There were no statistically significant differences between the

  15. In-vivo three-dimensional Doppler variance imaging for tumor angiogenesis on chorioallantoic membrane

    Science.gov (United States)

    Qi, Wenjuan; Liu, Gangjun; Chen, Zhongping

    2011-03-01

    Non-invasive tumor microvasculature visualization and characterization play significant roles in the detection of tumors and importantly, for aiding in the development of therapeutic strategies. The feasibility and effectiveness of a Doppler variance standard deviation imaging method for tumor angiogenesis on chorioallantoic membrane were tested in vivo on a rat glioma F98 tumor spheroid. Utilizing a high resolution Doppler Variance Optical Coherence Tomography (DVOCT) system with A-line rate of 20 kHz, three-dimensional mapping of a tumor with a total area of 3×2.5mm2 was completed within 15 seconds. The top-view image clearly visualized the complex vascular perfusion with the detection of capillaries as small as approximately 10μm. The results of the current study demonstrate the capability of the Doppler variance standard deviation imaging method as a non-invasive assessment of tumor angiogenesis, with the potential for its use in clinical settings.

  16. Limited Accuracy of Colour Doppler Ultrasound Dynamic Tissue Perfusion Measurement in Diabetic Adults

    Science.gov (United States)

    Stoperka, Felix; Karger, Claudia

    2016-01-01

    Dynamic tissue perfusion measurement (DTPM) is a pre-described and available method in pediatric ultrasound to quantify tissue perfusion in renal Doppler ultrasound by particular video analysis software. This study evaluates DTPM during single and between repeated visits after 6 months, calibrates repeated DTPM within different region of interest (ROI) and compares DTPM with kidney function markers in adult patients with early diabetic nephropathy (n = 17). During repeated measurements, no association of readings at the same patients in the same (n = 3 readings) as well as repeated visit (n = 2 visits) could be retrieved. No association between DTPM, MDRD-GFR, albuminuria, age and duration of diabetes was observed. These negative results are presumably related to inconsistency of DTPM due to non-fixed ROI position as could be shown in calibrating series. Further development of the method should be performed to enable reproducible DTPM readings in adults. PMID:28033403

  17. Perfusion assessment in rat spinal cord tissue using photoplethysmography and laser Doppler flux measurements

    Science.gov (United States)

    Phillips, Justin P.; Cibert-Goton, Vincent; Langford, Richard M.; Shortland, Peter J.

    2013-03-01

    Animal models are widely used to investigate the pathological mechanisms of spinal cord injury (SCI), most commonly in rats. It is well known that compromised blood flow caused by mechanical disruption of the vasculature can produce irreversible damage and cell death in hypoperfused tissue regions and spinal cord tissue is particularly susceptible to such damage. A fiberoptic photoplethysmography (PPG) probe and instrumentation system were used to investigate the practical considerations of making measurements from rat spinal cord and to assess its suitability for use in SCI models. Experiments to assess the regional perfusion of exposed spinal cord in anesthetized adult rats using both PPG and laser Doppler flowmetry (LDF) were performed. It was found that signals could be obtained reliably from all subjects, although considerable intersite and intersubject variability was seen in the PPG signal amplitude compared to LDF. We present results from 30 measurements in five subjects, the two methods are compared, and practical application to SCI animal models is discussed.

  18. Musculoskeletal colour/power Doppler in sports medicine: image parameters, artefacts, image interpretation and therapy

    DEFF Research Database (Denmark)

    Boesen, M I; Boesen, Mikael; Kønig, Merete Juhl;

    2010-01-01

    This review article discusses the aspects of sports medicine where musculoskeletal Doppler ultrasound has valuable contribution in diagnosis and/or treatment of some of the typical musculoskeletal sports injuries. Also, conditions where the Doppler ultrasound has no value are discussed. Some...... guidelines and recommendations are based on personal experience since no evidence in literature exists. The basic technical background of Doppler ultrasound and typical artefacts will be discussed, in order to understand and interpret the Doppler result. Recommendations for the Doppler settings are given...... in relevant sections. Ultrasound guided treatments where the Doppler result is used as a guide are mentioned and discussed....

  19. Inverse Monte Carlo in a multilayered tissue model: merging diffuse reflectance spectroscopy and laser Doppler flowmetry

    Science.gov (United States)

    Fredriksson, Ingemar; Burdakov, Oleg; Larsson, Marcus; Strömberg, Tomas

    2013-12-01

    The tissue fraction of red blood cells (RBCs) and their oxygenation and speed-resolved perfusion are estimated in absolute units by combining diffuse reflectance spectroscopy (DRS) and laser Doppler flowmetry (LDF). The DRS spectra (450 to 850 nm) are assessed at two source-detector separations (0.4 and 1.2 mm), allowing for a relative calibration routine, whereas LDF spectra are assessed at 1.2 mm in the same fiber-optic probe. Data are analyzed using nonlinear optimization in an inverse Monte Carlo technique by applying an adaptive multilayered tissue model based on geometrical, scattering, and absorbing properties, as well as RBC flow-speed information. Simulations of 250 tissue-like models including up to 2000 individual blood vessels were used to evaluate the method. The absolute root mean square (RMS) deviation between estimated and true oxygenation was 4.1 percentage units, whereas the relative RMS deviations for the RBC tissue fraction and perfusion were 19% and 23%, respectively. Examples of in vivo measurements on forearm and foot during common provocations are presented. The method offers several advantages such as simultaneous quantification of RBC tissue fraction and oxygenation and perfusion from the same, predictable, sampling volume. The perfusion estimate is speed resolved, absolute (% RBC×mm/s), and more accurate due to the combination with DRS.

  20. The implication of tissue Doppler echocardiography and cardiopulmonary exercise in early detection of cardiac dysfunction in systemic lupus erythematosus patients

    Science.gov (United States)

    Elnady, Basant M.; Abdelghafar, Ayman Saeed Mohamed; Khalik, El Shazly Abdul; Algethami, Mohammed Mesfer; Basiony, A.S.; Al-otaibi, Mona Dhaif Allah; Al-otaibi, Maram Eidhah

    2016-01-01

    Objective Systemic lupus erythematosus (SLE) can present limitations to exercise capacity and quality of life (QoL) because of various clinical conditions, such as pulmonary disease or heart disease. Tissue Doppler echocardiography (TDE) offers the promise of an objective measurement to quantify regional and global ventricular function through the assessment of myocardial velocity data. This study aimed to assess the intensity of left ventricular (LV) and right ventricular (RV) systolic and diastolic dysfunction in SLE patients by means of TDE and cardiopulmonary exercise (CPX) testing to determine their impact on QoL. Material and Methods Overall, 56 SLE patients within two tertiary healthcare centers as well as 50 healthy controls were examined with TDE after the exclusion of cardiovascular risk factors. TDE was performed for maximal systolic (S), early diastolic (E′), and late diastolic (A′) velocities of the mitral and tricuspid annulus. Pulsed wave (PW) Doppler of mitral and tricuspid valve inflow was performed in addition to the estimation of the left ventricle ejection fraction and assessment of right ventricle systolic function by tricuspid annular plane systolic excursion (TAPSE). Disease activity was assessed by the Systemic Lupus Activity Measure (SLAM), and the damage index was assessed by the Systemic Lupus International Collaborating Clinics (SLICC)/American College of Rheumatology (ACR) Damage Index (SDI). CPX tests according to the modified Bruce protocol were performed. Results SLE patients in both subgroups had more or less similar laboratory data and statistically higher values of ESR, CRP, and anticardiolipin (aCL) antibodies compared to the control group. LV function showed statistically insignificant EF compared to the control group, being lower in the patient group. Tissue Doppler image revealed that E′ and A′ of the mitral annulus were lower in the patient group than in the control group. Concerning RV, TAPSE in the patient group was

  1. Musculoskeletal colour/power Doppler in sports medicine: image parameters, artefacts, image interpretation and therapy

    DEFF Research Database (Denmark)

    Boesen, M I; Boesen, Mikael; Kønig, Merete Juhl

    2011-01-01

    guidelines and recommendations are based on personal experience since no evidence in literature exists. The basic technical background of Doppler ultrasound and typical artefacts will be discussed, in order to understand and interpret the Doppler result. Recommendations for the Doppler settings are given...

  2. Pulse subtraction Doppler

    Science.gov (United States)

    Mahue, Veronique; Mari, Jean Martial; Eckersley, Robert J.; Caro, Colin G.; Tang, Meng-Xing

    2010-01-01

    Recent advances have demonstrated the feasibility of molecular imaging using targeted microbubbles and ultrasound. One technical challenge is to selectively detect attached bubbles from those freely flowing bubbles and surrounding tissue. Pulse Inversion Doppler is an imaging technique enabling the selective detection of both static and moving ultrasound contrast agents: linear scatterers generate a single band Doppler spectrum, while non-linear scatterers generate a double band spectrum, one being uniquely correlated with the presence of contrast agents and non-linear tissue signals. We demonstrate that similar spectrums, and thus the same discrimination, can be obtained through a Doppler implementation of Pulse Subtraction. This is achieved by reconstructing a virtual echo using the echo generated from a short pulse transmission. Moreover by subtracting from this virtual echo the one generated from a longer pulse transmission, it is possible to fully suppress the echo from linear scatterers, while for non-linear scatterers, a signal will remain, allowing classical agent detection. Simulations of a single moving microbubble and a moving linear scatterer subject to these pulses show that when the virtual echo and the long pulse echo are used to perform pulsed Doppler, the power Doppler spectrum allows separation of linear and non-linear moving scattering. Similar results are obtained on experimental data acquired on a flow containing either microbubble contrast agents or linear blood mimicking fluid. This new Doppler method constitutes an alternative to Pulse Inversion Doppler and preliminary results suggest that similar dual band spectrums could be obtained by the combination of any non-linear detection technique with Doppler demodulation.

  3. Adaptive clutter rejection for 3D color Doppler imaging: preliminary clinical study.

    Science.gov (United States)

    Yoo, Yang Mo; Sikdar, Siddhartha; Karadayi, Kerem; Kolokythas, Orpheus; Kim, Yongmin

    2008-08-01

    In three-dimensional (3D) ultrasound color Doppler imaging (CDI), effective rejection of flash artifacts caused by tissue motion (clutter) is important for improving sensitivity in visualizing blood flow in vessels. Since clutter characteristics can vary significantly during volume acquisition, a clutter rejection technique that can adapt to the underlying clutter conditions is desirable for 3D CDI. We have previously developed an adaptive clutter rejection (ACR) method, in which an optimum filter is dynamically selected from a set of predesigned clutter filters based on the measured clutter characteristics. In this article, we evaluated the ACR method with 3D in vivo data acquired from 37 kidney transplant patients clinically indicated for a duplex ultrasound examination. We compared ACR against a conventional clutter rejection method, down-mixing (DM), using a commonly-used flow signal-to-clutter ratio (SCR) and a new metric called fractional residual clutter area (FRCA). The ACR method was more effective in removing the flash artifacts while providing higher sensitivity in detecting blood flow in the arcuate arteries and veins in the parenchyma of transplanted kidneys. ACR provided 3.4 dB improvement in SCR over the DM method (11.4 +/- 1.6 dB versus 8.0 +/- 2.0 dB, p < 0.001) and had lower average FRCA values compared with the DM method (0.006 +/- 0.003 versus 0.036 +/- 0.022, p < 0.001) for all study subjects. These results indicate that the new ACR method is useful for removing nonstationary tissue motion while improving the image quality for visualizing 3D vascular structure in 3D CDI.

  4. Cost-effectiveness of laser Doppler imaging in burn care in the Netherlands

    NARCIS (Netherlands)

    M.J. Hop (M. Jenda); J. Hiddingh (J.); C.M. Stekelenburg (C.); H.C. Kuipers (Hester); E. Middelkoop (Esther); M. Nieuwenhuis (Marianne); S. Polinder (Suzanne); M.E. van Baar (Margriet)

    2013-01-01

    textabstractBackground: Early accurate assessment of burn depth is important to determine the optimal treatment of burns. The method most used to determine burn depth is clinical assessment, which is the least expensive, but not the most accurate.Laser Doppler imaging (LDI) is a technique with which

  5. Cost-effectiveness of laser Doppler imaging in burn care in the Netherlands

    NARCIS (Netherlands)

    M.J. Hop (M. Jenda); J. Hiddingh (J.); C.M. Stekelenburg (C.); H.C. Kuipers (Hester); E. Middelkoop (Esther); M. Nieuwenhuis (Marianne); S. Polinder (Suzanne); M.E. van Baar (Margriet)

    2013-01-01

    textabstractBackground: Early accurate assessment of burn depth is important to determine the optimal treatment of burns. The method most used to determine burn depth is clinical assessment, which is the least expensive, but not the most accurate.Laser Doppler imaging (LDI) is a technique with which

  6. Doppler colour flow imaging of fetal intracerebral arteries relative to fetal behavioural states in normal pregnancy

    NARCIS (Netherlands)

    M.J. Noordam (Marja); F.M.E. Hoekstra (Franciska); W.C.J. Hop (Wim); J.W. Wladimiroff (Juriy)

    1994-01-01

    textabstractIn 14 normally developing term fetuses, the relationship between the blood flow velocity waveforms at cerebral arterial level (internal carotid artery, anterior, middle and posterior cerebral artery) and fetal behavioural states was studied using Doppler colour flow imaging. Behavioural

  7. Measuring isovolumic contraction peak velocity at the tricuspid annulus by Doppler tissue imaging to ;assess right heart function in patients with pulmonary hypertension%组织多普勒成像测量三尖瓣环等容收缩期峰值速度在评价肺高压患者右心功能中的应用

    Institute of Scientific and Technical Information of China (English)

    魏丽群; 李越; 王广义; 朱航; 王娟; 翟亚楠

    2014-01-01

    imaging. Methods In 41 patients with suspected diagnosis of PH, IVCv at the tricuspid annulus were measured by echocardiography and Doppler tissue imaging. The right heart systolic function parameters such as tricuspid annular plane systolic excursion (TAPSE), peak systolic velocity (PSv) and right ventricular fractional area change (RVFCA) were also measured. The pulmonary artery pressure was detected by right-heart catheterization (RHC). According to different levels of pulmonary arterial systolic pressure, patients were classiifed into four groups to compare and analyze if any signiifcance could be found, including without PH group, mild PH group, moderate PH group and severe PH group. The sensitivity and speciifcity for diagnosing right heart impairment were assessed by ROC curves. Last, correlation analysis was performed. Results IVCv was signiifcantly and positively correlated with the right heart systolic function parameters, such as TAPSE (r=0.557, P0.05). Using the lower limit of right ventricular systolic function parameter obtained by common echocardiographic assessment as standard (TAPSE<16 mm, PSv<10 cm/s and RVFAC<35%), the sensitivities of IVCv<6.5 cm/s for diagnosing right ventricular systolic function reduction were 91%, 96%and 87%and the speciifcities were 70%, 53%and 77%, respectively. Conclusions IVCv obtained by Doppler tissue imaging is a new objective parameter for diagnosing right ventricular systolic function reduction. It is worth further study and application in clinic.

  8. Evaluation of Right Ventricular Function by Tissue Doppler Echocardiography in Asthmatic Children

    Directory of Open Access Journals (Sweden)

    Mehdi Ghaderian

    2016-11-01

    Full Text Available BackgroundAsthma is the most chronic inflammatory disorder of the airways in children and asthmatic patients can experience cardiac dysfunction, pulmonary hypertension and finally cor pulmonale later in life. We aimed to investigate Right Ventricular (RV functions in asthmatic children by conventional and tissue Doppler echocardiography (TDE.Materials and Methods Pulmonary function tests, conventional and TDE examinations were performed on 42 asthmatic and 42 age- and gender matched healthy controls subjects (n=42.Results Compared with healthy children the RV wall was statistically thicker among asthmatic patients (P= 0.01. Conventional echocardiography had not significant difference between cases and controls, but TDE had significant difference between these two groups. Peak E’ velocity, A’ velocity, E’/A’ ratio and S’ in lateral and medial sites of tricuspid annulus valve, were significantly differ from control group in our patients (P

  9. Concurrent Reflectance Confocal Microscopy and Laser Doppler Flowmetry to Improve Skin Cancer Imaging: A Monte Carlo Model and Experimental Validation

    Science.gov (United States)

    Mowla, Alireza; Taimre, Thomas; Lim, Yah Leng; Bertling, Karl; Wilson, Stephen J.; Prow, Tarl W.; Soyer, H. Peter; Rakić, Aleksandar D.

    2016-01-01

    Optical interrogation of suspicious skin lesions is standard care in the management of skin cancer worldwide. Morphological and functional markers of malignancy are often combined to improve expert human diagnostic power. We propose the evaluation of the combination of two independent optical biomarkers of skin tumours concurrently. The morphological modality of reflectance confocal microscopy (RCM) is combined with the functional modality of laser Doppler flowmetry, which is capable of quantifying tissue perfusion. To realize the idea, we propose laser feedback interferometry as an implementation of RCM, which is able to detect the Doppler signal in addition to the confocal reflectance signal. Based on the proposed technique, we study numerical models of skin tissue incorporating two optical biomarkers of malignancy: (i) abnormal red blood cell velocities and concentrations and (ii) anomalous optical properties manifested through tissue confocal reflectance, using Monte Carlo simulation. We also conduct a laboratory experiment on a microfluidic channel containing a dynamic turbid medium, to validate the efficacy of the technique. We quantify the performance of the technique by examining a signal to background ratio (SBR) in both the numerical and experimental models, and it is shown that both simulated and experimental SBRs improve consistently using this technique. This work indicates the feasibility of an optical instrument, which may have a role in enhanced imaging of skin malignancies. PMID:27598157

  10. Concurrent Reflectance Confocal Microscopy and Laser Doppler Flowmetry to Improve Skin Cancer Imaging: A Monte Carlo Model and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Alireza Mowla

    2016-09-01

    Full Text Available Optical interrogation of suspicious skin lesions is standard care in the management of skin cancer worldwide. Morphological and functional markers of malignancy are often combined to improve expert human diagnostic power. We propose the evaluation of the combination of two independent optical biomarkers of skin tumours concurrently. The morphological modality of reflectance confocal microscopy (RCM is combined with the functional modality of laser Doppler flowmetry, which is capable of quantifying tissue perfusion. To realize the idea, we propose laser feedback interferometry as an implementation of RCM, which is able to detect the Doppler signal in addition to the confocal reflectance signal. Based on the proposed technique, we study numerical models of skin tissue incorporating two optical biomarkers of malignancy: (i abnormal red blood cell velocities and concentrations and (ii anomalous optical properties manifested through tissue confocal reflectance, using Monte Carlo simulation. We also conduct a laboratory experiment on a microfluidic channel containing a dynamic turbid medium, to validate the efficacy of the technique. We quantify the performance of the technique by examining a signal to background ratio (SBR in both the numerical and experimental models, and it is shown that both simulated and experimental SBRs improve consistently using this technique. This work indicates the feasibility of an optical instrument, which may have a role in enhanced imaging of skin malignancies.

  11. Concurrent Reflectance Confocal Microscopy and Laser Doppler Flowmetry to Improve Skin Cancer Imaging: A Monte Carlo Model and Experimental Validation.

    Science.gov (United States)

    Mowla, Alireza; Taimre, Thomas; Lim, Yah Leng; Bertling, Karl; Wilson, Stephen J; Prow, Tarl W; Soyer, H Peter; Rakić, Aleksandar D

    2016-09-01

    Optical interrogation of suspicious skin lesions is standard care in the management of skin cancer worldwide. Morphological and functional markers of malignancy are often combined to improve expert human diagnostic power. We propose the evaluation of the combination of two independent optical biomarkers of skin tumours concurrently. The morphological modality of reflectance confocal microscopy (RCM) is combined with the functional modality of laser Doppler flowmetry, which is capable of quantifying tissue perfusion. To realize the idea, we propose laser feedback interferometry as an implementation of RCM, which is able to detect the Doppler signal in addition to the confocal reflectance signal. Based on the proposed technique, we study numerical models of skin tissue incorporating two optical biomarkers of malignancy: (i) abnormal red blood cell velocities and concentrations and (ii) anomalous optical properties manifested through tissue confocal reflectance, using Monte Carlo simulation. We also conduct a laboratory experiment on a microfluidic channel containing a dynamic turbid medium, to validate the efficacy of the technique. We quantify the performance of the technique by examining a signal to background ratio (SBR) in both the numerical and experimental models, and it is shown that both simulated and experimental SBRs improve consistently using this technique. This work indicates the feasibility of an optical instrument, which may have a role in enhanced imaging of skin malignancies.

  12. Doppler Imaging of Black Hole SYSTEMS:XTE J1118+480.

    Science.gov (United States)

    Callanan, Paul; Perres-Torres, Manuel; Garcia, Michael

    We present time-resolved spectroscopy of the black-hole candidate XTE J1118+480 obtained during its approach to quiescence. Doppler imaging of the intense Hα line shows persistent emission with an origin in the gas stream/hotspot. In addition the Doppler maps show enhanced emission in the +Vx -Vy quadrant clearing incompatible with a stream/hotspot origin. We favour a non-uniform disk intensity distribution due to tidal effects as the origin of this emission. We compare our map with that of XTE J1118+480 in outburst as well as with those of other transient systems in quiescence

  13. Image analysis of placental issues using three-dimensional ultrasound and color power doppler

    Science.gov (United States)

    Wang, Qi; Cheng, Qiong; Liu, J. G.

    2007-12-01

    With the development of birthing-process medical science, and insurance requirement of prepotency, the ultrasound technique is widely used in the application of obstetrics realm, especially on the monitoring of embryo's growth. In the recent decade, the introduction of high resolution three-dimensional ultrasonic and color power Doppler scanner provides a much more direct, sensitive, forerunner method for the monitoring of embryo and gravida's prediction. A novel method that depends on examining images of vasculature of placenta to determine the growth of embryo is introduced in this paper. First, get a set of placenta vascularity images of the pregnant woman, taken by Color Doppler Ultrasonic Scanner, then mark some points in these images, where we get a section image, thus we can observe the internal blood vessel distribution at those points. This method provides an efficient tool for doctors.

  14. Confocal imaging of butterfly tissue.

    Science.gov (United States)

    Brunetti, Craig R

    2014-01-01

    To understand the molecular events responsible for morphological change requires the ability to examine gene expression in a wide range of organisms in addition to model systems to determine how the differences in gene expression correlate with phenotypic differences. There are approximately 12,000 species of butterflies, most, with distinct patterns on their wings. The most important tool for studying gene expression in butterflies is confocal imaging of butterfly tissue by indirect immunofluorescence using either cross-reactive antibodies from closely related species such as Drosophila or developing butterfly-specific antibodies. In this report, we describe how indirect immunofluorescence protocols can be used to visualize protein expression patterns on the butterfly wing imaginal disc and butterfly embryo.

  15. Assessment of strain and strain rate in embryonic chick heart in vivo using tissue Doppler optical coherence tomography

    Science.gov (United States)

    Li, Peng; Liu, Aiping; Shi, Liang; Yin, Xin; Rugonyi, Sandra; Wang, Ruikang K.

    2011-11-01

    We present a method to assess the in vivo radial strain and strain rate of the myocardial wall, which is of great importance to understand the biomechanics of cardiac development, using tissue Doppler optical coherence tomography (tissue-DOCT). Combining the structure and velocity information acquired from tissue-DOCT, the velocity distribution in the myocardial wall is plotted, from which the radial strain and strain rate are evaluated. The results demonstrate that tissue-DOCT can be used as a useful tool to describe tissue deformation, especially, the biomechanical characteristics of the embryonic heart.

  16. The efficacy of magnetic resonance imaging and color Doppler ultrasonography in diagnosis of salivary gland tumors.

    Science.gov (United States)

    Davachi, Behrooz; Imanimoghaddam, Mahrokh; Majidi, Mohamad Reza; Sahebalam, Ahmad; Johari, Masoomeh; Javadian Langaroodi, Adineh; Shakeri, Mohamad Taghi

    2014-01-01

    Background and aims. Although salivary gland tumors are not very common, early diagnosis and treatment is crucial because of their proximity to vital organs, and therefore, determining the efficacy of new imaging procedures becomes important. This study aimed to evaluate the efficacy of magnetic resonance imaging (MRI) and color doppler ultrasonography parameters in the diagnosis and differentiation of benign and malignant salivary gland tumors. Materials and methods. In this cross-sectional study, color doppler ultrasonography and MRI were performed for 22 patients with salivary gland tumor. Demographic data as well as MRI, color doppler ultrasonography, and surgical parameters including tumor site, signal in MRI images, ultrasound echo, tumor border, lymphadenopathy, invasion, perfusion, vascular resistance index (RI), vascular pulse index (PI) were analyzed using Chi-square test, Fisher's exact test, and independent t-test. Results. The mean age of patients was 46.59±13.97 years (8 males and 14females). Patients with malignant tumors were older (P color doppler ultrasonography in determining tumor site was 100% and 95%, respectively. No significant difference observed between RI and PI and the diagnosis of tumor. Conclusion. Both MRI and ultrasonography have high accuracy in the localization of tumors. Well-identified border was a sign of benign tumors. Also, invasion to adjacent structures was a predictive factor for malignancy.

  17. Right ventricular function assessed by tissue Doppler echocardiography in older subjects without evidence for structural cardiac disease.

    Science.gov (United States)

    Laszlo, Roman; Baumann, Tobias; Konz, Hanna; Dallmeier, Dhayana; Klenk, Jochen; Denkinger, Michael; Koenig, Wolfgang; Rothenbacher, Dietrich; Steinacker, Juergen Michael

    2016-05-31

    The aim of our study was to obtain right ventricular (RV) tissue Doppler imaging (TDI) data in older subjects (n = 95, mean age: 74.5 ± 4.6 years) without evidence of hemodynamically significant structural heart disease recruited from a large population-based cohort (ActiFE-Ulm study). Our data indicate that aging may be accompanied by decreasing RV diastolic function and at most little alterations of RV systolic function. Mean values of all parameters were still within the guideline-suggested reference range with most of them closer to the abnormality thresholds. On an individual basis, respective thresholds were also exceeded in some subjects (almost all parameters subjects, presumed pathological measures might still be compatible with physiological age-related alterations. Therefore, they always have to be interpreted across the clinical context and in relation to other parameters of morphology and function obtained by other ultrasound imaging techniques (M-mode, B-mode, etc.) in the context of echocardiographic evaluation of the right heart.

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

    Science.gov (United States)

    Wells, Peter N T; Liang, Hai-Dong

    2011-11-07

    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.

  19. A laser speckle imaging technique for measuring tissue perfusion.

    Science.gov (United States)

    Forrester, Kevin R; Tulip, J; Leonard, C; Stewart, C; Bray, Robert C

    2004-11-01

    Laser Doppler imaging (LDI) has become a standard method for optical measurement of tissue perfusion, but is limited by low resolution and long measurement times. We have developed an analysis technique based on a laser speckle imaging method that generates rapid, high-resolution perfusion images. We have called it laser speckle perfusion imaging (LSPI). This paper investigates LSPI output and compares it to LDI using blood flow models designed to simulate human skin at various levels of pigmentation. Results show that LSPI parameters can be chosen such that the instrumentation exhibits a similar response to changes in red blood cell concentration (0.1%-5%, 200 microL/min) and velocity (0-800 microL/min, 1% concentration) and, given its higher resolution and quicker response time, could provide a significant advantage over LDI for some applications. Differences were observed in the LDI and LSPI response to tissue optical properties. LDI perfusion values increased with increasing tissue absorption, while LSPI perfusion values showed a slight decrease. This dependence is predictable, owing to the perfusion algorithms specific to each instrument, and, if properly compensated for, should not influence each instrument's ability to measure relative changes in tissue perfusion.

  20. Evaluation of a new high power, wide separation laser Doppler probe : Potential measurement of deeper tissue blood flow

    NARCIS (Netherlands)

    Clough, Geraldine; Chipperfield, Andrew; Byrne, Christopher; de Mul, Frits; Gush, Rodney

    2009-01-01

    Objective: To compare the output from a novel high power, wide separation laser Doppler flow probe (DP1-V2-HP, 4 mm, with IRLD20) with that of a standard flow probe (DP1-V2, 0.5 mm, with DRT4) (Moor UK) and to explore its potential for use in the noninvasive measurement of blood flow in deeper tissu

  1. 组织多普勒成像评价2型糖尿病患者左心室纵向收缩功能%Evaluation of left ventricular systolic function with tissue Doppler imaging in patients with type 2 diabetes

    Institute of Scientific and Technical Information of China (English)

    张军; 项娟娟; 朱永胜

    2009-01-01

    Objective To evaluate the clinical application of the tissue Doppler imaging (TDI) in investigating the cardiac longitudinal systolic function in the patients with type 2 diabetes mellitus. Methods Forty-two patients with type 2 diabetes mellitus and 25 volunteers underwent TDI. The long axis myocardial peak systolic velocity (Sm), displacement (Dm) and strain rates (SRs) of 18 segments in different left ventricular walls were measured.Results The Dm and SRs of left ventricular wall in diabetic group dramatically decreased (P<0.01). Meanwhile, the diabetic combined hypertension group had much lower Sm of ventricular middle segments than the control group (P<0.05).Conclusion The stain rate and tissue tracking are sensitive and reliable to evaluate the early local cardiac systolic function in the patients with diabetes mellitus. TDI can be used as an noninvasive method to detect early systolic dysfunction.%目的 探讨组织多普勒成像技术(TDI)对评价2型糖尿病患者左心室纵向收缩功能改变的临床应用价值.方法 对42例2型糖尿病患者和25名健康志愿者行组织多普勒超声心动图检查,测量左心室各室壁基底段、中间段、心尖段共18个节段的心肌收缩期峰值运动速度(Sm)、位移值(Dm)及应变率(SRs).结果 两组糖尿病患者心肌收缩期最大位移和峰值应变率均较正常对照组有明显减低(P<0.01);合并高血压组左心室壁中间段心肌收缩期峰值运动速度也较对照组明显减低(P<0.05).结论 TDI技术为糖尿病心脏病变左心室收缩功能的早期检测提供了一种无创方法,局部心肌收缩期最大位移及峰值应变率能够成为检测糖尿病患者左心室收缩功能变化较敏感指标.

  2. Imaging of musculoskeletal soft tissue infections

    Energy Technology Data Exchange (ETDEWEB)

    Turecki, Marcin B.; Taljanovic, Mihra S.; Holden, Dean A.; Hunter, Tim B.; Rogers, Lee F. [University of Arizona HSC, Department of Radiology, Tucson, AZ (United States); Stubbs, Alana Y. [Southern Arizona VA Health Care System, Department of Radiology, Tucson, AZ (United States); Graham, Anna R. [University of Arizona HSC, Department of Pathology, Tucson, AZ (United States)

    2010-10-15

    Prompt and appropriate imaging work-up of the various musculoskeletal soft tissue infections aids early diagnosis and treatment and decreases the risk of complications resulting from misdiagnosis or delayed diagnosis. The signs and symptoms of musculoskeletal soft tissue infections can be nonspecific, making it clinically difficult to distinguish between disease processes and the extent of disease. Magnetic resonance imaging (MRI) is the imaging modality of choice in the evaluation of soft tissue infections. Computed tomography (CT), ultrasound, radiography and nuclear medicine studies are considered ancillary. This manuscript illustrates representative images of superficial and deep soft tissue infections such as infectious cellulitis, superficial and deep fasciitis, including the necrotizing fasciitis, pyomyositis/soft tissue abscess, septic bursitis and tenosynovitis on different imaging modalities, with emphasis on MRI. Typical histopathologic findings of soft tissue infections are also presented. The imaging approach described in the manuscript is based on relevant literature and authors' personal experience and everyday practice. (orig.)

  3. Right Ventricular Tissue Doppler Assessment in Space During Circulating Volume Modification using the Braslet-M Device

    Science.gov (United States)

    Hamilton, D. R.; Sargsyan, A. E.; Fincke, E. M.; Magnus, S. H.; Lonchakov, Y. V.; Alferova, I. V.; Dulchavsky, S. A.; Ebert, D.; Garcia, K.; Martin, D.; Matveev, V. P.; Voronkov, Y. I.; Melton, S. L.; Duncan, J. M.; Bogomolov, V. V.

    2009-01-01

    This joint U.S. - Russian work aims to establish a methodology for assessing cardiac function in microgravity in association with manipulation of central circulating volume. Russian Braslet-M occlusion cuffs were used to temporarily increase the volume of blood in the lower extremities, which effectively reduces the volume returning to the heart in the central circulation. A novel methodology was tested on the International Space Station (ISS) to assess the volume status of crewmembers by evaluating the responses to application and release of the Braslet-on-occlusion cuffs, as well as to modified Valsalva and Mueller maneuvers. Baseline echocardiographic tissue Doppler imaging (TDI) of the right ventricular free wall with no Braslet applied shows early diastolic E' (16 cm/sec), late diastolic A' (14 cm/sec), and systolic (12 cm/sec) velocities compatible with normal subjects on Earth. TDI of the RV free wall with Braslet applied shows that early diastolic E' decreased by 50% (8 cm/sec), late diastolic A' increased by 45%, and systolic S' remains unchanged. TDI of the RV free wall approximately 8 beats after the Braslet was released shows early diastolic E' (8 cm/sec), late diastolic A' (12 cm/sec), and systolic S' (13 cm/sec) velocities. During this portion of the release, early diastolic E' did not recover to baseline values but late diastolic A' and systolic S' recovered to pre-Braslet values. The pre-systolic cross-sectional area of the internal jugular vein with Braslet off was 1.07 cm(sup 2) and 1.13 cm(sup 2) 10 min after the Braslet was applied. The presystolic cross-sectional area of the common femoral vein with Braslet off was 0.50 cm(sup 2), and was 0.54 cm(sup 2) 10 min after the Braslet was applied. The right ventricular myocardial performance Tei index also was calculated for comparison with typical values found in healthy subjects on Earth. Baseline and Braslet-on values for Tei index were 0.25 and 0.22 respectively. Braslet Tei indices are within

  4. New adaptive clutter rejection based on spectral analysis for ultrasound color Doppler imaging: phantom and in vivo abdominal study.

    Science.gov (United States)

    Geunyong Park; Sunmi Yeo; Jae Jin Lee; Changhan Yoon; Hyun-Woo Koh; Hyungjoon Lim; Youngtae Kim; Hwan Shim; Yangmo Yoo

    2014-01-01

    Effective rejection of time-varying clutter originating from slowly moving vessels and surrounding tissues is important for depicting hemodynamics in ultrasound color Doppler imaging (CDI). In this paper, a new adaptive clutter rejection method based on spectral analysis (ACR-SA) is presented for suppressing nonstationary clutter. In ACR-SA, tissue and flow characteristics are analyzed by singular value decomposition and tissue acceleration of backscattered Doppler signals to determine an appropriate clutter filter from a set of clutter filters. To evaluate the ACR-SA method, 20 frames of complex baseband data were acquired by a commercial ultrasound system equipped with a research package (Accuvix V10, Samsung Medison, Seoul, Korea) using a 3.5-MHz convex array probe by introducing tissue movements to the flow phantom (Gammex 1425 A LE, Gammex, Middleton, WI, USA). In addition, 20 frames of in vivo abdominal data from five volunteers were captured. From the phantom experiment, the ACR-SA method provided 2.43 dB (p SCR) compared to static (STA) and down-mixing (ACR-DM) methods. Similarly, it showed smaller values in fractional residual clutter area (FRCA) compared to the STA and ACR-DM methods (i.e., 2.3% versus 5.4% and 3.7%, respectively, ). The consistent improvements in SCR from the proposed ACR-SA method were obtained with the in vivo abdominal data (i.e., 4.97 dB and 3.39 dB over STA and ACR-DM, respectively). The ACR-SA method showed less than 1% FRCA values for all in vivo abdominal data. These results indicate that the proposed ACR-SA method can improve image quality in CDI by providing enhanced rejection of nonstationary clutter.

  5. Diagnostic agreement between panoramic radiographs and color doppler images of carotid atheroma

    Directory of Open Access Journals (Sweden)

    Claudia Maria Romano-Sousa

    2009-02-01

    Full Text Available The aim of this study was to investigate the agreement between diagnoses of calcified atheroma seen on panoramic radiographs and color Doppler images. Our interest stems from the fact that panoramic images can show the presence of atheroma regardless of the level of obstruction detected by color Doppler images. Panoramic and color Doppler images of 16 patients obtained from the archives of the Health Department of the city of Valença, RJ, Brazil, were analyzed in this study. Both sides of each patient were observed on the images, with a total of 32 analyzed cervical regions. The level of agreement between diagnoses was analyzed using the Kappa statistics. There was a high level of agreement, with a Kappa value of 0.78. In conclusion, panoramic radiographs can help detecting calcifications in the cervical region of patients susceptible to vascular diseases predisposing to myocardial infarction and cerebrovascular accidents. If properly trained and informed, dentists can refer their patients to a physician for a cardiovascular evaluation in order to receive proper and timely medical treatment.

  6. Magnetic resonance imaging in the evaluation of placental adhesive disorders: correlation with color Doppler ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Masselli, Gabriele; Casciani, Emanuele; Polettini, Elisabetta; Gualdi, Gianfranco [Umberto I Hospital-La Sapienza University, Department of Radiology DEA, Rome (Italy); Brunelli, Roberto; Piccioni, Maria G.; Anceschi, Maurizio [Umberto I Hospital-La Sapienza University, Department of Gynecology and Obstetrics, Rome (Italy)

    2008-06-15

    The purpose of this study was to compare the value of pelvic ultrasound with color Doppler and magnetic resonance imaging (MRI) in: (1) the diagnosis of placental adhesive disorders (PADs), (2) the definition of the degree of placenta invasiveness, (3) determining the topographic correlation between the diagnostic images and the surgical results. Fifty patients in the third trimester of pregnancy with a diagnosis of placenta previa and at least one previous caesarean section underwent color Doppler ultrasound (US) and MRI. The sonographic and MRI diagnoses were compared with the final pathologic or operative findings. Outcomes at delivery were as follows: normal placenta (n = 38) and PAD (n = 12). MR and US Doppler showed no statistically difference in identiyfing patients with PAD (P = 0.74), while MRI was statistically better than US Doppler in evaluating the depth of placenta infiltration (P < 0.001). MRI accurately characterized the topography of invasion in 12/12 (100%) of the cases, while US accurately characterized the topography of invasion in 9/12 (75%) of the cases. In conclusion, we confirmed that pelvic US is highly reliable to diagnose or exclude the presence of PAD and found MRI to be an excellent tool for the staging and topographic evaluation of PAD. (orig.)

  7. Effect of right ventricular outflow tract pacing and right ventricular apex pacing on cardiac function by tissue Doppler imaging%组织多普勒成像评价右心室心尖部与右心室流出道间隔部起搏对心功能的影响

    Institute of Scientific and Technical Information of China (English)

    卜婕; 俞杉; 吴强; 安亚平

    2011-01-01

    Objective To explore the effects of right ventricular apex(RVA) pacing and right ventricular outflow tract (RVOT) pacing on cardiac function using tissue Doppler imaging technique.Methods 65 lentitude arrhythmia patients were randomly divided into RVA pacing group ( n =30), RVOT pacing group ( n =35).Before the pacemaker implantation, after 1 month, 3 months, 6 months and 12 months respectively, early diastolic mitral annulus velocity(E a), systolic velocity (Sa), Tel index were measured by tissue velocity-time curve; left ventricular ejection fraction(LVEF) was measured by SIMPSON method; mitral early diastolic peak velocity(E) was measured by pulsed Doppler,E,E and Ea ratio (E/Ea) were calculated.Results RVA and RVOT both groups before and after 1,3 months,all the indicators were not statistically significant.After 1, 3 months in the above two groups, LVEF was respectively(61.8913.37) % vs(61.51±3.11)% ,(60.22±4.85)% vs(60.32±4.25) % ,Sa (11.38± 1.14) cm/s vs (11.44±2.14) cm/s,(10.88±1.91) cm/s vs (11.02± 1.31) cm/s, E/A 0.96±0.19 vs 0.97± 0.23,0.95±0.15 vs 0.96±0.13,E/Ea 8.8±3.6 vs 8.4±4.3,9.1±4.3 vs 8.8±3.2,Tei index 0.48±0.05 vs 0.47±0.08,0.50±0.20 vs 0.47±0.11(all P >0.05).After 6 months,RVA pacing and RVOT pacing compared with tissue Doppler indexes,Tel index and E/Ea increased 0.76±0.26 vs 0.67 ± 0.32, 10.9 ± 3.96 vs 9.0 ± 2.8, all P < 0.05), after 12 months, Sa decreased, (8.22 ± 1.72) cm/s vs (9.52± 2.56) cm/s( P <0.05).Conclusion RVA pacing induced heart contractions are not synchronized to the detriment of left ventricular systolic and diastolic function.RVOT septai pacing obtains more optimal parameters of heart function than RVA pacing,and RVOT septal pacing is a good right ventricular pacing site.%目的 运用组织多普勒成像技术(TDI)比较右心室流出道(RVOT)间隔部起搏和右心室心尖部(RVA)起搏对心功能的影响.方法 将缓慢心律失常患者65例随机分为RVA起搏组(n=30)

  8. Fibromatosis colli: findings at high-resolution ultrasound and color Doppler images

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Deok Hee; Shin, Myung Jin; Choi, Hye Young; Choi, Soo Na Mi; Kim, Yong Hwan [University of Ulsan College of Medicine, Asan Medical Center, Ulsan (Korea, Republic of)

    1993-12-15

    Fibromatosis colli is a unique mass of sternocleidomastoid muscle, which usually presents in neonatal period and disappears within one year of age. The diagnosis of this disease is not difficult with the findings of ultrasound and the unique clinical behavior of the mass. The purposes of this study are to evaluate the detailed sonographic features of fibromatosis colli and to find the value of color Doppler studies on the initial examinations and the follow-up of the patients. Twenty-four patients who were diagnosed as fibromatosis colli by the clinical history and ultrasound examination were studied. Among them, 11 patients underwent follow-up studies including color Doppler imaging. We evaluated the size, shape and echogenicity of the mass. The sonographic features and the findings at color Doppler imaging of 11 follow-up studies were compared with those of the initial examinations. Most of the masses were identified at about 3 weeks of age. The mean size of the masses was30x10x15mm. Most of the masses were round (n=13,54%) or fusiform (n=8,33%) in shape. The chogenicity of the mass was iso- (n=15,63%) or slightly hyperechoic (n=9,37%) to that of the surrounding muscles. All 8 cases examined with color Doppler showed branching pattern of arterial signal within the mass at the initial examination. On the follow-up studies, most of the lesions decreased in size and increased in their echogenicity. There was no color Doppler signal on the follow-up study in 7 out of 8 patients in whom both the initial and the follow-up color Doppler imagings were performed. In conclusion, the sonographic findings of fibromatosis coli were more complicated than those described by previous literatures and color Doppler examination could give more information about this disease especially on follow-up studies. A long term follow-up of larger series is required to know the practical significance of the results of follow-up studies

  9. Assessment of Right Ventricular Function by Tissue Doppler Imaging and Right dp/dt Technique in Patients with Cor Pulmonale%组织多普勒成像及右室内压力变化速率评价肺心病患者右室功能

    Institute of Scientific and Technical Information of China (English)

    梁丽萍; 郑艳芬; 邬彩虹

    2012-01-01

    Purpose To discuss the clinical value of right ventricular function in patients with cor pulmonale assessed by TDI and dp/dt measurement. Materials and Methods Subjects were classified as cor pulmonale patient group (90 cases) and normal comparison groups (30 cases) simply having tricuspid regurgitation. Routine echocardiographic examination with color flow continue Doppler wave were performed to measure tricuspid regurgitation and estimate pulmonary arterial pressure as well as right ventricular dp/dt. Tissue Doppler imaging (TDI) technique was used to measure peak flow velocity in early diastolic phase (Em), peak flow velocity in late diastolic phase (Am) and ratio of Em to Am (Em/Am). Peak flow velocity in systolic period (Sm) was also measured. Results Dp/dt, Em, Em/Am and Sm in cor pulmonale patient group were lower than those of normal comparison group (P < 0.01); Am was higher than normal comparison group (P < 0.01). The systole and diastole function of right ventricle in cor pulmonale patients were decreased. There was negative correlation between pulmonary arterial pressure and dp/dt (r =-0.764, P < 0.01). Conclusion TDI with dp/dt measurement is accurate, convenient and repeatable as a new non-invasive diagnostic technique to assess right ventricle function in cor pulmonale patients and provides meaningful clinical information.%目的 探讨应用组织多普勒成像( TDI)技术及右室内压力变化速率(dp/dt)综合评价肺心病患者右室功能的临床价值.资料与方法 90例肺心病患者(肺心病组)和30例单纯三尖瓣反流患者(对照组)常规行超声心动图检查,用血流连续多普勒测量三尖瓣反流,估测肺动脉压(PG)及右心室室内压力变化速率( dp/dt).然后应用组织多普勒成像(TDI)技术从心尖四腔观获得右室侧壁三尖瓣环的运动速度频谱图,测量舒张早期负向E峰峰值速度(Em)、舒张晚期负向A蜂峰值速度(Am)及二者峰值比Em/Am,同时测量收缩期正

  10. Intra- and inter-frame differential Doppler imaging

    Science.gov (United States)

    Schmoll, T.; Ivascu, I. R.; Singh, A. S. G.; Unterhuber, A.; Leitgeb, R. A.

    2011-06-01

    We present a method to contrast the blood flow of retinal vessels from the surrounding static tissue. It is based on the extinction of the interference fringes by phase shifts of π. If moving particles within the sample introduce an additional phase shift, the signal from these particles will, in contrast to the signal from static tissue, not be attenuated. We demonstrate different variants of this method, where we introduce phase shifts during single A-scans, consecutive A-scans and consecutive B-scans. We show proof-of-principle measurements with a piezo mirror, as well as in-vivo measurements of the human retina for the different phase shifting schemes. We demonstrate its capability to contrast a wide range of perfused retinal vessels; from large vessels present in the optic nerve head region to the capillary network surrounding the fovea.

  11. Doppler coherence imaging of ion dynamics in VINETA.II and ASDEX-upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Gradic, Dorothea; Ford, Oliver; Wolf, Robert [Max-Planck-Institut fuer Plasmaphysik, Greifswald (Germany); Lunt, Tilmann [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

    2016-07-01

    In magnetically confining plasma experiments, diagnosis of ion flows is of great importance to measure the plasma response to the magnetic field or the exhaust particle flows in the divertor areas. Doppler coherence imaging spectroscopy (CIS) is a relatively new technique for the observation of plasma bulk ion dynamics. It is a passive optical diagnostic enabling line-integrated measurements to obtain 2D images of the ion flow and ion temperature. The general principle is similar to traditional Doppler spectroscopy, however CIS uses an imaging interferometer to perform narrow-bandwidth Fourier spectroscopy. A major advantage of the coherence imaging technique is the large amount of spatial information recovered. This allows tomographic inversion of the line-integrated measurements. With existing CIS setups, scrape-off-layer and high field side edge impurity flows could be observed in the MAST, core and edge poloidal He II flows in the WEGA stellarator and divertor impurity flows in DIII-D. The main objective of this study is the research of ion dynamics in the small linear plasma experiment VINETA.II and ASDEX-Upgrade. First Doppler CIS measurements from Ar-II plasma discharges in VINETA.II and He-II, C-III divertor flows in ASDEX-Upgrade and their preliminary interpretation will be presented.

  12. Doppler imaging of the double-lined active binary V824 Ara

    CERN Document Server

    Kriskovics, Levente; Kővári, Zsolt; Garcia-Alvarez, David; Oláh, Katalin

    2013-01-01

    We introduce an iterative spectral disentangling technique combined with Doppler imaging in order to recover surface temperature maps for both components of double-lined active binary systems. Our method provides an opportunity to separate spectra of the active components while minimizing the unwanted disturbances on the given line profile from the other component. The efficiency of the method is demonstrated on real data of the double-lined RS CVn-type binary V824 Ara. The resulting Doppler images reveal cool spots on the polar regions as well as low-latitude features on both of the stars. Moreover, both components have hot spots, that are facing each other. This may indicate interconnection between the stellar magnetic fields.

  13. An all-fiber image-reject homodyne coherent Doppler wind lidar

    DEFF Research Database (Denmark)

    Foroughi Abari, Farzad; Pedersen, Anders Tegtmeier; Mann, Jakob

    2014-01-01

    In this paper, we present an alternative approach to the down-conversion (translation) of the received optical signals collected by the antenna of an all-fiber coherent Doppler lidar (CDL). The proposed method, widely known as image-reject, quadrature detection, or in-phase/quadrature-phase detec......In this paper, we present an alternative approach to the down-conversion (translation) of the received optical signals collected by the antenna of an all-fiber coherent Doppler lidar (CDL). The proposed method, widely known as image-reject, quadrature detection, or in......-phase/quadrature-phase detection, utilizes the advances in fiber optic communications such that the received signal can be optically down-converted into baseband where not only the radial velocity but also the direction of the movement can be inferred. In addition, we show that by performing a cross-spectral analysis, enabled...

  14. Magnetic Doppler imaging considering atmospheric structure modifications due to local abundances: a luxury or a necessity?

    CERN Document Server

    Kochukhov, O; Shulyak, D

    2012-01-01

    Magnetic Doppler imaging is currently the most powerful method of interpreting high-resolution spectropolarimetric observations of stars. This technique has revealed the presence of unexpected small-scale magnetic fields on the surfaces of Ap stars. These studies were recently criticisied by Stift et al. (2012), who claimed that magnetic inversions are not robust and are undermined by neglecting a feedback on the Stokes line profiles from the local atmospheric structure in the regions of enhanced metal abundance. We show that Stift et al. misinterpreted published magnetic Doppler imaging results and neglected some of the most fundamental principles behind magnetic mapping. We demonstrate that the variation of atmospheric structure across the surface of a star with chemical spots affects the local continuum intensity but is negligible for the normalised local Stokes profiles. For the disk-integrated spectra of an Ap star with extreme abundance variations, we find that the assumption of a mean model atmosphere ...

  15. Relevance of tissue Doppler in the quantification of stress echocardiography for the detection of myocardial ischemia in clinical practice

    Directory of Open Access Journals (Sweden)

    Sicari Rosa

    2005-01-01

    Full Text Available Abstract In the present article we review the main published data on the application of Tissue Doppler Imaging (TDI to stress echocardiography for the detection of myocardial ischemia. TDI has been applied to stress echocardiography in order to overcome the limitations of visual analysis for myocardial ischemia. The introduction of a new technology for clinical routine use should pass through the different phases of scientific assessment from feasibility studies to large multicenter studies, from efficacy to effectiveness studies. Nonetheless the pro-technology bias plays a major role in medicine and expensive and sophisticated techniques are accepted before their real usefulness and incremental value to the available ones is assessed. Apparently, TDI is not exempted by this approach : its applications are not substantiated by strong and sound results. Nonetheless, conventional stress echocardiography for myocardial ischemia detection is heavily criticized on the basis of its subjectivity. Stress echocardiography has a long lasting history and the evidence collected over 20 years positioned it as an established tool for the detection and prognostication of coronary artery disease. The quantitative assessment of myocardial ischemia remains a scientific challenge and a clinical goal but time has not come for these newer ultrasonographic techniques which should be restricted to research laboratories.

  16. Left ventricular long axis tissue Doppler systolic velocity is independently related to heart rate and body size.

    Science.gov (United States)

    Peverill, Roger E; Chou, Bon; Donelan, Lesley

    2017-01-01

    The physiological factors which affect left ventricular (LV) long-axis function are not fully defined. We investigated the relationships of resting heart rate and body size with the peak velocities and amplitudes of LV systolic and early diastolic long axis motion, and also with long-axis contraction duration. Two groups of adults free of cardiac disease underwent pulsed-wave tissue Doppler imaging at the septal and lateral mitral annular borders. Group 1 (n = 77) were healthy subjects heart rate, height or body surface area (BSA) for either LV wall in either group, but SDur was inversely correlated with heart rate for both walls and both groups, and after adjustment for heart rate, males in both groups had a shorter septal SDur. Septal and lateral s` were independently and positively correlated with SExc, heart rate and height in both groups, independent of sex and age. There were no correlations of heart rate, height or BSA with either e` or EDExc for either wall in either group. Heart rate and height independently modify the relationship between s` and SExc, but neither are related to EDExc or e`. These findings suggest that s` and SExc cannot be used interchangeably for the assessment of LV long-axis contraction.

  17. 左心室纵向收缩应变与组织多普勒成像在心脏再同步化治疗中的应用%Application of longitudinal systolic strain and tissue Doppler imaging in cardiac resynchronisation therapy

    Institute of Scientific and Technical Information of China (English)

    赵德霞; 丁连芹; 孙宇; 刘敏

    2013-01-01

    Objective To compare the value of longitudinal systolic strain (LS) and tissue Doppler imaging (TDD for the assessment of mechanical dyssynchrony and prediction of cardiac resynchronisation therapy (CRT) responders. Methods Sixty-six clinical responders and 17 nonresponders to CRT were evaluated by LS and TDI. Mechanical delay (MD) and e-Iectromechanical EMD delay (EMD) intervals were acquired before and after pacemaker implantation. Results Before implantation, MD measured by LS was >60 ms in all responders, while EMD measured by TDI was >60 ms in 75. 76% of responders. Nonresponders had time delay ≤60 ms measured by both techniques. After implantation, LS showed shortened delay values in all responders. However, EMD measured by TDI did not diminish in 29. 41% of the positive clinical responders. Nonresponders had worsen delay measured with LS, but not with TDI. Conclusion Responders to CRT can be excellently predicted when MD measured by LS delay is >60 ms before implantation. LS delay appears to be superior to TDI to predict the response to CRT.%目的 比较左心室纵向收缩应变(LS)及TDI两种方法在评价左心室机械收缩不同步性及预测心脏再同步化治疗(CRT)应答中的价值.方法 选择66例CRT应答者及17例CRT无应答者,分别应用LS和TDI评价左心室收缩的不同步性.在起搏器植入前后,记录LS测量的机械延迟间期(MD)及TDI测量的电机械延迟间期(EMD).结果 植入起搏器前,LS测量所有CRT应答者的MD均>60 ms,TDI测量75.76% CRT应答者的EMD>60 ms,无应答者两种方法测量的延迟时间均≤60 ms.植入起搏器后,LS测量所有CRT应答者的MD均降低,TDI测量29.41% CRT应答者的EMD未下降,LS测量无应答者的MD增高,TDI测量无应答者的EMD却无变化.结论 LS延迟间期>60 ms可以精确预测CRT应答.对于预测CRT应答,LS明显优于TDI.

  18. 组织多普勒成像对射血分数正常的心衰患者左心功能评价%Evaluation of Left Ventricular Function by Tissue Doppler Imaging in Patients of Heart Failure with Normal Ejection Fraction

    Institute of Scientific and Technical Information of China (English)

    杨洁梅; 赵进军; 修春红; 沈景霞; 刘慧; 薛凤华

    2012-01-01

    Objective: To evaluate the variation of left ventricular function in the patients of heart failure with normal ejection fraction by Tissue doppler imaging. Methods: 30 healthy individuals(Group I), 30 patients of heart failure with EF>50% (Group II) a-nd 30 patients with EF50%, DSp and IVRTp had the biggest area under ROC curve respectively in the five sites. Conclusions: The patients of heart failure with normal ejection fraction have systolic dysfunction in left ventricular long-axis. DSm and Tem are effective parameters to diagnose left ventricular function in the patients of heart failure with EF>50%. DSp and Tep are the optimal sites for assessing left ventricular function in the patients of heart failure with normal ejection fraction.%目的:探讨组织多普勒成像(TDI)技术评价射血分数正常的心衰患者左室长轴功能特点.方法:选取30名健康人(Ⅰ组)、EF> 50%的心衰患者30名(Ⅱ组)和EF<50%的心衰患者30名(Ⅲ组)作为研究对象,采用TDI在二尖瓣环室间隔(ivs)、侧壁(1)、前壁(a)、后壁(p)、下壁(d)测量其Sm、DSm、IVCTm、TSm、Em、Am、IVRTm、TEm等指标.结果:Ⅰ组、Ⅱ组、Ⅲ组DSm、Sm逐渐减低,(P<0.05);而ⅣVCTm、TSm逐渐升高(P<0.05);ⅣVRTm、TEm在Ⅰ组、Ⅲ组、Ⅱ组逐渐升高(P<0.05);DSm及TEm在诊断EF>50%心衰患者心功能的指标中ROC曲线下面积最大,同样DSp及TEp在五个位点中ROC曲线下面积最大.结论:射血分数正常的心衰患者存在收缩减低;DSm及TEm是诊断EF>50%心衰患者心功能比较有效的指标;后壁是诊断的最佳位点.

  19. New Approaches For Asteroid Spin State and Shape Modeling From Delay-Doppler Radar Images

    Science.gov (United States)

    Raissi, Chedy; Lamee, Mehdi; Mosiane, Olorato; Vassallo, Corinne; Busch, Michael W.; Greenberg, Adam; Benner, Lance A. M.; Naidu, Shantanu P.; Duong, Nicholas

    2016-10-01

    Delay-Doppler radar imaging is a powerful technique to characterize the trajectories, shapes, and spin states of near-Earth asteroids; and has yielded detailed models of dozens of objects. Reconstructing objects' shapes and spins from delay-Doppler data is a computationally intensive inversion problem. Since the 1990s, delay-Doppler data has been analyzed using the SHAPE software. SHAPE performs sequential single-parameter fitting, and requires considerable computer runtime and human intervention (Hudson 1993, Magri et al. 2007). Recently, multiple-parameter fitting algorithms have been shown to more efficiently invert delay-Doppler datasets (Greenberg & Margot 2015) - decreasing runtime while improving accuracy. However, extensive human oversight of the shape modeling process is still required. We have explored two new techniques to better automate delay-Doppler shape modeling: Bayesian optimization and a machine-learning neural network.One of the most time-intensive steps of the shape modeling process is to perform a grid search to constrain the target's spin state. We have implemented a Bayesian optimization routine that uses SHAPE to autonomously search the space of spin-state parameters. To test the efficacy of this technique, we compared it to results with human-guided SHAPE for asteroids 1992 UY4, 2000 RS11, and 2008 EV5. Bayesian optimization yielded similar spin state constraints within a factor of 3 less computer runtime.The shape modeling process could be further accelerated using a deep neural network to replace iterative fitting. We have implemented a neural network with a variational autoencoder (VAE), using a subset of known asteroid shapes and a large set of synthetic radar images as inputs to train the network. Conditioning the VAE in this manner allows the user to give the network a set of radar images and get a 3D shape model as an output. Additional development will be required to train a network to reliably render shapes from delay-Doppler

  20. MR imaging of multiple fibroadenoma in breast: comparison with color doppler images and histologic findings

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Soo Young; Yang, Ik; Park, Hai Jung; Lee, Yul; Chung, Bong Wha; Ahn, Hye Kyung [Hallym Univ. College of Medicine, Seoul (Korea, Republic of)

    1997-10-01

    To understand the different signal intensities seen on contrast enhanced magnetic resonance imaging (MRI) in multiple fibroadenoma of the breast, and to compare these with color Doppler ultrasonographic (CDUS) and histologic findings. MRI (1.0 Tesla, TIWI, T2WI, 3D-gradient echo dynamic contrast enhancement study) findings of 24 histologically proven cases of fibroadenoma in five patients were evaluated and compared with the histologic components (myxoid, adenomatous, fibrous). In addition, vascular flow, as seen on CDUS and histologic section, was compared. The observed degree of signal intensity waw classified into three groups, as follows: negative, 8.3%, mild to moderate, 54.2%; marked, 37.5%. On histologic section, the greater the fibrotic component, the higher the intensity of MRI enhancement, the greater the glandular component, and the intensity. CDUS showed vascular flow in only one tumor larger than 3cm in diameter. Vascular patterns of tumors on CDUS were dots in mass and detouring pattern, but in this case and in strongly enhanced cases, tumor vascularity-as seen on histologic section-showed no significant increase. Different signal intensities seen on contrast enhanced MRI in multiple fibroadenoma of the breast may be related more to the amount of glandular and fibrotic component than to increased tumor vascularity.

  1. Volumetric vessel reconstruction method for absolute blood flow velocity measurement in Doppler OCT images

    Science.gov (United States)

    Qi, Li; Zhu, Jiang; Hancock, Aneeka M.; Dai, Cuixia; Zhang, Xuping; Frostig, Ron D.; Chen, Zhongping

    2017-02-01

    Doppler optical coherence tomography (DOCT) is considered one of the most promising functional imaging modalities for neuro biology research and has demonstrated the ability to quantify cerebral blood flow velocity at a high accuracy. However, the measurement of total absolute blood flow velocity (BFV) of major cerebral arteries is still a difficult problem since it not only relates to the properties of the laser and the scattering particles, but also relates to the geometry of both directions of the laser beam and the flow. In this paper, focusing on the analysis of cerebral hemodynamics, we presents a method to quantify the total absolute blood flow velocity in middle cerebral artery (MCA) based on volumetric vessel reconstruction from pure DOCT images. A modified region growing segmentation method is first used to localize the MCA on successive DOCT B-scan images. Vessel skeletonization, followed by an averaging gradient angle calculation method, is then carried out to obtain Doppler angles along the entire MCA. Once the Doppler angles are determined, the absolute blood flow velocity of each position on the MCA is easily found. Given a seed point position on the MCA, our approach could achieve automatic quantification of the fully distributed absolute BFV. Based on experiments conducted using a swept-source optical coherence tomography system, our approach could achieve automatic quantification of the fully distributed absolute BFV across different vessel branches in the rodent brain.

  2. Doppler images of the RS CVn binary II Pegasi during the years 1994-2002

    CERN Document Server

    Lindborg,; Korpi,; J., M; Hackman,; T.,; Tuominen,; I.,; Ilyin,; I.,; Piskunov,; N,

    2010-01-01

    We publish 16 Doppler imaging temperature maps for the years 1994-2002 of the active RS CVn star II Peg. The six maps from 1999-2002 are based on previously unpublished observations. Through Doppler imaging we want to study the spot evolution of the star and in particular compare this with previous results showing a cyclic spot behaviour and persistent active longitudes. The observations were collected with the SOFIN spectrograph at the Nordic Optical Telescope. The temperature maps were calculated using a Doppler imaging code based on Tikhonov regularization. During 1994-2001, our results show a consistent trend in the derived longitudes of the principal and secondary temperature minima over time such that the magnetic structure appears to rotate somewhat more rapidly than the orbital period of this close binary. A sudden phase jump of the active region occured between the observing seasons of 2001 and 2002. No clear trend over time is detected in the derived latitudes of the spots, indicating that the syste...

  3. Imaging in cellular and tissue engineering

    CERN Document Server

    Yu, Hanry

    2013-01-01

    Details on specific imaging modalities for different cellular and tissue engineering applications are scattered throughout articles and chapters in the literature. Gathering this information into a single reference, Imaging in Cellular and Tissue Engineering presents both the fundamentals and state of the art in imaging methods, approaches, and applications in regenerative medicine. The book underscores the broadening scope of imaging applications in cellular and tissue engineering. It covers a wide range of optical and biological applications, including the repair or replacement of whole tiss

  4. Stokes-Doppler coherence imaging for ITER boundary tomography

    Science.gov (United States)

    Howard, J.; Kocan, M.; Lisgo, S.; Reichle, R.

    2016-11-01

    An optical coherence imaging system is presently being designed for impurity transport studies and other applications on ITER. The wide variation in magnetic field strength and pitch angle (assumed known) across the field of view generates additional Zeeman-polarization-weighting information that can improve the reliability of tomographic reconstructions. Because background reflected light will be somewhat depolarized analysis of only the polarized fraction may be enough to provide a level of background suppression. We present the principles behind these ideas and some simulations that demonstrate how the approach might work on ITER. The views and opinions expressed herein do not necessarily reflect those of the ITER Organization.

  5. Clearing of psoriasis documented by laser Doppler perfusion imaging contrasts remaining elevation of dermal expression levels of CD31

    NARCIS (Netherlands)

    Hendriks, A.G.M.; Kerkhof, van de P.C.M.; Jonge, de C.S.; Lucas, M.; Steenbergen, W.; Seyger, M.M.B.

    2015-01-01

    Background Vascular modifications represent a key feature in psoriatic plaques. Previous research with Laser Doppler Perfusion Imaging (LDPI) revealed a remarkable heterogeneity in the cutaneous perfusion within homogenous-appearing psoriatic lesions. Insights in the relation between perfusion durin

  6. Clearing of psoriasis documented by laser Doppler perfusion imaging contrasts remaining elevation of dermal expression levels of CD31

    NARCIS (Netherlands)

    Hendriks, A.G.M.; Kerkhof, P.C.M. van de; Jonge, C.S. de; Lucas, M.; Steenbergen, W.; Seyger, M.M.B.

    2015-01-01

    BACKGROUND: Vascular modifications represent a key feature in psoriatic plaques. Previous research with Laser Doppler Perfusion Imaging (LDPI) revealed a remarkable heterogeneity in the cutaneous perfusion within homogenous-appearing psoriatic lesions. Insights in the relation between perfusion duri

  7. Reproducibility of transcutaneous oximetry and laser Doppler flowmetry in facial skin and gingival tissue.

    Science.gov (United States)

    Svalestad, J; Hellem, S; Vaagbø, G; Irgens, A; Thorsen, E

    2010-01-01

    Laser Doppler flowmetry (LDF) and transcutaneous oximetry (TcPO(2)) are non-invasive techniques, widely used in the clinical setting, for assessing microvascular blood flow and tissue oxygen tension, e.g. recording vascular changes after radiotherapy and hyperbaric oxygen therapy. With standardized procedures and improved reproducibility, these methods might also be applicable in longitudinal studies. The aim of this study was to evaluate the reproducibility of facial skin and gingival LDF and facial skin TcPO(2). The subjects comprised ten healthy volunteers, 5 men, aged 31-68 years. Gingival perfusion was recorded with the LDF probe fixed to a custom made, tooth-supported acrylic splint. Skin perfusion was recorded on the cheek. TcPO(2) was recorded on the forehead and cheek and in the second intercostal space. The reproducibility of LDF measurements taken after vasodilation by heat provocation was greater than for basal flow in both facial skin and mandibular gingiva. Pronounced intraday variations were observed. Interweek reproducibility assessed by intraclass correlation coefficient ranged from 0.74 to 0.96 for LDF and from 0.44 to 0.75 for TcPO(2). The results confirm acceptable reproducibility of LDF and TcPO(2) in longitudinal studies in a vascular laboratory where subjects serve as their own controls. The use of thermoprobes is recommended. Repeat measurements should be taken at the same time of day.

  8. Influence to the doppler images by the defects of SAE in the probe of medical ultrasonic scanners

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Sung [Dept. of Radiotechnology, Cheju Halla University, Cheju (Korea, Republic of)

    2015-04-15

    A ultrasonic probe is very important in medical ultrasonic image, but the frequency of probe defects are often. Therefore practical tools for probe based ultrasonic QA should be developed. Advanced research on the effects of the probe defects on the quality of ultrasonic images is required. This study has investigated the effects of the defects in the probe elements influence Doppler images in the medical ultrasonic scanners. Especially the defects in a set of adjacent elements(SAE) electrically disconnected influence Doppler images were tested. The results show Doppler brightness and velocity became rapidly reduced as the defected elements is located centrally, as the defected elements is activated. The more the defected elements increased, the more Doppler brightness and velocity increased. As a set of the element disconnected moved, it appeared Doppler velocity starting to decrease and then was followed by brightness. The strength is not consistent with the velocity in the number and location of the defected elements. The defects in the probe elements influence Doppler velocity when the defected elements got out of the elements activated at Doppler mode.

  9. Nonlinear spectral imaging of biological tissues

    Science.gov (United States)

    Palero, J. A.

    2007-07-01

    The work presented in this thesis demonstrates live high resolution 3D imaging of tissue in its native state and environment. The nonlinear interaction between focussed femtosecond light pulses and the biological tissue results in the emission of natural autofluorescence and second-harmonic signal. Because biological intrinsic emission is generally very weak and extends from the ultraviolet to the visible spectral range, a broad-spectral range and high sensitivity 3D spectral imaging system is developed. Imaging the spectral characteristics of the biological intrinsic emission reveals the structure and biochemistry of the cells and extra-cellular components. By using different methods in visualizing the spectral images, discrimination between different tissue structures is achieved without the use of any stain or fluorescent label. For instance, RGB real color spectral images of the intrinsic emission of mouse skin tissues show blue cells, green hair follicles, and purple collagen fibers. The color signature of each tissue component is directly related to its characteristic emission spectrum. The results of this study show that skin tissue nonlinear intrinsic emission is mainly due to the autofluorescence of reduced nicotinamide adenine dinucleotide (phosphate), flavins, keratin, melanin, phospholipids, elastin and collagen and nonlinear Raman scattering and second-harmonic generation in Type I collagen. In vivo time-lapse spectral imaging is implemented to study metabolic changes in epidermal cells in tissues. Optical scattering in tissues, a key factor in determining the maximum achievable imaging depth, is also investigated in this work.

  10. Imaging features of gray-scale and contrast-enhanced color doppler US for the differentiation of transient renal arterial ischemia and arterial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byung Kwan; Kim Seung Hyup [Seoul National University Hospital, Seoul (Korea, Republic of); Moon, Min Hwan; Jung, Sung Il [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2005-09-15

    To characterize the imaging features on gray-scale and contrast-enhanced color Doppler US images which differentiate renal ischemia from renal infarction. The segmental renal arteries of eight healthy rabbits were surgically ligated. In four of these rabbits, the ligated renal artery was released 60 minutes after arterial occlusion to cause transient ischemia. In the remaining four rabbits, the arterial ligation was retained to cause a permanent infarction. The gray-scale and contrast-enhanced color Doppler US imaging features of the involved renal parenchymal of both ischemia and infarction groups were compared with respect to the presence or absence of parenchymal swelling, echogenicity changes, tissue loss and perfusion defects. Parenchyma swelling, echogenic changes, tissue loss and perfusion defects were found to be more extensive in the infarction than the ischemia group. The hyperechoic areas reperfused with blood flow recovered normal echogenicity and perfusion, whereas the hyperechoic areas without reperfusion became renal infarcts. Gray-scale and contrast-enhanced color Doppler US showed that the hyperechoic areas with reperfusion may reverse to normal parenchyma and allow the differentiation of renal ischemia from renal infarction.

  11. Magnetic resonance imaging of the placenta identifies placental vascular abnormalities independently of Doppler ultrasound.

    Science.gov (United States)

    Messerschmidt, A; Baschat, A; Linduska, N; Kasprian, G; Brugger, P C; Bauer, A; Weber, M; Prayer, D

    2011-06-01

    To evaluate the relationship between placental vascular pathology detected by prenatal magnetic resonance imaging (MRI) and perinatal outcome. This was a retrospective, hospital-based, cross-sectional study in which all fetal MRI examinations of singleton pregnancies with vascular placental pathology (i.e. infarction with/without hemorrhage, subchorionic thrombi/hemorrhages, intervillous thrombi/hemorrhages, or retroplacental hematoma) in the period 2002-2007 were included. The extent of the pathology was expressed as a percentage of the total placental volume. Abnormalities of umbilical artery Doppler ultrasound examinations within 7 days between MRI and ultrasound examination were noted. Death in utero or postnatally was the primary outcome. Gestational age at MRI and at birth and the occurrence of intrauterine growth restriction (IUGR) were noted. Logistic regression analysis was performed to assess the impact of gestational age at MRI, extent of the vascular lesion and presence of pathological Doppler ultrasound measurements on the prediction of mortality. Fifty-nine structurally normal singleton pregnancies with placental vascular abnormalities were included in the analysis. Mortality rate was 36%; among the survivors, 87% were born before 37 + 0 gestational weeks and 50% suffered from IUGR. In 55% of the pregnancies pathological umbilical artery Doppler findings were identified, of which 27% were non-survivors. Mortality was predicted by earlier gestational age at fetal MRI for placental pathology (P < 0.05) and increasing extent of the vascular lesion (P < 0.05), but not by the presence of pathological Doppler ultrasound data. Accuracy of the prediction was 82%, sensitivity was 67% and specificity 89%. MRI-detected vascular placental pathologies may help to identify pregnancies at risk for adverse outcome and fetal death independently of umbilical artery Doppler status. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.

  12. The Split-field Etalon Doppler Imager (SEDI) - A Compact Thermosphere Wind Profiler

    Science.gov (United States)

    Marchant, A.; Whalen, S.; Stromberg, E. M.; Swenson, C.; Fish, C. S.

    2012-12-01

    The dynamics of the Earth's thermosphere remains an important target for scientific exploration. The primary energy input is solar EUV but during solar events additional energy is deposited into the high-latitude thermosphere in the form of Joule heating and particle precipitation, driving global changes in thermosphere temperature profiles and circulation. Thermosphere wind and temperature profiles are important factors for understanding the dynamic response of the earth system to solar storms, for building and maintaining global weather and climate models, and for making operational space weather predictions. We report progress in miniaturized sensor technology for orbital monitoring of wind and neutral temperature profiles in the upper thermosphere, 200 - 350 km. These profiles are sensed using the atomic oxygen airglow at 630.0 nm. The split-field etalon Doppler imager (SEDI) focuses forward and aft scenes of the earth limb onto a single EMCCD focal plane through a single Fabry-Perot etalon (Figure 1). The size of the SEDI optical system is 14 x 18 x 7 cm. The instrument has no moving parts and is easily packaged in a 6U CubeSat. Strips of the dual interferogram are analyzed with respect to fringe width and radial phase to yield profiles of the neutral temperature and Doppler shift. Instrument calibration is maintained on-orbit using the 630.4 nm reference line from a neon glow lamp. The prediction of Doppler sensitivity vs. tangent height against the limb is plotted in Figure 2 for a profiling resolution of 5 km. Forward-view Doppler profiles are combined with aft-view profiles collected approximately 5 minutes later to create localized 2D wind profiles. A constellation of SEDI CubeSats could provide global monitoring of the thermosphere wind field and its dynamics.; Figure 1. Layout of the SEDI instrument. ; Figure 2. Doppler sensitivity of the SEDI instrument.

  13. Four-dimensional structural and Doppler optical coherence tomography imaging on graphics processing units.

    Science.gov (United States)

    Sylwestrzak, Marcin; Szlag, Daniel; Szkulmowski, Maciej; Gorczynska, Iwona; Bukowska, Danuta; Wojtkowski, Maciej; Targowski, Piotr

    2012-10-01

    The authors present the application of graphics processing unit (GPU) programming for real-time three-dimensional (3-D) Fourier domain optical coherence tomography (FdOCT) imaging with implementation of flow visualization algorithms. One of the limitations of FdOCT is data processing time, which is generally longer than data acquisition time. Utilizing additional algorithms, such as Doppler analysis, further increases computation time. The general purpose computing on GPU (GPGPU) has been used successfully for structural OCT imaging, but real-time 3-D imaging of flows has so far not been presented. We have developed software for structural and Doppler OCT processing capable of visualization of two-dimensional (2-D) data (2000 A-scans, 2048 pixels per spectrum) with an image refresh rate higher than 120 Hz. The 3-D imaging of 100×100 A-scans data is performed at a rate of about 9 volumes per second. We describe the software architecture, organization of threads, and optimization. Screen shots recorded during real-time imaging of a flow phantom and the human eye are presented.

  14. Comparison of transrectal photoacoustic, Doppler, and magnetic resonance imaging for prostate cancer detection

    Science.gov (United States)

    Ishihara, Miya; Horiguchi, Akio; Shinmoto, Hiroshi; Tsuda, Hitoshi; Irisawa, Kaku; Wada, Takatsugu; Asano, Tomohiko

    2016-03-01

    Transrectal ultrasonography (TRUS) is the most popular imaging modality for diagnosing and treating prostate cancer. TRUS-guided prostate biopsy is mandatory for the histological diagnosis of patients with elevated serum prostatespecific antigen (PSA), but its diagnostic accuracy is not satisfactory due to TRUS's low resolution. As a result, a considerable number of patients are required to undergo an unnecessary repeated biopsy. Photoacoustic imaging (PAI) can be used to provide microvascular network imaging using hemoglobin as an intrinsic, optical absorption molecule. We developed an original TRUS-type PAI probe consisting of a micro-convex array transducer with an optical illumination system to provide superimposed PAI and ultrasound images. TRUS-type PAI has the advantage of having much higher resolution and greater contrast than does Doppler TRUS. The purpose of this study was to demonstrate the clinical feasibility of the transrectal PAI system. We performed a clinical trial to compare the image of the cancerous area obtained by transrectal PAI with that obtained by TRUS Doppler during prostate biopsy. The obtained prostate biopsy cores were stained with anti-CD34 antibodies to provide a microvascular distribution map. We also confirmed its consistency with PAI and pre-biopsy MRI findings. Our study demonstrated that transrectal identification of tumor angiogenesis under superimposed photoacoustic and ultrasound images was easier than that under TRUS alone. We recognized a consistent relationship between PAI and MRI findings in most cases. However, there were no correspondences in some cases.

  15. Mechanical Dyssynchrony by Tissue Doppler Cross-Correlation is Associated with Risk for Complex Ventricular Arrhythmias after Cardiac Resynchronization Therapy

    DEFF Research Database (Denmark)

    Tayal, Bhupendar; Gorcsan, John; Delgado-Montero, Antonia;

    2015-01-01

    BACKGROUND: Tissue Doppler cross-correlation analysis has been shown to be associated with long-term survival after cardiac resynchronization defibrillator therapy (CRT-D). Its association with ventricular arrhythmia (VA) is unknown. METHODS: From two centers 151 CRT-D patients (New York Heart.......0; 95% CI, 1.8-13.5; P = .002). CONCLUSIONS: Persistent and new mechanical dyssynchrony after CRT-D was associated with subsequent complex VA. Dyssynchrony after CRT-D is a marker of poor prognosis....

  16. Comparison of laser Doppler and laser speckle contrast imaging using a concurrent processing system

    Science.gov (United States)

    Sun, Shen; Hayes-Gill, Barrie R.; He, Diwei; Zhu, Yiqun; Huynh, Nam T.; Morgan, Stephen P.

    2016-08-01

    Full field laser Doppler imaging (LDI) and single exposure laser speckle contrast imaging (LSCI) are directly compared using a novel instrument which can concurrently image blood flow using both LDI and LSCI signal processing. Incorporating a commercial CMOS camera chip and a field programmable gate array (FPGA) the flow images of LDI and the contrast maps of LSCI are simultaneously processed by utilizing the same detected optical signals. The comparison was carried out by imaging a rotating diffuser. LDI has a linear response to the velocity. In contrast, LSCI is exposure time dependent and does not provide a linear response in the presence of static speckle. It is also demonstrated that the relationship between LDI and LSCI can be related through a power law which depends on the exposure time of LSCI.

  17. Adaptive anisotropic diffusion for noise reduction of phase images in Fourier domain Doppler optical coherence tomography.

    Science.gov (United States)

    Xia, Shaoyan; Huang, Yong; Peng, Shizhao; Wu, Yanfeng; Tan, Xiaodi

    2016-08-01

    Phase image in Fourier domain Doppler optical coherence tomography offers additional flow information of investigated samples, which provides valuable evidence towards accurate medical diagnosis. High quality phase images are thus desirable. We propose a noise reduction method for phase images by combining a synthetic noise estimation criteria based on local noise estimator (LNE) and distance median value (DMV) with anisotropic diffusion model. By identifying noise and signal pixels accurately and diffusing them with different coefficients respectively and adaptive iteration steps, we demonstrated the effectiveness of our proposed method in both phantom and mouse artery images. Comparison with other methods such as filtering method (mean, median filtering), wavelet method, probabilistic method and partial differential equation based methods in terms of peak signal-to-noise ratio (PSNR), equivalent number of looks (ENL) and contrast-to-noise ratio (CNR) showed the advantages of our method in reserving image energy and removing noise.

  18. Monitoring free tissue transfer using laser speckle imaging

    Science.gov (United States)

    Winchester, Leonard W.; Chou, Nee-Yin

    2006-02-01

    Blood velocity information can be extracted by analyzing, either temporally or spatially, laser speckle (LS) patterns generated when a laser source illuminates the tissue. While a temporal analysis, such as that used for laser Doppler velocimetry (LDV), provides high spatial resolution, the time required to obtain flow data in vivo on large areas of tissue limits its utility. The LS imaging (LSI) technique combines the nonscanning, full-field, LS method and the modified multiple scattering algorithms developed for LDV analysis to retrieve blood velocity parameters. It provides a noninvasive means for realtime, quantitative measurements of subtle changes in the tissue vasculature. This paper describes the use of the LSI technique on free flap measurements of a swine model and compares the results with those obtained using an LDV probe. Both the LSI and the LDV measurements showed similar results - blood velocity and flow decreased about 10%-33% from the tip to the caudal base of the flap, respectively. The difference between the tip and the caudal base is a measure of flap ischemia. However, tissue pigmentation affects the blood flow parameters retrieved from the LDV measurements, it does not affect the blood velocity parameters retrieved from the LSI measurements. Both techniques were also used during free tissue transfer procedures in patients to demonstrate the utility of the LSI for monitoring the status of the graft.

  19. Importance and inter-relationship of tissue Doppler variables for predicting adverse outcomes in high-risk patients: an analysis of 388 diabetic patients referred for coronary angiography

    DEFF Research Database (Denmark)

    Andersson, Charlotte; Gislason, Gunnar H; Møgelvang, Rasmus;

    2012-01-01

    AIMS: To investigate the relative importance of individual tissue Doppler imaging variables to predict adverse events in a high-risk population with diabetes, ischaemic heart disease, and/or systolic dysfunction. METHODS AND RESULTS: Transthoracic echocardiograms were analysed in 388 diabetic...... patients without significant valve disease, bundle branch block, and atrial fibrillation who underwent coronary angiography. Multivariable Cox's regression analyses were used to establish the association between peak systolic (s'), early diastolic (e'), and late diastolic (a') tissue velocities...... and outcomes (hospitalization for heart failure or death). The mean age and left ventricular ejection fraction (LVEF) was 66 ± 10 years and 45 ± 12%, respectively. During 2.3 (±1.0) years of follow-up, 91 patients (24%) met the combined endpoint. After adjustment for LVEF, coronary artery pathology, heart...

  20. Color Tissue Doppler to Analyze Fetal Cardiac Time Intervals: Normal Values and Influence of Sample Gate Size.

    Science.gov (United States)

    Willruth, A M; Steinhard, J; Enzensberger, C; Axt-Fliedner, R; Gembruch, U; Doelle, A; Dimitriou, I; Fimmers, R; Bahlmann, F

    2016-02-04

    Purpose: To assess the time intervals of the cardiac cycle in healthy fetuses in the second and third trimester using color tissue Doppler imaging (cTDI) and to evaluate the influence of different sizes of sample gates on time interval values. Materials and Methods: Time intervals were measured from the cTDI-derived Doppler waveform using a small and large region of interest (ROI) in healthy fetuses. Results: 40 fetuses were included. The median gestational age at examination was 26 + 1 (range: 20 + 5 - 34 + 5) weeks. The median frame rate was 116/s (100 - 161/s) and the median heart rate 143 (range: 125 - 158) beats per minute (bpm). Using small and large ROIs, the second trimester right ventricular (RV) mean isovolumetric contraction times (ICTs) were 39.8 and 41.4 ms (p = 0.17), the mean ejection times (ETs) were 170.2 and 164.6 ms (p < 0.001), the mean isovolumetric relaxation times (IRTs) were 52.8 and 55.3 ms (p = 0.08), respectively. The left ventricular (LV) mean ICTs were 36.2 and 39.4 ms (p = 0.05), the mean ETs were 167.4 and 164.5 ms (p = 0.013), the mean IRTs were 53.9 and 57.1 ms (p = 0.05), respectively. The third trimester RV mean ICTs were 50.7 and 50.4 ms (p = 0.75), the mean ETs were 172.3 and 181.4 ms (p = 0.49), the mean IRTs were 50.2 and 54.6 ms (p = 0.03); the LV mean ICTs were 45.1 and 46.2 ms (p = 0.35), the mean ETs were 175.2 vs. 172.9 ms (p = 0.29), the mean IRTs were 47.1 and 50.0 ms (p = 0.01), respectively. Conclusion: Isovolumetric time intervals can be analyzed precisely and relatively independent of ROI size. In the near future, automatic time interval measurement using ultrasound systems will be feasible and the analysis of fetal myocardial function can become part of the clinical routine.

  1. Phase contrast imaging of cochlear soft tissue.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S.; Hwang, M.; Rau, C.; Fishman, A.; Lee, W.; Richter, C. (X-Ray Science Division); (Northwestern Univ.); (Diamond Light Source, Ltd.)

    2011-01-01

    A noninvasive technique to image soft tissue could expedite diagnosis and disease management in the auditory system. We propose inline phase contrast imaging with hard X-rays as a novel method that overcomes the limitations of conventional absorption radiography for imaging soft tissue. In this study, phase contrast imaging of mouse cochleae was performed at the Argonne National Laboratory Advanced Photon Source. The phase contrast tomographic reconstructions show soft tissue structures of the cochlea, including the inner pillar cells, the inner spiral sulcus, the tectorial membrane, the basilar membrane, and the Reissner's membrane. The results suggest that phase contrast X-ray imaging and tomographic techniques hold promise to noninvasively image cochlear structures at an unprecedented cellular level.

  2. Synthetic aperture tissue and flow ultrasound imaging

    DEFF Research Database (Denmark)

    Nikolov, Svetoslav

    them: the use of sparse one- and two-dimensional arrays; the use of multiple elements in transmit to create virtual sources of ultrasound; the use of virtual sources of ultrasound to improve the resolution of the images in the elevation plane; the use of temporal and spatial encoding to increase...... imaging applied to medical ultrasound. It is divided into two major parts: tissue and blood flow imaging. Tissue imaging using synthetic aperture algorithms has been investigated for about two decades, but has not been implemented in medical scanners yet. Among the other reasons, the conventional scanning...

  3. Evaluation of Cardiovascular System in Fibromyalgia Syndrome: Tissue Doppler Echocardiographic Investigation

    Directory of Open Access Journals (Sweden)

    Selma YAZICI

    2010-05-01

    Full Text Available Aim: We aim to investigate besides the cardiac structures and functions by both conventionalmethods and Tissue Doppler Echocardiography (TDE which is a new and useful method inpatients with Fibromyalgia (FM. Additionally, we evaluated QT parameters (QT maximum,QT minimum and QT dispertion with the use of electrocardiography in order to measure theautonomic dysfunction which is a possible mechanism in the pathogenesis of the disease. Methods: The study was performed on 42 patients (mean age 41 years, 38 female and 38completely healthy subjects (35 female, mean age of 42 years who were admitted to the sameclinic were collected as the control group. All the individuals were undergone a completephysical examination, electrocardiography (recordings were displayed at 50 mm/s speed andechocardiography evaluation (both conventional methods and TDE.Results: Analysis of electrocardiographic recordings revealed mildly increased mean QTdispertion in the patient group, but this difference was statistically insignificant. Analysis ofconventional echocardiographic parameters revealed similar results between the patient groupand the control cases. However, an important finding of this study is that significant diastolicdysfunction was found in the patient group which was recorded with the TDE technique. Emwave velocity and Em/Am ratios were significantly lower in patients with FM compared withcontrols (p<0.005, p<0.01, respectively. Sm and Am waves velocities were similar in bothgroups. Conclusion: In this study, significant left ventricular diastolic dysfunction which was detectedby TDE technique can partly explain several symptoms such as fatigue and dyspnea in FM. Inaddition, fully cardiac evaluation of patients with FM might be obtained supporting findingsthe autonomic dysfunction theory in fibromyalgia pathogenesis.

  4. Imaging challenges in biomaterials and tissue engineering.

    Science.gov (United States)

    Appel, Alyssa A; Anastasio, Mark A; Larson, Jeffery C; Brey, Eric M

    2013-09-01

    Biomaterials are employed in the fields of tissue engineering and regenerative medicine (TERM) in order to enhance the regeneration or replacement of tissue function and/or structure. The unique environments resulting from the presence of biomaterials, cells, and tissues result in distinct challenges in regards to monitoring and assessing the results of these interventions. Imaging technologies for three-dimensional (3D) analysis have been identified as a strategic priority in TERM research. Traditionally, histological and immunohistochemical techniques have been used to evaluate engineered tissues. However, these methods do not allow for an accurate volume assessment, are invasive, and do not provide information on functional status. Imaging techniques are needed that enable non-destructive, longitudinal, quantitative, and three-dimensional analysis of TERM strategies. This review focuses on evaluating the application of available imaging modalities for assessment of biomaterials and tissue in TERM applications. Included is a discussion of limitations of these techniques and identification of areas for further development.

  5. Effects of chronic severe pulmonary regurgitation and percutaneous valve repair on right ventricular geometry and contractility assessed by tissue Doppler echocardiography

    DEFF Research Database (Denmark)

    Kjaergaard, Jesper; Iversen, Kasper K; Vejlstrup, Niels G;

    2010-01-01

    Pulmonary regurgitation (PR) following repair of right ventricular (RV) outflow obstruction is related to slowly progressive RV dilatation and heart failure and will eventually require surgical intervention, but optimal timing of pulmonary valve replacement is challenging. Tissue Doppler based...

  6. Stokes-polarimetry imaging of tissue

    Science.gov (United States)

    Wu, Paul J.

    A novel Stokes-polarimetry imaging system and technique was developed to quantify fully the polarization properties of light remitted from tissue. The uniqueness of the system and technique is established in the incident polarization. Here, the diffuse illumination is varied and controlled with the intention to improve the visibility of tissue structures. Since light retains some polarization even after multiple-scattering events, the polarization of remitted light depends upon the interactions within the material. Differentiation between tissue structures is accomplished by two-dimensional mapping of the imaged area using metrics such as the degree of linear polarization, degree of circular polarization, ellipticity, and Stokes parameters. While Stokes-polarimetry imaging can be applied to a variety of tissues and conditions, this thesis focuses on tissue types associated with the disease endometriosis. The current standard in diagnosing endometriosis is visual laparoscopy with tissue biopsy. The documented correlation between laparoscopy inspection and histological confirmation of suspected lesions was at best 67%. Endometrial lesions vary greatly in their appearance and depth of infiltration. Although laparoscopy permits tissue to be assessed by color and texture, to advance beyond the state-of-the-art, a new imaging modality involving polarized light was investigated; in particular, Stokes-polarimetry imaging was used to determine the polarization signature of light that interacted with tissue. Basic science studies were conducted on rat tails embedded within turbid gelatin. The purpose of these experiments was to determine how identification of sub-surface structures could be improved. Experimental results indicate image contrast among various structures such as tendon, soft tissue and intervertebral discs. Stokes-polarimetry imaging experiments were performed on various tissues associated with endometriosis to obtain a baseline characterization for each

  7. Evaluation of the microcirculation in a rabbit hemorrhagic shock model using laser Doppler imaging.

    Science.gov (United States)

    Luo, Zhenchun; Wang, Pengfei; Zhang, An; Zuo, Guoqing; Zheng, Yuanyi; Huang, Yan

    2015-01-01

    The aim of this study is to evaluate the feasibility of Laser Doppler imaging (LDI) for noninvasive and dynamic assessment of hemorrhagic shock in a rabbit model. A rabbit model of hemorrhagic shock was generated and LDI of the microcirculation in the rabbit ears was performed before and at 0, 30, 60, and 90 min after hemorrhage. The CCD (Charge Coupled Device) image of the ears, the mean arterial pressure (MAP) and the heart rate (HR) were monitored. The mean LDI flux was calculated. The HR of rabbits was significantly (p 0.05). Both the flux numbers and the red-to-blue color changes on LDI imaging showed the reduction of the microcirculation. LDI imaging is a noninvasive and non-contact approach to evaluate the microcirculation and may offer benefits in the diagnosis and treatment of hemorrhage shock. Further studies are needed to confirm its effectiveness in clinical practice.

  8. Evaluation of the microcirculation in a rabbit hemorrhagic shock model using laser Doppler imaging.

    Directory of Open Access Journals (Sweden)

    Zhenchun Luo

    Full Text Available The aim of this study is to evaluate the feasibility of Laser Doppler imaging (LDI for noninvasive and dynamic assessment of hemorrhagic shock in a rabbit model. A rabbit model of hemorrhagic shock was generated and LDI of the microcirculation in the rabbit ears was performed before and at 0, 30, 60, and 90 min after hemorrhage. The CCD (Charge Coupled Device image of the ears, the mean arterial pressure (MAP and the heart rate (HR were monitored. The mean LDI flux was calculated. The HR of rabbits was significantly (p 0.05. Both the flux numbers and the red-to-blue color changes on LDI imaging showed the reduction of the microcirculation. LDI imaging is a noninvasive and non-contact approach to evaluate the microcirculation and may offer benefits in the diagnosis and treatment of hemorrhage shock. Further studies are needed to confirm its effectiveness in clinical practice.

  9. Enhanced sensitivity in H photofragment detection by two-color reduced-Doppler ion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Epshtein, Michael; Portnov, Alexander; Kupfer, Rotem; Rosenwaks, Salman; Bar, Ilana, E-mail: ibar@bgu.ac.il [Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)

    2013-11-14

    Two-color reduced-Doppler (TCRD) and one-color velocity map imaging (VMI) were used for probing H atom photofragments resulting from the ∼243.1 nm photodissociation of pyrrole. The velocity components of the H photofragments were probed by employing two counterpropagating beams at close and fixed wavelengths of 243.15 and 243.12 nm in TCRD and a single beam at ∼243.1 nm, scanned across the Doppler profile in VMI. The TCRD imaging enabled probing of the entire velocity distribution in a single pulse, resulting in enhanced ionization efficiency, as well as improved sensitivity and signal-to-noise ratio. These advantages were utilized for studying the pyrrole photodissociation at ∼243.1 and 225 nm, where the latter wavelength provided only a slight increase in the H yield over the self-signal from the probe beams. The TCRD imaging enabled obtaining high quality H{sup +} images, even for the low H photofragment yields formed in the 225 nm photolysis process, and allowed determining the velocity distributions and anisotropy parameters and getting insight into pyrrole photodissociation.

  10. Tissue Harmonic Synthetic Aperture Ultrasound Imaging

    DEFF Research Database (Denmark)

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

    2014-01-01

    , and data were recorded with and without pulse inversion for tissue harmonic imaging. Data were acquired using a Sound Technol- ogy 192 element convex array transducer from both a wire phantom and a tissue mimicking phantom to investigate spatial resolution and pen- etration. In-vivo scans were also......Synthetic aperture sequential beamforming (SASB) and tissue har- monic imaging (THI) are combined to improve the image quality of medical ultrasound imaging. The technique is evaluated in a compar- ative study against dynamic receive focusing (DRF). The objective is to investigate if SASB combined...... with THI improves the image qual- ity compared to DRF-THI. The major benet 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 oine evaluation. The acquisition was made interleaved between methods...

  11. Nonlinear spectral imaging of biological tissues

    NARCIS (Netherlands)

    Palero, J.A.

    2007-01-01

    The work presented in this thesis demonstrates live high resolution 3D imaging of tissue in its native state and environment. The nonlinear interaction between focussed femtosecond light pulses and the biological tissue results in the emission of natural autofluorescence and second-harmonic signal.

  12. Nonlinear spectral imaging of biological tissues

    NARCIS (Netherlands)

    Palero, J.A.

    2007-01-01

    The work presented in this thesis demonstrates live high resolution 3D imaging of tissue in its native state and environment. The nonlinear interaction between focussed femtosecond light pulses and the biological tissue results in the emission of natural autofluorescence and second-harmonic signal.

  13. Imaging shear wave propagation for elastic measurement using OCT Doppler variance method

    Science.gov (United States)

    Zhu, Jiang; Miao, Yusi; Qu, Yueqiao; Ma, Teng; Li, Rui; Du, Yongzhao; Huang, Shenghai; Shung, K. Kirk; Zhou, Qifa; Chen, Zhongping

    2016-03-01

    In this study, we have developed an acoustic radiation force orthogonal excitation optical coherence elastography (ARFOE-OCE) method for the visualization of the shear wave and the calculation of the shear modulus based on the OCT Doppler variance method. The vibration perpendicular to the OCT detection direction is induced by the remote acoustic radiation force (ARF) and the shear wave propagating along the OCT beam is visualized by the OCT M-scan. The homogeneous agar phantom and two-layer agar phantom are measured using the ARFOE-OCE system. The results show that the ARFOE-OCE system has the ability to measure the shear modulus beyond the OCT imaging depth. The OCT Doppler variance method, instead of the OCT Doppler phase method, is used for vibration detection without the need of high phase stability and phase wrapping correction. An M-scan instead of the B-scan for the visualization of the shear wave also simplifies the data processing.

  14. Reproducibility of the capsaicin-induced dermal blood flow response as assessed by laser Doppler perfusion imaging

    OpenAIRE

    Van der Schueren, B. J.; Hoon, J.N.; Vanmolkot, F H; Van Hecken, A; Depre, M; Kane, S A; De Lepeleire, I.; Sinclair, S R

    2007-01-01

    What is already known about this subjectCapsaicin rapidly produces local neurogenic inflammation (characterized by oedema and erythema) when locally administered to the human skin by binding to the TRPV1 receptor present on dermal sensory nerve endings.In nonhuman primates, a pharmacodynamic assay has been described and validated using capsaicin-induced dermal vasodilation measured by laser Doppler perfusion imaging to assess calcitonin gene-related peptide antagonist activity.Laser Doppler p...

  15. Evaluation of cardiac longitudinal systolic function in patients with heart transplant using two dimensional speckle tracking echocardiography and tissue Doppler imaging%二维斑点追踪及组织多普勒技术评价移植心脏纵向收缩功能的临床研究

    Institute of Scientific and Technical Information of China (English)

    李政; 潘翠珍; 舒先红; 陈昊; 王春生

    2014-01-01

    目的 应用二维斑点追踪技术及组织多普勒技术分别评价移植心脏左、右室纵向收缩功能.方法 56例心脏移植患者,根据心内膜心肌活检及长期临床随访结果分为无排异组(A组)和排异组(B组),随机入选36例健康志愿者归入C组,测量左室射血分数(LVEF)、肺动脉收缩压、三尖瓣瓣环位移(TAPSE)和三尖瓣瓣环收缩期速度(TA-S')等指标.应用Qlab 9.0软件分析获得左室整体纵向应变值(global longitudinal strain,GLS).结果 B组较C组LVEF降低(P<0.01).三组间GLS、TAPSE及TA-S'值比较差异均有统计学意义(P均<0.01),B组<A组<C组;GLS与LVEF、TAPSE、TA-S'有较好的负相关性(r分别为-0.64,-0.69,-0.71,P均<0.01).结论 心脏移植患者左、右室纵向收缩功能均有不同程度降低.%Objective To investigate longitudinal systolic function of transplanted heart using two dimensional speckle tracking echocardiography and tissue Doppler imaging.Methods 56 consecutive patients with heart transplant were recruited,according to myocardial biopsy and 1 year's follow up,they were divided into non-rejection group (group A) and rejection group (group B).36 healthy controls (group C) were also randomly recruited.Left ventricular ejection fraction (LVEF),pulmonary arterial systolic pressure,tricuspid annular plane systolic excursion (TAPSE),tricuspid annular plane systolic velocity (TAS') and global longitudinal strain (GLS) were calculated via Qlab 9.0 analysis software offline.Results Compared with group C,LVEF was reduced in group B (P <0.01).Differences of GLS,TAPSE,and TA-S' among groups were all statistically significant (P <0.01),group B<group A< group C.LVEF,TAPSE and TA-S' were correlated with GLS (r =-0.64,r =-0.69,r =-0.71 ; all P < 0.01).Conclusions Left and right ventricles were a functional unity,the systolic function of which was impaired in patients with heart transplant.

  16. Study on tissue Doppler imaging in diagnosis of right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease%组织多普勒成像技术诊断矽肺肺心病患者右心室肥大的研究

    Institute of Scientific and Technical Information of China (English)

    陈功泉

    2014-01-01

    Objective To investigate the value of tissue Doppler imaging (TDI) in the diagnosis of right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease.Methods A total of 50 cases of silicosis complicated by chronic pulmonary heart disease in our hospital underwent conventional electrocardiography (ECG) and TDI.The detection rates for right ventricular hypertrophy by two methods were compared.Results Of 50 cases of silicosis complicated by chronic pulmonary heart disease,19 were diagnosed with right ventricular hypertrophy by ECG,with a detection rate of 38.0%; 29 were diagnosed with right ventricular hypertrophy by TDI,with a detection rate off 58.0%.Statistical analysis suggested that TDI leads to a significantly higher detection rate for right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease (x2=4.006,P=0.036).Conclusion Both TDI and ECG can be used for detecting right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease,but the detection rate is higher when TDI is employed.In addition,ECG cannot directly reflect the increase in pulmonary artery pressure.Therefore,TDI is more suitable for the diagnosis of right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease and provides a strong diagnostic basis for the clinical treatment of silicosis complicated by pulmonary heart disease.%目的 探讨组织多普勒成像在矽肺并发慢性肺源性心脏病患者右心室肥大的诊断价值.方法 将本院50例矽肺并发慢性肺源性心脏病患者,分别行常规心电图和组织多普勒成像检查,比较两种方法右心室肥大检出率.结果 入组的50例矽肺并发慢性肺源性心脏病患者经心电图检查,发现右心室肥大患者19例,检出率为38.0%,而组织多普勒成像技术检查发现右心室肥大患者29例,检出率为58.0%,组织多

  17. 组织多普勒成像在急性心肌缺血心功能异常中的实验研究%Experimental study of Doppler tissue imaging on functional abnormality of the acute myocardial ischemia in pigs

    Institute of Scientific and Technical Information of China (English)

    田瑞霞; 左鲁生; 南苏红; 李熹; 朱先存; 张爱玲; 赵宝珍

    2001-01-01

    目的运用组织多普勒成像 (TDI)技术对急性心肌缺血区域和二尖瓣环侧壁处的运动速度、移动振幅进行检测,探讨TDI技术在急性心肌缺血、心肌梗死中的应用价值。方法 10只开胸猪结扎左冠状动脉前降支(LAD),通过TDI技术速度模式检测缺血区域和心尖四腔观二尖瓣环侧壁处的色泽变化及收缩、舒张期运动速度(VS,VE,VA)、移动振幅(MD,MDe,MDa)、等容收缩期时间,并与基础状态对照分析。结果 LAD结扎后,缺血区域和二尖瓣环处色泽暗淡,局部心肌色彩缺失。结扎15 s时收缩期、舒张早期运动速度、移动振幅显著降低,等容收缩期时间延长。结论 TDI技术能准确反映缺血梗死区域运动异常,精确测定局部收缩、舒张期运动速度、移动振幅,尤其二尖瓣环处的运动能反映整体心肌的运动,为临床早期评价局部心肌缺血及心功能异常提供了一种无创性的检查手段。%Objective To determine the motion velocity and mobile amplitude of acute myocardial ischemia(AMI), myocardial infarcted region and lateral wall of mitral annular using tissue Doppler imaging (TDI) and to study the available value of TDI on AMI and myocardial infarction.Methods Ligated descending anterior branch of left coronary artery(LAD) of 10 open-chest pigs, determined the color changes of ischemia region and view mitral annular apital four-chamber lateral wall and measwred the systotic and diastotic motion velocities (VS, VE, VA), displacement (MD, MDe, MDa) and isometric contraction time interval, and compared them with that of basal states.Results The colors of ischemia region and mitral annular were faint, local myocardial color lost after ligatured LAD. After having ligated for 15 s, the systolic and diastolic early motion velocities and mobile amplitude were decreased, time of isometric contraction was prolonged.Conclusions TDI can accurately reflect ischemia, infarcted

  18. 组织多普勒等容收缩期参数评价2型糖尿病患者右心室功能%Isovolumic contraction parameters of tissue Doppler imaging in evaluation on right ventricular function in patients with type 2 diabetes

    Institute of Scientific and Technical Information of China (English)

    马秀丽; 刘书丽; 王燕霞; 夏稻子

    2012-01-01

    目的 应用脉冲组织多普勒参数评价无临床症状2型糖尿病患者的右心室功能.方法 应用超声心动图脉冲组织多普勒技术检测血压正常的糖尿病患者(DM组,n=24)、合并高血压的糖尿病患者(DMHT组,n=22)及30名正常人(NC组)的右心室功能,得出常规二维超声测值及组织多普勒参数值,包括等容收缩期加速度(IVA)、等容收缩期峰值流速(IVV)、收缩期峰值流速(Sa)、舒张早期峰值流速(Ea)、舒张晚期峰值流速(Aa)、Ea/Aa、E/Ea及Tei指数,并进行统计学分析.结果 3组间常规二维超声测值差异无统计学意义.DMHT组和DM组的右心室脉冲组织多普勒参数中,Ea、Aa、Ea/Aa、E/Ea、IVA及Tei指数与NC组相比差异有统计学意义;其中DMHT组与DM组比较E/Ea及Tei指数差异有统计学意义,而IVA值差异无统计学意义.Sa及IVV在各组间比较差异均无统计学意义.IVA与Ea/Aa呈正相关(r=0.31,P<0.01),与E/Ea呈负相关(r=-0.44,P<0.05),与Tei指数呈负相关(r=-0.56,P<0.05).结论 脉冲组织多普勒等容收缩期参数可早期无创评价糖尿病患者右心室收缩和舒张功能.%Objective To assess the impact of preclinical diabetes mellitus (DM) on right ventricular function by using pulse wave tissue Doppler imaging (PW-TDI)-derived indices. Methods Totally 46 patients with type 2 DM (24 with DM only [DM group] and 22 coexisting DM and hypertension [DMHT group]) and 30 normal controls (NC group) were enrolled. Conventional two-dimensional (2D) parameters of right heart and TDI-derived systolic velocities of tricuspid annu-lus, including isovolumic myocardial acceleration (IVA), peak myocardial velocity during isovolumic contraction (IVV), peak systolic velocity during ejection period (Sa), early diastolic peak velocity (Ea), late diastolic peak velocity (Aa), E/ Ea, Ea/Aa and Tei index were measured and statistically analyzed. Results Conventional 2D parameters of right heart had no statistical

  19. Surface differential rotation of IL Hya from time-series Doppler images

    CERN Document Server

    Kővári, Zsolt; Oláh, Katalin; Vida, Krisztián; Bartus, János; Strassmeier, Klaus G; Weber, Michael

    2013-01-01

    We present a time-series Doppler imaging study of the K-subgiant component in the RS CVn-type binary system IL Hya (P orb=12.905 d). From re-processing the unique long-term spectroscopic dataset of 70 days taken in 1996/97, we perform a thorough cross-correlation analysis to derive surface differential rotation. As a result we get solar-type differential rotation with a shear value alpha of 0.05, in agreement with preliminary suggestions from previous attempts. A possible surface pattern of meridional circulation is also detected.

  20. Deep tissue imaging by enhanced photon collection

    Directory of Open Access Journals (Sweden)

    Viera Crosignani

    2014-09-01

    Full Text Available We have developed a two-photon fluorescence microscope capable of imaging up to 4mm in turbid media with micron resolution. The key feature of this instrument is the innovative detector, capable of collecting emission photons from a wider surface area of the sample than detectors in traditional two-photon microscopes. This detection scheme is extremely efficient in the collection of emitted photons scattered by turbid media which allows eight fold increase in the imaging depth when compared with conventional two-photon microscopes. Furthermore, this system also has in-depth fluorescence lifetime imaging microscopy (FLIM imaging capability which increases image contrast. The detection scheme captures emission light in a transmission configuration, making it extremely efficient for the detection of second harmonic generation (SHG signals, which is generally forward propagating. Here we present imaging experiments of tissue phantoms and in vivo and ex vivo biological tissue performed with this microscope.

  1. Real-time ultrasound Doppler enhances precision in image-guided approaches to the cerebello-pontine angle.

    Science.gov (United States)

    Baghdasaryan, Davit; Albrecht, Marcel; Shahnazaryan, Mihr; Rosahl, Steffen

    2017-08-10

    To evaluate efficacy and reliability of intraoperative Doppler sonography in localizing the transverse and sigmoid sinuses during lateral suboccipital craniotomy. A 16-Mhz intraoperative micro-Doppler ultrasound (16Mhz, Multi-Dop pro®, Compumedics, Germany) was applied to detect the medial border of the sigmoid sinus and the inferior border of the transverse sinus in 25 patients. Micro-Doppler measurements were compared to MR- and CT-based image-guidance (Kolibri®, Brainlab, Germany). Visual detectability of the sinuses under the operating microscope was also documented. Inadvertent incision of the transverse or sigmoid sinuses did not occur in any case when the two localizing methods have been used in combination. The mean mismatch of image-guided system and micro-Doppler was 2.64mm (range 0-6mm, SD 1.55 mm). Under the microscope the transverse sinus was invisible in seven cases, the sigmoid sinus was visually undetectable in one case. The micro-Doppler indicated blood flow outside the visible borders of the sinuses in five cases. A combination of image-guidance and micro-Doppler enhances the accuracy in localizing the margins of the transverse and sigmoid sinuses in the retrosigmoid approach, thus preventing inadvertent injury. The method could potentially be applied during other craniotomies involving the exposure of a venous sinus. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Tissue characterization by using narrow band imaging

    Science.gov (United States)

    Gono, Kazuhiro

    2010-02-01

    NBI (Narrow Band Imaging) was first introduced in the market in 2005 as a technique enabling to enhance image contrast of capillaries on a mucosal surface(1). It is classified as an Optical-Digital Method for Image-Enhanced Endoscopy(2). To date, the application has widely spread not only to gastrointestinal fields such as esophagus, stomach and colon but also the organs such as bronchus and bladder. The main target tissue of NBI enhancement is capillaries. However, findings of many clinical studies conducted by endoscopy physicians have revealed that NBI observation enables to enhance more other structures in addition to capillaries. There is a close relationship between those enhanced structures and histological microstructure of a tissue. This report introduces the tissue microstructures enhanced by NBI and discusses the possibility of optimized illumination wavelength in observing living tissues.

  3. MEMS-based handheld fourier domain Doppler optical coherence tomography for intraoperative microvascular anastomosis imaging.

    Directory of Open Access Journals (Sweden)

    Yong Huang

    Full Text Available To demonstrate the feasibility of a miniature handheld optical coherence tomography (OCT imager for real time intraoperative vascular patency evaluation in the setting of super-microsurgical vessel anastomosis.A novel handheld imager Fourier domain Doppler optical coherence tomography based on a 1.3-µm central wavelength swept source for extravascular imaging was developed. The imager was minimized through the adoption of a 2.4-mm diameter microelectromechanical systems (MEMS scanning mirror, additionally a 12.7-mm diameter lens system was designed and combined with the MEMS mirror to achieve a small form factor that optimize functionality as a handheld extravascular OCT imager. To evaluate in-vivo applicability, super-microsurgical vessel anastomosis was performed in a mouse femoral vessel cut and repair model employing conventional interrupted suture technique as well as a novel non-suture cuff technique. Vascular anastomosis patency after clinically successful repair was evaluated using the novel handheld OCT imager.With an adjustable lateral image field of view up to 1.5 mm by 1.5 mm, high-resolution simultaneous structural and flow imaging of the blood vessels were successfully acquired for BALB/C mouse after orthotopic hind limb transplantation using a non-suture cuff technique and BALB/C mouse after femoral artery anastomosis using a suture technique. We experimentally quantify the axial and lateral resolution of the OCT to be 12.6 µm in air and 17.5 µm respectively. The OCT has a sensitivity of 84 dB and sensitivity roll-off of 5.7 dB/mm over an imaging range of 5 mm. Imaging with a frame rate of 36 Hz for an image size of 1000(lateral×512(axial pixels using a 50,000 A-lines per second swept source was achieved. Quantitative vessel lumen patency, lumen narrowing and thrombosis analysis were performed based on acquired structure and Doppler images.A miniature handheld OCT imager that can be used for intraoperative evaluation of

  4. Pulsed-wave tissue Doppler and color tissue Doppler echocardiography: calibration with M-mode, agreement, and reproducibility in a clinical setting

    DEFF Research Database (Denmark)

    Olsen, Niels Thue; Jons, Christian; Fritz-Hansen, Thomas

    2009-01-01

    of the two methods in a routine clinical setting. METHODS: For Study A, the displacements of 63 basal myocardial segments from 13 patients were examined with M-mode and compared with the velocity-time integral of PWTD and CTD velocities. For Study B, the basal lateral segments from 58 patients were examined...... 2.29 +/- 1.82 cm/sec; P numerically smaller tissue velocities than PWTD, mostly due to an overestimation of true tissue motion by PWTD...

  5. LASER-DOPPLER VELOCIMETRY AND MONTE-CARLO SIMULATIONS ON MODELS FOR BLOOD PERFUSION IN TISSUE

    NARCIS (Netherlands)

    DEMUL, FFM; KOELINK, MH; KOK, ML; HARMSMA, PJ; GREVE, J; GRAAFF, R; AARNOUDSE, JG

    1995-01-01

    Laser Doppler flow measurements and Monte Carlo simulations on small blood perfusion flow models at 780 nm are presented and compared. The dimensions of the optical sample volume are investigated as functions of the distance of the laser to the detector and as functions of the angle of penetration o

  6. Photon dynamics in tissue imaging

    Science.gov (United States)

    Chance, Britton; Haselgrove, John C.; Wang, NaiGuang; Maris, Michael B.; Sevick-Muraca, Eva M.

    1991-11-01

    The emerging need for a fast, safe economical approach to global and localized measures of desaturation of hemoglobin with oxygen (HbO2) in the human brain motivates further research on time-resolved spectroscopy in four areas of study. (1) To afford quantization of hemoglobin saturation through time-resolved spectroscopy in the time domain (TD) and in the frequency domain (FD). Evaluation of dual-wavelength TD and FD spectrometers for determining quantitatively hemoglobin desaturation and blood-volume changes by calculations that are insensitive to mutual interference is proposed. The diffusion equation, as it applies especially to TD studies, and the absorption ((mu) a) and scattering ((mu) s) coefficients provide their independent determination from the late and early respective portions of the kinetics of the emergent photons in response to a short input pulse (50-100 psec). (2) The identification of the photon-pathlength change due to the arterial pulse in the brain tissue by FD methods with Fourier transformation affords an opportunity to employ principles of pulse oximetry to vessels localized deep within the brain tissue. (3) Localization of desaturation of hemoglobin in portions of the brain can be achieved through dual-wavelength scanning of the input/output optical fibers across the head for an X-Y coordinate and varying the distance between input and output ((rho) ) or the time delay in data acquisition to afford an in-depth Z scan. Localizations of shed blood, which have an effective concentration of over 10 times that of capillary-bed blood, are identified by X, Y, Z scans using only a single wavelength. (4) Independent measurements of absorption ((mu) a) and scattering ((mu) s) coefficients, particularly by TD techniques, affords structural mapping of the brain, which can be used to diagnose brain tumor and neuronal degeneration. Two experimental systems are used to critically evaluate these studies; the first, a hemoglobin/lipid/yeast model in which

  7. Laser Doppler blood flow complementary metal oxide semiconductor imaging sensor with analog on-chip processing.

    Science.gov (United States)

    Gu, Quan; Hayes-Gill, Barrie R; Morgan, Stephen P

    2008-04-20

    A 4 x 4 pixel array with analog on-chip processing has been fabricated within a 0.35 mum complementary metal oxide semiconductor process as a prototype sensor for laser Doppler blood flow imaging. At each pixel the bandpass and frequency weighted filters necessary for processing laser Doppler blood flow signals have been designed and fabricated. Because of the space constraints of implementing an accurate omega(0.5) filter at the pixel level, this has been approximated using the "roll off" of a high-pass filter with a cutoff frequency set at 10 kHz. The sensor has been characterized using a modulated laser source. Fixed pattern noise is present that is demonstrated to be repeatable across the array and can be calibrated. Preliminary blood flow results on a finger before and after occlusion demonstrate that the sensor array provides the potential for a system that can be scaled to a larger number of pixels for blood flow imaging.

  8. The role of colour Doppler imaging in the management of Peyronie's disease.

    Science.gov (United States)

    Ahmed, M; Chilton, C P; Munson, K W; Williams, J H; Pallan, J H; Turner, G

    1998-04-01

    To determine the role of colour Doppler imaging (CDI) in the investigation of erectile dysfunction in patients with Peyronie's disease. Fifty consecutive patients (age 35-75 years) with Peyronie's disease who were considered suitable for surgical treatment were investigated using CDI to determine the haemodynamic variables of penile vasculature after an intracorporeal injection of 20 microg of alprostadil (with manual self-stimulation). A clinician independently recorded the quality of erection and the deformity. Twenty of 50 patients (40%) considered they had normal erectile function despite their penile deformity and all had normal responses, although they tended to exaggerate the degree of penile deformity. Of the 30 remaining patients, 21 who considered themselves to have erectile dysfunction had normal clinical and CDI haemodynamic responses to alprostadil. The remaining nine patients had a variety of erectile problems and whilst CDI showed altered haemodynamic values, in no case did CDI alter the proposed treatment based on the clinically apparent features of those patients. Colour Doppler imaging of the penis after pharmacologically induced erection gives anatomical and functional information in patients with Peyronie's disease but does not provide useful additional information to aid the selection of surgical treatment for the disease.

  9. Magnetic Doppler imaging of the roAp star HD 24712

    CERN Document Server

    Lüftinger, T; Ryabchikova, T; Piskunov, N; Weiss, W W; Ilyin, I

    2009-01-01

    We present the first magnetic Doppler images of a rapidly oscillating Ap (roAp) star. We deduce information about magnetic field geometry and abundance distributions of a number of chemical elements on the surface of the hitherto best studied roAp star, HD 24712, using the magnetic Doppler imaging (MDI) code, INVERS10, which allows us to reconstruct simultaneously and consistently the magnetic field geometry and elemental abundance distributions on a stellar surface. For this purpose we analyse time series spectra obtained in Stokes I and V parameters with the SOFIN polarimeter at the Nordic Optical Telescope and recover surface abundance structures of sixteen different chemical elements, respectively ions, including Mg, Ca, Sc, Ti, Cr, Fe, Co, Ni, Y, La, Ce, Pr, Nd, Gd, Tb, and Dy. For the rare earth elements (REE) Pr and Nd separate maps were obtained using lines of the first and the second ionization stage. We find and confirm a clear dipolar structure of the surface magnetic field and an unexpected correl...

  10. Impacts of acute severe pulmonary regurgitation on right ventricular geometry and contractility assessed by tissue-Doppler echocardiography

    DEFF Research Database (Denmark)

    Kjaergaard, Jesper; K. Iversen, Kasper; G Vejlstrup, Niels

    2010-01-01

    model. METHODS AND RESULTS: Transthoracic echocardiography, including tissue-Doppler echocardiography for the evaluation of regional longitudinal function, was performed immediately before and after induction of severe PR by deployment of a stent in the pulmonary valve annulus of 32 farm pigs. Acute PR....... No changes in global or regional longitudinal contractility or deformation were observed despite significant changes in the cardiac chamber geometry. An increase in radial shortening may imply that the RV compensates by increasing radial contraction as an adjunct to dilatation....

  11. Performance evaluation of an all-fiber image-reject homodyne coherent Doppler wind lidar

    Directory of Open Access Journals (Sweden)

    C. F. Abari

    2015-04-01

    Full Text Available The main purpose of this study is to evaluate the near-zero wind velocity measurement performance of two separate 1.5 μm all-fiber coherent Doppler lidars (CDL. The performance characterization is performed through the presentation of the results from two separate atmospheric field campaigns. In one campaign, a recently developed continuous wave (CW CDL benefiting from an image-reject front-end was deployed. The other campaign utilized a different CW CDL, benefiting from a heterodyne receiver with intermediate frequency (IF sampling. In both field campaigns the results are compared against a sonic anemometer, as the reference instrument. The measurements clearly show that the image-reject architecture results in more accurate measurements of radial wind velocities close to zero. Close-to-zero velocities are usually associated with the vertical component of the wind and are important to characterize.

  12. Doppler standard deviation imaging for clinical monitoring of in vivo human skin blood flow

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yonghua; Chen, Zhongping; Saxer, Christopher; Shen, Qimin; Xiang, Shaohua; Boer, Johannes F. de; Nelson, J. Stuart

    2000-09-15

    We used a novel phase-resolved optical Doppler tomographic (ODT) technique with very high flow-velocity sensitivity (10 {mu}m/s) and high spatial resolution (10 {mu}m) to image blood flow in port-wine stain (PWS) birthmarks in human skin. In addition to the regular ODT velocity and structural images, we use the variance of blood flow velocity to map the PWS vessels. Our device combines ODT and therapeutic systems such that PWS blood flow can be monitored in situ before and after laser treatment. To the authors' knowledge this is the first clinical application of ODT to provide a fast semiquantitative evaluation of the efficacy of PWS laser therapy in situ and in real time. (c) 2000 Optical Society of America.

  13. A comparison between 133Xenon washout technique and Laser Doppler flowmetry in the measurement of local vasoconstrictor effects on the microcirculation in subcutaneous tissue and skin

    DEFF Research Database (Denmark)

    Kastrup, J; Bülow, J; Lassen, N A

    1987-01-01

    level. The measurements were performed in tissue with and without sympathetic innervation. In five subjects, who all had been cervically sympathectomized for manual hyperhidrosis, the Laser Doppler and 133Xenon blood flow measurements were performed simultaneously on the sympathetically denervated...... forearm, and on the calf with preserved sympathetic nerve supply. The Laser Doppler method registered a 23% reduction in skin blood flow during lowering of the extremities independently of the sympathetic nerve supply to the skin. The 133Xenon method recorded a 44% decrease in blood flow in innervated...... and unchanged blood flow in denervated subcutaneous tissue during lowering of the extremities. Our results indicate that the Laser Doppler method and 133Xenon method are not comparable, and that the Laser Doppler method is not useful in measuring local sympathetic mediated blood flow changes....

  14. Doppler laser imaging predicts response to topical minoxidil in the treatment of female pattern hair loss.

    Science.gov (United States)

    McCoy, J; Kovacevic, M; Situm, M; Stanimirovic, A; Bolanca, Z; Goren, A

    2016-01-01

    Topical minoxidil is the only drug approved by the US FDA for the treatment of female pattern hair loss. Unfortunately, following 16 weeks of daily application, less than 40% of patients regrow hair. Several studies have demonstrated that sulfotransferase enzyme activity in plucked hair follicles predicts topical minoxidil response in female pattern hair loss patients. However, due to patients’ discomfort with the procedure, and the time required to perform the enzymatic assay it would be ideal to develop a rapid, non-invasive test for sulfotransferase enzyme activity. Minoxidil is a pro-drug converted to its active form, minoxidil sulfate, by sulfotransferase enzymes in the outer root sheath of hair. Minoxidil sulfate is the active form required for both the promotion of hair regrowth and the vasodilatory effects of minoxidil. We thus hypothesized that laser Doppler velocimetry measurement of scalp blood perfusion subsequent to the application of topical minoxidil would correlate with sulfotransferase enzyme activity in plucked hair follicles. In this study, plucked hair follicles from female pattern hair loss patients were analyzed for sulfotransferase enzyme activity. Additionally, laser Doppler velocimetry was used to measure the change in scalp perfusion at 15, 30, 45, and 60 minutes, after the application of minoxidil. In agreement with our hypothesis, we discovered a correlation (r=1.0) between the change in scalp perfusion within 60 minutes after topical minoxidil application and sulfotransferase enzyme activity in plucked hairs. To our knowledge, this is the first study demonstrating the feasibility of using laser Doppler imaging as a rapid, non-invasive diagnostic test to predict topical minoxidil response in the treatment of female pattern hair loss.

  15. Imaging white adipose tissue with confocal microscopy.

    Science.gov (United States)

    Martinez-Santibañez, Gabriel; Cho, Kae Won; Lumeng, Carey N

    2014-01-01

    Adipose tissue is composed of a variety of cell types that include mature adipocytes, endothelial cells, fibroblasts, adipocyte progenitors, and a range of inflammatory leukocytes. These cells work in concert to promote nutrient storage in adipose tissue depots and vary widely based on location. In addition, overnutrition and obesity impart significant changes in the architecture of adipose tissue that are strongly associated with metabolic dysfunction. Recent studies have called attention to the importance of adipose tissue microenvironments in regulating adipocyte function and therefore require techniques that preserve cellular interactions and permit detailed analysis of three-dimensional structures in fat. This chapter summarizes our experience with the use of laser scanning confocal microscopy for imaging adipose tissue in rodents.

  16. Histology and imaging of soft tissue sarcomas

    Energy Technology Data Exchange (ETDEWEB)

    Kind, Michele [Departement d' Imagerie Medicale, Institut Bergonie, 229 cours de l' Argonne, 33076 Bordeaux Cedex (France)], E-mail: kind@bergonie.org; Stock, Nathalie; Coindre, Jean Michel [Departement de Pathologie, Institut Bergonie, 229 cours de l' Argonne, 33076 Bordeaux Cedex (France); Universite Victor Segalen Bordeaux 2, 146 rue Leo Saignat, 33076 Bordeaux Cedex (France)

    2009-10-15

    Imaging and histology are two complementary morphological techniques which play a fundamental role in the diagnosis and management of soft tissue sarcomas. Imaging allows to identify some pseudosarcomatous benign lesions such as myositis ossificans, intramuscular hemangioma, angiomyolipoma, intramuscular lipoma, giant cell tumour of tendon sheath, desmoid tumour and elastofibroma. There is no formal criterion for diagnosing a sarcoma on magnetic resonance imaging (MRI) but malignancy is strongly suspected with the presence of necrosis and vascular, bone or joint invasion. Imaging may also suggest some histological types of sarcoma such as well-differentiated liposarcoma, dedifferentiated liposarcoma, synovial sarcoma or extraskeletal osteosarcoma. Imaging is also extremely helpful in determining the appropriate kind of sampling to carry out and in guiding the performance of a microbiopsy. The appearance observed on imaging should always be taken into consideration for the interpretation of the microbiopsy by the pathologist.

  17. Comparing differential tissue harmonic imaging with tissue harmonic and fundamental gray scale imaging of the liver.

    Science.gov (United States)

    Chiou, See-Ying; Forsberg, Flemming; Fox, Traci B; Needleman, Laurence

    2007-11-01

    The purpose of this study was to compare fundamental gray scale sonography, tissue harmonic imaging (THI), and differential tissue harmonic imaging (DTHI) for depicting normal and abnormal livers. The in vitro lateral resolution of DTHI, THI, and sonography was assessed in a phantom. Sagittal and transverse images of right and left hepatic lobes of 5 volunteers and 20 patients and images of 27 liver lesions were also acquired. Three independent blinded readers scored all randomized images for noise, detail resolution, image quality, and margin (for lesions) on a 7-point scale. Next, images from the same location obtained with all 3 modes were compared blindly side by side and rated by all readers. Contrast-to-noise ratios were calculated for the lesions, and the depth of penetration (centimeters) was determined for all images. In vitro, the lateral resolution of DTHI was significantly better than fundamental sonography (P = .009) and showed a trend toward significance versus THI (P = .06). In the far field, DTHI performed better than both modes (P images were scored, and for all parameters, DTHI and THI did better than sonography (P tissue harmonic imaging scored significantly higher than THI with regard to detail resolution and image quality (P Tissue harmonic imaging and DTHI do better than fundamental sonography for hepatic imaging, with DTHI being rated the best of the 3 techniques.

  18. Intravascular ultrasound tissue harmonic imaging in vivo.

    Science.gov (United States)

    Frijlink, Martijn E; Goertz, David E; van Damme, Luc C A; Krams, Rob; van der Steen, Antonius F W

    2006-10-01

    Tissue harmonic imaging (THI) has been shown to increase image quality of medical ultrasound in the frequency range from 2 to 10 MHz and might, therefore, also be used to improve image quality in intravascular ultrasound (IVUS). In this study we constructed a prototype IVUS system that could operate in both fundamental frequency and second harmonic imaging modes. This system uses a conventional, continuously rotating, single-element IVUS catheter and was operated in fundamental 20 MHz, fundamental 40 MHz, and harmonic 40 MHz modes (transmit 20 MHz, receive 40 MHz). Hydrophone beam characterization measurements demonstrated the build-up of a second harmonic signal as a function of increasing pressure. Imaging experiments were conducted in both a tissue-mimicking phantom and in an atherosclerotic animal model in vivo. Acquisitions of fundamental 20 and 40 MHz and second harmonic acquisitions resulted in cross sections of the phantom and a rabbit aorta. The harmonic results of the imaging experiments showed the feasibility of intravascular THI with a conventional IVUS catheter both in a phantom and in vivo. The harmonic acquisitions also showed the potential of THI to reduce image artifacts compared to fundamental imaging.

  19. Tissue harmonic synthetic aperture ultrasound imaging.

    Science.gov (United States)

    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.

  20. Diffuse reflection imaging of sub-epidermal tissue haematocrit using a simple RGB camera

    Science.gov (United States)

    Leahy, Martin J.; O'Doherty, Jim; McNamara, Paul; Henricson, Joakim; Nilsson, Gert E.; Anderson, Chris; Sjoberg, Folke

    2007-05-01

    This paper describes the design and evaluation of a novel easy to use, tissue viability imaging system (TiVi). The system is based on the methods of diffuse reflectance spectroscopy and polarization spectroscopy. The technique has been developed as an alternative to current imaging technology in the area of microcirculation imaging, most notably optical coherence tomography (OCT) and laser Doppler perfusion imaging (LDPI). The system is based on standard digital camera technology, and is sensitive to red blood cells (RBCs) in the microcirculation. Lack of clinical acceptance of both OCT and LDPI fuels the need for an objective, simple, reproducible and portable imaging method that can provide accurate measurements related to stimulus vasoactivity in the microvasculature. The limitations of these technologies are discussed in this paper. Uses of the Tissue Viability system include skin care products, drug development, and assessment spatial and temporal aspects of vasodilation (erythema) and vasoconstriction (blanching).

  1. Clinically low-risk prostate cancer: evaluation with transrectal doppler ultrasound and functional magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Maria Inês Novis

    2011-01-01

    Full Text Available OBJECTIVES: To evaluate transrectal ultrasound, amplitude Doppler ultrasound, conventional T2-weighted magnetic resonance imaging, spectroscopy and dynamic contrast-enhanced magnetic resonance imaging in localizing and locally staging low-risk prostate cancer. INTRODUCTION: Prostate cancer has been diagnosed at earlier stages and the most accepted classification for low-risk prostate cancer is based on clinical stage T1c or T2a, Gleason score <6, and prostate-specific antigen (PSA <10 ng/ml. METHODS: From 2005 to 2006, magnetic resonance imaging was performed in 42 patients, and transrectal ultrasound in 26 of these patients. Seven patients were excluded from the study. Mean patient age was 64.94 years and mean serum PSA was 6.05 ng/ml. The examinations were analyzed for tumor identification and location in prostate sextants, detection of extracapsular extension, and seminal vesicle invasion, using surgical pathology findings as the gold standard. RESULTS: Sixteen patients (45.7% had pathologically proven organ-confined disease, 11 (31.4% had positive surgical margin, 8 (28.9% had extracapsular extension, and 3 (8.6% presented with extracapsular extension and seminal vesicle invasion. Sensitivity, specificity, positive predictive value (PPV, negative predictive value (NPV and accuracy values for localizing low-risk prostate cancer were 53.1%, 48.3%, 63.4%, 37.8% and 51.3% for transrectal ultrasound; 70.4%, 36.2%, 65.1%, 42.0% and 57.7% for amplitude Doppler ultrasound; 71.5%, 58.9%, 76.6%, 52.4% and 67.1% for magnetic resonance imaging; 70.4%, 58.7%, 78.4%, 48.2% and 66.7% for magnetic resonance spectroscopy; 67.2%, 65.7%, 79.3%, 50.6% and 66.7% for dynamic contrast-enhanced magnetic resonance imaging, respectively. Sensitivity, specificity, PPV, NPV and accuracy values for detecting extracapsular extension were 33.3%, 92%, 14.3%, 97.2% and 89.7% for transrectal ultrasound and 50.0%, 77.6%, 13.7%, 95.6% and 75.7% for magnetic resonance imaging

  2. Photoacoustic & pulsed laser-doppler monitoring of blood concentration and perfusion in tissue

    OpenAIRE

    Kolkman, Roy Gerardus Maria

    2002-01-01

    In medicine there are situations that require continuous bedside monitoring of perfusion and blood volume. Such a situation can occur when children are born prematurely. Those children have a high risk to develop a handicap, which is most likely caused by cerebral damage due to impaired brain perfusion. Monitoring cerebral perfusion can provide information for preventive treatment. In this thesis we have explored the potential of photoacoustics and laser Doppler flowmetry for measurement of c...

  3. Cardiovascular assessment of patients with Ullrich-Turner's Syndrome on Doppler echocardiography and magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Castro Ana Valéria Barros de

    2002-01-01

    Full Text Available OBJECTIVE: To assess the cardiovascular features of Ullrich-Turner's syndrome using echocardiography and magnetic resonance imaging, and to correlate them with the phenotype and karyotype of the patients. The diagnostic concordance between the 2 methods was also assessed. METHODS: Fifteen patients with the syndrome were assessed by echocardiography and magnetic resonance imaging (cardiac chambers, valves, and aorta. Their ages ranged from 10 to 28 (mean of 16.7 years. The karyotype was analyzed in 11 or 25 metaphases of peripheral blood lymphocytes, or both. RESULTS: The most common phenotypic changes were short stature and spontaneous absence of puberal development (100%; 1 patient had a cardiac murmur. The karyotypes detected were as follows: 45,X (n=7, mosaics (n=5, and deletions (n=3. No echocardiographic changes were observed. In regard to magnetic resonance imaging, coarctation and dilation of the aorta were found in 1 patient, and isolated dilation of the aorta was found in 4 patients. CONCLUSION: The frequencies of coarctation and dilation of the aorta detected on magnetic resonance imaging were similar to those reported in the literature (5.5% to 20%, and 6.3% to 29%, respectively. This confirmed the adjuvant role of magnetic resonance imaging to Doppler echocardiography for diagnosing cardiovascular alterations in patients with Ullrich-Turner's syndrome.

  4. Doppler Spectrum-Based NRCS Estimation Method for Low-Scattering Areas in Ocean SAR Images

    Directory of Open Access Journals (Sweden)

    Hui Meng

    2017-02-01

    Full Text Available The image intensities of low-backscattering areas in synthetic aperture radar (SAR images are often seriously contaminated by the system noise floor and azimuthal ambiguity signal from adjacent high-backscattering areas. Hence, the image intensity of low-backscattering areas does not correctly reflect the backscattering intensity, which causes confusion in subsequent image processing or interpretation. In this paper, a method is proposed to estimate the normalized radar cross-section (NRCS of low-backscattering area by utilizing the differences between noise, azimuthal ambiguity, and signal in the Doppler frequency domain of single-look SAR images; the aim is to eliminate the effect of system noise and azimuthal ambiguity. Analysis shows that, for a spaceborne SAR with a noise equivalent sigma zero (NESZ of −25 dB and a single-look pixel of 8 m × 5 m, the NRCS-estimation precision of this method can reach −38 dB at a resolution of 96 m × 100 m. Three examples are given to validate the advantages of this method in estimating the low NRCS and the filtering of the azimuthal ambiguity.

  5. Time-resolved measurement of bubble cavitation by using power Doppler ultrasound image

    Science.gov (United States)

    Koda, Ren; Izumi, Yosuke; Nagai, Hayato; Yamakoshi, Yoshiki

    2017-04-01

    In this study, a novel measurement method for a secondary ultrasound wave irradiated by microbubble cavitation is proposed. High-intensity ultrasound (h-US, 1.0–1.5 MPa), which produces bubble cavitation, is irradiated with a fixed time delay after introducing imaging US, whose frequency is different from that of the h-US. The bubble cavitation signal (BCS) is detected by the signal-processing unit of an ultrasound power Doppler imaging instrument. By this method, both a spatially resolved bubble image (S-image) and the temporal transition of the BCS (T-image) are monitored simultaneously. A feature of the method is that the BCS is observed in situ with sub-µs time resolution. The accuracy of the method is evaluated and it is found that the maximum deviation of the amplitude of the simulated BCS is 4.80%. This method is applied to measure the BCS of ultrasound contrast agent microbubbles. As a result, the dependence of the inherent temporal transition of the BCS on the sound pressure of the h-US (0.6–1.2 MPa) is observed.

  6. Accuracy of color Doppler ultrasonography and magnetic resonance imaging in diagnosis of placenta accreta: A survey of 82 cases

    Directory of Open Access Journals (Sweden)

    Sedigheh Ayati

    2017-08-01

    Full Text Available Background: Placenta adhesive disorder (PAD is one of the most common causes of postpartum hemorrhage and peripartum hysterectomy. The main risk factors are placenta previa and prior uterine surgery such as cesarean section. Diagnosis of placenta adhesive disorders can lead to a decrease of maternal mortality and morbidities. Objective: The purpose of this study was to compare the accuracy of color Doppler ultrasonography and magnetic resonance imaging (MRI in the diagnosis of PADs. Materials and Methods: In this is cross-sectional study, Eighty-two pregnant women who were high risk for PAD underwent color Doppler ultrasound and MRI after 18 weeks of gestation. The sonographic and MRI findings were compared with the final pathologic or clinical findings. P<0.05 was considered statistically significant. Results: Mean maternal age was 31.42±4.2 years. The average gravidity was third pregnancy. 46% of patients had placenta previa. The history of the previous cesarean section was seen in 79 cases (96%. The diagnosis of placenta adhesive disorder was found in 17 cases (21%. Doppler sonography sensitivity was 87% and MRI sensitivity was 76% (p=0.37. Doppler sonography specificity was 63% and MRI specificity was 83% (p=0.01. Conclusion: Women with high-risk factors for PAD should undergo Doppler ultrasonography at first. When results on Doppler sonography are equivocal for PAD, MRI can be performed due to its high specificity

  7. The chromospherically active binary star EI Eridani II. Long-term Doppler imaging

    CERN Document Server

    Washuettl, A; Weber, M

    2008-01-01

    Data from 11 years of continuous spectroscopic observations of the active RS CVn-type binary star EI Eridani - gained at NSO/McMath-Pierce, KPNO/Coude Feed and during the MUSICOS 98 campaign - were used to obtain 34 Doppler maps in three spectroscopic lines for 32 epochs, 28 of which are independent of each other. Various parameters are extracted from our Doppler maps: average temperature, fractional spottedness, and longitudinal and latitudinal spot-occurrence functions. We find that none of these parameters show a distinct variation nor a correlation with the proposed activity cycle as seen from photometric long-term observations. This suggests that the photometric brightness cycle may not necessarily be due to just a cool spot cycle. The general morphology of the spot pattern remains persistent over the whole period of 11 years. A large cap-like polar spot was recovered from all our images. A high degree of variable activity was noticed near latitudes of approx. 60-70 degrees where the appendages of the po...

  8. The High-Resolution Doppler Imager: status update 12 years after launch

    Science.gov (United States)

    Skinner, Wilbert R.; Marshall, Alan R.; Gell, David A.; Raines, Jim

    2003-11-01

    The High Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite (UARS) has been measuring winds in the stratosphere, mesosphere and lower thermosphere since November, 1991. The winds are determined by measuring the Doppler shift of emission and absorption lines in the O2 Atmospheric Band that are located between 630 and 762 nm. HRDI is a triple-etalon Fabry-Perot interferometer that has a resolution of ~0.05 cm-1 and very good white light rejection. A multi-channel detector with 31 channels is used to examine a spectral region 0.5 cm-1 wide and an adjustable filter wheel permits the selection of any one of 13 spectral bands. The long life of this instrument has presented many challenges in keeping the calibrations current and in compensating for inevitable degradations in instrument and spacecraft performance. Some of the problems with the UARS spacecraft the affect HRDI operations are: limited power due to the solar array drive failure; loss of data resulting from a failure of the tape recorders, and loss of attitude knowledge caused by the failure of the star trackers. HRDI has shown little loss in capability over the years with only a decrease in the azimuth rate of the telescope motor a significant sign of aging. This paper will discuss some of these challenges and how they have been met.

  9. Multiphoton imaging of renal tissues in vitro.

    Science.gov (United States)

    Peti-Peterdi, János

    2005-06-01

    The highly inhomogeneous and light-scattering structure of living renal tissue makes the application of conventional imaging techniques more difficult compared with other parenchymal organs. On the other hand, key physiological processes of the kidney, such as regulation of glomerular filtration, hemodynamics, concentration, and dilution, involve complex interactions between multiple cell types and otherwise inaccessible structures that necessitate visual approaches. An ideal solution is multiphoton excitation fluorescence microscopy, a state-of-the-art imaging technique superior for deep optical sectioning of living tissue samples. Here, we review the basics and advantages of multiphoton microscopy and provide examples for its application in renal physiology using dissected cortical and medullary tissues in vitro. In combination with microperfusion techniques, the major functions of the juxtaglomerular apparatus, tubuloglomerular feedback and renin release, can be studied with high spatial and temporal resolution. Salt-dependent changes in macula densa cell volume, vasoconstriction of the afferent arteriole, and activity of an intraglomerular precapillary sphincter composed of renin granular cells are visualized in real time. Release and tissue activity of renin can be studied on the individual granule level. Imaging of the living inner medulla shows how interstitial cells interconnect cells of the vasa recta, loop of Henle, and collecting duct. In summary, multiphoton microscopy is an exciting new optical sectioning technique that has great potential for numerous future developments and is ideal for applications that require deep optical sectioning of living tissue samples.

  10. Stokes polarimetry imaging of dog prostate tissue

    Science.gov (United States)

    Kim, Jihoon; Johnston, William K., III; Walsh, Joseph T., Jr.

    2010-02-01

    Prostate cancer is the second leading cause of death in the United States in 2009. Radical prostatectomy (complete removal of the prostate) is the most common treatment for prostate cancer, however, differentiating prostate tissue from adjacent bladder, nerves, and muscle is difficult. Improved visualization could improve oncologic outcomes and decrease damage to adjacent nerves and muscle important for preservation of potency and continence. A novel Stokes polarimetry imaging (SPI) system was developed and evaluated using a dog prostate specimen in order to examine the feasibility of the system to differentiate prostate from bladder. The degree of linear polarization (DOLP) image maps from linearly polarized light illumination at different visible wavelengths (475, 510, and 650 nm) were constructed. The SPI system used the polarization property of the prostate tissue. The DOLP images allowed advanced differentiation by distinguishing glandular tissue of prostate from the muscular-stromal tissue in the bladder. The DOLP image at 650 nm effectively differentiated prostate and bladder by strong DOLP in bladder. SPI system has the potential to improve surgical outcomes in open or robotic-assisted laparoscopic removal of the prostate. Further in vivo testing is warranted.

  11. Confocal microscopy imaging of solid tissue

    Science.gov (United States)

    Confocal laser scanning microscopy (CLSM) is a technique that is capable of generating serial sections of whole-mount tissue and then reassembling the computer acquired images as a virtual 3-dimensional structure. In many ways CLSM offers an alternative to traditional sectioning ...

  12. Color Doppler flow imaging diagnosis and treatment selection for erectile dysfunction

    Institute of Scientific and Technical Information of China (English)

    XUAN Xu-jun; ZHANG Cai-xia; HUANG Jian; Rong Lu; SUN Peng; LIU Hai-nan

    2011-01-01

    Background Targeted therapy for erectile dysfunction (ED) involves fewer screening tests and provides a variety of treatment choices for patients.Although the advantage of targeted therapy in diagnosis and therapy for ED has been recognized,the rational mode for oriented ED therapy has not been established.This study aimed to investigate targeted diagnosis and therapy for ED.Methods A total of 198 patients with ED were included in the study.After intracavernosal vasoactive agent injection was given,color Doppler flow imaging was performed and penile rigidity was classified as Schramek grade 5 (10 minutes duration),grade 4 (10 minutes duration),grade 3 and grade 2,defining four patient groups as group Ⅴ (143 cases),group Ⅳ (23 cases),group Ⅲ (18 cases),and group Ⅱ (14 cases).Appropriate and acceptable treatment was recommended to patients according to erection grade.Results In 198 patients with ED,the peak systolic velocity,end diastolic velocity,and resistance index in the cavemosal artery and dorsal artery and the flow velocity in the deep dorsal vein were not significantly different before injection (P >0.05).After injection,peak systolic velocity,end diastolic velocity,and resistance index in the cavernosal artery were different among the four groups (P<0.05).Between each two groups,the difference in resistance index was significant (P <0.05).The statistical differences in other indexes were not significant (P >0.05).Selective targeted therapy based on erection grade by color Doppler flow imaging improved the clinical satisfaction rate to 91.91% (182/198).Conclusions Based on the routine diagnosis of ED,blood flow indexes in the cavernosal artery are measured by color Doppler flow imaging following minimally invasive intercavernosal injection,which is combined with the Schramek grade of erection.The most appropriate and acceptable treatment is recommended according to the different groups,which improves the clinical satisfaction of treatment for

  13. Magnetic Doppler imaging considering atmospheric structure modifications due to local abundances: a luxury or a necessity?

    Science.gov (United States)

    Kochukhov, O.; Wade, G. A.; Shulyak, D.

    2012-04-01

    Magnetic Doppler imaging is currently the most powerful method of interpreting high-resolution spectropolarimetric observations of stars. This technique has provided the very first maps of stellar magnetic field topologies reconstructed from time series of full Stokes vector spectra, revealing the presence of small-scale magnetic fields on the surfaces of Ap stars. These studies were recently criticised by Stift et al., who claimed that magnetic inversions are not robust and are seriously undermined by neglecting a feedback on the Stokes line profiles from the local atmospheric structure in the regions of enhanced metal abundance. We show that Stift et al. misinterpreted published magnetic Doppler imaging results and consistently neglected some of the most fundamental principles behind magnetic mapping. Using state-of-the-art opacity sampling model atmosphere and polarized radiative transfer codes, we demonstrate that the variation of atmospheric structure across the surface of a star with chemical spots affects the local continuum intensity but is negligible for the normalized local Stokes profiles except for the rare situation of a very strong line in an extremely Fe-rich atmosphere. For the disc-integrated spectra of an Ap star with extreme abundance variations, we find that the assumption of a mean model atmosphere leads to moderate errors in Stokes I but is negligible for the circular and linear polarization spectra. Employing a new magnetic inversion code, which incorporates the horizontal variation of atmospheric structure induced by chemical spots, we reconstructed new maps of magnetic field and Fe abundance for the bright Ap star α2 CVn. The resulting distribution of chemical spots changes insignificantly compared to the previous modelling based on a single model atmosphere, while the magnetic field geometry does not change at all. This shows that the assertions by Stift et al. are exaggerated as a consequence of unreasonable assumptions and

  14. Time-series Doppler imaging of the red giant HD 208472. Active longitudes and differential rotation

    Science.gov (United States)

    Özdarcan, O.; Carroll, T. A.; Künstler, A.; Strassmeier, K. G.; Evren, S.; Weber, M.; Granzer, T.

    2016-10-01

    Context. HD 208472 is among the most active RS CVn binaries with cool starspots. Decade-long photometry has shown that the spots seem to change their longitudinal appearance with a period of about six years, coherent with brightness variations. Aims: Our aim is to spatially resolve the stellar surface of HD 208472 and relate the photometric results to the true longitudinal and latitudinal spot appearance. Furthermore, we investigate the surface differential rotation pattern of the star. Methods: We employed three years of high-resolution spectroscopic data with a high signal-to-noise ratio (S/N) from the STELLA robotic observatory and determined new and more precise stellar physical parameters. Precalculated synthetic spectra were fit to each of these spectra, and we provide new spot-corrected orbital elements. A sample of 34 absorption lines per spectrum was used to calculate mean line profiles with a S/N of several hundred. A total of 13 temperature Doppler images were reconstructed from these line profiles with the inversion code iMap. Differential rotation was investigated by cross-correlating successive Doppler images in each observing season. Results: Spots on HD 208472 are distributed preferably at high latitudes and less frequently around mid-to-low latitudes. No polar-cap like structure is seen at any epoch. We observed a flip-flop event between 2009 and 2010, manifested as a flip of the spot activity from phase 0.0 to phase 0.5, while the overall brightness of the star continued to increase and reached an all-time maximum in 2014. Cross-correlation of successive Doppler images suggests a solar-like differential rotation that is ≈15 times weaker than that of the Sun. Based on data obtained with the STELLA robotic telescope in Tenerife, an AIP facility jointly operated by AIP and IAC, and the Potsdam Automatic Photoelectric Telescopes (APT) in Arizona, jointly operated by AIP and Fairborn Observatory.Radial velocity measurements are only available at the

  15. Utilization of laser Doppler flowmetry and tissue spectrophotometry for burn depth assessment using a miniature swine model.

    Science.gov (United States)

    Lotter, Oliver; Held, Manuel; Schiefer, Jennifer; Werner, Ole; Medved, Fabian; Schaller, Hans-Eberhard; Rahmanian-Schwarz, Afshin; Jaminet, Patrick; Rothenberger, Jens

    2015-01-01

    Currently, the diagnosis of burn depth is primarily based on a visual assessment and can be dependent on the surgeons' experience. The goal of this study was to determine the ability of laser Doppler flowmeter combined with a tissue spectrophotometer to discriminate burn depth in a miniature swine burn model. Burn injuries of varying depth, including superficial-partial, deep-partial, and full thickness, were created in seven Göttingen minipigs using an aluminium bar (100 °C), which was applied to the abdominal skin for periods of 1, 3, 6, 12, 30, and 60 seconds with gravity alone. The depth of injury was evaluated histologically using hematoxylin and eosin staining. All burns were assessed 3 hours after injury using a device that combines a laser light and a white light to determine blood flow, hemoglobin oxygenation, and relative amount of hemoglobin. The blood flow (41 vs. 124 arbitrary units [AU]) and relative amount of hemoglobin (32 vs. 52 AU) were significantly lower in full thickness compared with superficial-partial thickness burns. However, no significant differences in hemoglobin oxygenation were observed between these depths of burns (61 vs. 60%). These results show the ability of laser Doppler flowmeter and tissue spectrophotometer in combination to discriminate between various depths of injury in the minipig model, suggesting that this device may offer a valuable tool for burn depth assessment influencing burn management. © 2014 by the Wound Healing Society.

  16. Coded excitation for ultrasound tissue harmonic imaging.

    Science.gov (United States)

    Song, Jaehee; Kim, Sangwon; Sohn, Hak-Yeol; Song, Tai-Kyong; Yoo, Yang Mo

    2010-05-01

    Coded excitation can improve the signal-to-noise ratio (SNR) in ultrasound tissue harmonic imaging (THI). However, it could suffer from the increased sidelobe artifact caused by incomplete pulse compression due to the spectral overlap between the fundamental and harmonic components of ultrasound signal after nonlinear propagation in tissues. In this paper, three coded tissue harmonic imaging (CTHI) techniques based on bandpass filtering, power modulation and pulse inversion (i.e., CTHI-BF, CTHI-PM, and CTHI-PI) were evaluated by measuring the peak range sidelobe level (PRSL) with varying frequency bandwidths. From simulation and in vitro studies, the CTHI-PI outperforms the CTHI-BF and CTHI-PM methods in terms of the PRSL, e.g., -43.5dB vs. -24.8dB and -23.0dB, respectively. Copyright 2010 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2017-04-01

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

  18. 多普勒组织成像结合心肌声学造影评估无复流时心脏收缩和舒张功能的变化%Evaluation of cardiac contractility and relaxation during no-reflow phenomenon by the combination of Doppler tissue imaging with myocardial contrast echocardiography

    Institute of Scientific and Technical Information of China (English)

    焦阳; 陈立新; 陶红; 朱向明

    2008-01-01

    AIM: To evaluate the cardiac contractility and relaxation by Doppler tissue imaging (DTI) combined with myocardial contrast echocardiography (MCE) via injection of contrast media, Albunex. METHODS: Nineteen healthy mongrel dogs were conducted 60 min ligation of left anterior descending coronary artery (LAD), followed by reperfusion of 60, 120 and 180 min to establish an acute myocardial ischemic-reperfused canine model. (1) MCE was performed by bolus injection of Albunex at pre-reperfusion and at post-reperfusion. The perfused defect area defined by MCE at pre-reperfusion was regarded as risk area (RAMCE), while perfused defect area at post-reperfusion was regarded as no-reflow area (NRAMCE). When the ratio of NRAMCE to RAMCE exceeded 25%, myocardial reperfusion was considered incomplete, I.e., no-reflow group; If the ratio was <25%, myocardial reperfusion was considered adequate, I.e., reflow group. (2) Left ventricular ejection fraction (LVEF) and wall thickness ratio (△T%) of LV anterior wall were determined. (3)S-wave, e-wave and a-wave velocities at the LV anterior wall were determined by DTI. The e/a ratio was measured. RESULTS: The results of MCE showed 7 dogs in reflow group and 10 dogs in no-reflow group. (1) LVEF in reflow group gradually increased with time course after myocardial reperfusion, and in no-reflow group, however, LVEF increasingly declined with ongoing myocardial reperfusion. At the same reperfusion time point, LVEF of no-reflow group was significantly lower than that of reflow group. (2) △T% in reflow group improved gradually, and however, it can not come back to that of baseline at 180-min reperfusion. △T% in no-reflow group had no signal of recovery with progressive reperfusion. (3) S-wave, e-wave velocities measured by DTI significantly declined after ligation of LAD, and a-wave velocity increased, leading to decline of e/a. After myocardial reperfusion, s-wave, e-wave velocities and e/a in reflow group gradually increased at

  19. Synchronous assessment of mechanical charaterization of left and right myocardial band of interventricular septum by dual Doppler tissue imaging%双多普勒组织成像技术同步评价室间隔左右肌带运动特征

    Institute of Scientific and Technical Information of China (English)

    陈玲玲; 尹立雪

    2013-01-01

    Objective To reveal the potential different longitudinal motion characteristics and differences of left and right muscular band (L-MB,R-MB)of interventricular septum (IVS) during systole and diastole in normal subjects.Methods Dual Doppler tissue imaging was applied for the longitudinal velocity curves of L-MB and R-MB of anterior and posterior interventricular septum(P-IVS,A-IVS) at basal,mid,and apical levels in eighty-two healthy subjects.Peak isovolumetric contraction (VIVC),systolic (Vs),early(Ve) and late (Va) diastolic velocities were measured,and myocardial velocity gradient(MVG)and Ve/Va ratio of each segment of L-MB and R-MB were calculated.Results ①Peak velocity of MB:the VrvC,Vs,Ve and Va of R-MB of both A-IVS and P-IVS were higher than those of L-MB; the VrvC,Vs,Ve and Va were gradually decreased from the base to apex of both A-IVS and P-IVS;the VIVC and Vs of A-IVS were higher than those of P-IVS; the Ve and Va of A-IVS were lower than those of P-IVS.②Correlation and MVG analyses of peak velocity of MB:the systolic and diastolic velocities between L-MB and R-MB of both A-IVS and P-IVS have shown a very strong positive correlation;the isovolumetric systolic MVG1 of L-MBof A-IVS,systolic MVG1 of R-MB of P-IVS and the diastolic MVG1 of both A-IVS and P-IVS were higher than those of MVG2.Conclusions The heterogeneity of longitudinal peak systolic and diastolic velocity and regional myocardial compliance,the consistency of moving direction and positive correlation of longitudinal peak systolic and diastolic velocity between L-MB and R-MB of both A-IVS and P-IVS have been demonstrated in normal subjects.%目的 评价正常成年人室间隔(IVS)左、右侧肌带纵向收缩舒张运动特征及其差异.方法 应用双多普勒组织成像技术获得正常成人前后室间隔左右侧肌带基底段、中间段和心尖段的心肌纵向运动曲线,测量等容收缩期峰值速度(Vwc)、射血期峰值速度(Vs)、舒张早期

  20. SNR enhancement for composite application using multiple Doppler vibrometers based laser ultrasonic propagation imager

    Science.gov (United States)

    Truong, Thanh Chung; Lee, Jung Ryul

    2016-09-01

    In recent years, the technology of using laser ultrasonic propagation imaging for damage visualization of composite structures were applied to real-world applications. Among many choices of sensor for the Ultrasonic Propagation Imager, the laser interferometry has several advantages: it is non-invasive, and portable, and with extraordinarily long-range measurement. However, the critical issue with interferometry sensing is its low signal-to-noise ratio (SNR), where the background noise can mask the damage-induced waves and making it impossible to identify the damages, especially in composite structures. In this paper, we propose a hardware-based SNR enhancement technique using multiple Laser Doppler Vibrometers (LDVs). The out-of-plane mode of ultrasonic signals are measured by multiple LDVs at a common sensing point and then averaged in real time. We showed that the SNR enhancement in experiments was consistent with the theoretical prediction, and also the test results showed a clear improvement for damage visualization of structures using Ultrasonic Wave Propagation Imaging and Ultrasonic Wavenumber Imaging algorithms.

  1. Zeeman-Doppler Imaging of II Peg - The magnetic field restructuring from 2004 to 2007

    CERN Document Server

    Carroll, T A; Strassmeier, K G; Ilyin, I; Tuominen, I

    2009-01-01

    We present Zeeman-Doppler images of the active K2 star II Peg for the years 2004 and 2007. The surface magnetic field was reconstructed with our new ZDI code "iMap" which provides a full polarized radiative transfer driven inversion to simultaneously reconstruct the surface temperature and magnetic vector field distribution. II Peg shows a remarkable large scale magnetic field structure for both years. The magnetic field is predominantly located at high latitudes and is arranged in active longitudes. A dramatic evolution in the magnetic field structure is visible for the two years, where a dominant and largely unipolar field in 2004 has developed into two distinct and large scale bipolar structures in 2007.

  2. Improved Helioseismic Analysis of Medium-l Data from the Michelson Doppler Imager

    CERN Document Server

    Larson, Tim

    2015-01-01

    We present a comprehensive study of one method for measuring various parameters of global modes of oscillation of the Sun. Using velocity data taken by the Michelson Doppler Imager (MDI), we analyze spherical harmonic degrees l <= 300. Both current and historical methodologies are explained, and the various differences between the two are investigated to determine their effects on global-mode parameters and systematic errors in the analysis. These differences include a number of geometric corrections made during spherical harmonic decomposition; updated routines for generating window functions, detrending timeseries, and filling gaps; and consideration of physical effects such as mode profile asymmetry, horizontal displacement at the solar surface, and distortion of eigenfunctions by differential rotation. We apply these changes one by one to three years of data, and then reanalyze the entire MDI mission applying all of them, using both the original 72-day long timeseries and 360-day long timeseries. We fi...

  3. First Zeeman Doppler imaging of a cool star using all four Stokes parameters

    CERN Document Server

    Rosén, Lisa; Wade, Gregg A

    2015-01-01

    Magnetic fields are ubiquitous in active cool stars but they are in general complex and weak. Current Zeeman Doppler imaging (ZDI) studies of cool star magnetic fields chiefly employ circular polarization observations because linear polarization is difficult to detect and requires a more sophisticated radiative transfer modeling to interpret. But it has been shown in previous theoretical studies, and in the observational analyses of magnetic Ap stars, that including linear polarization in the magnetic inversion process makes it possible to correctly recover many otherwise lost or misinterpreted magnetic features. We have obtained phase-resolved observations in all four Stokes parameters of the RS CVn star II Peg at two separate epochs. Here we present temperature and magnetic field maps reconstructed for this star using all four Stokes parameters. This is the very first such ZDI study of a cool active star. Our magnetic inversions reveal a highly structured magnetic field topology for both epochs. The strengt...

  4. Semiquantitative Evaluation of Extrasynovial Soft Tissue Inflammation in the Shoulders of Patients with Polymyalgia Rheumatica and Elderly-Onset Rheumatoid Arthritis by Power Doppler Ultrasound

    Science.gov (United States)

    Yoshida, Ryochi; Okamoto, Akiko; Seri, Yu

    2017-01-01

    Objectives. To develop a scoring system for evaluating the extrasynovial soft tissue inflammation of the shoulders in patients with polymyalgia rheumatica (PMR) and elderly-onset rheumatoid arthritis with PMR-like onset (pm-EORA) using ultrasound. Methods. We analyzed stored power Doppler (PD) images obtained by the pretreatment examination of 15 PMR patients and 15 pm-EORA patients. A semiquantitative scoring system for evaluating the severity of PD signals adjacent to the anterior aspect of the subscapularis tendon was designed. Results. A four-point scale scoring for the hyperemia on the subscapularis tendon was proposed as follows in brief: 0 = absent or minimal flow, 1 = single vessel dots or short linear-shape signals, 2 = long linear-shape signals or short zone-shape signals, or 3 = long zone-shape signals. This scoring system showed good intra- and interobserver reliability and good correlation to quantitative pixel-counting evaluation. By using it, we demonstrated that inflammation in PMR is dominantly localized in extrasynovial soft tissue as compared with pm-EORA. Conclusions. We proposed a reliable semiquantitative scoring system using ultrasound for the evaluation of extrasynovial soft tissue inflammation of the shoulders in patients with both PMR and pm-EORA. This system is simple to use and can be utilized in future investigations. PMID:28293635

  5. Cost-effectiveness of laser Doppler imaging in burn care in the Netherlands

    Directory of Open Access Journals (Sweden)

    Hop M Jenda

    2013-02-01

    Full Text Available Abstract Background Early accurate assessment of burn depth is important to determine the optimal treatment of burns. The method most used to determine burn depth is clinical assessment, which is the least expensive, but not the most accurate. Laser Doppler imaging (LDI is a technique with which a more accurate (>95% estimate of burn depth can be made by measuring the dermal perfusion. The actual effect on therapeutic decisions, clinical outcomes and the costs of the introduction of this device, however, are unknown. Before we decide to implement LDI in Dutch burn care, a study on the effectiveness and cost-effectiveness of LDI is necessary. Methods/design A multicenter randomised controlled trial will be conducted in the Dutch burn centres: Beverwijk, Groningen and Rotterdam. All patients treated as outpatient or admitted to a burn centre within 5 days post burn, with burns of indeterminate depth (burns not obviously superficial or full thickness and a total body surface area burned of ≤ 20% are eligible. A total of 200 patients will be included. Burn depth will be diagnosed by both clinical assessment and laser Doppler imaging between 2–5 days post burn in all patients. Subsequently, patients are randomly divided in two groups: ‘new diagnostic strategy’ versus ‘current diagnostic strategy’. The results of the LDI-scan will only be provided to the treating clinician in the ‘new diagnostic strategy’ group. The main endpoint is the effect of LDI on wound healing time. In addition we measure: a the effect of LDI on other patient outcomes (quality of life, scar quality, b the effect of LDI on diagnostic and therapeutic decisions, and c the effect of LDI on total (medical and non-medical costs and cost-effectiveness. Discussion This trial will contribute to our current knowledge on the use of LDI in burn care and will provide evidence on its cost-effectiveness. Trial registration NCT01489540

  6. Doppler Tomography

    CERN Document Server

    Marsh, T R

    2000-01-01

    I review the method of Doppler tomography which translates binary-star line profiles taken at a series of orbital phases into a distribution of emission over the binary. I begin with a discussion of the basic principles behind Doppler tomography, including a comparison of the relative merits of maximum entropy regularisation versus filtered back-projection for implementing the inversion. Following this I discuss the issue of noise in Doppler images and possible methods for coping with it. Then I move on to look at the results of Doppler Tomography applied to cataclysmic variable stars. Outstanding successes to date are the discovery of two-arm spiral shocks in cataclysmic variable accretion discs and the probing of the stream/magnetospheric interaction in magnetic cataclysmic variable stars. Doppler tomography has also told us much about the stream/disc interaction in non-magnetic systems and the irradiation of the secondary star in all systems. The latter indirectly reveals such effects as shadowing by the a...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-10-04

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

  8. Investigating the effect of a targets time-varying doppler generating axis of rotation on isar image distortion

    CSIR Research Space (South Africa)

    Abdul Gaffar, MY

    2007-10-01

    Full Text Available in ISAR imaging mostly under the limited assumption that a targets axis of rotation is constant over the CPI. This paper investigates how the targets time-varying Doppler generating axis of rotation, caused by the complex 3D motion of a target at sea...

  9. Perfusion of burn wounds assessed by Laser Doppler Imaging is related to burn depth and healing time

    NARCIS (Netherlands)

    Kloppenberg, FWH; Beerthuizen, GIJM; ten Duis, HJ

    Average perfusion in various burn wounds was assessed using Laser Doppler Imaging (LDI). The time necessary for a complete healing of the wound was compared to the results of the LDI measurements. A certain depth of burn was associated with a typical pattern of perfusion in the course of time. There

  10. Perfusion of burn wounds assessed by Laser Doppler Imaging is related to burn depth and healing time

    NARCIS (Netherlands)

    Kloppenberg, FWH; Beerthuizen, GIJM; ten Duis, HJ

    2001-01-01

    Average perfusion in various burn wounds was assessed using Laser Doppler Imaging (LDI). The time necessary for a complete healing of the wound was compared to the results of the LDI measurements. A certain depth of burn was associated with a typical pattern of perfusion in the course of time. There

  11. Ecocardiografia por Doppler tecidual no diagnóstico de rejeição após transplante cardíaco Ecocardiografía con Doppler tisular en el diagnóstico de rechazo después de transplante cardíaco Tissue doppler echocardiography in the diagnosis of heart transplantation rejection

    Directory of Open Access Journals (Sweden)

    Marcos Valério Coimbra Resende

    2011-07-01

    ,3%, especificidad de 73,8% (p = 0,001. En el análisis multivariado, la a'LAT (p = 0,001, a'SEP (p = 0,002, relación e'/a' LAT (p = 0,006, relación e'Mitral/e'LAT (p = 0,014, SINF (p = 0,009 fueron predictores de RC > 3A. Obtuvimos un escore con sensibilidad de 88,2%, precisión de 79,6%, y valor predictivo negativo de 92.9% para diagnosticar RC > 3A . El Doppler convencional (flujo mitral y pulmonar venoso no fue relevante para predecir la RC > 3A. CONCLUSIÓN: El estudio de IDT agregó información diagnóstica para predecir RC > 3A cuando fue comparado al Doppler convencional. El modelo basado en IDT puede volverse un método en potencial para detectar RC > 3A después de TC.BACKGROUND: Endomyocardial biopsy (EMB is the gold standard method for the diagnosis of cellular rejection (CR after heart transplantation (HT. OBJECTIVE: To test the hypothesis that tissue Doppler imaging (TDI could detect CR > 3A and add diagnostic information compared to conventional Doppler. METHODS: Fifty-four HT patients underwent 129 EMB and a TDI echocardiographic study within 24 hours. We compared HT patients with CR > 3A versus HT patients with CR 3A in 39/129 (30.2% EMB. The best isolated predictor for CR diagnosis was a'LAT, with a sensitivity of 76.3%, specificity of 73.8% (p = 0.001. In the multivariate analysis, a'LAT (p = 0.001, a'SEP (p = 0.002, e'/a' LAT ratio (p = 0.006, e'Mitral/ e'LAT ratio (p = 0.014, SINF (p = 0.009 predicted CR > 3A. We obtained a score with a sensitivity of 88.2%, accuracy of 79.6% and negative predictive value of 92.9% to diagnose CR > 3A. Conventional Doppler (mitral and pulmonary venous flow was not relevant to predict CR > 3A. CONCLUSION: TDI added diagnostic information to predict CR > 3A compared to conventional Doppler. A TDI-based model could become a potential method to detect CR > 3A after Heart Transplantation.

  12. Application of a new laser Doppler imaging system in planning and monitoring of surgical flaps

    Science.gov (United States)

    Schlosser, Stefan; Wirth, Raphael; Plock, Jan A.; Serov, Alexandre; Banic, Andrej; Erni, Dominique

    2010-05-01

    There is a demand for technologies able to assess the perfusion of surgical flaps quantitatively and reliably to avoid ischemic complications. The aim of this study is to test a new high-speed high-definition laser Doppler imaging (LDI) system (FluxEXPLORER, Microvascular Imaging, Lausanne, Switzerland) in terms of preoperative mapping of the vascular supply (perforator vessels) and postoperative flow monitoring. The FluxEXPLORER performs perfusion mapping of an area 9×9 cm with a resolution of 256×256 pixels within 6 s in high-definition imaging mode. The sensitivity and predictability to localize perforators is expressed by the coincidence of preoperatively assessed LDI high flow spots with intraoperatively verified perforators in nine patients. 18 free flaps are monitored before, during, and after total ischemia. 63% of all verified perforators correspond to a high flow spot, and 38% of all high flow spots correspond to a verified perforator (positive predictive value). All perfused flaps reveal a value of above 221 perfusion units (PUs), and all values obtained in the ischemic flaps are beneath 187 PU. In summary, we conclude that the present LDI system can serve as a reliable, fast, and easy-to-handle tool to detect ischemia in free flaps, whereas perforator vessels cannot be detected appropriately.

  13. Motility Contrast Imaging and Tissue Dynamics Spectroscopy

    Science.gov (United States)

    Nolte, David D.; An, Ran; Turek, John

    Motion is the defining physiological characteristic of living matter. If we are interested in how things function, then the way they move is most informative. Motion provides an endogenous and functional suite of biomarkers that are sensitive to subtle changes that occur under applied pharmacological doses or cellular stresses. This chapter reviews the application of biodynamic imaging to measure cellular dynamics in three-dimensional tissue culture for drug screening applications. Nanoscale and microscale motions are detected through statistical fluctuations in dynamic speckle across an ensemble of cells within each resolution voxel. Tissue dynamics spectroscopy generates drug-response spectrograms that serve as phenotypic fingerprints of drug action and can differentiate responses from heterogeneous regions of tumor tissue.

  14. Imaging carious dental tissues with multiphoton fluorescence lifetime imaging microscopy

    Science.gov (United States)

    Lin, Po-Yen; Lyu, Hong-Chou; Hsu, Chin-Ying Stephen; Chang, Chia-Seng; Kao, Fu-Jen

    2011-01-01

    In this study, multiphoton excitation was utilized to image normal and carious dental tissues noninvasively. Unique structures in dental tissues were identified using the available multimodality (second harmonic, autofluorescence, and fluorescence lifetime analysis) without labeling. The collagen in dentin exhibits a strong second harmonic response. Both dentin and enamel emit strong autofluorescence that reveals in detail morphological features (such as dentinal tubules and enamel rods) and, despite their very similar spectral profiles, can be differentiated by lifetime analysis. Specifically, the carious dental tissue exhibits a greatly reduced autofluorescence lifetime, which result is consistent with the degree of demineralization, determined by micro-computed tomography. Our findings suggest that two-photon excited fluorescence lifetime imaging may be a promising tool for diagnosing and monitoring dental caries. PMID:21326645

  15. Monitoring of renal hemodynamics during acute hemorrhagic shock with Doppler ultrasonic imaging: an experimental study

    Directory of Open Access Journals (Sweden)

    Rui-hong LIU

    2015-07-01

    Full Text Available Objective To evaluate the value of color Doppler flow imaging (CDFI and pulsed-wave Doppler (PWD in monitoring renal hemodynamics in rabbits with acute hemorrhagic shock. Methods The experimental model of acute hemorrhagic shock was reproduced in 16 normal New Zealand white rabbits by controlled exsanguination which was divided into 4 different grades: normal (100% MAP, mild (70% MAP, moderate (50% MAP, and severe (40% MAP. The right kidney of the experimental animal was examined by gray-scale ultrasound (2DUS, CDFI and PWD. The structure of the right kidney was observed with 2DUS. CDFI was used to monitor the change in right renal hemodynamics along with the progression of shock. The hemodynamic parameters of main renal artery (MRA, segmental renal artery (SRA and interlobar renal artery (IRA were measured by PWD, including the peak systolic velocity (Vmax, minimum diastolic velocity (Vmin and resistive index (RI. Results The animal model of hemorrhagic shock was successfully reproduced in 16 healthy New Zealand rabbits, of which 14 rabbits survived at the end of the experiment, and 2 died of severe shock. The mean arterial pressure (MAP declined, while the respiratory rate and heart rate increased as the circulation changed from normal to severe shock (P<0.05. Observation of the right renal structure by 2DUS revealed no obvious changes after bleeding in different degrees. CDFI showed a gradually reduced distribution of blood flow in renal hemodynamics along with the progression of hemorrhagic shock. Vmax and Vmin declined gradually, while RI intensity increased as the hemorrhagic shock progressed from minor to severe. There was statistically significant difference in RI intensity between different grades of shock (P<005. Conclusion CDFI and PWD can quantitatively assess the renal hemodynamics during acute hemorrhagic shock, so it can be used as a noninvasive monitoring tool in the diagnosis and treatment of hemorrhagic shock. DOI: 10

  16. Adaptive nonlinear microscopy for whole tissue imaging

    Science.gov (United States)

    Müllenbroich, M. Caroline; McGhee, Ewan J.; Wright, Amanda J.; Anderson, Kurt I.; Mathieson, Keith

    2013-02-01

    Nonlinear microscopy is capable of imaging biological tissue non-invasively with sub-cellular resolution in three dimensions. For efficient multiphoton signal generation, it is necessary to focus high power, ultra-fast laser pulses into a volume of femtolitres. Aberrations introduced either by the system's optical setup or the sample under investigation cause a broadening of the diffraction limited focal spot which leads to loss of image intensity and resolution. Adaptive optics provides a means to compensate for these aberrations and is capable of restoring resolution and signal strength when imaging at depth. We describe the use of a micro-electro-mechanical systems (MEMS) deformable membrane mirror in a multiphoton adaptive microscope. The aberration correction is determined in a wavefront sensorless approach by rapidly altering the mirror shape with a random search algorithm until the fluorescence or second harmonic signal intensity is improved. We demonstrate the benefits of wavefront correction in a wide-variety of samples, including urea crystals, convallaria and organotypic tissue cultures. We show how the optimization algorithm can be adjusted, for example by including a bleaching compensation, to allow the user to switch between different imaging modalities, producing a versatile approach to aberration correction.

  17. Doppler Tissue Evaluation of Atrial Conduction Properties in Patients With Non-alcoholic Fatty-liver Disease.

    Science.gov (United States)

    Ozveren, Olcay; Izgi, Cemil; Eroglu, Elif; Simsek, Mustafa Aytek; Turer, Ayca; Kucukdurmaz, Zekeriya; Cinar, Veysel; Degertekin, Muzaffer

    2016-05-01

    Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in clinical practice, and there is an increasing trend in its prevalence in the general population. Recent studies have demonstrated increased risk of atrial fibrillation (AF) in NAFLD. However, information on the mechanism of increased risk of AF in NAFLD is lacking. Impaired atrial conduction is an important factor in the pathophysiology of AF. We aimed to investigate atrial conduction properties in patients with NAFLD by tissue Doppler echocardiography. Fifty-nine ultrasound diagnosed NAFLD patients without clinical diagnosis of hypertension, diabetes mellitus, or cardiac disease and 22 normal subjects as controls were included in this study. Atrial conduction properties were assessed by electromechanical delay (EMD) derived from Doppler tissue echocardiography examination and P-wave dispersion (PWD) calculated from the 12-lead electrocardiogram. Inter-atrial and intra-atrial EMD intervals were significantly longer in NAFLD patients than in controls (inter-atrial EMD, 31.9 ± 8.5 ms vs. 23.4 ± 4.6 ms,p= 0.0001, and intra-atrial EMD, 14.3 ± 5.2 vs. 10.2 ± 4.0 ms,p= 0.001). Similarly, PWD was significantly higher in NAFLD patients compared with controls (49.2 ± 6.3 ms vs. 43.3 ± 4.2 ms,p= 0.0001). Maximum left atrial volume was also significantly higher in the NAFLD group than in controls (51 ± 11 mL vs. 34 ± 9 mL,pNAFLD. Also, in a patient population of NAFLD without any clinical diagnosis of cardiac disease, diabetes, or hypertension, left atrial volume was increased compared with controls. These findings suggest impaired atrial conduction as a factor in increased risk of AF in NAFLD.

  18. Inverse Problem for Color Doppler Ultrasound-Assisted Intracardiac Blood Flow Imaging

    Directory of Open Access Journals (Sweden)

    Jaeseong Jang

    2016-01-01

    Full Text Available For the assessment of the left ventricle (LV, echocardiography has been widely used to visualize and quantify geometrical variations of LV. However, echocardiographic image itself is not sufficient to describe a swirling pattern which is a characteristic blood flow pattern inside LV without any treatment on the image. We propose a mathematical framework based on an inverse problem for three-dimensional (3D LV blood flow reconstruction. The reconstruction model combines the incompressible Navier-Stokes equations with one-direction velocity component of the synthetic flow data (or color Doppler data from the forward simulation (or measurement. Moreover, time-varying LV boundaries are extracted from the intensity data to determine boundary conditions of the reconstruction model. Forward simulations of intracardiac blood flow are performed using a fluid-structure interaction model in order to obtain synthetic flow data. The proposed model significantly reduces the local and global errors of the reconstructed flow fields. We demonstrate the feasibility and potential usefulness of the proposed reconstruction model in predicting dynamic swirling patterns inside the LV over a cardiac cycle.

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

    Science.gov (United States)

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

    2014-05-01

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

  20. [Meta-analysis on the diagnostic value of laser Doppler imaging for burn depth].

    Science.gov (United States)

    Huang, Y; Qiu, L; Mei, A L; Li, J X

    2017-05-20

    Objective: To evaluate the value of laser Doppler imaging (LDI) in diagnosing deep or superficial partial-thickness burn wound with meta-analysis. Methods: Databases including PubMed, Cochrane Library were searched using key words " burn, burns, burn depth, laser Doppler imaging, laser Doppler perfusion imaging, LDI, LDPI" , and Chinese Journals Full-text Database, Wanfang Database, VIP Database were searched using Chinese key words ",,,," to obtain the published trials of LDI in diagnosing deep or superficial partial-thickness burn wound from the establishment of each database to October 2015. The risk of bias and applicability concerns of the included studies were evaluated by Quality Assessment of Diagnostic Accuracy Studies-2. Data were processed with Meta-DiSc 1.4 statistical software. The heterogeneity among the included studies was evaluated. The pooled estimates of LDI in diagnosing deep or superficial partial-thickness burn wound in the included studies, including sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, as well as the area under the curve of summary receiver operating characteristic and index of Q(*) were calculated. The stability of results of the overall pooled estimates of the included studies was validated by sensitivity analysis. The sources of heterogeneity among the included studies were sought through subgroup analysis. The publication bias caused by the results of the included studies was evaluated by drawing the Deek's funnel plot. Results: A total of 5 articles conforming to the inclusion criteria, involving 138 patients and 179 burn wounds, were included. One of the included studies had low risk of bias, while the other 4 studies had high/unclear risk of bias. In applicability concern aspect, one of the included studies had high/unclear concerns regarding applicability, while the other 4 studies had low concerns regarding applicability. There was no heterogeneity caused by threshold

  1. Quantification of colour Doppler activity in the wrist in patients with rheumatoid arthritis - the reliability of different methods for image selection and evaluation

    DEFF Research Database (Denmark)

    Ellegaard, K.; Torp-Pedersen, S.; Lund, H.;

    2008-01-01

    Purpose: The amount Of colour Doppler activity in the inflamed synovium is used to quantity inflammatory activity. The measurements may vary due to image selection, quantification method, and point in cardiac cycle. This study investigated the test-retest reliability Of ultrasound colour Doppler ...

  2. Multispectral imaging of acute wound tissue oxygenation

    Directory of Open Access Journals (Sweden)

    Audrey Huong

    2017-05-01

    Full Text Available This paper investigates the appropriate range of values for the transcutaneous blood oxygen saturation (StO2 of granulating tissues and the surrounding tissue that can ensure timely wound recovery. This work has used a multispectral imaging system to collect wound images at wavelengths ranging between 520nm and 600nm with a resolution of 10nm. As part of this research, a pilot study was conducted on three injured individuals with superficial wounds of different wound ages at different skin locations. The StO2 value predicted for the examined wounds using the Extended Modified Lambert–Beer model revealed a mean StO2 of 61±10.3% compared to 41.6±6.2% at the surrounding tissues, and 50.1±1.53% for control sites. These preliminary results contribute to the existing knowledge on the possible range and variation of wound bed StO2 that are to be used as indicators of the functioning of the vasomotion system and wound health. This study has concluded that a high StO2 of approximately 60% and a large fluctuation in this value should precede a good progression in wound healing.

  3. SU-E-J-31: Biodynamic Imaging of Cancer Tissue and Response to Chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Nolte, D; Turek, J; Childress, M; An, R; Merrill, D [Purdue University, West Lafayette, IN (United States); Matei, D [Indiana University School of Medicine, Indianapolis, IN (United States)

    2014-06-01

    Purpose: To measure intracellular motions inside three-dimensional living cancer tissue samples to establish a novel set of biodynamic biomarkers that assess tissue proliferative activity and sensitivity or resistance to chemotherapy. Methods: Biodynamic imaging (BDI) uses digital holography with low-coherence low-intensity light illumination to construct 3D holograms from depths up to a millimeter deep inside cancer tissue models that include multicellular tumor spheroids and ex vivo cancer biopsies from canine non-Hodgkins lymphoma and epithelial ovarian cancer (EOC) mouse explants. Intracellular motions modulate the holographic intensity with frequencies related to the Doppler effect caused by the motions of a wide variety of intracellular components. These motions are affected by applied therapeutic agents, and BDI produces unique fingerprints of the action of specific drugs on the motions in specific cell types. In this study, chemotherapeutic agents (doxorubicin for canine lymphoma and oxoplatin for ovarian) are applied to the living tissue models and monitored over 10 hours by BDI. Results: Multicellular spheroids and patient biopsies are categorized as either sensitive or insensitive to applied therapeutics depending on the intracellular Doppler signatures of chemotherapy response. For both lymphoma and EOC there is strong specificity to the two types of sensitivities, with sensitive cell lines and biopsies exhibiting a global cessation of proliferation and strong suppression of metabolic activity, while insensitive cell lines and biopsies show moderate activation of Doppler frequencies associated with membrane processes and possible membrane trafficking. Conclusion: This work supports the hypothesis that biodynamic biomarkers from three-dimensional living tumor tissue, that includes tissue heterogeneity and measured within 24 hours of surgery, is predictive of near-term patient response to therapy. Future work will correlate biodynamic biomarkers with

  4. Comparison between /sup 133/Xenon washout technique and Laser Doppler flowmetry in the measurement of local vasoconstrictor effects on the microcirculation in subcutaneous tissue and skin

    Energy Technology Data Exchange (ETDEWEB)

    Kastrup, J.; Buelow, J.; Lassen, N.A.

    1987-10-01

    Changes in skin blood flow measured by Laser Doppler flowmetry and changes in subcutaneous blood flow measured by /sup 133/Xenon washout technique were compared during activation of the local sympathetic mediated veno-arteriolar vaso-constrictor reflex by lowering the area of investigation below heart level. The measurements were performed in tissue with and without sympathetic innervation. In five subjects, who all had been cervically sympathectomized for manual hyperhidrosis, the Laser Doppler and /sup 133/Xenon blood flow measurements were performed simultaneously on the sympathetically denervated forearm, and on the calf with preserved sympathetic nerve supply. The Laser Doppler method registered a 23% reduction in skin blood flow during lowering of the extremities independently of the sympathetic nerve supply to the skin. The /sup 133/Xenon method recorded a 44% decrease in blood flow in innervated and unchanged blood flow in denervated subcutaneous tissue during lowering of the extremities. Our results indicate that the Laser Doppler method and /sup 133/Xenon method are not comparable, and that the Laser Doppler method is not useful in measuring local sympathetic mediated blood flow changes.

  5. Validation of Doppler ultrasound and magnetic resonance imaging velocity measurements by means of a test object

    NARCIS (Netherlands)

    Oostayen, J.A. van; Bezemer, R.A.; Wasser, M.N.J.M.; Teirlinck, C.J.P.M.

    1996-01-01

    Objective: To validate Doppler ultrasound and MRI mean velocity measurements in a test object in which mean velocities are known and can be chosen within a range of 10-100 cm/s in tubes of 4 and 8 mm. This validation was carried out to check the performance of a duplex Doppler ultrasound system that

  6. Comparison of conventional B-scan, tissue harmonic imaging, compound imaging and tissue harmonic compound imaging in neck lesion characterisation.

    Science.gov (United States)

    Bozzato, Alessandro; Loika, Anne; Hornung, Joachim; Koch, Michael; Zenk, Johannes; Uter, Wolfgang; Iro, Heinrich

    2010-10-01

    In recent years, further technical developments of ultrasound scanning techniques, such as tissue harmonic imaging (THI) and compound imaging (CI), have become available and promise considerable improvement in image quality. No comparative assessments have yet been made of their systematic use in the head and neck. We studied 313 lesions of the head and neck detected on ultrasound scanning. Ultrasound images were obtained using a state-of-the-art scanning system. Two experts evaluated the images obtained for each lesion with conventional B-scan mode (BSCAN), THI, CI, and tissue harmonic compound imaging (THICI) with respect to four different aspects of image quality. Largely concordant results were found for each of the parameters studied: overall image quality, tissue contrast, lesion conspicuity, and internal structure. Evaluations of CI and THICI were frequently ranked higher (p Images obtained in BSCAN mode often had better scores than images in THI mode alone (p imaging methods improve image quality of the soft tissues of neck and may be included in the routine settings of ultrasound systems.

  7. A review of Doppler ultrasound quality assurance protocols and test devices.

    Science.gov (United States)

    Browne, Jacinta E

    2014-11-01

    In this paper, an overview of Doppler ultrasound quality assurance (QA) testing will be presented in three sections. The first section will review the different Doppler ultrasound parameters recommended by professional bodies for use in QA protocols. The second section will include an evaluation and critique of the main test devices used to assess Doppler performance, while the final section of this paper will discuss which of the wide range of test devices have been found to be most suitable for inclusion in Doppler QA programmes. Pulsed Wave Spectral Doppler, Colour Doppler Imaging QA test protocols have been recommended over the years by various professional bodies, including the UK's Institute of Physics and Engineering in Medicine (IPEM), the American Institute for Ultrasound in Medicine (AIUM), and the International Electrotechnical Commission (IEC). However, despite the existence of such recommended test protocols, very few commercial or research test devices exist which can measure the full range of both PW Doppler ultrasound and colour Doppler imaging performance parameters, particularly quality control measurements such as: (i) Doppler sensitivity (ii) colour Doppler spatial resolution (iii) colour Doppler temporal resolution (iv) colour Doppler velocity resolution (v) clutter filter performance and (vi) tissue movement artefact suppression. In this review, the merits of the various commercial and research test devices will be considered and a summary of results obtained from published studies which have made use of some of these Doppler test devices, such as the flow, string, rotating and belt phantom, will be presented.

  8. High-speed swept source optical coherence Doppler tomography for deep brain microvascular imaging

    Science.gov (United States)

    Chen, Wei; You, Jiang; Gu, Xiaochun; Du, Congwu; Pan, Yingtian

    2016-12-01

    Noninvasive microvascular imaging using optical coherence Doppler tomography (ODT) has shown great promise in brain studies; however, high-speed microcirculatory imaging in deep brain remains an open quest. A high-speed 1.3 μm swept-source ODT (SS-ODT) system is reported which was based on a 200 kHz vertical-cavity-surface-emitting laser. Phase errors induced by sweep-trigger desynchronization were effectively reduced by spectral phase encoding and instantaneous correlation among the A-scans. Phantom studies have revealed a significant reduction in phase noise, thus an enhancement of minimally detectable flow down to 268.2 μm/s. Further in vivo validation was performed, in which 3D cerebral-blood-flow (CBF) networks in mouse brain over a large field-of-view (FOV: 8.5 × 5 × 3.2 mm3) was scanned through thinned skull. Results showed that fast flows up to 3 cm/s in pial vessels and minute flows down to 0.3 mm/s in arterioles or venules were readily detectable at depths down to 3.2 mm. Moreover, the dynamic changes of the CBF networks elicited by acute cocaine such as heterogeneous responses in various vessel compartments and at different cortical layers as well as transient ischemic events were tracked, suggesting the potential of SS-ODT for brain functional imaging that requires high flow sensitivity and dynamic range, fast frame rate and a large FOV to cover different brain regions.

  9. 乳腺实性病灶组织多普勒超声弹性成像时间-应变曲线分析%Tissue Doppler and strain curve of tissue Doppler ultrasound elatography of breast solid lesions

    Institute of Scientific and Technical Information of China (English)

    刘卫勇; 隋秀芳; 李红苗; 赵志宏; 张琼; 周海红

    2012-01-01

    Objective To investigate the value of tissue Doppler ultrasound elastography (TDUE)in the diagnosis of breast solid lesions. Methods TDUE was used to examine 46 cases with 54 breast solid lesions(39 benign lesions and 15 malignant lesions). The pathological confirmations were performed after surgical resection. After a size of 1cm2 region of interest( ROI) was placed in the subcutaneous adipose tissue and target lesion ,the corresponding type of tissue Doppler and strain curve was achieved . Maximal absolute relaxed strain ( max-ARS) of adipose tissues , benign lesions and malignant lesions were also recorded . Results The elastography was performed 3 times for each solid lesion and adipose tissue adjacent to the lesion . Totally 162 curves of adipose tissues ,117 curves of benign lesions ,and 45 curves of malignant lesions in ROI were acquired with elastographic modality. Two categories of curve, positive wave and negative wave , were achieved. There were all positive waves and no negative waves in 162 curves of adipose tissues. Numbers of positive and negative waves in 117 curves of breast benign lesions were 108 and 9,respectively. Numbers of positive and negative waves in 45 curves of breast malignant lesions were 12 and 33, respectively. The categories of curves among the adipose tissues , benign lesions and malignant lesions had statistically significant difference ( corrected size of test, x2 = 172.37 ,P <0.0001). The difference was significant for the types of curves between adipose tissues and benign lesions ( Fisher exact test, P = 0. 0003 ) and between adipose tissues and malignant lesions ( Fisher exact test ,P <0.0001). The types of curves between malignant lesions and benign lesions were also considered statistically significant (x = 72. 92,P <0. 0001). The mean max-ARS of adipose tissues, benign and malignant lesions was (15. 57 ± 8. 91 ) % , ( 6. 78 ± 4. 48 ) % and (1.14 ±2.71)% ,respectively ,and the difference among them was significant (F

  10. Added value products for imaging remote sensing by processing actual GNSS reflectometry delay doppler maps

    Science.gov (United States)

    Schiavulli, Domenico; Frappart, Frédéric; Ramilien, Guillaume; Darrozes, José; Nunziata, Ferdinando; Migliaccio, Maurizio

    2016-04-01

    Global Navigation Satellite System Reflectometry (GNSS-R) is an innovative and promising tool for remote sensing. It is based on the exploitation of GNSS signals reflected off Earth's surface as signals of opportunity to infer geophysical information of the reflecting surface. The main advantages of GNSS-R with respect dedicated sensors are: the unprecedented spatial-temporal coverage due to the availability of a great amount of transmitting satellite, e.g. GPS, Galileo, Glonass, etc…, long term GNSS mission life and cost effectiveness. In fact only a simple receiver is needed. In the last years several works demonstrated the meaningful of this technique in several Earth Observation applications. All these applications presented results obtained by using a receiver mounted on an aircraft or on a fixed platform. Moreover, space borne missions have been launched or are planned: UK-DMC, TechDemoSat-1 (TDS-1), NASA CYGNSS, Geros ISS. Practically, GNSS-R can be seen as a bistatic radar system where the GNSS satellites continuously transmit the L-band all-weather night-and-day signals that are reflected off a surface, called Glistening Zone (GZ), and a receiver measures the scattered microwave signals in terms of Delay-Doppler maps (DDMs) or delay waveforms. These two products have been widely studied in the literature to extract compact parameters for different remote sensing applications. However, products measured in the Delay Doppler (DD) domain are not able to provide any spatial information of the scattering scene. This could represent a drawback for applications related to imaging remote sensing, e.g. target detection, sea/land and sea/ice transition, oil spill detection, etc…. To overcome these limitations some deconvolution techniques have been proposed in the state of the art aiming at the reconstruction of a radar image of the observed scene by processing the measured DDMs. These techniques have been tested on DDMs related to simulated marine scenario

  11. Laser Doppler Flare Imaging and Quantitative Thermal Thresholds Testing Performance in Small and Mixed Fiber Neuropathies

    Science.gov (United States)

    Alabdali, Majed; Alsulaiman, Abdulla; Breiner, Ari; Barnett, Carolina; Katzberg, Hans D.; Lovblom, Leif E.; Perkins, Bruce A.; Bril, Vera

    2016-01-01

    Introduction Small fiber neuropathy might be a part of typical mixed small and large fiber neuropathy, or a distinct entity, affecting exclusively small nerve fibers. Objectives Explore the utility of small nerve fiber testing in patients with clinical presentation suggesting small fiber neuropathy, with and without evidence for concomitant large fiber neuropathy. Methods Patients attending the neuromuscular clinic from 2012 to 2015 with a clinical presentation suggesting small nerve fiber impairment, who had Laser Doppler flare imaging (LDIFlare) and quantitative thermal testing (QTT) were evaluated for this study. Patients with clinical or electrophysiological evidence for concomitant large fiber neuropathy were not excluded. Results The sensitivities of LDIFlare, cooling and heat threshold testing were 64%, 36%, and 0% respectively for clinically highly suggestive small fiber neuropathy, 64%, 56%, and 19% respectively for mixed fiber neuropathy, and 86%, 79%, and 29% respectively for diabetic mixed fiber neuropathy. Discussion LDIFlare and cooling thresholds testing are non-invasive small nerve fiber testing modalities, with moderate performance in patients with small and mixed fiber neuropathy, and excellent performance in diabetic mixed fiber neuropathy. PMID:27824912

  12. Feasibility of creating a normative database of colour Doppler imaging parameters in glaucomatous eyes and controls.

    Science.gov (United States)

    Rusia, Deepam; Harris, Alon; Pernic, Allison; Williamson, Kathleen M; Moss, Adam M; Shoshani, Yochai Z; Siesky, Brent

    2011-09-01

    Colour Doppler imaging (CDI) is a frequently cited methodology for quantifying ocular blood flow velocities. This investigation reviews the feasibility of creating a normative database of CDI parameters in glaucoma patients and controls. A literature search was conducted for CDI studies involving glaucomatous eyes. Using data from these studies, a weighted mean was derived for the peak systolic velocity, end diastolic velocity and Pourcelot's resistive index in the ophthalmic, central retinal and posterior ciliary arteries. A multivariate analysis was performed to identify whether methodological characteristics contributed to the inter-study variance in CDI values. Data from 3061 glaucoma patients and 1072 controls were included. The mean values for glaucomatous eyes were within one standard deviation of the values for controls for most CDI parameters. Gender mix (p=0.043), intraocular pressure status (p=0.017), frequency of the ultrasound transducer (p=0.02) and whether the patients were on antihypertensive therapy (p=0.004) contributed to the variance. Methodological differences create inter-study variance in CDI values, complicating the construction of a normative database and limiting its utility. Because the mean values for glaucomatous and normal eyes have overlapping ranges, caution should be used when classifying glaucoma status based on a single CDI measurement.

  13. Time-series Doppler imaging of the red giant HD 208472. Active longitudes and differential rotation

    CERN Document Server

    Özdarcan, O; Künstler, A; Strassmeier, K G; Evren, S; Weber, M; Granzer, T

    2016-01-01

    HD 208472 is among the most active RS~CVn binaries with cool starspots. Decade-long photometry has shown that the spots seem to change their longitudinal appearance with a period of about six years, coherent with brightness variations. Our aim is to spatially resolve the stellar surface of HD 208472 and relate the photometric results to the true longitudinal and latitudinal spot appearance. Furthermore, we investigate the surface differential rotation pattern of the star. We employed three years of high-resolution spectroscopic data with a high signal-to-noise ratio (S/N) from the STELLA robotic observatory and determined new and more precise stellar physical parameters. Precalculated synthetic spectra were fit to each of these spectra, and we provide new spot-corrected orbital elements. A sample of 34 absorption lines per spectrum was used to calculate mean line profiles with a S/N of several hundred. A total of 13 temperature Doppler images were reconstructed from these line profiles with the inversion code...

  14. Diagnostic accuracy of laser Doppler imaging in burn depth assessment: Systematic review and meta-analysis.

    Science.gov (United States)

    Shin, Jin Yong; Yi, Hyung Suk

    2016-11-01

    Accurate assessment of burn depth is important for determination of treatment modality. Laser Doppler imaging (LDI) is known to be an objective and effective measurement tool in burn depth assessment. Our study evaluated the diagnostic accuracy of LDI across enrolled studies and subgroups. A systematic literature review and meta-analysis were performed using MEDLINE, EMBASE, and Cochrane databases. Data from LDI cases were extracted from all primary studies and categorized into four cell values (true positives, false positives, true negatives, and false negatives). Subgroup analyses were performed according to perfusion units of LDI, clinical criteria of superficial and deep burns during the treatment period, and publication date of enrolled studies. The search strategy identified 321 publications. After screening, 10 articles were selected for review. The pooled sensitivity and specificity of LDI in all enrolled studies and subgroups were found to be similarly high. However, the sensitivity of LDI in our meta-analysis was not as high as that identified in previous studies. Although LDI in burn depth assessment was identified as an accurate measurement tool in this meta-analysis, careful clinical assessment should be performed along with LDI in patients with deep burns. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  15. Role of color Doppler flow imaging in applicable anatomy of spleen vessels

    Institute of Scientific and Technical Information of China (English)

    Wei-Li Xu; Suo-Lin Li; Yan Wang; Meng Li; Ai-Guo Niu

    2009-01-01

    AIM: To explore the role of color Doppler flow imaging (CDFI) in visualization of spleen vessels and to define its value for spleen micro-invasive operation. METHODS: A total of 36 patients requiring laparoscopic splenectomy (LS) for various hematopathies and autoimmune diseases were randomly selected from April 2005 to May 2008. Anatomic types of spleen pedicle, adjacent relations between spleen vessels and pancreas, diameters of spleen artery and vein were detected and recorded by preoperative CDFI. Different operative procedures were performed according to different anatomic frameworks. The parameters were recorded by telerecording during LS and compared with those by preoperative CDFI using Chi-square test. RESULTS: Two anatomic types of spleen pedicle and four different adjacent relations between spleen vessels and pancreas were detected by CDFI. The diameters of spleen artery and vein detected by CDFI were 0.46 ± 0.09 cm and 0.85 ± 0.35 cm, respectively. There was no statistical difference between the parameters recorded by CDFI and by telerecording (χ2 = 0.250, 0.677, P > 0.05). LS was successfully performed following the anatomic information provided by preoperative CDFI.CONCLUSION: Different anatomic frameworks of spleen vessels can be provided by preoperative CDFI,which instructs micro-invasive operation of spleen and increase the safety of operation.

  16. Fourier-Doppler Imaging of Line Profile Variations in ζ Ophiuchi

    Science.gov (United States)

    Jankov, S.; Janot-Pacheco, E.; Leister, N. V.

    2000-09-01

    We present, for the first time, the Fourier-Doppler Imaging (FDI) analysis of periodic line profile variations in a ζ Oph-type star. For this purpose we obtained, in the period from 1996 May 3 to May 5, a total of 242 high-resolution, high signal-to-noise ratio spectra of the Be star ζ Oph itself. Using the FDI technique, we examine the variations in both time and wavelength and complement it with time series analysis. This kind of analysis is valid for both the nonradial pulsator model and the rotation modulation model, but we discuss the results in terms of the former model, considering it the more likely explanation for the observed line profile variability. Two distinct groups of modes are detected: medium (4high-degree modes (which could be associated with 13high-frequency oscillations were strongly confined to an equatorial belt narrower than 20° and that the line profile variability was caused predominantly by sectoral modes, although tesseral modes |m|=l-1 are not excluded in taking into account the effect of fast rotation. We discuss the modal nature of the waves with respect to the characteristic oscillation periods in the corotating frame and the high amplitude of the projected rotational velocity variations (~20 km s-1).

  17. An all-fiber image-reject homodyne coherent Doppler wind lidar.

    Science.gov (United States)

    Abari, Cyrus F; Pedersen, Anders T; Mann, Jakob

    2014-10-20

    In this paper, we present an alternative approach to the down-conversion (translation) of the received optical signals collected by the antenna of an all-fiber coherent Doppler lidar (CDL). The proposed method, widely known as image-reject, quadrature detection, or in-phase/quadrature-phase detection, utilizes the advances in fiber optic communications such that the received signal can be optically down-converted into baseband where not only the radial velocity but also the direction of the movement can be inferred. In addition, we show that by performing a cross-spectral analysis, enabled by the presence of two independent signal observations with uncorrelated noise, various noise sources can be suppressed and a more simplified velocity estimation algorithm can be employed in the spectral domain. Other benefits of this architecture include, but are not limited to, a more reliable measurement of radial velocities close to zero and an improved bandwidth. The claims are verified through laboratory implementation of a continuous wave CDL, where measurements both on a hard and diffuse target have been performed and analyzed.

  18. Role of Color Doppler Imaging in Early Diagnosis and Prediction of Progression in Glaucoma

    Directory of Open Access Journals (Sweden)

    Fatima Jimenez-Aragon

    2013-01-01

    Full Text Available This longitudinal and prospective study analyzes the ability of orbital blood flow measured by color Doppler imaging (CDI to predict glaucoma progression in patients with glaucoma risk factors. Patients with normal perimetry but having glaucoma risk factors and patients in the initial phase of glaucoma were prospectively included in the study and divided, after a five-year follow-up, into two groups: “Progression” and “No Progression” based on the changes in the Moorfields regression analysis (MRA classification of Heidelberg retina tomograph (HRT. An orbital CDI was performed in all patients and the parameters obtained were correlated with changes in HRT. A logistic discrimination function (LDF was calculated for ophthalmic artery (OA and central retinal artery (CRA parameters. Receiver operating characteristics curves (ROC were used to assess the usefulness of LDFs to predict glaucomatous progression. A total of 71 eyes were included. End-diastolic velocity, time-averaged velocity, and resistive index in the OA and CRA were significantly different (P<0.05 between the Progression and No Progression groups. The area under the ROC curves calculated for both LDFs was of 0.695 (OA and 0.624 (CRA. More studies are needed to evaluate the ability of CDI to perform early diagnosis and to predict progression in glaucoma in eyes.

  19. FIRST ZEEMAN DOPPLER IMAGING OF A COOL STAR USING ALL FOUR STOKES PARAMETERS

    Energy Technology Data Exchange (ETDEWEB)

    Rosén, L.; Kochukhov, O. [Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala (Sweden); Wade, G. A. [Department of Physics, Royal Military College of Canada, Box 17000, Station Forces, Kingston, ON K7K 7B4 (Canada)

    2015-06-01

    Magnetic fields are ubiquitous in active cool stars, but they are in general complex and weak. Current Zeeman Doppler imaging (ZDI) studies of cool star magnetic fields chiefly employ circular polarization observations because linear polarization is difficult to detect and requires a more sophisticated radiative transfer modeling to interpret. But it has been shown in previous theoretical studies, and in the observational analyses of magnetic Ap stars, that including linear polarization in the magnetic inversion process makes it possible to correctly recover many otherwise lost or misinterpreted magnetic features. We have obtained phase-resolved observations in all four Stokes parameters of the RS CVn star II Peg at two separate epochs. Here we present temperature and magnetic field maps reconstructed for this star using all four Stokes parameters. This is the very first such ZDI study of a cool active star. Our magnetic inversions reveal a highly structured magnetic field topology for both epochs. The strength of some surface features is doubled or even quadrupled when linear polarization is taken into account. The total magnetic energy of the reconstructed field map also becomes about 2.1–3.5 times higher. The overall complexity is also increased as the field energy is shifted toward higher harmonic modes when four Stokes parameters are used. As a consequence, the potential field extrapolation of the four Stokes parameter ZDI results indicates that magnetic field becomes weaker at a distance of several stellar radii due to a decrease of the large-scale field component.

  20. Global mesospheric tidal winds observed by the high resolution Doppler imager on board the upper atmosphere research satellite

    Energy Technology Data Exchange (ETDEWEB)

    Morton, Y.T.; Lieberman, R.S.; Hays, P.B.; Ortland, D.A.; Marshall, A.R.; Wu, D.; Skinner, W.R.; Burrage, M.D.; Gell, D.A.; Yee, J.H.

    1993-06-18

    This paper presents results of mesospheric and lower thermospheric wind tides. The observations come from the high resolution doppler imager (HRDI) on board the upper atmosphere research satellite. From these observations, the authors report the observation of tidal effects on top of the meridonal winds observed in this region. Previous measurements have been mainly limited to radar measurements from fixed ground stations, which do not give consistent results, and do not provide a global picture of the wave structure.

  1. Accuracy of early burn depth assessment by laser Doppler imaging on different days post burn.

    Science.gov (United States)

    Hoeksema, Henk; Van de Sijpe, Karlien; Tondu, Thiery; Hamdi, Moustapha; Van Landuyt, Koenraad; Blondeel, Phillip; Monstrey, Stan

    2009-02-01

    Accurate diagnosis of burn depth is essential in selecting the most appropriate treatment. Early assessment of burn depth by clinical means only has been shown to be inaccurate, resulting in unnecessary operations or delay of grafting procedures. Laser Doppler imaging (LDI) was reported as an objective technique to determine the depth of a burn wound, but the accuracy on very early days post burn has never been investigated yet. In 40 patients with intermediate depth burns, we prospectively evaluated and compared the accuracy of the LDI measurements with the clinical assessments on days 0, 1, 3, 5, 8. Clinical evaluation of the depth of the burn was performed by two observers blinded to the LDI images. Accuracies were assessed by comparison with outcome: healing times longer than 21 days were considered to be equivalent to a biopsy finding of a deep dermal wound. Obviously superficial and full thickness wounds were excluded. LDI flux level was used for LDI prediction of outcome: less than 220PU to predict non-healing at day 21. The accuracies of burn depth assessments on the day of burn and post burn days 0, 1, 3, 5 and 8 using LDI were 54%, 79.5%, 95%, 97% and 100% compared with clinical assessment accuracies of 40.6%, 61.5%, 52.5%, 71.4% and 100%, respectively. LDI accuracy was significantly higher than clinical accuracy on day 3 (pBurn depth conversion was also considered. This is the first study to quantify the advantage of LDI scanning over clinical assessments during these important early after burn days.

  2. Color Doppler ultrasound and gamma imaging of intratumorally injected 500 nm iron-silica nanoshells.

    Science.gov (United States)

    Liberman, Alexander; Wu, Zhe; Barback, Christopher V; Viveros, Robert; Blair, Sarah L; Ellies, Lesley G; Vera, David R; Mattrey, Robert F; Kummel, Andrew C; Trogler, William C

    2013-07-23

    Perfluoropentane gas filled iron-silica nanoshells have been developed as stationary ultrasound contrast agents for marking tumors to guide surgical resection. It is critical to establish their long-term imaging efficacy, as well as biodistribution. This work shows that 500 nm Fe-SiO2 nanoshells can be imaged by color Doppler ultrasound over the course of 10 days in Py8119 tumor bearing mice. The 500 nm nonbiodegradable SiO2 and biodegradable Fe-SiO2 nanoshells were functionalized with diethylenetriamine pentaacetic acid (DTPA) ligand and radiolabeled with (111)In(3+) for biodistribution studies in nu/nu mice. The majority of radioactivity was detected in the liver and kidneys following intravenous (IV) administration of nanoshells to healthy animals. By contrast, after nanoshells were injected intratumorally, most of the radioactivity remained at the injection site; however, some nanoshells escaped into circulation and were distributed similarly as those given intravenously. For intratumoral delivery of nanoshells and IV delivery to healthy animals, little difference was seen between the biodistribution of SiO2 and biodegradable Fe-SiO2 nanoshells. However, when nanoshells were administered IV to tumor bearing mice, a significant increase was observed in liver accumulation of SiO2 nanoshells relative to biodegradable Fe-SiO2 nanoshells. Both SiO2 and Fe-SiO2 nanoshells accumulate passively in proportion to tumor mass, during intravenous delivery of nanoshells. This is the first report of the biodistribution following intratumoral injection of any biodegradable silica particle, as well as the first report demonstrating the utility of DTPA-(111)In labeling for studying silica nanoparticle biodistributions.

  3. Color Doppler Imaging of the Appendix: Criteria to Improve Specificity for Appendicitis in the Borderline-Size Appendix.

    Science.gov (United States)

    Xu, Yingding; Jeffrey, R Brooke; Shin, Lewis K; DiMaio, Michael A; Olcott, Eric W

    2016-10-01

    To test the hypothesis that continuous intramural vascular signal measuring at least 3 mm on color Doppler imaging is highly specific for appendicitis in patients with diagnostically borderline-size appendices. Two blinded observers independently reviewed color Doppler images of the appendix in 94 consecutive patients who had undergone sonography for suspected appendicitis and whose appendices were of diagnostically borderline size (6-8 mm maximum outer diameter). Intramural vascular flow on color Doppler images was classified as absent, type 1 (only punctate and dispersed signal), or type 2 (continuous linear or curvilinear signal measuring at least 3.0 mm in long- or short-axis views). Histopathologic examination and clinical follow-up served as reference standards. Proportions were assessed by the exact binomial test. Of the 94 patients, 33 (35.1%) had type 1 flow (of whom 5 [15.2%] had appendicitis); 23 (24.5%) had type 2 flow (of whom 20 [87.0%] had appendicitis); and 38 (40.4%) had absent flow (of whom 10 [26.3%] had appendicitis). The sensitivity, specificity, and odds ratio of type 2 flow as an indicator of appendicitis were 57.1%, 94.9%, and 24.9 (Pappendicitis in noncompressible appendices of diagnostically borderline size (6-8 mm).

  4. Quantitative analysis of smooth muscle motion of aortic wall in different geometric configuration stage of left ventricle by tissue Doppler imaging in patients with essential hypertension%不同组织多普勒技术对高血压病左心室不同几何构型阶段主动脉壁平滑肌运动定量分析研究

    Institute of Scientific and Technical Information of China (English)

    高继康; 郑凤华; 袁华芳; 马芳花

    2013-01-01

      目的探讨应用不同组织多普勒技术评估高血压病不同左心室几何构型阶段主动脉壁平滑肌运动的价值.方法测定高血压病患者主动脉壁的组织速度显像、组织追踪显像、应变显像和应变率显像曲线,并且分别测量每一曲线上的收缩期峰值速度(AOPVs)、舒张早期运动速度(AOVe)、舒张晚期运动速度(AOVa)、收缩期峰值位移(AOPDs)、收缩期峰值应变(AOPSs)、收缩期峰值应变率(AOPSRs)、舒张早期应变率(AOEsr)、舒张晚期应变率(AOAsr);并计算AOVe/AOVa,AOEsr/AOAsr.结果对照组与正常构型组、向心性重构组、向心性肥厚组、离心性肥厚组的AOPSs、AOVe、AOVa、AOEsr、AOEsr/Asr测值,向心性重构组、向心性肥厚组、离心性肥厚组的AOPDs测值,正常构型组、向心性重构组、向心性肥厚组的AOVe/Va测值差异均有统计学意义(均P<0.05);正常构型组与对照组、向心性重构组、向心性肥厚组、离心性肥厚组的AOPVs、AOPDs测值差异均有统计学意义(均P<0.05);向心性重构组与对照组、向心性肥厚组、离心性肥厚组的AOPVs测值,正常构型组、向心性肥厚组、离心性肥厚组的 AOPSs测值差异均有统计学意义(均P<0.05);离心性肥厚组与对照组、正常构型组、向心性重构组、向心性肥厚组的AOAsr、AOVe/Va测值差异均有统计学意义(均P<0.05);正常构型组、离心性肥厚组与对照组、向心性重构组、向心性肥厚组的AOPSRs测值、正常构型组、向心性重构组与向心性肥厚组、离心性肥厚组的AOEsr/Asr测值差异具有统计学意义(均P<0.05).结论(1)组织多普勒技术可评价高血压病不同左心室几何构型阶段的主动脉壁平滑肌的运动;(2)利用组织多普勒参数可定量评估高血压病在不同左心室几何构型阶段主动脉壁平滑肌的功能.%Objective To evaluate the application of tissue Doppler imaging in measurement of

  5. Doppler Imaging of Young Late-Type Stars: HII 686, HII 3163, and P1724

    Science.gov (United States)

    Stout-Batalha, Natalie Marie

    Maximum entropy image reconstruction (Doppler imaging) is applied to HII 686 (K4V, v sin i=64 km s-1) and HII 3163 (K0, v sin i=70 km s-1), two zero-age main sequence stars of the Pleiades cluster, and the weak-lined T Tauri star Parenago 1724 (K0, v sin i=71 km s-1). Their surface temperature distributions are determined in order to study the nature of magnetic activity in young ultra-fast rotators. Specific intensity line profiles used in the DI algorithm are synthesized. The sensitivity of the reconstructions to the choice of input stellar and atomic data is investigated. The quality of the fit to the average disk integrated line profile is found to be more important to DI analysis than the exact parameters used to generate the fit when the shape of the disk integrated line profile is dominated by rotational broadening. Fifteen absorption lines are used to generate fifteen individual reconstructions of each Pleiades target. Averaging reduces noise in the reconstructions. However, spurious features can persist at sub-observer longitudes. Such 'phase-ghosting' can largely be eliminated by including broad-band photometric observations in the analysis. Using the large number of reconstructions for a given star, uncertainties in the images are estimated. HII 686 shows one predominant feature at 77o latitude which is 700 K cooler than the surrounding photosphere. HII 3163 also shows one predominant feature centered at approximately 70o latitude. A spot temperature 1000 K cooler than the photosphere best reproduces the observations. P1724 shows a predominant feature (or features) centered at 30o latitude which is 800 K cooler than its photosphere. These results are discussed in light of recent theoretical observations and existing image reconstructions of similar objects. No correlations are found among reconstructions which could be attributed to line characteristics: equivalent width, excitation potential or depth of formation. This is also true for the LiI and KI

  6. Prostaglandin E1 Increases Microcirculation in Random Pattern Flaps on Rats Measured with Laser Doppler Perfusion Imaging

    Science.gov (United States)

    Sneistrup, Christian; Berg, Thomas Moe

    2017-01-01

    Background: Reconstructive procedures with pedicled and free flaps are associated with a risk of ischemia. Prostaglandin E1 (PGE1) is a hormone-like substance with known antiischemic and tissue-protective effects. The aim of this study was to evaluate the effect of PGE1 on the microcirculation in random pattern skin flaps on rats. Methods: Twenty-four rats were divided into 2 groups: an intervention group given PGE1 for 6 hours and a control group given saline. The flap (2 × 10 cm) was created on the back of the rats, and the microcirculation was monitored with laser Doppler perfusion imaging in 5 different zones (1, proximal; 5, distal) before surgery and after 60, 180, and 360 minutes postoperatively. Results: Before surgery, there was no difference in the perfusion in any zones between the intervention group and the control group. The mean perfusion values in zone 1 in the intervention group were significantly higher than those in the control group at 60, 180, and 360 minutes postoperatively (P = 0.02, P = 0.05, and P = 0.04, respectively). At 360 minutes, we also found significantly higher levels of perfusion in the intervention group in zones 4 and 5 (P = 0.05 and P = 0.03, respectively) compared with the controls. Comparing the perfusion at 360 to 60 minutes in the intervention group, we found a significant increase in microcirculation in all zones, which were not seen in the control group. Conclusion: PGE1 increased perfusion in the dermal random pattern flaps on rats. PMID:28203503

  7. Diagnosis of umbilical cord entanglement in a monochorionic diamniotic twin pregnancy with spontaneous septostomy of the dividing membranes using dual-gate Doppler imaging.

    Science.gov (United States)

    Ito, Ayumu; Nakata, Masahiko; Oji, Ayako; Takano, Mayumi; Umemura, Nahomi; Nagasaki, Sumito; Maemura, Toshimitsu; Morita, Mineto

    2017-05-08

    Umbilical cord entanglement is the leading cause of fetal mortality in monoamniotic twin pregnancies and a pseudo monoamniotic environment. Published methods for detecting this complication include color Doppler and pulsed Doppler sonography; however, no method provides an absolute diagnosis. In this case, we report the diagnosis of umbilical cord entanglement using dual-gate Doppler imaging. A 35-year-old woman was referred to our hospital at 28 weeks of gestation for prenatal management because of diagnosis of a monochorionic diamniotic twin pregnancy with spontaneous septostomy of the dividing membranes. Each fetus displayed normal fetal growth without obvious discordance and anatomical abnormalities. However, the dividing membrane was not detected, and an entangled cord was suspected. Dual-gate Doppler examination was carried out. Two regions of interest were considered at different areas of the umbilical arteries, and when each Doppler image showed two different heart rates at the same time, we considered this to be evidence of umbilical cord entanglement. Cesarean section was performed at 32 weeks of gestation and twins were delivered. The delivered umbilical cords had sixfold entanglement. In this case, dual-gate Doppler seems to have been more accurate than conventional single-gate Doppler for the diagnosis of cord entanglement because we confirmed two different heart rates at the same time with dual-gate Doppler.

  8. Improved Left Ventricular Diastolic Function with Exercise Training in Hypertension: A Doppler Imaging Study

    Directory of Open Access Journals (Sweden)

    Huan Zheng

    2011-01-01

    Full Text Available Objective. To study the effects of 6 months’ exercise training on ventricular function in hypertensive patients. Methods. Both groups received routine anti-hypertensive pharmacological therapy and one received a 6 months’ exercise program in addition. All patients underwent incremental cardiopulmonary exercise test and echocardiography in baseline and after 6 months. Results. (1 In 6 months’ follow-up, PeakVO2, Powermax (max workload, AT (anaerobic threshold, VO2AT (VO2 at anaerobic threshold, tAT (time from beginning to anaerobic threshold (<.05, were increased in the exercise group. HRrest (Heart rate at rest was decreased (<.05. LAVI (left atrial volume index, peak mitral filling velocities during early (E and late (A diastole E/A ratio, DT(deceleration time of the mitral E wave, IVST(Interventricular septum thickness in diastole, tissue Doppler indice Mean Ea/Aa ratio (<.05 were also improved. (2 Correlation analysis: 4 variates had significant effect on change of PeakVO2 in the exercise group: age (=−0.39, change of HRrest (=0.59, change of E/A (=0.55, change of Mean Ea/Aa (=0.58; Through analyzing 2 groups patients’ baseline values, their age (=−0.32, VO2AT (=0.29, HRrest (=−0.25, LAVI (=−0.24, E/A (=0.41 were found to be independent predictors of MeanEa/Aa. -value under .05 was considered statistically significant. Conclusion. 6 months’ exercise could enhance hypertensive patients’ aerobic exercise level and diastolic function to a certain extent.

  9. Tissue Doppler, strain and strain rate in ischemic heart disease "how I do it".

    Science.gov (United States)

    Mada, Razvan O; Duchenne, Jürgen; Voigt, Jens-Uwe

    2014-09-18

    Echocardiography is the standard method for assessing myocardial function in patients with ischemic heart disease. The acquisition and interpretation of echocardiographic images, however, remains a highly specialized task which often relies entirely on the subjective visual assessment of the reader and requires therefore, particular training and expertise. Myocardial deformation imaging allows quantifying myocardial function far beyond what can be done with sole visual assessment. It can improve the interpretation of regional dysfunction and offers sensitive markers of induced ischemia which can be used for stress tests. In the following, we recapitulate shortly the pathophysiological and technical basics and explain in a practical manner how we use this technique in investigating patients with ischemic heart disease.

  10. Objective breast tissue image classification using Quantitative Transmission ultrasound tomography

    Science.gov (United States)

    Malik, Bilal; Klock, John; Wiskin, James; Lenox, Mark

    2016-12-01

    Quantitative Transmission Ultrasound (QT) is a powerful and emerging imaging paradigm which has the potential to perform true three-dimensional image reconstruction of biological tissue. Breast imaging is an important application of QT and allows non-invasive, non-ionizing imaging of whole breasts in vivo. Here, we report the first demonstration of breast tissue image classification in QT imaging. We systematically assess the ability of the QT images’ features to differentiate between normal breast tissue types. The three QT features were used in Support Vector Machines (SVM) classifiers, and classification of breast tissue as either skin, fat, glands, ducts or connective tissue was demonstrated with an overall accuracy of greater than 90%. Finally, the classifier was validated on whole breast image volumes to provide a color-coded breast tissue volume. This study serves as a first step towards a computer-aided detection/diagnosis platform for QT.

  11. Modelling Brain Tissue using Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Dyrby, Tim Bjørn

    2008-01-01

    Diffusion MRI, or diffusion weighted imaging (DWI), is a technique that measures the restricted diffusion of water molecules within brain tissue. Different reconstruction methods quantify water-diffusion anisotropy in the intra- and extra-cellular spaces of the neural environment. Fibre tracking...... models then use the directions of greatest diffusion as estimates of white matter fibre orientation. Several fibre tracking algorithms have emerged in the last few years that provide reproducible visualizations of three-dimensional fibre bundles. One class of these algorithms is probabilistic...... be used. Within a two year period, no statistical inter- or intra-brain difference in the diffusion coefficient was found in perfusion fixated minipig brains. However, a decreasing tendency in the diffusion coefficient was found at the last time points about 24 months post mortem and might be explained...

  12. Zeeman-Doppler imaging of active young solar-type stars

    Science.gov (United States)

    Hackman, T.; Lehtinen, J.; Rosén, L.; Kochukhov, O.; Käpylä, M. J.

    2016-03-01

    Context. By studying young magnetically active late-type stars, i.e. analogues to the young Sun, we can draw conclusions on the evolution of the solar dynamo. Aims: We determine the topology of the surface magnetic field and study the relation between the magnetic field and cool photospheric spots in three young late-type stars. Methods: High-resolution spectropolarimetry of the targets was obtained with the HARPSpol instrument mounted at the ESO 3.6 m telescope. The signal-to-noise ratios of the Stokes IV measurements were boosted by combining the signal from a large number of spectroscopic absorption lines through the least squares deconvolution technique. Surface brightness and magnetic field maps were calculated using the Zeeman-Doppler imaging technique. Results: All three targets show clear signs of magnetic fields and cool spots. Only one of the targets, V1358 Ori, shows evidence of the dominance of non-axisymmetric modes. In two of the targets, the poloidal field is significantly stronger than the toroidal one, indicative of an α2-type dynamo, in which convective turbulence effects dominate over the weak differential rotation. In two of the cases there is a slight anti-correlation between the cool spots and the strength of the radial magnetic field. However, even in these cases the correlation is much weaker than in the case of sunspots. Conclusions: The weak correlation between the measured radial magnetic field and cool spots may indicate a more complex magnetic field structure in the spots or spot groups involving mixed magnetic polarities. Comparison with a previously published magnetic field map shows that on one of the stars, HD 29615, the underlying magnetic field changed its polarity between 2009 and 2013. Based on observations made with the HARPSpol instrument on the ESO 3.6 m telescope at La Silla (Chile), under the program ID 091.D-0836.

  13. EVALUATION OF THE DIAGNOSTIC CRITERIA FOR THE LOCALIZATION OF ACQUIRED ARTERIOVENOUS FISTULAS BY COLOR DOPPLER FLOW IMAGING

    Institute of Scientific and Technical Information of China (English)

    李建初; 蔡胜; 姜玉新; 张缙熙; 王岩青

    2001-01-01

    Objective. To evaluate the diagnostic criteria for the localization of acquired arteriovenous fistulas (AVFs)by color Doppler flow imaging (CDFI) based on the features of their hemodynamic changes.Methods. The shape and hemodynamic changes of involved vessels which could be helpful to localize thesites of fistulas were studied according to the observation of 10 cases of acquired AVFs.Results. The s tes of the fistulas could be shown by two-dimensional ultrasonography and color flow imagingin 40% and 80% tases, respectively. In all cases, turbulent high-velocity flow was present at the sites of thefistulas, low resistant flow was present in the arteries proximal to the fistulas, and artery-like flow was detected inthe veins.Conclusion. C OFt was accurate for the localization of acquired AVFs, which were mainly localized by theirhemodynamic changes shown by pulse Doppler ultrasound.``

  14. Assessment of left ventricular functions with tissue Doppler, strain, and strain rate echocardiography in patients with familial Mediterranean fever.

    Science.gov (United States)

    Ceylan, Özben; Özgür, Senem; Örün, Utku Arman; Doğan, Vehbi; Yılmaz, Osman; Keskin, Mahmut; Arı, Mehmet Emre; Erdoğan, Özlem; Karademir, Selmin

    2015-08-01

    This study assessed the early changes in regional and global systolic and diastolic myocardial functions in patients with familial Mediterranean fever without any cardiovascular symptoms using tissue Doppler and strain and strain rate echocardiography and compared them to the results of a control group. This study has a cross-sectional and observational design. FMF patients with normal left ventricular function were included in the study. We excluded patients who had arrhythmia, acquired/congenital heart disease, pericarditis, or acute attack. We compared 45 children with familial Mediterranean fever on colchicine therapy and 45 age- and sex-matched healthy children. The 45 patients with familial Mediterranean fever included 24 (55.3%) girls and 21 (46.7%) boys with a mean age of 11.3 ± 3.7 (range 2-18) years. The mean disease duration was 4.6 ± 2.4 (range 0.5-10) years. In the patient group, the homozygous M694V mutation was the most common (64.4%) mutation. The patients with familial Mediterranean fever had statistically lower longitudinal global strain, radial global strain, and strain rates (-14.44 ± 4.77%, 14.80 ± 6.29%, and 0.59 ± 0.24 s, respectively) than the controls (-17.40 ± 1.79%, 17.53 ± 4.63%, and 0.83 ± 0.51 s) (p familial Mediterranean fever who are subclinical from a cardiac aspect might have normal left ventricular function as measured by conventional echocardiography. However, the disease affects their myocardial tissue, and these patients should be followed with conventional, strain, and strain rate echocardiography techniques regularly.

  15. Imaging of the pediatric hand: Soft tissue abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, R. Mauricio [Department of Radiology, Children' s Hospital of Philadelphia, 34th Street and Civic Center Blvd., Philadelphia, PA 19104 (United States); Jaramillo, Diego [Department of Radiology, Children' s Hospital of Philadelphia, 34th Street and Civic Center Blvd., Philadelphia, PA 19104 (United States)]. E-mail: jaramillo@email.chop.edu; Connolly, Susan A. [Children' s Hospital Boston (United States)

    2005-12-15

    This review attempts to demonstrate the spectrum of soft tissue masses encountered in the child's hand. The diagnosis may be suggested by the combination of physical exam and radiographs. Frequently the etiology of a soft tissue mass cannot be established by conventional radiographs and further imaging is necessary. MRI by virtue of its ability to provide detailed soft tissue characterization is the preferred method of imaging the problematic soft tissue mass.

  16. Effects of chronic severe pulmonary regurgitation and percutaneous valve repair on right ventricular geometry and contractility assessed by tissue Doppler echocardiography

    DEFF Research Database (Denmark)

    Kjaergaard, Jesper; K. Iversen, Kasper; G Vejlstrup, Niels;

    2010-01-01

    replacement (PPVR) was performed. Tissue Doppler derived measures of global and regional myocardial contractility were obtained by transthoracic echocardiography, and compared to a sham-operated control group (N = 9).RESULTS: Free PR is associated with RV dilatation (RV end-diastolic area increased from 15...... ± 3 to 23 ± 7 cm(2) /m(2) , P strain, and strain rate were unchanged after free PR and after PPVR. No consistent relation...

  17. Separation of Target Rigid Body and Micro-Doppler Effects in ISAR/SAR Imaging

    Science.gov (United States)

    2006-09-01

    returned from the surface of the vehicle. From micro-Doppler modulations in the engine vibration signal, one can distinguish whether it is a gas turbine...v~hicule peuvent ýtre d~tect~es par des signaux radars r~fl~chis d la surface du v~hicule. Ak partir de mo- dulations micro-Doppler du signal de...fenetre large uine forte concentration du signal correspondant aux parties du corps rigide. La deuxi~me technique se fonide sur le traitement des

  18. Diagnose human colonic tissues by terahertz near-field imaging

    Science.gov (United States)

    Chen, Hua; Ma, Shihua; Wu, Xiumei; Yang, Wenxing; Zhao, Tian

    2015-03-01

    Based on a terahertz (THz) pipe-based near-field imaging system, we demonstrate the capability of THz imaging to diagnose freshly surgically excised human colonic tissues. Through THz near-field scanning the absorbance of the colonic tissues, the acquired images can clearly distinguish cancerous tissues from healthy tissues fast and automatically without pathological hematoxylin and eosin stain diagnosis. A statistical study on 58 specimens (20 healthy tissues and 38 tissues with tumor) from 31 patients (mean age: 59 years; range: 46 to 79 years) shows that the corresponding diagnostic sensitivity and specificity on colonic tissues are both 100%. Due to its capability to perform quantitative analysis, our study indicates the potential of the THz pipe-based near-field imaging for future automation on human tumor pathological examinations.

  19. In vivo photoacoustic imaging of transverse blood flow using Doppler broadening of bandwidth

    OpenAIRE

    Yao, Junjie; Maslov, Konstantin I.; Shi, Yunfei; Taber, Larry A.; Lihong V. Wang

    2010-01-01

    A new method is proposed to measure transverse blood flow using photoacoustic Doppler broadening of bandwidth. By measuring bovine blood flowing through a plastic tube, the linear dependence of the broadening on the flow speed was validated. The blood flow of the microvasculature in a mouse ear and a chicken embryo (stage 16) was also studied.

  20. In vivo photoacoustic imaging of transverse blood flow by using Doppler broadening of bandwidth

    OpenAIRE

    Yao, Junjie; Maslov, Konstantin I.; Shi, Yunfei; Taber, Larry A.; Lihong V. Wang

    2010-01-01

    A method is proposed to measure transverse blood flow by using photoacoustic Doppler broadening of bandwidth. By measuring bovine blood flowing through a plastic tube, the linear dependence of the broadening on the flow speed was validated. The blood flow of the microvasculature in a mouse ear and a chicken embryo (stage 16) was also studied.

  1. Performance evaluation of an all-fiber image-reject homodyne coherent Doppler wind lidar

    DEFF Research Database (Denmark)

    Abari, Cyrus F.; Pedersen, Anders Tegtmeier; Dellwik, Ebba

    2015-01-01

    The main purpose of this study is to evaluate the near-zero wind velocity measurement performance of two separate 1.5 µm all-fiber coherent Doppler lidars (CDLs). The performance characterization is carried out through the presentation of the results from two separate atmospheric field campaigns...

  2. The application of color Doppler flow imaging in the diagnosis and therapeutic effect evaluation of erectile dysfunction

    Directory of Open Access Journals (Sweden)

    Xu-Jun Xuan

    2016-01-01

    Full Text Available We aim to investigate the correlations between hemodynamic parameters, penile rigidity grading, and the therapeutic effects of phosphodiesterase type 5 inhibitors using color Doppler flow imaging after intracavernosal injection in patients with erectile dysfunction. This study involved 164 patients. After intracavernosal injection with a mixture of papaverine (60 mg, prostaglandin E 1 (10 mg, and lidocaine (2%, 0.5-1 ml, the penile vessels were assessed using color Doppler flow imaging. Penile rigidity was classified based on the Erection Hardness Score system as Grades 4, 3, 2 or 1 (corresponding to Schramek Grades V to II. Then, the patients were given oral sildenafil (50-100 mg and scored according to the International Index of Erectile Function (IIEF-5 questionnaire. The number of patients with penile rigidities of Schramek Grades II to V was 14, 18, 21, and 111, respectively. The IIEF-5 score was positively correlated with the refilling index of the penile cavernosal artery (r = 0.79, P< 0.05, the peak systolic velocity (r = 0.45, P< 0.05, and penile rigidity (r = 0.75, P< 0.05, and was negatively correlated with the end diastolic velocity (r = −0.74, P< 0.05. For patients with erectile dysfunction, both the IIEF-5 score after sildenafil administration, which is correlated with penile rigidity, and the hemodynamic parameters detected using color Doppler flow imaging may predict the effects of phosphodiesterase type 5 inhibitor treatment and could provide a reasonable model for the targeted-treatment of erectile dysfunction.

  3. Intra-abdominal fat. Part I. The images of the adipose tissue localized beyond organs.

    Science.gov (United States)

    Smereczyński, Andrzej; Kołaczyk, Katarzyna; Bernatowicz, Elżbieta

    2015-09-01

    Unaltered fat is a permanent component of the abdominal cavity, even in slim individuals. Visceral adiposity is one of the important factors contributing to diabetes, cardiovascular diseases and certain neoplasms. Moreover, the adipose tissue is an important endocrine and immune organ of complex function both when normal and pathological. Its role in plastic surgery, reconstruction and transplantology is a separate issue. The adipose tissue has recently drawn the attention of research institutes owing to being a rich source of stem cells. This review, however, does not include these issues. The identification of fat is relatively easy using computed tomography and magnetic resonance imaging. It can be more difficult in an ultrasound examination for several reasons. The aim of this paper is to present various problems associated with US imaging of unaltered intra-abdominal fat located beyond organs. Based on the literature and experience, it has been demonstrated that the adipose tissue in the abdominal cavity has variable echogenicity, which primarily depends on the amount of extracellular fluid and the number of connective tissue septa, i.e. elements that potentiate the number of areas that reflect and scatter ultrasonic waves. The normal adipose tissue presents itself on a broad gray scale: from a hyperechoic area, through numerous structures of lower reflection intensity, to nearly anechoic regions mimicking the presence of pathological fluid collections. The features that facilitate proper identification of this tissue are: sharp margins, homogeneous structure, high compressibility under transducer pressure, no signs of infiltration of the surrounding structures and no signs of vascularization when examined with the color and power Doppler. The accumulation of fat tissue in the abdominal cavity can be generalized, regional or focal. The identification of the adipose tissue in the abdominal cavity using ultrasonography is not always easy. When in doubt, the

  4. Evaluation of Influence of Acupuncture and Electro-Acupuncture for Blood Perfusion of Stomach by Laser Doppler Blood Perfusion Imaging

    OpenAIRE

    Zhang Dong; Li Shun-Yue; Wang Shu-You; Ma Hui-Min

    2011-01-01

    The objective of this study is to observe effects of acupuncture and electro-acupuncture (EA) on blood perfusion in the stomach, and probe into the application of laser Doppler blood perfusion imaging technique in the study of the effect of acupuncture and moxibustion on the entrails. In the acupuncture group of 20 rats, acupuncture was given at “Zusanli” (ST 36) and in EA group of 18 rats, EA was applied at “Zusanli” (ST 36), with 18 rats without acupuncture used as control group. Changes of...

  5. Noninvasive monitoring of myocardial function after surgical and cytostatic therapy in a peritoneal metastasis rat model: assessment with tissue Doppler and non-Doppler 2D strain echocardiography

    Directory of Open Access Journals (Sweden)

    Wernecke Klaus-Dieter

    2007-07-01

    Full Text Available Abstract Objective We sought to evaluate the impact of different antineoplastic treatment methods on systolic and diastolic myocardial function, and the feasibility estimation of regional deformation parameters with non-Doppler 2D echocardiography in rats. Background The optimal method for quantitative assessment of global and regional ventricular function in rats and the impact of complex oncological multimodal therapy on left- and right-ventricular function in rats remains unclear. Methods 90 rats after subperitoneal implantation of syngenetic colonic carcinoma cells underwent different onclogical treatment methods and were diveded into one control group and five treatment groups (with 15 rats in each group: group 1 = control group (without operation and without medication, group 2 = operation group without additional therapy, group 3 = combination of operation and photodynamic therapy, group 4 = operation in combination with hyperthermic intraoperative peritoneal chemotherapy with mitomycine, and group 5 = operation in combination with hyperthermic intraoperative peritoneal chemotherapy with gemcitabine, group 6 = operation in combination with taurolidin i.p. instillation. Echocardiographic examination with estimation of wall thickness, diameters, left ventricular fractional shortening, ejection fraction, early and late diastolic transmitral and myocardial velocities, radial and circumferential strain were performed 3–4 days after therapy. Results There was an increase of LVEDD and LVESD in all groups after the follow-up period (P = 0.0037. Other LV dimensions, FS and EF as well as diastolic mitral filling parameters measured by echocardiography were not significantly affected by the different treatments. Values for right ventricular dimensions and function remained unchanged, whereas circumferential 2D strain of the inferior wall was slightly, but significantly reduced under the treatment (-18.1 ± 2.5 before and -16.2 ± 2.9 % after

  6. Functional imaging of small tissue volumes with diffuse optical tomography

    Science.gov (United States)

    Klose, Alexander D.; Hielscher, Andreas H.

    2006-03-01

    Imaging of dynamic changes in blood parameters, functional brain imaging, and tumor imaging are the most advanced application areas of diffuse optical tomography (DOT). When dealing with the image reconstruction problem one is faced with the fact that near-infrared photons, unlike X-rays, are highly scattered when they traverse biological tissue. Image reconstruction schemes are required that model the light propagation inside biological tissue and predict measurements on the tissue surface. By iteratively changing the tissue-parameters until the predictions agree with the real measurements, a spatial distribution of optical properties inside the tissue is found. The optical properties can be related to the tissue oxygenation, inflammation, or to the fluorophore concentration of a biochemical marker. If the model of light propagation is inaccurate, the reconstruction process will lead to an inaccurate result as well. Here, we focus on difficulties that are encountered when DOT is employed for functional imaging of small tissue volumes, for example, in cancer studies involving small animals, or human finger joints for early diagnosis of rheumatoid arthritis. Most of the currently employed image reconstruction methods rely on the diffusion theory that is an approximation to the equation of radiative transfer. But, in the cases of small tissue volumes and tissues that contain low scattering regions diffusion theory has been shown to be of limited applicability Therefore, we employ a light propagation model that is based on the equation of radiative transfer, which promises to overcome the limitations.

  7. Evaluation of tissue optical properties from light distribution images

    Science.gov (United States)

    Tsai, Cheng-Lun; Chang, Ming; Hsieh, Jui-Hsiang; Yang, Yi-Fong; Chou, Yi-Sheong

    2000-06-01

    Images of light distribution in biological soft tissue we used to study the optical characteristics of tissue. The light distribution image was taken under a microscope with light injected through a pinhole close to the edge of the top surface. Images taken on skin, fat, and muscle tissues were compared to study the effect of cellular structure and temperature on the light intensity distribution. Monte Carlo simulation with the same conditions was also performed to simulate the light intensity distribution in tissue for comparison. The anisotropy scattering of light in tissue is affected by the tissue microscopic structure, such as the direction of muscle tissue fibers. The change in optical properties of fat and muscle tissue with temperature was observed. The two-dimensional light distribution images offer more information than general reflectance and transmission measurements. By matching the simulated light intensity distribution with the light distribution image, the optical properties of biological tissue could be estimated. This method might be applied in tissue engineering as an economic way for evaluating the microscopic structure of tissue.

  8. The Evaluation of Diastolic Dysfunction with Tissue Doppler Echocardiography in Women with Subclinical Hypothyroidism and the Effect of L-Thyroxine Treatment on Diastolic Dysfunction: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Gulbanu Erkan

    2011-01-01

    Full Text Available Background. Subclinical hypothyroidism (SH predominantly affects women. The necessity of treatment in SH is controversial. Objective. We aimed to investigate the response of diastolic dysfunction to thyroid hormone replacement therapy (THRT in women. Methods and Results. Twenty-two female subjects with SH and 20 euthyroid female controls were enrolled. Baseline and follow-up biochemical, hormonal, and echocardiographic evaluations were performed. Repeat echocardiograms were performed three months after the achievement of a euthyroid status with THRT. Mean baseline myocardial performance index (MPI was 0.27±0.08 in the SH group, and 0.22±0.06 in the control group (P=0.03. MPI did not change significantly after THRT. Pulsed-wave Doppler findings were not different among the groups. However, tissue Doppler-derived mitral annular E’ velocities were significantly lower in the SH group. A moderate but significant improvement was observed in E’ velocities after THRT (13.2±3.87 versus 14.53±2.75, P=0.04. We also observed left ventricular concentric remodeling in SH patients which was reversible with THRT. Conclusions. Tissue Doppler echocardiography may be a useful tool for monitoring the response of diastolic dysfunction to thyroid hormone replacement therapy in patients with SH. Our findings suggest that THRT may reverse diastolic dysfunction in women with SH.

  9. The evaluation of diastolic dysfunction with tissue Doppler echocardiography in women with subclinical hypothyroidism and the effect of L-thyroxine treatment on diastolic dysfunction: a pilot study.

    Science.gov (United States)

    Erkan, Gulbanu; Erkan, Aycan Fahri; Cemri, Mustafa; Karaahmetoglu, Selma; Cesur, Mustafa; Cengel, Atiye

    2011-01-01

    Background. Subclinical hypothyroidism (SH) predominantly affects women. The necessity of treatment in SH is controversial. Objective. We aimed to investigate the response of diastolic dysfunction to thyroid hormone replacement therapy (THRT) in women. Methods and Results. Twenty-two female subjects with SH and 20 euthyroid female controls were enrolled. Baseline and follow-up biochemical, hormonal, and echocardiographic evaluations were performed. Repeat echocardiograms were performed three months after the achievement of a euthyroid status with THRT. Mean baseline myocardial performance index (MPI) was 0.27 ± 0.08 in the SH group, and 0.22 ± 0.06 in the control group (P = 0.03). MPI did not change significantly after THRT. Pulsed-wave Doppler findings were not different among the groups. However, tissue Doppler-derived mitral annular E' velocities were significantly lower in the SH group. A moderate but significant improvement was observed in E' velocities after THRT (13.2 ± 3.87 versus 14.53 ± 2.75, P = 0.04). We also observed left ventricular concentric remodeling in SH patients which was reversible with THRT. Conclusions. Tissue Doppler echocardiography may be a useful tool for monitoring the response of diastolic dysfunction to thyroid hormone replacement therapy in patients with SH. Our findings suggest that THRT may reverse diastolic dysfunction in women with SH.

  10. Third-harmonic generation imaging of breast tissue biopsies.

    Science.gov (United States)

    Lee, Woowon; Kabir, Mohammad M; Emmadi, Rajyasree; Toussaint, Kimani C

    2016-11-01

    We demonstrate for the first time the imaging of unstained breast tissue biopsies using third-harmonic generation (THG) microscopy. As a label-free imaging technique, THG microscopy is compared to phase contrast and polarized light microscopy which are standard imaging methods for breast tissues. A simple feature detection algorithm is applied to detect tumour-associated lymphocyte rich regions in unstained breast biopsy tissue and compared with corresponding regions identified by a pathologist from bright-field images of hematoxylin and eosin stained breast tissue. Our results suggest that THG imaging holds potential as a complementary technique for analysing breast tissue biopsies. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

  11. Confocal Imaging of Biological Tissues Using Second Harmonic Generation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, B-M.; Stoller, P.; Reiser, K.; Eichler, J.; Yan, M.; Rubenchik, A.; Da Silva, L.

    2000-03-06

    A confocal microscopy imaging system was devised to selectively detect Second harmonic signals generated by biological tissues. Several types of biological tissues were examined using this imaging system, including human teeth, bovine blood vessels, and chicken skin. All these tissues generated strong second harmonic signals. There is considerable evidence that the source of these signals in tissue is collagen. Collagen, the predominant component of most tissues, is known to have second order nonlinear susceptibility. This technique may have diagnostic usefulness in pathophysiological conditions characterized by changes in collagen structure including malignant transformation of nevi, progression of diabetic complications, and abnormalities in wound healing.

  12. Early detection of left ventricular dysfunction in asymptomatic diabetic patient using strain and strain rate echocardiographic imaging

    Directory of Open Access Journals (Sweden)

    Rania Gaber

    2014-03-01

    Conclusion: Type 2 diabetes mellitus deteriorate both LV systolic and diastolic performance. Strain and strain rate by tissue Doppler Imaging is superior to conventional Doppler in early detection and evaluation of systolic and diastolic dysfunction in type 2 diabetic patients.

  13. Sonographic classification of testicular tumors by tissue harmonic imaging: experience of 58 cases.

    Science.gov (United States)

    Kawamoto, Atsuo; Hatano, Tadashi; Saito, Kazuhiro; Inoue, Rie; Nagao, Toshitaka; Sanada, Shigeru

    2017-03-20

    To evaluate the relationship between our proposed sonographic classification of testicular tumors by tissue harmonic imaging and histological type. We retrospectively analyzed 58 testicular tumors and tumor-like lesions [seminomatous germ cell tumor (SGCT): 28; non-seminomatous germ cell tumor (NSGCT): 16; lymphoid and hematopoietic tumor (LHT): 7; Leydig cell tumor: 1; epidermal cyst: 2; and tumor of paratesticular structure (TPS): 4]. We divided a sonographic image into six types for morphological criteria and three types for color Doppler criteria. We examined the relationship between the sonographic classification and histological type. For morphological criteria, there were 21 cases of Type I (36%), 15 Type II (26%), 9 Type III (15%), five Type IV (9%), five Type V (9%), and three Type VI (5%). For color Doppler criteria, there were 47 cases classified as hypervascular (81%), eight as hypovascular (14%), and three as avascular (5%). Most of the SGCTs were divided into types I and II; the NSGCTs into types III, IV, and V; the LHTs into only type II; and the TPSs into type VI. We established a sonographic classification of testicular tumors with various histological types. This sonographic classification is potentially useful for estimating the histological type of testicular tumors.

  14. Medical image of the week: granulation tissue

    Directory of Open Access Journals (Sweden)

    Ganesh A

    2014-03-01

    Full Text Available A 57 year old woman presented with a tickling sensation in the back of throat and intermittent bleeding from the healing stoma one month after decannulation of her tracheostomy tube. On bronchoscopy a granuloma with surrounding granulation tissue was present in the subglottic space (Figure 1. Argon plasma coagulation (APC was performed to cauterize the granulation tissue (Figure 2. Formation of granulation tissue after tracheostomy is a common complication which can result in tracheal stenosis. APC and electrocautery using flexible bronchoscopy has been shown to safely and effectively remove the granulation tissue.

  15. Ultrahigh-velocity resolution imaging of the microcirculation in-vivo using color Doppler optical coherence tomography

    Science.gov (United States)

    Yazdanfar, Siavash; Rollins, Andrew M.; Izatt, Joseph A.

    2001-05-01

    Color Doppler optical coherence tomography (CDOCT) is a method for noninvasive cross-sectional imaging of blood flow in vivo. In previous implementations, velocity estimates were obtained by measuring the frequency shift of discrete depth-resolved backscatter spectra, resulting in a velocity resolution on the order of 1 mm/s. We present a novel processing method that detects Doppler shifts calculated across sequential axial scans, enabling ultrahigh velocity resolution (~1 micron/s) flow measurement in scattering media. This method of sequential scan processing was calibrated with a moving mirror mounted on a precision motorized translator. Latex microspheres suspended in deuterium oxide were used as a highly scattering test phantom. Laminar flow profiles down to ~15 micron/s centerline velocity (0.02 cc/hr) were observed with a sensitivity of 1.2 micron/s. Finally, vessels on the order of 10 microns in diameter were imaged in living human skin, with a relative frequency sensitivity less than 4 x 10-5. To our knowledge, these results are the lowest velocities ever measured with CDOCT.

  16. Imaging techniques for the diagnosis of soft tissue tumors

    Directory of Open Access Journals (Sweden)

    Afonso PD

    2015-04-01

    Full Text Available P Diana Afonso,1,2 VV Mascarenhas21Department of Radiology, Hospital Beatriz Angelo, Loures, 2Department of Radiology, Hospital da Luz, Lisbon, PortugalAbstract: The primary aim in soft tissue tumor imaging should be to reach a specific diagnosis or to narrow the differential diagnosis, and to help to decide whether biopsy, surgical intervention, or simple observation is required for further management. In addition to contributing toward diagnosis, imaging has an important role in the staging of soft tissue malignancies and potentially in response assessment. This general review article highlights a rational diagnostic imaging approach to patients presenting with soft tissue tumors, emphasizing the fundamental principles inherent to soft tissue tumor imaging and diagnosis.Keywords: soft tissue tumors, ultrasound, CT, PET, MRI

  17. Photoacoustic imaging of blood vessels in tissues

    Science.gov (United States)

    de Mul, Frits F. M.; Pilatou, Magdalena C.; Kolkman, Roy G. M.; Hondebrink, Erwin; Steenbergen, Wiendelt

    2002-10-01

    To localize and monitor the blood content in tissue we developed very sensitive photoacoustical detectors. In these detectors a PVdF-layer has been used as piezo-electric material and also fibers for the illumination of the sample are integrated. The resolution is about 20 im in depth and about 50-100 im laterally. The wavelengths ofthe laser light were 532and 1064 nm. With these colors we can measure at different depths in tissue. We will report measurements on real tissue: vessels in chicken breast, in the human arm, and in test animals at various positions.

  18. Duplex synthetic aperture imaging with tissue motion compensation

    DEFF Research Database (Denmark)

    Gammelmark, Kim; Jensen, Jørgen Arendt

    2003-01-01

    This paper investigates a method for tissue motion estimation and compensation in synthetic transmits aperture imaging. The approach finds the tissue velocity and the direction of the motion at very tissue region by cross-correlating high resolution lines beamformed along multiple directions...... at each image points. Compensation is applied in the beamformer by tracking the image points using the velocity and angle estimates from the closest estimation point. Simulation results using Field II show nearly perfect motion compensation with no appreciable difference in contrast resolution after...

  19. Incision for pleural tissue biopsy (image)

    Science.gov (United States)

    ... the pleural tissue is removed through a surgical incision in the chest. After the sample is obtained, a chest tube is placed and the incision is closed with stitches. Abnormal results may indicate ...

  20. Tissue MALDI Mass Spectrometry Imaging (MALDI MSI) of Peptides.

    Science.gov (United States)

    Beine, Birte; Diehl, Hanna C; Meyer, Helmut E; Henkel, Corinna

    2016-01-01

    Matrix assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) is a technique to visualize molecular features of tissues based on mass detection. This chapter focuses on MALDI MSI of peptides and provides detailed operational instructions for sample preparation of cryoconserved and formalin-fixed paraffin-embedded (FFPE) tissue. Besides sample preparation we provide protocols for the MALDI measurement, tissue staining, and data analysis. On-tissue digestion and matrix application are described for two different commercially available and commonly used spraying devices: the SunCollect (SunChrom) and the ImagePrep (Bruker Daltonik GmbH).

  1. Diagnosis of neonatal hemochromatosis with MR imaging and duplex Doppler sonography

    Energy Technology Data Exchange (ETDEWEB)

    Oddone, M.; Toma, P. [Dept. of Radiology, G. Gaslini Children' s Research Hospital, Genoa (Italy); Bellini, C.; Bonacci, W.; Bartocci, M.; Serra, G. [Department of Pediatrics, Neonatal Intensive Care Unit, University of Genoa, G. Gaslini Children' s Research Hospital, Largo G. Gaslini, 5, I-16147 Genoa (Italy)

    1999-07-01

    Neonatal hemochromatosis is a rare congenital disorder which affects both fetuses and newborns. It is characterized by hepatocellular failure, often appearing on the first day of life in the form of coagulopathy, hypoalbuminemia, hypoglycemia, and jaundice. Most of the affected infants die early in life, and definitive diagnosis has often been made only by post-mortem evaluation. With the help of MRI, plus increasing awareness of the disorder, diagnosis is now often made early, even in utero. Duplex Doppler sonography does not provide information on siderosis but shows abnormalities in the liver or blood-flow patterns associated with liver disease. (orig.)

  2. Doppler shift of the quiet region measured by meridional scans with the EUV Imaging Spectrometer onboard Hinode

    CERN Document Server

    Kitagawa, N; Yokoyama, T

    2015-01-01

    Spatially averaged (> 50'') EUV spectral lines in the transition region of solar quiet regions are known to be redshifted. Because the mechanism underlying this phenomenon is unclear, we require additional physical information on the lower corona for limiting the theoretical models. To acquire this information, we measured the Doppler shifts over a wide coronal temperature range (log T[K]=5.7--6.3) using the spectroscopic data taken by the Hinode EUV Imaging Spectrometer. By analyzing the data over the center-to-limb variations covering the meridian from the south to the north pole, we successfully measured the velocity to an accuracy of 3 km/s. Below log T[K] = 6.0, the Doppler shifts of the emission lines were almost zero with an error of 1--3 km/s; above this temperature, they were blueshifted with a gradually increasing magnitude, reaching - 6.3 +/- 2.1 km/s at log T[K]=6.25.

  3. Avaliação com Doppler colorido e espectral da veia porta de cães Evaluation of portal vein in dogs by color and spectral Doppler imaging

    Directory of Open Access Journals (Sweden)

    Raquel Sartor

    2009-04-01

    Full Text Available A perfusão total do fígado e suas contribuições relativas, pelo sistema portal e pela artéria hepática, podem estar alteradas por vários processos hepáticos, como doença hepato-celular difusa, neoplasia e shunts intra-hepáticos. O estudo do comportamento do fluxo sangüíneo nos vasos do fígado por meio da ultra-sonografia Doppler tem demonstrado que este é um método viável não-invasivo e de grande auxílio, principalmente na avaliação da hemodinâmica portal. São duas as modalidades de ultra-sonografia Doppler com maior aplicação na rotina para avaliação de fluxo nos vasos abdominais, o Doppler espectral e o Doppler colorido. Na doença hepática crônica, ocorre alteração da complacência hepática devido à fibrose ou à cirrose, as quais acarretam alterações vasculares, levando ao aumento da pressão venosa portal. As principais indicações desse exame são os casos em que há suspeita de hipertensão portal. A hemodinâmica portal é avaliada pela mensuração de sua área, da velocidade média, do volume de fluxo no vaso e do índice de congestão portal. Esta revisão de literatura tem como objetivo descrever os princípios físicos básicos da ultra-sonografia Doppler e sua aplicação na avaliação da hemodinâmica portal nos cães.Total hepatic perfusion by portal system and hepatic arteria as well as its respective average contributions, can be affected for several hepatic processes, such as diffuse liver disease, neoplasm and intrahepatic shunts. Blood flow exams of the liver vessels using Doppler ultrasonography, appeared as a viable, non-invasive and helpful diagnostic method for the hemoportal dynamic evaluation. There are two Doppler ultrasonographic modalities most frequently used in routine for evaluation of the abdominal vessels flow, spectral Doppler imaging and color-flow Doppler imaging. In chronic liver disease, alteration of hepatic complacency occurs because of either fibrosis or cirrhosis

  4. Wide-field lensfree imaging of tissue slides

    Science.gov (United States)

    Morel, Sophie Nhu An; Delon, Antoine; Blandin, Pierre; Bordy, Thomas; Cioni, Olivier; Hervé, Lionel; Fromentin, Catherine; Dinten, Jean-Marc; Allier, Cédric

    2015-07-01

    We developed a new imaging tool that can help pathologists in recording wide-field images of tissue slides. We present a simple cost-effective lens-free imaging method to record 2-4μm resolution wide-field (10 mm2 - 6 cm2) images of stained and unstained tissue slides. To our knowledge, our method is the first technique that enables fast (less than 5 minutes) wide-field lens-free imaging of such dense samples. Multiple holograms are recorded with different wavelength illumination, and a multispectral algorithm is used to retrieve both amplitude and phase. Our method can be used to retrieve images of stained tissue slides. For such absorbing object, the useful information is included in the modulus of the reconstructed complex field. Our method can also be applied to retrieve images of unstained tissue slides, where the useful information is in the retrieved phase. This technique is much cheaper and compact than a conventional microscope and could be made portable. Moreover, it enables wide field unstained tissue slides imaging, which could quickly provide useful information, for example on frozen section biopsies, when a rapid diagnosis is needed during surgery.

  5. Imaging of connective tissue diseases of the head and neck.

    Science.gov (United States)

    Abdel Razek, Ahmed Abdel Khalek

    2016-06-01

    We review the imaging appearance of connective tissue diseases of the head and neck. Bilateral sialadenitis and dacryoadenitis are seen in Sjögren's syndrome; ankylosis of the temporo-mandibular joint with sclerosis of the crico-arytenoid joint are reported in rheumatoid arthritis and lupus panniculitis with atypical infection are reported in patients with systemic lupus erythematosus. Relapsing polychondritis shows subglottic stenosis, prominent ear and saddle nose; progressive systemic sclerosis shows osteolysis of the mandible, fibrosis of the masseter muscle with calcinosis of the subcutaneous tissue and dermatomyositis/polymyositis shows condylar erosions and autoimmune thyroiditis. Vascular thrombosis is reported in antiphospholipid antibodies syndrome; cervical lymphadenopathy is seen in adult-onset Still's disease, and neuropathy with thyroiditis reported in mixed connective tissue disorder. Imaging is important to detect associated malignancy with connective tissue disorders. Correlation of the imaging findings with demographic data and clinical findings are important for the diagnosis of connective tissue disorders.

  6. Brain tumor imaging of rat fresh tissue using terahertz spectroscopy

    Science.gov (United States)

    Yamaguchi, Sayuri; Fukushi, Yasuko; Kubota, Oichi; Itsuji, Takeaki; Ouchi, Toshihiko; Yamamoto, Seiji

    2016-07-01

    Tumor imaging by terahertz spectroscopy of fresh tissue without dye is demonstrated using samples from a rat glioma model. The complex refractive index spectrum obtained by a reflection terahertz time-domain spectroscopy system can discriminate between normal and tumor tissues. Both the refractive index and absorption coefficient of tumor tissues are higher than those of normal tissues and can be attributed to the higher cell density and water content of the tumor region. The results of this study indicate that terahertz technology is useful for detecting brain tumor tissue.

  7. In vivo spectral micro-imaging of tissue

    Science.gov (United States)

    Demos, Stavros G; Urayama, Shiro; Lin, Bevin; Saroufeem, Ramez; Ghobrial, Moussa

    2012-11-27

    In vivo endoscopic methods an apparatuses for implementation of fluorescence and autofluorescence microscopy, with and without the use of exogenous agents, effectively (with resolution sufficient to image nuclei) visualize and categorize various abnormal tissue forms.

  8. Infrared thermal imaging in connective tissue diseases.

    Science.gov (United States)

    Chojnowski, Marek

    2017-01-01

    Infrared thermal imaging (IRT) is a non-invasive, non-contact technique which allows one to measure and visualize infrared radiation. In medicine, thermal imaging has been used for more than 50 years in various clinical settings, including Raynaud's phenomenon and systemic sclerosis. Imaging and quantification of surface body temperature provides an indirect measure of the microcirculation's overall performance. As such, IRT is capable of confirming the diagnosis of Raynaud's phenomenon, and, with additional cold or heat challenge, of differentiating between the primary and secondary condition. In systemic sclerosis IRT has a potential role in assessing disease activity and monitoring treatment response. Despite certain limitations, thermal imaging can find a place in clinical practice, and with the introduction of small, low-cost infrared cameras, possibly become a part of routine rheumatological evaluation.

  9. Imaging with second-harmonic radiation probes in living tissue.

    Science.gov (United States)

    Grange, Rachel; Lanvin, Thomas; Hsieh, Chia-Lung; Pu, Ye; Psaltis, Demetri

    2011-09-01

    We demonstrate that second-harmonic radiation imaging probes are efficient biomarkers for imaging in living tissue. We show that 100 nm and 300 nm BaTiO(3) nanoparticles used as contrast markers could be detected through 50 μm and 120 μm of mouse tail tissue in vitro or in vivo. Experimental results and Monte-Carlo simulations are in good agreement.

  10. Imaging with second-harmonic radiation probes in living tissue

    OpenAIRE

    GRANGE, Rachel; Lanvin, Thomas; Hsieh, Chia-Lung; Pu, Ye; Psaltis, Demetri

    2011-01-01

    We demonstrate that second-harmonic radiation imaging probes are efficient biomarkers for imaging in living tissue. We show that 100 nm and 300 nm BaTiO_3 nanoparticles used as contrast markers could be detected through 50 μm and 120 μm of mouse tail tissue in vitro or in vivo. Experimental results and Monte-Carlo simulations are in good agreement.

  11. Quantitative permeability imaging of plant tissues

    NARCIS (Netherlands)

    Sibgatullin, T.; Vergeldt, F.J.; Gerkema, E.; As, van H.

    2010-01-01

    A method for mapping tissue permeability based on time-dependent diffusion measurements is presented. A pulsed field gradient sequence to measure the diffusion encoding time dependence of the diffusion coefficients based on the detection of stimulated spin echoes to enable long diffusion times is co

  12. Digital pathology and image analysis in tissue biomarker research.

    Science.gov (United States)

    Hamilton, Peter W; Bankhead, Peter; Wang, Yinhai; Hutchinson, Ryan; Kieran, Declan; McArt, Darragh G; James, Jacqueline; Salto-Tellez, Manuel

    2014-11-01

    Digital pathology and the adoption of image analysis have grown rapidly in the last few years. This is largely due to the implementation of whole slide scanning, advances in software and computer processing capacity and the increasing importance of tissue-based research for biomarker discovery and stratified medicine. This review sets out the key application areas for digital pathology and image analysis, with a particular focus on research and biomarker discovery. A variety of image analysis applications are reviewed including nuclear morphometry and tissue architecture analysis, but with emphasis on immunohistochemistry and fluorescence analysis of tissue biomarkers. Digital pathology and image analysis have important roles across the drug/companion diagnostic development pipeline including biobanking, molecular pathology, tissue microarray analysis, molecular profiling of tissue and these important developments are reviewed. Underpinning all of these important developments is the need for high quality tissue samples and the impact of pre-analytical variables on tissue research is discussed. This requirement is combined with practical advice on setting up and running a digital pathology laboratory. Finally, we discuss the need to integrate digital image analysis data with epidemiological, clinical and genomic data in order to fully understand the relationship between genotype and phenotype and to drive discovery and the delivery of personalized medicine.

  13. Second harmonic generation imaging of fascia within thick tissue block

    Science.gov (United States)

    Pfeffer, Christian P.; Olsen, Bjorn R.; Légaré, François

    2007-06-01

    Comparing the SHG image formation for thin sections of tail tendon fascia and skeletal muscle fascia, we demonstrate that the forward (F) and backward (B) SHG images are vastly different. In addition, despite the different arrangement of the collagen Type I fibrillar architecture forming these two fascias, their ratios of forward over backward signal (F/B) are nearly equal. SHG images of thick tissue blocks of the fascia-muscle unit show only backward features, as opposed to SHG images of tissue blocks of the fascia-tendon unit. These images are an amalgamation of forward and backward features due to the backscattering of forward components within tendon. These forward features disappear when this tissue block is immersed in glycerol as backscattering is hereby suppressed.

  14. NMR imaging of cell phone radiation absorption in brain tissue

    OpenAIRE

    Gultekin, David H.; Moeller, Lothar

    2012-01-01

    A method is described for measuring absorbed electromagnetic energy radiated from cell phone antennae into ex vivo brain tissue. NMR images the 3D thermal dynamics inside ex vivo bovine brain tissue and equivalent gel under exposure to power and irradiation time-varying radio frequency (RF) fields. The absorbed RF energy in brain tissue converts into Joule heat and affects the nuclear magnetic shielding and the Larmor precession. The resultant temperature increase is measured by the resonance...

  15. Doppler imaging of chemical spots on magnetic Ap/Bp stars. Numerical tests and assessment of systematic errors

    CERN Document Server

    Kochukhov, O

    2016-01-01

    Doppler imaging (DI) is a powerful spectroscopic inversion technique that enables conversion of a line profile time series into a two-dimensional map of the stellar surface inhomogeneities. In this paper we investigate the accuracy of chemical abundance DI of Ap/Bp stars and assess the impact of several different systematic errors on the reconstructed spot maps. We simulate spectroscopic observational data for different spot distributions in the presence of a moderately strong dipolar magnetic field. We then reconstruct chemical maps using different sets of spectral lines and making different assumptions about line formation in the inversion calculations. Our numerical experiments demonstrate that a modern DI code successfully recovers the input chemical spot distributions comprised of multiple circular spots at different latitudes or an element overabundance belt at the magnetic equator. For the optimal reconstruction the average reconstruction errors do not exceed ~0.10 dex. The errors increase to about 0.1...

  16. Blood perfusion values of laser speckle contrast imaging and laser Doppler flowmetry: is a direct comparison possible?

    Science.gov (United States)

    Binzoni, Tiziano; Humeau-Heurtier, Anne; Abraham, Pierre; Mahe, Guillaume

    2013-05-01

    Laser Doppler flowmetry (LDF) and laser speckle contrast imaging (LSCI) allow the monitoring of microvascular blood perfusion. The relationship between the measurements obtained by these two techniques remains unclear. In the present contribution, we demonstrate, experimentally and theoretically, that skin blood flow measurements obtained by LDF and LSCI techniques cannot be compared directly even after "classical" normalization procedure. This technical problem is generated by the nonlinear relationship existing between LDF and LSCI flow data. The experiments have been performed on five healthy voluntary subjects (forearm) by using repeated ischemia/reperfusion cycles to induce the necessary skin blood flow changes. LDF and LSCI data were simultaneously acquired on the same region of interest. Considering the importance of this problem from the clinical point of view, it is concluded that the definition of new corrected algorithms for LSCI is probably a mandatory step that must be taken into account if LDF and LSCI blood flow have to be compared.

  17. Revisiting the Rigidly Rotating Magnetosphere model for $\\sigma$ Ori E - II. Magnetic Doppler imaging, arbitrary field RRM, and light variability

    CERN Document Server

    Oksala, M E; Krticka, J; Townsend, R H D; Wade, G A; Prvak, M; Mikulasek, Z; Silvester, J; Owocki, S P

    2015-01-01

    The initial success of the Rigidly Rotating Magnetosphere (RRM) model application to the B2Vp star sigma OriE by Townsend, Owocki & Groote (2005) triggered a renewed era of observational monitoring of this archetypal object. We utilize high-resolution spectropolarimetry and the magnetic Doppler imaging (MDI) technique to simultaneously determine the magnetic configuration, which is predominately dipolar, with a polar strength Bd = 7.3-7.8 kG and a smaller non-axisymmetric quadrupolar contribution, as well as the surface distribution of abundance of He, Fe, C, and Si. We describe a revised RRM model that now accepts an arbitrary surface magnetic field configuration, with the field topology from the MDI models used as input. The resulting synthetic Ha emission and broadband photometric observations generally agree with observations, however, several features are poorly fit. To explore the possibility of a photospheric contribution to the observed photometric variability, the MDI abundance maps were used to ...

  18. Differentiating fatty and non-fatty tissue using photoacoustic imaging

    Science.gov (United States)

    Pan, Leo; Rohling, Robert; Abolmaesumi, Purang; Salcudean, Septimiu; Tang, Shuo

    2014-03-01

    In this paper, we demonstrate a temporal-domain intensity-based photoacoustic imaging method that can differentiate between fatty and non-fatty tissues. PA pressure intensity is partly dependent on the tissue's speed of sound, which increases as temperature increases in non-fatty tissue and decreases in fatty tissue. Therefore, by introducing a temperature change in the tissue and subsequently monitoring the change of the PA intensity, it is possible to distinguish between the two types of tissue. A commercial ultrasound system with a 128-element 5-14 MHz linear array transducer and a tunable ND:YAG laser were used to produce PA images. Ex-vivo bovine fat and porcine liver tissues were precooled to below 10°C and then warmed to room-temperature over ~1 hour period. A thermocouple monitored the temperature rise while PA images were acquired at 0.5°C intervals. The averaged intensity of the illuminated tissue region at each temperature interval was plotted and linearly fitted. Liver samples showed a mean increase of 2.82 %/°C, whereas bovine fat had a mean decrease of 6.24 %/°C. These results demonstrate that this method has the potential to perform tissue differentiation in the temporal-domain.

  19. Measurement of retinal blood flow in the rat by combining Doppler Fourier-domain optical coherence tomography with fundus imaging

    Science.gov (United States)

    Werkmeister, René M.; Vietauer, Martin; Knopf, Corinna; Fürnsinn, Clemens; Leitgeb, Rainer A.; Reitsamer, Herbert; Gröschl, Martin; Garhöfer, Gerhard; Vilser, Walthard; Schmetterer, Leopold

    2014-10-01

    A wide variety of ocular diseases are associated with abnormalities in ocular circulation. As such, there is considerable interest in techniques for quantifying retinal blood flow, among which Doppler optical coherence tomography (OCT) may be the most promising. We present an approach to measure retinal blood flow in the rat using a new optical system that combines the measurement of blood flow velocities via Doppler Fourier-domain optical coherence tomography and the measurement of vessel diameters using a fundus camera-based technique. Relying on fundus images for extraction of retinal vessel diameters instead of OCT images improves the reliability of the technique. The system was operated with an 841-nm superluminescent diode and a charge-coupled device camera that could be operated at a line rate of 20 kHz. We show that the system is capable of quantifying the response of 100% oxygen breathing on the retinal blood flow. In six rats, we observed a decrease in retinal vessel diameters of 13.2% and a decrease in retinal blood velocity of 42.6%, leading to a decrease in retinal blood flow of 56.7%. Furthermore, in four rats, the response of retinal blood flow during stimulation with diffuse flicker light was assessed. Retinal vessel diameter and blood velocity increased by 3.4% and 28.1%, respectively, leading to a relative increase in blood flow of 36.2%;. The presented technique shows much promise to quantify early changes in retinal blood flow during provocation with various stimuli in rodent models of ocular diseases in rats.

  20. Calibrating Doppler imaging of preterm intracerebral circulation using a microvessel flow phantom

    Directory of Open Access Journals (Sweden)

    Fleur A. Camfferman

    2015-01-01

    Full Text Available Introduction. Preterm infants are born during critical stages of brain development, in which the adaptive capacity of the fetus to extra-uterine environment is limited. Inadequate brain perfusion has been directly linked to preterm brain damage. Advanced high-frequency ultrasound probes and processing algorithms allow visualization of microvessels and depiction of regional variation. To assess whether visualization and flow velocity estimates of preterm cerebral perfusion using Doppler techniques is accurate, we conducted an in vitro experiment using a microvessel flow phantom.Materials and Methods. An in-house developed flow phantom containing two microvessels (inner diameter 200 and 700 microns with attached syringe pumps, filled with blood-mimicking fluid, was used to generate non-pulsatile perfusion of variable flow. Measurements were performed using an Esaote MyLab70 scanner.Results. Microvessel mimicking catheters with velocities as low as 1cm/sec were adequately visualized with a linear ultrasound probe. With a convex probe velocities <2 cm/sec could not be depicted. Within settings, velocity and diameter measurements were highly reproducible (intra class correlation 0.997 (95% CI 0.996-0.998 and 0.914 (0.864-0.946. Overall, mean velocity was overestimated up to 3-fold, especially in high velocity ranges. Significant differences were seen in velocity measurements when using steer angle correction and in vessel diameter estimation (p<0.05.Conclusion. Visualization of microvessel size catheters mimicking small brain vessels is feasible. Reproducible velocity and diameter results can be obtained, although important overestimation of the values is observed. Before velocity estimates of microcirculation can find its use in clinical practice, calibration of the ultrasound machine for any specific Doppler purpose is essential. The ultimate goal is to develop a sonographic tool that can be used for objective study of regional perfusion in routine

  1. Steerable Doppler transducer probes

    Energy Technology Data Exchange (ETDEWEB)

    Fidel, H.F.; Greenwood, D.L.

    1986-07-22

    An ultrasonic diagnostic probe is described which is capable of performing ultrasonic imaging and Doppler measurement consisting of: a hollow case having an acoustic window which passes ultrasonic energy and including chamber means for containing fluid located within the hollow case and adjacent to a portion of the acoustic window; imaging transducer means, located in the hollow case and outside the fluid chamber means, and oriented to direct ultrasonic energy through the acoustic window toward an area which is to be imaged; Doppler transducer means, located in the hollow case within the fluid chamber means, and movably oriented to direct Doppler signals through the acoustic window toward the imaged area; means located within the fluid chamber means and externally controlled for controllably moving the Doppler transducer means to select one of a plurality of axes in the imaged area along which the Doppler signals are to be directed; and means, located external to the fluid chamber means and responsive to the means for moving, for providing an indication signal for identifying the selected axis.

  2. X-ray Phase Contrast Imaging of Calcified Tissue and Biomaterial Structure in Bioreactor Engineered Tissues

    Energy Technology Data Exchange (ETDEWEB)

    Appel, Alyssa A. [Illinois Inst. of Technology, Chicago, IL (United States); Edward Hines Jr. VA Hospital, IL (United States); Larson, Jeffery C. [Illinois Inst. of Technology, Chicago, IL (United States); Edward Hines Jr. VA Hospital, IL (United States); Garson, III, Alfred B. [George Washington Univ., Washington, DC (United States); Guan, Huifeng [George Washington Univ., Washington, DC (United States); Zhong, Zhong [Brookhaven National Lab. (BNL), Upton, NY (United States); Nguyen, Bao-Ngoc [Univ. of Maryland, College Park, MD (United States); Fisher, John P. [Univ. of Maryland, College Park, MD (United States); Anastasio, Mark A. [George Washington Univ., Washington, DC (United States); Brey, Eric M. [Illinois Inst. of Technology, Chicago, IL (United States); Edward Hines Jr. VA Hospital, IL (United States)

    2014-11-04

    Tissues engineered in bioreactor systems have been used clinically to replace damaged tissues and organs. In addition, these systems are under continued development for many tissue engineering applications. The ability to quantitatively assess material structure and tissue formation is critical for evaluating bioreactor efficacy and for preimplantation assessment of tissue quality. These techniques allow for the nondestructive and longitudinal monitoring of large engineered tissues within the bioreactor systems and will be essential for the translation of these strategies to viable clinical therapies. X-ray Phase Contrast (XPC) imaging techniques have shown tremendous promise for a number of biomedical applications owing to their ability to provide image contrast based on multiple X-ray properties, including absorption, refraction, and scatter. In this research, mesenchymal stem cell-seeded alginate hydrogels were prepared and cultured under osteogenic conditions in a perfusion bioreactor. The constructs were imaged at various time points using XPC microcomputed tomography (µCT). Imaging was performed with systems using both synchrotron- and tube-based X-ray sources. XPC µCT allowed for simultaneous three-dimensional (3D) quantification of hydrogel size and mineralization, as well as spatial information on hydrogel structure and mineralization. Samples were processed for histological evaluation and XPC showed similar features to histology and quantitative analysis consistent with the histomorphometry. Furthermore, these results provide evidence of the significant potential of techniques based on XPC for noninvasive 3D imaging engineered tissues grown in bioreactors.

  3. X-ray phase contrast imaging of calcified tissue and biomaterial structure in bioreactor engineered tissues.

    Science.gov (United States)

    Appel, Alyssa A; Larson, Jeffery C; Garson, Alfred B; Guan, Huifeng; Zhong, Zhong; Nguyen, Bao-Ngoc B; Fisher, John P; Anastasio, Mark A; Brey, Eric M

    2015-03-01

    Tissues engineered in bioreactor systems have been used clinically to replace damaged tissues and organs. In addition, these systems are under continued development for many tissue engineering applications. The ability to quantitatively assess material structure and tissue formation is critical for evaluating bioreactor efficacy and for preimplantation assessment of tissue quality. Techniques that allow for the nondestructive and longitudinal monitoring of large engineered tissues within the bioreactor systems will be essential for the translation of these strategies to viable clinical therapies. X-ray Phase Contrast (XPC) imaging techniques have shown tremendous promise for a number of biomedical applications owing to their ability to provide image contrast based on multiple X-ray properties, including absorption, refraction, and scatter. In this research, mesenchymal stem cell-seeded alginate hydrogels were prepared and cultured under osteogenic conditions in a perfusion bioreactor. The constructs were imaged at various time points using XPC microcomputed tomography (µCT). Imaging was performed with systems using both synchrotron- and tube-based X-ray sources. XPC µCT allowed for simultaneous three-dimensional (3D) quantification of hydrogel size and mineralization, as well as spatial information on hydrogel structure and mineralization. Samples were processed for histological evaluation and XPC showed similar features to histology and quantitative analysis consistent with the histomorphometry. These results provide evidence of the significant potential of techniques based on XPC for noninvasive 3D imaging engineered tissues grown in bioreactors.

  4. Adaptive image segmentation applied to plant reproduction by tissue culture

    Science.gov (United States)

    Vazquez Rueda, Martin G.; Hahn, Federico; Zapata, Jose L.

    1997-04-01

    This paper presents that experimental results obtained on indoor tissue culture using the adaptive image segmentation system. The performance of the adaptive technique is contrasted with different non-adaptive techniques commonly used in the computer vision field to demonstrate the improvement provided by the adaptive image segmentation system.

  5. Breast Imaging after Breast Augmentation with Autologous Tissues

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Kyu Won; Seo, Bo Kyung; Shim, Eddeum; Song, Sung Eun; Cho, Kyu Ran [Dept. of Radiology, Korea University Anam Hospital, Seoul (Korea, Republic of); Yoon, Eul Sik [Korea University Ansan Hospital, Ansan (Korea, Republic of); Woo, Ok Hee [Dept. of Radiology, Korea University Guro Hospital, Seoul (Korea, Republic of)

    2012-06-15

    The use of autologous tissue transfer for breast augmentation is an alternative to using foreign implant materials. The benefits of this method are the removal of unwanted fat from other body parts, no risk of implant rupture, and the same feel as real breast tissue. However, sometimes there is a dilemma about whether or not to biopsy for calcifications or masses detected after the procedure is completed. The purpose of this study is to illustrate the procedures of breast augmentation with autologous tissues, the imaging features of various complications, and the role of imaging in the diagnosis and management of complications and hidden breast diseases.

  6. Three-dimensional ultrasonic Nakagami imaging for tissue characterization

    Energy Technology Data Exchange (ETDEWEB)

    Tsui, Po-Hsiang [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan (China); Hsu, Cheng-Wei; Chang, Chien-Cheng [Division of Mechanics, Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan (China); Ho, Ming-Chih [Department of Surgery, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan (China); Chen, Yung-Sheng [Department of Electrical Engineering, Yuan Ze University, Chung Li, Taiwan (China); Lin, Jen-Jen [Department of Applied Statistics and Information Science, Ming Chuan University, Taoyuan, Taiwan (China); Chu, Chin-Chou, E-mail: mechang@iam.ntu.edu.t [Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan (China)

    2010-10-07

    The two-dimensional (2D) Nakagami image complements the ultrasound B-scan image when attempting to visualize the scatterer properties of tissues. The resolution of the Nakagami image is lower than that of the B-scan image, since the former is produced by processing the raw envelope data using a 2D sliding window with side lengths typically corresponding to three times the pulse length of the incident ultrasound. This paper proposes using three-dimensional (3D) Nakagami imaging for improving the resolution of the obtained Nakagami image and providing more complete information of scatterers for a better tissue characterization. The 3D Nakagami image is based on a voxel array composed of the Nakagami parameters constructed using a 3D sliding cube to process the 3D backscattered raw data. Experiments on phantoms with different scatterer concentrations were carried out to determine the optimal size of the sliding cube for a stable estimation of the Nakagami parameter. Tissue measurements on rat livers without and with fibrosis formation were further used to explore the practical feasibility of 3D Nakagami imaging. The results indicated that the side length of the cube used to construct the 3D Nakagami image must be at least two times the pulse length, which improved the resolution for each Nakagami image frame in the 3D Nakagami image. The results further demonstrated that the 3D Nakagami image is better than the conventional 2D Nakagami image for complementing the B-scan in detecting spatial variations in the scatterer concentration and classifying normal and fibrotic livers. This study suggests that 3D Nakagami imaging has the potential to become a new 3D quantitative imaging approach.

  7. Three-dimensional ultrasonic Nakagami imaging for tissue characterization

    Science.gov (United States)

    Tsui, Po-Hsiang; Hsu, Cheng-Wei; Ho, Ming-Chih; Chen, Yung-Sheng; Lin, Jen-Jen; Chang, Chien-Cheng; Chu, Chin-Chou

    2010-10-01

    The two-dimensional (2D) Nakagami image complements the ultrasound B-scan image when attempting to visualize the scatterer properties of tissues. The resolution of the Nakagami image is lower than that of the B-scan image, since the former is produced by processing the raw envelope data using a 2D sliding window with side lengths typically corresponding to three times the pulse length of the incident ultrasound. This paper proposes using three-dimensional (3D) Nakagami imaging for improving the resolution of the obtained Nakagami image and providing more complete information of scatterers for a better tissue characterization. The 3D Nakagami image is based on a voxel array composed of the Nakagami parameters constructed using a 3D sliding cube to process the 3D backscattered raw data. Experiments on phantoms with different scatterer concentrations were carried out to determine the optimal size of the sliding cube for a stable estimation of the Nakagami parameter. Tissue measurements on rat livers without and with fibrosis formation were further used to explore the practical feasibility of 3D Nakagami imaging. The results indicated that the side length of the cube used to construct the 3D Nakagami image must be at least two times the pulse length, which improved the resolution for each Nakagami image frame in the 3D Nakagami image. The results further demonstrated that the 3D Nakagami image is better than the conventional 2D Nakagami image for complementing the B-scan in detecting spatial variations in the scatterer concentration and classifying normal and fibrotic livers. This study suggests that 3D Nakagami imaging has the potential to become a new 3D quantitative imaging approach.

  8. Ontology-based, Tissue MicroArray oriented, image centered tissue bank

    Directory of Open Access Journals (Sweden)

    Viti Federica

    2008-04-01

    Full Text Available Abstract Background Tissue MicroArray technique is becoming increasingly important in pathology for the validation of experimental data from transcriptomic analysis. This approach produces many images which need to be properly managed, if possible with an infrastructure able to support tissue sharing between institutes. Moreover, the available frameworks oriented to Tissue MicroArray provide good storage for clinical patient, sample treatment and block construction information, but their utility is limited by the lack of data integration with biomolecular information. Results In this work we propose a Tissue MicroArray web oriented system to support researchers in managing bio-samples and, through the use of ontologies, enables tissue sharing aimed at the design of Tissue MicroArray experiments and results evaluation. Indeed, our system provides ontological description both for pre-analysis tissue images and for post-process analysis image results, which is crucial for information exchange. Moreover, working on well-defined terms it is then possible to query web resources for literature articles to integrate both pathology and bioinformatics data. Conclusions Using this system, users associate an ontology-based description to each image uploaded into the database and also integrate results with the ontological description of biosequences identified in every tissue. Moreover, it is possible to integrate the ontological description provided by the user with a full compliant gene ontology definition, enabling statistical studies about correlation between the analyzed pathology and the most commonly related biological processes.

  9. Multimodal tissue perfusion imaging using multi-spectral and thermographic imaging systems applied on clinical data

    Science.gov (United States)

    Klaessens, John H. G. M.; Nelisse, Martin; Verdaasdonk, Rudolf M.; Noordmans, Herke Jan

    2013-03-01

    Clinical interventions can cause changes in tissue perfusion, oxygenation or temperature. Real-time imaging of these phenomena could be useful for surgical strategy or understanding of physiological regulation mechanisms. Two noncontact imaging techniques were applied for imaging of large tissue areas: LED based multispectral imaging (MSI, 17 different wavelengths 370 nm-880 nm) and thermal imaging (7.5 to 13.5 μm). Oxygenation concentration changes were calculated using different analyzing methods. The advantages of these methods are presented for stationary and dynamic applications. Concentration calculations of chromophores in tissue require right choices of wavelengths The effects of different wavelength choices for hemoglobin concentration calculations were studied in laboratory conditions and consequently applied in clinical studies. Corrections for interferences during the clinical registrations (ambient light fluctuations, tissue movements) were performed. The wavelength dependency of the algorithms were studied and wavelength sets with the best results will be presented. The multispectral and thermal imaging systems were applied during clinical intervention studies: reperfusion of tissue flap transplantation (ENT), effectiveness of local anesthetic block and during open brain surgery in patients with epileptic seizures. The LED multispectral imaging system successfully imaged the perfusion and oxygenation changes during clinical interventions. The thermal images show local heat distributions over tissue areas as a result of changes in tissue perfusion. Multispectral imaging and thermal imaging provide complementary information and are promising techniques for real-time diagnostics of physiological processes in medicine.

  10. Correlation of ascending aorta elasticity and the severity of coronary artery stenosis in hypertensive patients with coronary heart disease assessed by M-mode and tissue Doppler echocardiography.

    Science.gov (United States)

    Lu, Qixiu; Liu, Houlin

    2015-03-01

    The main objective of this study is to investigate the relationship between ascending aorta elasticity and the severity of coronary artery stenosis in essential hypertensive patients with coronary heart disease (CHD) using M-mode and tissue Doppler echocardiography. A total of 184 hypertensive patients with CHD were enrolled. Patients were divided into three groups based on the severity of coronary stenosis measured by coronary arteriography (CAG): slight stenosis (group 1), moderate stenosis (group 2) and serious stenosis (group 3). M-mode and tissue Doppler echocardiography were performed, and elasticity indexes of ascending aorta including stiffness index, distensibility index, and S wave speed of anterior wall were calculated and correlated with the severity of coronary stenosis. Ascending aorta stiffness index was increased, whereas distensibility index and S wave speed of anterior wall were decreased in moderate and severe stenosis groups compared with slight stenosis group (P coronary artery, and there was a significant correlation between aortic elasticity and severity of coronary artery by Pearson correlation analysis (P coronary stenosis. Elasticity indexes of ascending aorta can serve as predictors for coronary arterial lesion in hypertensive patients.

  11. Determinants and Regression Equations for the Calculation of z Scores of Left Ventricular Tissue Doppler Longitudinal Indexes in a Healthy Italian Pediatric Population

    Directory of Open Access Journals (Sweden)

    Veronica Fibbi

    2015-01-01

    Full Text Available Aim. We investigated the predictors of tissue Doppler left ventricular (LV longitudinal indexes in a healthy Italian pediatric population and established normative data and regression equations for the calculation of z scores. Methods and Results. A total of 369 healthy subjects aged 1–17 years (age of 6.4 ± 1.1 years, 49.1% female underwent echocardiography. LV peak longitudinal velocity at systole (s', early diastole (e', and late diastole (a' was determined by tissue Doppler. The ratio of peak early diastolic LV filling velocity to e' was calculated. Age was the only independent determinant of s' (β=0.491, p<0.0001 and the strongest determinant of e' (β=0.334, p<0.0001 and E/e' (β=-0.369, p<0.0001. Heart rate was the main determinant of a' (β=0.265, p<0.0001. Male gender showed no effects except for a weak association with lateral s', suggesting no need of gender-specific reference ranges. Age-specific reference ranges, regression equations, and scatterplots for the calculation of z scores were determined for each index. Conclusion. In a pediatric Italian population, age was the strongest determinant of LV longitudinal dynamics. The availability of age-specific normality data for the calculation of z scores may allow for correctly detecting LV dysfunction in pediatric pathological populations.

  12. Ontology-based, Tissue MicroArray oriented, image centered tissue bank

    OpenAIRE

    Viti Federica; Merelli Ivan; Caprera Andrea; Lazzari Barbara; Stella Alessandra; Milanesi Luciano

    2008-01-01

    Abstract Background Tissue MicroArray technique is becoming increasingly important in pathology for the validation of experimental data from transcriptomic analysis. This approach produces many images which need to be properly managed, if possible with an infrastructure able to support tissue sharing between institutes. Moreover, the available frameworks oriented to Tissue MicroArray provide good storage for clinical patient, sample treatment and block construction information, but their util...

  13. Photoacoustic imaging in both soft and hard biological tissue

    Energy Technology Data Exchange (ETDEWEB)

    Li, T; Dewhurst, R J, E-mail: richard.dewhurst@manchester.ac.u [Photon Science Institute, University of Manchester, Alan Turing Building, Oxford road, Manchester, M13 9PL (United Kingdom)

    2010-03-01

    To date, most Photoacoustic (PA) imaging results have been from soft biotissues. In this study, a PA imaging system with a near-infrared pulsed laser source has been applied to obtain 2-D and 3-D images from both soft tissue and post-mortem dental samples. Imaging results showed that the PA technique has the potential to image human oral disease, such as early-stage teeth decay. For non-invasive photoacoustic imaging, the induced temperature and pressure rises within biotissues should not cause physical damage to the tissue. Several simulations based on the thermoelastic effect have been applied to predict initial temperature and pressure fields within a tooth sample. Predicted initial temperature and pressure rises are below corresponding safety limits.

  14. Detection of Breast Microcalcifications Under Ultrasound Using Power Doppler and Acoustic Resonance Imaging

    Science.gov (United States)

    2003-07-01

    2241 010511 imaging, including magnetic resonance Radiology 2002; 224:265-269 Calcium carbonate particles embed- imaging, scintigraphy , and...characterize calcifications. digitized M-mode images: gestational dif- ways feasible because calcifications can- ferences of fetal lung . Ultrasound Med Biol

  15. Measurement depth enhancement in terahertz imaging of biological tissues.

    Science.gov (United States)

    Oh, Seung Jae; Kim, Sang-Hoon; Jeong, Kiyoung; Park, Yeonji; Huh, Yong-Min; Son, Joo-Hiuk; Suh, Jin-Suck

    2013-09-09

    We demonstrate the use of a THz penetration-enhancing agent (THz-PEA) to enhance the terahertz (THz) wave penetration depth in tissues. The THz-PEA is a biocompatible material having absorption lower than that of water, and it is easily absorbed into tissues. When using glycerol as a THz-PEA, the peak value of the THz signal which was transmitted through the fresh tissue and reflected by a metal target, was almost doubled compared to that of tissue without glycerol. THz time-of-flight imaging (B-scan) was used to display the sequential glycerol delivery images. Enhancement of the penetration depth was confirmed after an artificial tumor was located below fresh skin. We thus concluded that the THz-PEA technique can potentially be employed to enhance the image contrast of the abnormal lesions below the skin.

  16. Imaging through flesh tissue using fs electronic holographic gating method

    Institute of Scientific and Technical Information of China (English)

    侯比学; 陈国夫; 郝志琦; 丰善; 王淑岩; 王屹山; 王国志

    1999-01-01

    The experimental results of imaging through flesh tissue using fs electronic holographic gating method is reported. In the experiment, Ti: sapphire mode-locked laser is used as light source, of which the repetition rate is 100 MHz, central wavelength 800 mn, duration of pulse 20 fs, output power 80 mW. Tissue is a 7 mm thick chicken slice, and the imaged object is a metal wire with diameter of 0.5 mm. A general CCD is used to record holograms and a clear image of metal wire is obtained. Several relevant problems are discussed.

  17. In vivo multimodal nonlinear optical imaging of mucosal tissue

    Science.gov (United States)

    Sun, Ju; Shilagard, Tuya; Bell, Brent; Motamedi, Massoud; Vargas, Gracie

    2004-05-01

    We present a multimodal nonlinear imaging approach to elucidate microstructures and spectroscopic features of oral mucosa and submucosa in vivo. The hamster buccal pouch was imaged using 3-D high resolution multiphoton and second harmonic generation microscopy. The multimodal imaging approach enables colocalization and differentiation of prominent known spectroscopic and structural features such as keratin, epithelial cells, and submucosal collagen at various depths in tissue. Visualization of cellular morphology and epithelial thickness are in excellent agreement with histological observations. These results suggest that multimodal nonlinear optical microscopy can be an effective tool for studying the physiology and pathology of mucosal tissue.

  18. Performance evaluation of ultrasonic Nakagami image in tissue characterization.

    Science.gov (United States)

    Tsui, Po-Hsiang; Yeh, Chih-Kuang; Chang, Chien-Cheng; Chen, Wen-Shiang

    2008-04-01

    Conventional ultrasonic B-mode images qualitatively describe tissue structures but are unsuitable for quantitative analyses of scatterer properties. We have recently developed an ultrasonic parametric imaging technique based on the Nakagami statistical distribution that is able to quantify scatterer concentrations. The aim of the present study is to further explore both the behavior of a Nakagami image in characterizing different scatterer structures at different signal-to-noise ratios (SNRs) and the feasibility of Nakagami imaging using a general commercial ultrasound scanner for tissue examinations. Simulations, experiments on a tissue-mimicking phantom and in vitro measurements on a muscle tissue before and after microwave treatment were carried out. The SNR and contrast-to-noise ratio (CNR) were estimated to quantify image performance. The results demonstrate that a Nakagami image can differentiate different scatterer concentrations for single, hypoechoic and hyperechoic targets. Also, a Nakagami image, when combined with an ultrasound scanner, can complement the B-scan to characterize tissue and to identify the region of interest with a larger CNR. However, the noise effect can degrade the performance of a Nakagami image. When the signal SNR decreased to 15 dB in simulations and to 8 dB in experiments, the CNR of the hyperechoic Nakagami image decreased by 4% and 27%, respectively, and that of the hypoechoic one decreased by 42% and 80%, respectively. These results indicate that a Nakagami image behaves well in identifying regions with high scatterer concentrations but does not perform well when both the scatterer concentration and SNR are low.

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

    Science.gov (United States)

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

    2014-08-01

    Ultrasound Nakagami parametric imaging is a useful tool for tissue characterization. Previous literature has suggested using a square with side lengths corresponding to 3 times the transducer pulse length as the minimum window for constructing the Nakagami image. This criterion does not produce sufficiently smooth images for the Nakagami image to characterize homogeneous tissues. To improve image smoothness, we proposed window-modulated compounding (WMC) Nakagami imaging based on summing and averaging the Nakagami images formed using sliding windows with varying window side lengths from 1 to N times the transducer pulse length in 1 pulse length step. Simulations (the number densities of scatterers: 2-16 scatterers/mm(2)) and experiments on fully developed speckle phantoms (the scatterer diameters: 20-106 μm) were conducted to suggest an appropriate number of frames N and to evaluate the image smoothness and resolution by analyzing the full width at half maximum (FWHM) of the parameter distribution and the widths of the image autocorrelation function (ACF), respectively. In vivo ultrasound measurements on rat livers without and with cirrhosis were performed to validate the practical performance of the WMC Nakagami image in tissue characterization. The simulation results showed that using a range of N from 7 to 10 as the number of frames for image compounding reduces the estimation error to less than 5%. Based on this criterion, the Nakagami parameter obtained from the WMC Nakagami image increased from 0.45 to 0.95 after increasing the number densities of scatterers from 2 to 16 scatterers/mm(2). The FWHM of the parameter distribution (bins=40) was 13.5±1.4 for the Nakagami image and 9.1±1.43 for the WMC Nakagami image, respectively (p-valueNakagami and WMC Nakagami images were 454±5.36 and 458±4.33, respectively (p-value>.05). In the phantom experiments, we also found that the FWHM of the parameter distribution for the WMC Nakagami image was smaller than that

  20. Optical fiber based imaging of bioengineered tissue construct

    Science.gov (United States)

    Sapoznik, Etai; Niu, Guoguang; Lu, Peng; Zhou, Yu; Xu, Yong; Soker, Shay

    2016-04-01

    Imaging cells and tissues through opaque and turbid media is challenging and presents a major barrier for monitoring maturation and remodeling of bioengineered tissues. The fiber optics based imaging system described here offers a new approach for fluorescent cell imaging. A micro imaging channel is embedded in a Polycaprolactone (PCL) electrospun scaffold designed for cell seeding, which allows us to use an optical fiber to locally deliver excitation laser close to the fluorescent cells. The emission is detected by an Electron Multiplying Charge Coupled Device (EMCCD) detector and image reconstruction of multiple excitation points is achieved with a working distance of several centimeters. The objective of this study is to assess the effects of system parameters on image reconstruction outcomes. Initial studies using fluorescent beads indicated that scaffold thickness had a small effect on image quality, whereas scaffold composition (collagen content), fluorophore spectra, and the reconstruction window size had a large effect. The results also suggest that a far-red fluorescent emission is preferential when using collagenous scaffolds with a thickness of up to 500 μm. Using these optimized parameters, we were able to image fluorescently labeled cells on a scaffold with a resolution of 15-20 μm, and have also measured muscle progenitor cell differentiation and scaffold surface coverage with endothelial cells. In the future, this imaging platform can be applied to other bioengineered tissues for non-invasive monitoring both in vitro and in vivo.

  1. Application of tissue characterization in intravascular ultrasound imaging

    Science.gov (United States)

    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.

  2. The potential value of power Doppler ultrasound imaging compared with grey-scale ultrasound findings in the diagnosis of local recurrence after radical prostatectomy

    Energy Technology Data Exchange (ETDEWEB)

    Tamsel, S. [Department of Radiology, Ege University Hospital, Bornova, Izmir (Turkey); Killi, R. [Department of Radiology, Ege University Hospital, Bornova, Izmir (Turkey); Apaydin, E. [Department of Urology, Ege University Hospital, Bornova, Izmir (Turkey); Hekimgil, M. [Department of Pathology, Ege University Hospital, Bornova, Izmir (Turkey); Demirpolat, G. [Department of Radiology, Ege University Hospital, Bornova, Izmir (Turkey)

    2006-04-15

    AIM: To determine the value of power Doppler ultrasound (PDUS) imaging during transrectal ultrasonography (TRUS) in detecting local recurrence after radical retropubic prostatectomy (RRP). MATERIALS AND METHODS: Eighteen patients were evaluated in whom local recurrence of prostate cancer was suspected on the basis of elevated serum prostate-specific antigen (PSA) levels (above 0.4 ng/ml) after RRP with no evidence of metastatic disease. Grey-scale TRUS and PDUS-guided biopsies of the vesicourethral anastomosis (VUA) and perianastomotic soft tissues were obtained after TRUS examinations of the prostatic fossa. The ability to detect locally recurrent prostate cancer using grey-scale TRUS alone was compared with TRUS combined with PDUS. RESULTS: Fifteen of the 18 patients (83%) had positive biopsies for local recurrent tumour at histological examination. TRUS alone detected grey-scale abnormalities in 15 of 18 patients (83%), of whom 14 (77%) had positive TRUS-guided biopsies. PDUS during TRUS showed hypervascularity in 14 of 18 patients (77%). Biopsies of these hypervascular regions were positive in all patients (100%). The sensitivity and specificity of TRUS alone in detecting recurrent tumour were 93 and 67%, respectively, with a positive predictive value (PPV) of 93% and a negative predictive value (NPV) of 67%. TRUS combined with PDUS had a sensitivity and specificity of 93 and 100%, respectively, with a PPV and a NPV of 100 and 75%, respectively.

  3. Image-based characterization of foamed polymeric tissue scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Mather, Melissa L; Morgan, Stephen P; Crowe, John A [School of Electrical and Electronic Engineering, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); White, Lisa J; Shakesheff, Kevin M [School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Tai, Hongyun; Howdle, Steven M [School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Kockenberger, Walter [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)], E-mail: john.crowe@nottingham.ac.uk

    2008-03-01

    Tissue scaffolds are integral to many regenerative medicine therapies, providing suitable environments for tissue regeneration. In order to assess their suitability, methods to routinely and reproducibly characterize scaffolds are needed. Scaffold structures are typically complex, and thus their characterization is far from trivial. The work presented in this paper is centred on the application of the principles of scaffold characterization outlined in guidelines developed by ASTM International. Specifically, this work demonstrates the capabilities of different imaging modalities and analysis techniques used to characterize scaffolds fabricated from poly(lactic-co-glycolic acid) using supercritical carbon dioxide. Three structurally different scaffolds were used. The scaffolds were imaged using: scanning electron microscopy, micro x-ray computed tomography, magnetic resonance imaging and terahertz pulsed imaging. In each case two-dimensional images were obtained from which scaffold properties were determined using image processing. The findings of this work highlight how the chosen imaging modality and image-processing technique can influence the results of scaffold characterization. It is concluded that in order to obtain useful results from image-based scaffold characterization, an imaging methodology providing sufficient contrast and resolution must be used along with robust image segmentation methods to allow intercomparison of results.

  4. Doppler tomography in fusion plasmas and astrophysics

    CERN Document Server

    Salewski, Mirko; Heidbrink, Bill; Jacobsen, Asger Schou; Korsholm, Soren Bang; Leipold, Frank; Madsen, Jens; Moseev, Dmitry; Nielsen, Stefan Kragh; Rasmussen, Jesper; Stagner, Luke; Steeghs, Danny; Stejner, Morten; Tardini, Giovani; Weiland, Markus

    2015-01-01

    Doppler tomography is a well-known method in astrophysics to image the accretion flow, often in the shape of thin discs, in compact binary stars. As accretion discs rotate, all emitted line radiation is Doppler-shifted. In fast-ion D-alpha (FIDA) spectroscopy measurements in magnetically confined plasma, the D-alpha-photons are likewise Doppler-shifted ultimately due to gyration of the fast ions. In either case, spectra of Doppler-shifted line emission are sensitive to the velocity distribution of the emitters. Astrophysical Doppler tomography has lead to images of accretion discs of binaries revealing bright spots, spiral structures, and flow patterns. Fusion plasma Doppler tomography has lead to an image of the fast-ion velocity distribution function in the tokamak ASDEX Upgrade. This image matched numerical simulations very well. Here we discuss achievements of the Doppler tomography approach, its promise and limits, analogies and differences in astrophysical and fusion plasma Doppler tomography, and what ...

  5. Doppler Ultrasound: What Is It Used for?

    Science.gov (United States)

    ... in your neck (carotid artery stenosis) A Doppler ultrasound can estimate how fast blood flows by measuring the rate of change in its pitch (frequency). During a Doppler ultrasound, a technician trained in ultrasound imaging (sonographer) presses ...

  6. Different imaging methods in the comparative assessment of vascular lesions: color-coded duplex sonography, laser Doppler perfusion imaging, and infrared thermography

    Science.gov (United States)

    Urban, Peter; Philipp, Carsten M.; Weinberg, Lutz; Berlien, Hans-Peter

    1997-12-01

    Aim of the study was the comparative investigation of cutaneous and subcutaneous vascular lesions. By means of color coded duplex sonography (CCDS), laser doppler perfusion imaging (LDPI) and infrared thermography (IT) we examined hemangiomas, vascular malformations and portwine stains to get some evidence about depth, perfusion and vascularity. LDI is a helpful method to get an impression of the capillary part of vascular lesions and the course of superficial vessels. CCDS has disadvantages in the superficial perfusion's detection but connections to deeper vascularizations can be examined precisely, in some cases it is the only method for visualizing vascular malformations. IT gives additive hints on low blood flow areas or indicates arterial-venous-shunts. Only the combination of all imaging methods allows a complete assessment, not only for planning but also for controlling the laser treatment of vascular lesions.

  7. Autofluorescence-based diagnostic UV imaging of tissues and cells

    Science.gov (United States)

    Renkoski, Timothy E.

    Cancer is the second leading cause of death in the United States, and its early diagnosis is critical to improving treatment options and patient outcomes. In autofluorescence (AF) imaging, light of controlled wavelengths is projected onto tissue, absorbed by specific molecules, and re-emitted at longer wavelengths. Images of re-emitted light are used together with spectral information to infer tissue functional information and diagnosis. This dissertation describes AF imaging studies of three different organs using data collected from fresh human surgical specimens. In the ovary study, illumination was at 365 nm, and images were captured at 8 emission wavelengths. Measurements from a multispectral imaging system and fiber optic probe were used to map tissue diagnosis at every image pixel. For the colon and pancreas studies, instrumentation was developed extending AF imaging capability to sub-300 nm excitation. Images excited in the deep UV revealed tryptophan and protein content which are believed to change with disease state. Several excitation wavelength bands from 280 nm to 440 nm were investigated. Microscopic AF images collected in the pancreas study included both cultured and primary cells. Several findings are reported. A method of transforming fiber optic probe spectra for direct comparison with imager spectra was devised. Normalization of AF data by green reflectance data was found useful in correcting hemoglobin absorption. Ratio images, both AF and reflectance, were formulated to highlight growths in the colon. Novel tryptophan AF images were found less useful for colon diagnostics than the new ratio techniques. Microscopic tryptophan AF images produce useful visualization of cellular protein content, but their diagnostic value requires further study.

  8. An Alternative Paper Based Tissue Washing Method for Mass Spectrometry Imaging: Localized Washing and Fragile Tissue Analysis

    National Research Council Canada - National Science Library

    Amstalden van Hove, Erika R; Smith, Donald F; Fornai, Lara; Glunde, Kristine; Heeren, Ron M. A

    2011-01-01

    .... Here, we present a new surface washing procedure for mass spectrometry imaging. This procedure uses solvent wetted fiber-free paper to enable local washing of tissue sections for mass spectrometry imaging and tissue profiling experiments...

  9. Effects of permanent magnets on resting skin blood perfusion in healthy persons assessed by laser Doppler flowmetry and imaging.

    Science.gov (United States)

    Mayrovitz, H N; Groseclose, E E; Markov, M; Pilla, A A

    2001-10-01

    Effects on skin blood perfusion of permanent ceramic magnets [0.1 T (1000 G) surface field], individually (disk shaped, 4 cm diameter x 1 cm thick) or in the form of a 11 x 7 in pad ( approximately 28 x 17.8 cm) with an array of 16 rectangular magnets (4.5 x 2.2 cm), were investigated in 16 female volunteers (27.4 +/- 1.7 years, range 21-48 years) using three separate protocols. In protocol A, a disk magnet was placed on the palmar surface of the hand in contact with the thenar eminence (n = 5). In protocol B, the magnet was placed on the hand dorsum overlying the thenar eminence (n = 5). In protocol C, the entire palm and fingers rested on the magnetic pad (n = 6). Magnets were in place for 36 min on one hand, and a sham was in place on the other hand. Blood perfusion was measured on the middle finger dorsum by laser Doppler flowmetry (LDF) and on the index finger by laser Doppler imaging (LDI). Perfusion measurements were simultaneously taken in sham and magnet exposed hands, before and during the entire magnet exposure interval. Magnetic field effects were tested by comparing skin blood perfusion sequences in magnet and sham exposed regions. Results showed no significant changes in either LDF or LDI perfusion at magnet or sham sites during exposure, nor were there any significant differences between sham and magnet sites for any protocol. Measurements of skin temperature at the LDF measurement sites also showed no significant change. It is concluded that in the healthy subjects studied with normal, unstressed circulation, magnets of the type and for the duration used, showed no detectible effect on skin blood perfusion in the anatomical area studied.

  10. Doppler imaging of orbital vessels in the assessment of the activity and severity of thyroid-associated orbitopathy

    Directory of Open Access Journals (Sweden)

    Dorota Walasik-Szemplińska

    2015-12-01

    Full Text Available Patients with symptoms of thyroid-associated orbitopathy are classifi ed on the basis of the clinical activity score (CAS proposed by Mourits in 1989. Despite its undoubted clinical usefulness, it has several limitations which can decide about the success or failure of the implemented treatment. Numerous reports mention the presence of hemodynamic changes in orbital and bulbar vessels in the course of an orbitopathy called Graves’ disease. The usage of Doppler sonography in the diagnosis of numerous ophthalmologic vascular diseases suggests that changes in thyroid-associated orbitopathy can correlate with the activity and severity of the disease. This paper presents the overview of the state-of-the-art concerning the usefulness of Doppler imaging in patient selection for the treatment of thyroid-associated orbitopathy. It has been shown that the velocity of blood fl ow in the superior ophthalmic vein, which is the most susceptible to changes in anatomical conditions in the enclosed orbital space, decreases in a statistically signifi cant way. A decrease in blood fl ow velocity is closely associated with the active stage of the disease whereas reverse fl ow or its absence attest to severe orbitopathy and constitute a risk factor of ocular neuropathy. The activity of the infl ammatory process in the eyeball is also confi rmed by an increase in peak systolic velocity (PSV in the ophthalmic artery and central retinal artery as well as end-diastolic velocity (EDV in the ophthalmic artery. Resistance index values decrease in the ophthalmic artery and increase in the central retinal artery mainly in cases with considerable expansion of the extraocular muscles.

  11. Is there a difference between laser speckle and laser Doppler in depth sensitivity?

    Science.gov (United States)

    Thompson, O. B.; Hirst, E. R.; Andrews, M. K.

    2011-03-01

    Laser speckle and laser Doppler perfusion measurements apply different analyses to the same physical phenomenon and so should produce the same results. However, there is some evidence that laser Doppler can measure perfusion at greater depths than laser speckle. Using phantom measurements and comparison to spatially modulated imaging, we show why this might be the case. Various implementations of imaging laser Doppler and speckle systems have different optical setups, producing different effective distances between the illumination and detector points on the surface of the tissue. Separating the effective source and detector regions in tissue measurements biases the measurements towards deeper tissues, and when the effective source and detector regions coincide, the measurement is biased towards surface tissues. Probe-based or scanning laser Doppler systems with point illumination can separate the source and detector regions to interrogate deeper tissues, while whole-field imaging laser Doppler systems and laser speckle contrast systems have broad illumination covering the measurement areas. The volume of tissue informing a measurement at any point in a whole-field system, and hence the depth sensitivity, is determined by the optical properties of the tissue at the working wavelength.

  12. A Primer on the Physical Principles of Tissue Harmonic Imaging.

    Science.gov (United States)

    Anvari, Arash; Forsberg, Flemming; Samir, Anthony E

    2015-01-01

    Tissue harmonic imaging (THI) is a routinely used component of diagnostic ultrasonography (US). In this method, higher-frequency harmonic waves produced by nonlinear fundamental US wave propagation are used to generate images that contain fewer artifacts than those seen on conventional fundamental wave US tissue imaging. Harmonic frequencies are integer multiples of the fundamental frequency. The majority of current clinical US systems use second harmonic echoes for THI image formation. Image processing techniques (ie, bandwidth receive filtering, pulse inversion, side-by-side phase cancellation, and pulse-coded harmonics) are used to eliminate the fundamental frequency echoes, and the remaining harmonic frequency data are used to generate the diagnostic image. Advantages of THI include improved signal-to-noise ratio and reduced artifacts produced by side lobes, grating lobes, and reverberation. THI has been accepted in US practice, and variations of the technology are available on most US systems typically used for diagnostic imaging in radiologic practice. Differential THI is a further improvement that combines the advantages of THI, including superior tissue definition and reduced speckle artifact, with the greater penetration of lower frequency US, which permits high-quality harmonic imaging at greater depth than could previously be performed with conventional THI. (©)RSNA, 2015.

  13. NMR imaging of cell phone radiation absorption in brain tissue.

    Science.gov (United States)

    Gultekin, David H; Moeller, Lothar

    2013-01-02

    A method is described for measuring absorbed electromagnetic energy radiated from cell phone antennae into ex vivo brain tissue. NMR images the 3D thermal dynamics inside ex vivo bovine brain tissue and equivalent gel under exposure to power and irradiation time-varying radio frequency (RF) fields. The absorbed RF energy in brain tissue converts into Joule heat and affects the nuclear magnetic shielding and the Larmor precession. The resultant temperature increase is measured by the resonance frequency shift of hydrogen protons in brain tissue. This proposed application of NMR thermometry offers sufficient spatial and temporal resolution to characterize the hot spots from absorbed cell phone radiation in aqueous media and biological tissues. Specific absorption rate measurements averaged over 1 mg and 10 s in the brain tissue cover the total absorption volume. Reference measurements with fiber optic temperature sensors confirm the accuracy of the NMR thermometry.

  14. Image-based metrology of porous tissue engineering scaffolds

    Science.gov (United States)

    Rajagopalan, Srinivasan; Robb, Richard A.

    2006-03-01

    Tissue engineering is an interdisciplinary effort aimed at the repair and regeneration of biological tissues through the application and control of cells, porous scaffolds and growth factors. The regeneration of specific tissues guided by tissue analogous substrates is dependent on diverse scaffold architectural indices that can be derived quantitatively from the microCT and microMR images of the scaffolds. However, the randomness of pore-solid distributions in conventional stochastic scaffolds presents unique computational challenges. As a result, image-based characterization of scaffolds has been predominantly qualitative. In this paper, we discuss quantitative image-based techniques that can be used to compute the metrological indices of porous tissue engineering scaffolds. While bulk averaged quantities such as porosity and surface are derived directly from the optimal pore-solid delineations, the spatially distributed geometric indices are derived from the medial axis representations of the pore network. The computational framework proposed (to the best of our knowledge for the first time in tissue engineering) in this paper might have profound implications towards unraveling the symbiotic structure-function relationship of porous tissue engineering scaffolds.

  15. Quantitative Assessment of Synovial Vascularity Using Contrast-Enhanced Power Doppler Ultrasonography: Correlation with Histologic Findings and MR Imaging Findings in Arthritic Rabbit Knee Model

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hoon; Shin, Myung Jin; Kim, Seong Moon; Kim, Namkug; Suh, Sang Hyun [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Suh, Jin Suck [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2008-02-15

    To validate contrast-enhanced power Doppler ultrasonography (PD US) for the evaluation of synovial vascularity in an arthritic rabbit knee model in correlation with MR and histological findings. Power Doppler ultrasonography was performed for carrageenin-induced arthritic left knee and control right knee of 13 rabbits, first without and then with sonic contrast agent enhancement (Levovist, Schering, Berlin Germany), followed by gadolinium-enhanced MR imaging. Synovial vascularity was quantitatively assessed by calculating the color pixel area in power Doppler sonography using a computer-aided image analysis program and by grading the enhancement on MR images: grade 1, enhancement of knee joint is less than one-third of the area; grade 2, one-third to two-thirds enhancement; and grade 3, more than two-thirds enhancement. Microvessel density (MVD) was measured on slides stained immunohistochemically for CD31 antigen for histological assessment. The mean area of color pixels in PD US changed from 4.37 to 16.42 mm{sup 2} in the arthritic knee after enhancement (p < 0.05), whereas it changed from 0.77 to 2.31 mm{sup 2} in the control knee (p < 0.05). Arthritic knees had greater power Doppler signal than control knees both before and after contrast administration (p < 0.05). The average MVD was 88 in arthritic knees and 46 in control knees. MVDs correlated with color pixel areas of contrast-enhanced power Doppler imaging in arthritic knees. In MR grading of arthritic knees, five were grade 2 and eight were grade 3. MVD and PD US revealed no significant difference between grade 2 and 3 arthritic knees (p > 0.05). Sonic contrast-enhanced PD US improves the visualization of synovial vascularity and allows quantitative measurement in experimentally induced rabbit arthritic knees.

  16. Breast image pre-processing for mammographic tissue segmentation.

    Science.gov (United States)

    He, Wenda; Hogg, Peter; Juette, Arne; Denton, Erika R E; Zwiggelaar, Reyer

    2015-12-01

    During mammographic image acquisition, a compression paddle is used to even the breast thickness in order to obtain optimal image quality. Clinical observation has indicated that some mammograms may exhibit abrupt intensity change and low visibility of tissue structures in the breast peripheral areas. Such appearance discrepancies can affect image interpretation and may not be desirable for computer aided mammography, leading to incorrect diagnosis and/or detection which can have a negative impact on sensitivity and specificity of screening mammography. This paper describes a novel mammographic image pre-processing method to improve image quality for analysis. An image selection process is incorporated to better target problematic images. The processed images show improved mammographic appearances not only in the breast periphery but also across the mammograms. Mammographic segmentation and risk/density classification were performed to facilitate a quantitative and qualitative evaluation. When using the processed images, the results indicated more anatomically correct segmentation in tissue specific areas, and subsequently better classification accuracies were achieved. Visual assessments were conducted in a clinical environment to determine the quality of the processed images and the resultant segmentation. The developed method has shown promising results. It is expected to be useful in early breast cancer detection, risk-stratified screening, and aiding radiologists in the process of decision making prior to surgery and/or treatment.

  17. First cosmic-ray images of bone and soft tissue

    Science.gov (United States)

    Mrdja, Dusan; Bikit, Istvan; Bikit, Kristina; Slivka, Jaroslav; Hansman, Jan; Oláh, László; Varga, Dezső

    2016-11-01

    More than 120 years after Roentgen's first X-ray image, the first cosmic-ray muon images of bone and soft tissue are created. The pictures, shown in the present paper, represent the first radiographies of structures of organic origin ever recorded by cosmic rays. This result is achieved by a uniquely designed, simple and versatile cosmic-ray muon-imaging system, which consists of four plastic scintillation detectors and a muon tracker. This system does not use scattering or absorption of muons in order to deduct image information, but takes advantage of the production rate of secondaries in the target materials, detected in coincidence with muons. The 2D image slices of cow femur bone are obtained at several depths along the bone axis, together with the corresponding 3D image. Real organic soft tissue, polymethyl methacrylate and water, never seen before by any other muon imaging techniques, are also registered in the images. Thus, similar imaging systems, placed around structures of organic or inorganic origin, can be used for tomographic imaging using only the omnipresent cosmic radiation.

  18. Imaging of the elastic properties of tissue--a review.

    Science.gov (United States)

    Gao, L; Parker, K J; Lerner, R M; Levinson, S F

    1996-01-01

    Recently, a number of methods have been developed that make it possible to image the elastic properties of soft tissues. Because certain types of tissues such as malignant lesions, for example, have elastic properties that are markedly different from surrounding tissues, elasticity imaging could provide a significant adjunct to current diagnostic ultrasonic methods. Further, elasticity imaging techniques could be used to augment the study of tissues that change their elastic properties, such as skeletal and cardiac muscle. In this paper, we survey some of the previous work done in the related field of biomechanics, and we review measurement techniques from the 1950s to the 1980s. Different approaches to elastic imaging and signal processing are then discussed and a lexicography for elastic imaging is introduced. It is hoped that this nomenclature will provide a meaningful categorization of various approaches and will make evident the inherent parameters displayed and conditions applied in deriving the resulting images. Key assumptions and signal processing approaches are also reviewed. Finally, directions for future work are suggested.

  19. Developments in target micro-Doppler signatures analysis: radar imaging, ultrasound and through-the-wall radar

    Science.gov (United States)

    Clemente, Carmine; Balleri, Alessio; Woodbridge, Karl; Soraghan, John J.

    2013-12-01

    Target motions, other than the main bulk translation of the target, induce Doppler modulations around the main Doppler shift that form what is commonly called a target micro-Doppler signature. Radar micro-Doppler signatures are generally both target and action specific and hence can be used to classify and recognise targets as well as to identify possible threats. In recent years, research into the use of micro-Doppler signatures for target classification to address many defence and security challenges has been of increasing interest. In this article, we present a review of the work published in the last 10 years on emerging applications of radar target analysis using micro-Doppler signatures. Specifically we review micro-Doppler target signatures in bistatic SAR and ISAR, through-the-wall radar and ultrasound radar. This article has been compiled to provide radar practitioners with a unique reference source covering the latest developments in micro-Doppler analysis, extraction and mitigation techniques. The article shows that this research area is highly active and fast moving and demonstrates that micro-Doppler techniques can provide important solutions to many radar target classification challenges.

  20. Model experiments on imaging subsurface fracture permeability by pulsed Doppler borehole televiewer; Pulse doppler borehole televiewer ni yoru kiretsu tosuisei hyoka ni kansuru model jikken

    Energy Technology Data Exchange (ETDEWEB)

    Inagaki, Y.; Niitsuma, H. [Tohoku University, Sendai (Japan). Faculty of Engineering

    1996-05-01

    This paper reports model experiments to evaluate flow rates of fluids passing through a fracture by using a Doppler borehole televiewer (DBHTV). A supersonic transducer disposed on a well axis transmits transmission pulses, and a transducer receives scattered waves generated by particulates in water and waves reflected on a well wall. This signal is applied with time gating to extract only the scattered waves from particulates in the vicinity of the well wall. Deriving spectra in the recorded Doppler signal obtains flow velocity components in the direction of the well radius. A model was made with a polyvinylchloride pipe with a diameter of 14.6 cm to simulate a well, to which an aluminum pipe with an inner diameter of 2 mm is connected to be used as a simulated fracture, and mud water is circulated in the pipe. The result of deriving a passed flow volume in this model by integrating flow rate distribution derived by using the above method to a predetermined range in the vicinity of the fracture showed a good proportional relationship with actual flow rate in the simulated fracture. 1 ref., 7 figs.

  1. Multimodal imaging in the differential diagnosis of soft tissue calcinosis

    Directory of Open Access Journals (Sweden)

    G. Garlaschi

    2011-11-01

    Full Text Available Soft tissue calcinosis is a common radiographic finding, which may be related to different types of pathological processes. Multimodality imaging, combined with analysis of clinical and laboratory data, plays an important role for the differential diagnosis of these conditions. Conventional radiography is considered the first line approach to soft tissue calcinosis; CT and MRI may provide further information to better characterize calcified deposits. Imaging may help to distinguish metabolic calcification, such as primary tumoral calcinosis and the secondary one (associated with acquired disorders of calcium or phosphate regulation, from dystrophic calcification, which is associated to normal blood values of phosphate. The sedimentation sign typical of tumoral calcinosis has been demonstrated by plain film radiography, CT, MRI, and, more recently, by ultrasonography. Other types of soft tissue calcinosis may have a degenerative, metaplastic or neoplastic origin, and their characterization strongly relies on multimodality imaging.

  2. Imaging of oral pathological tissue using optical coherence tomography

    Science.gov (United States)

    Canjau, Silvana; Todea, Carmen; Sinescu, Cosmin; Duma, Virgil-Florin; Topala, Florin I.; Podoleanu, Adrian G.

    2014-01-01

    Oral squamous cell carcinoma (OSCC) constitutes 90% of oral cancer. Early detection is a cornerstone to improve survival. Interaction of light with tissues may highlight changes in tissue structure and metabolism. We propose optical coherence tomography (OCT), as a non-invasive diagnosis method, being a new high-resolution optical technique that permits tri-dimensional (3-D), real-time imaging of near surface abnormalities in complex tissues. In this study half of the excisional biopsy was directed to the pathologist and the other half was assigned for OCT investigation. Histopathology validated the results. Areas of OSCC of the buccal mucosa were identified in the OCT images. The elements obserced included extensive epithelial down-growth, the disruption of the basement membrane, with areas of erosion, an epithelial layer that was highly variable in thickness and invasion into the sub-epithelial layers. Therefore, OCT appears to be a highly promising imaging modality.

  3. Color Doppler imaging of the ophthalmic artery in patients with chronic heart failure

    Directory of Open Access Journals (Sweden)

    Daniela B. Almeida-Freitas

    2011-10-01

    Full Text Available Purpose: