An evaluation of the use of new Doppler methods for detecting longitudinal function abnormalities in a pacing-induced heart failure model

NASA Technical Reports Server (NTRS)

Tabata, Tomotsugu; Cardon, Lisa A.; Armstrong, Guy P.; Fukamach, Kiyotaka; Takagaki, Masami; Ochiai, Yoshie; McCarthy, Patrick M.; Thomas, James D.

2003-01-01

BACKGROUND: Doppler tissue echocardiography and color M-mode Doppler flow propagation velocity have proven useful in evaluating cross-sections of patients with left ventricular (LV) dysfunction, but experience with serial changes is limited. Purpose and methods: We tested their use by evaluating the temporal changes of LV function in a pacing-induced congestive heart failure model. Rapid ventricular pacing was initiated and maintained in 20 dogs for 4 weeks. Echocardiography was performed at baseline and weekly during brief pacing cessation. RESULTS: With rapid pacing, LV volume significantly increased and ejection fraction (57%-28%), stroke volume (37-18 mL), and mitral annulus systolic velocity (16.1-6.6 cm/s) by Doppler tissue echocardiography significantly decreased, with ejection fraction and mitral annulus systolic velocity closely correlated (r = 0.706, P <.0001). In contrast to the mitral inflow velocities, mitral annulus early diastolic velocity decreased steadily (12.3-7.3 cm/s) resulting in a dramatic decrease in mitral annulus early/late (1.22-0.57) diastolic velocity with no tendency toward pseudonormalization. The color M-mode Doppler flow propagation velocity also showed significant steady decrease (57-24 cm/s) throughout the pacing period. Multiple regression analysis chose mitral annulus systolic velocity (r = 0.895, P <.0001) and propagation velocity (r = 0.782, P <.0001) for the most important factor predicting LV systolic and diastolic function, respectively. CONCLUSIONS: Doppler tissue echocardiography and color M-mode Doppler flow could evaluate the serial deterioration in LV dysfunction throughout the pacing period. These were more useful in quantifying progressive LV dysfunction than conventional ehocardiographic techniques, and were probably relatively independent of preload. These techniques could be suitable for longitudinal evaluation in addition to the cross-sectional study.

Assessment of diastolic function by tissue Doppler echocardiography: comparison with standard transmitral and pulmonary venous flow

NASA Technical Reports Server (NTRS)

Farias, C. A.; Rodriguez, L.; Garcia, M. J.; Sun, J. P.; Klein, A. L.; Thomas, J. D.

1999-01-01

The objective of this study was to determine the utility of Doppler tissue echocardiography in the evaluation of diastolic filling and in discriminating between normal subjects and those with various stages of diastolic dysfunction. We measured myocardial velocities in 51 patients with various stages of diastolic dysfunction and in 27 normal volunteers. The discriminating power of each of the standard Doppler indexes of left ventricular filling, pulmonary venous flow, and myocardial velocities was determined with the use of Spearman rank correlation and analysis of variance F statistics. Early diastolic myocardial velocity (E(m)) was higher in normal subjects (16.0 +/- 3.8 cm/s) than in patients with either delayed relaxation (n = 15, 7.5 +/- 2.2 cm/s), pseudonormal filling (n = 26, 7.6 +/- 2.3 cm/s), or restrictive filling (n = 10, 7.4 +/- 2.4 cm/s, P <.0001). E(m ) was the best single discriminator between control subjects and patients with diastolic dysfunction (P =.7, F = 64.5). Myocardial velocities assessed by Doppler tissue echocardiography are useful in differentiating patients with normal from those with abnormal diastolic function. Myocardial velocity remains reduced even in those stages of diastolic dysfunction characterized by increased preload compensation.

The Pathophysiology of Decompression Sickness and the Effects of Doppler Detectable Bubbles.

DTIC Science & Technology

1980-12-18

Doppler Ultrasound and a calibrated 6 1 Venous Gas Embol i Scale. C. Electronic Counting of Doppler Bubble Signals 72 £ III. Pulmonary Embolism Studies...IA. Background 75 B. Right Ventricular Systolic Pressure following Gas 81 Embolization and Venous Gas Phase Content IC. Effects of Pulmonary Gas... Embolism on the Development 9 of Limb-Bend Decompression Sickness 1 IV. Gas Phase Formation in Highly Perfused Tissues IA. Renal 9 B. Cerebral 9 1 I I V

Left ventricular diastolic dysfunction without left ventricular hypertrophy in obese children and adolescents: a Tissue Doppler Imaging and Cardiac Troponin I Study.

PubMed

El Saiedi, Sonia A; Mira, Marwa F; Sharaf, Sahar A; Al Musaddar, Maysoun M; El Kaffas, Rania M H; AbdelMassih, Antoine F; Barsoum, Ihab H Y

2018-01-01

Obesity increases the risk for various cardiovascular problems. Increase in body mass index is often an independent risk factor for the development of elevated blood pressure and clustering of various cardiovascular risk factors. To determine early markers of left ventricular affection in obese patients before the appearance of left ventricular hypertrophy. In this cross-sectional study, we evaluated 42 obese patients and 30 healthy controls. Their ages ranged from 6 to 19 years. Studied children were subjected to anthropometric, lipid profile, and serum Troponin I level measurements. Echocardiographic evaluation performed to assess the left ventricle included left ventricular dimension measurement using motion-mode echocardiography, based on which patients with left ventricular hypertrophy (10 patients) were eliminated, as well as conventional and tissue Doppler imaging. Tissue Doppler findings in the study groups showed that the ratio of transmitral early diastolic filling velocity to septal peak early diastolic myocardial velocity (E/e') was significantly higher in cases compared with controls [6.9±1.4 versus 9.0±1.6, p (Pearson's coefficient)=0.001, respectively]. The level of cardiac troponin I was significantly higher in cases compared with controls [0.14±0.39 ng/ml versus 0.01±0.01 ng/ml, p (Pearson's coefficient)=0.047, respectively] and there was a significant correlation between troponin I and transmitral early diastolic filling velocity to septal peak early diastolic myocardial velocity ratio (E/e') [R (correlation coefficient)=0.6]. Tissue Doppler Imaging and Troponin I evaluation proved useful tools to detect early affection of the left ventricle in obese patients even in the absence of left ventricular hypertrophy.

Renewed interest in preejectional isovolumic phase: new applications of tissue Doppler indexes: implications to ventricular dyssynchrony.

PubMed

Veyrat, Colette; Larrazet, Fabrice; Pellerin, Denis

2005-10-01

There is renewed interest in isovolumic contraction (IC) in tissue Doppler echocardiography of the myocardial walls, which is revisited in this editorial with new regional velocity data. The aims are to recall traditional background information and to emphasize the need to master the rapidly evolving tissue Doppler procedures for the accurate display of brief IC. IC, a preejectional component of great physiologic interest, is very demanding in terms of ultrasound technology. The onset and end of its motion velocities should be unambiguously defined versus the QRS complex and ejection wall motion. This is a prerequisite for exploiting the new information as guidance toward new therapeutic strategies from a practical viewpoint. However, IC preload dependence should be kept in mind, because of its limited potential for contractility studies. Finally, when only duration measurements are made in the assessment of ventricular dyssynchrony, regional preejectional duration is the pertinent tool to single out the onset of ejection local wall motion.

Do adjunctive flap-monitoring technologies impact clinical decision making? An analysis of microsurgeon preferences and behavior by body region.

PubMed

Bellamy, Justin L; Mundinger, Gerhard S; Flores, José M; Wimmers, Eric G; Yalanis, Georgia C; Rodriguez, Eduardo D; Sacks, Justin M

2015-03-01

Multiple perfusion assessment technologies exist to identify compromised microvascular free flaps. The effectiveness, operability, and cost of each technology vary. The authors investigated surgeon preference and clinical behavior with several perfusion assessment technologies. A questionnaire was sent to members of the American Society for Reconstructive Microsurgery concerning perceptions and frequency of use of several technologies in varied clinical situations. Demographic information was also collected. Adjusted odds ratios were calculated using multinomial logistic regression accounting for clustering of similar practices within institutions/regions. The questionnaire was completed by 157 of 389 participants (40.4 percent response rate). Handheld Doppler was the most commonly preferred free flap-monitoring technology (56.1 percent), followed by implantable Doppler (22.9 percent) and cutaneous tissue oximetry (16.6 percent). Surgeons were significantly more likely to opt for immediate take-back to the operating room when presented with a concerning tissue oximetry readout compared with a concerning handheld Doppler signal (OR, 2.82; p < 0.01), whereas other technologies did not significantly alter postoperative management more than simple handheld Doppler. Clinical decision making did not significantly differ by demographics, training, or practice setup. Although most surgeons still prefer to use standard handheld Doppler for free flap assessment, respondents were significantly more likely to opt for immediate return to the operating room for a concerning tissue oximetry reading than an abnormal Doppler signal. This suggests that tissue oximetry may have the greatest impact on clinical decision making in the postoperative period.

Left atrial appendage function in prediction of paroxysmal atrial fibrilation in patients with untreated hypertension.

PubMed

Tenekecioglu, Erhan; Agca, Fahriye Vatansever; Karaagac, Kemal; Ozluk, Ozlem Arican; Peker, Tezcan; Kuzeytemiz, Mustafa; Senturk, Muhammed; Yılmaz, Mustafa

2014-01-01

Abstract The onset of AF results in a significant increase in mortality rates and morbidity in hypertensive patients and this rhythm disorder exposes patients to a significantly increased risk of cerebral or peripheral embolisms. Tissue Doppler imaging was found to be useful in early detection of myocardial dysfunction in several diseases. It was shown that tissue Doppler analysis of the walls of the left atrial appendage (LAA) can give accurate information about the function of the LAA in hypertensive patients. In this study, we aimed to investigate and identify the specific predictive parameters for the onset of AF in patients with hypertension with tissue Doppler imaging of LAA. We studied age and sex matched 57 untreated hypertensive patients with paroxysmal atrial fibrillation (PAF) and 27 untreated hypertensive subjects without PAF. With transthoracic echocardiography, diastolic mitral A-velocity and LA maximal volume index which reflects reservoir function of left atrium was measured, with transesophageal echocardiography, LAA emptying velocity (LAA-PW D2) and tissue Doppler contracting velocity of LAA (LAA-TDI-D2) were measured. LA maximal volume index of the groups (22.28 ± 3.59 mL/m(2) in Group 1 versus 20.37 ± 3.97 mL/m(2) in Group 2, p = 0.07) and diastolic mitral A-velocity [0.93 (0.59-1.84) m/s in patients with PAF versus 0.90 (0.62-1.76) m/s in patients without PAF, p = 0.26] was not significantly different between study groups, during TEE, LAA-PW D2 (0.31 ± 0.04 m/s in Group 1 versus 0.33 ± 0.03 m/s in Group 2, p = 0.034) and LAA-TDI-D2 (0.18 ± 0.04 m/s in Group 1 versus 0.21 ± 0.05 m/s in Group 2, p = 0.014) were significantly decreased in Group 1. In this study, we found that in hypertensive PAF patients despite normal global LA functions, LAA contracting function was deteriorated. Tissue Doppler analysis of LAA is clinically usefull approach to detect the risk of developing PAF in hypertensives.

Assessment of cardiac function in absence of congenital and acquired heart disease in patients with Down syndrome.

PubMed

Balli, Sevket; Yucel, Ilker Kemal; Kibar, Ayse Esin; Ece, Ibrahim; Dalkiran, Eylem Sen; Candan, Sukru

2016-11-01

Extra genetic material in patients with Down syndrome (DS) may affect the function of any organ system. We evaluated cardiac functions using conventional tissue Doppler and two-dimensional speckle tracking echocardiography in patients with DS in the absence of congenital and acquired heart disease in patients. A total of 115 patients with DS between 6 and 13 years of age with clinically and anatomically normal heart and 55 healthy children were included in this cross-sectional study. DS was diagnosed by a karyotype test. Patients with mosaic type were not included in this study. Systolic and diastolic functions were evaluated by echocardiography. Pulsed waved Doppler transmitral early/late inflow velocity (E/A), tissue Doppler mitral annular early/late diastolic peak velocity (Ea/Aa), transtricuspid E/A and tricuspid valve annulus Ea/Aa, pulmonary venous Doppler systolic/diastolic (S/D) wave ratio were lower in patients with Down syndrome than in the control group (P=0.04, P=0.001, P<0.05, P<0.001, P<0.001, respectively). Mitral and tricuspid annular Ea were lower in patients with DS (P<0.001). The right and left ventricular myocardial performance indexes were higher in patients with DS than in the controls (P<0.01). They had significantly higher left ventricular mass, ejection fraction, the mitral annular plane systolic excursion values. However, the Down syndrome group compared with the controls had a lower strain values examined by two-dimensional longitudinal speckle-tracking strain echocardiography. These findings suggest conventional tissue Doppler and two-dimensional longitudinal speckletracking strain echocardiography were useful methods of investigating ventricular function and identifying a higher incidence of biventricular dysfunction in patients with Down syndrome compared with the healthy controls.

Ultrasound Doppler method of remote elastometry

NASA Astrophysics Data System (ADS)

Timanin, E. M.; Eremin, E. V.; Belyaev, R. V.; Mansfel'd, A. D.

2015-03-01

The paper presents the theoretical relations constituting the basis of remote measurements of the shear elasticity of biological tissues using the ultrasound Doppler method. It also describes the hardware-software setup implementing this approach, as well as the results of experiments with these tools on a biological tissue phantom and on human liver in vivo.

Acute Effects of Lateral Thigh Foam Rolling on Arterial Tissue Perfusion Determined by Spectral Doppler and Power Doppler Ultrasound.

PubMed

Hotfiel, Thilo; Swoboda, Bernd; Krinner, Sebastian; Grim, Casper; Engelhardt, Martin; Uder, Michael; Heiss, Rafael U

2017-04-01

Hotfiel, T, Swoboda, B, Krinner, S, Grim, C, Engelhardt, M, Uder, M, and Heiss, R. Acute effects of lateral thigh foam rolling on arterial tissue perfusion determined by spectral Doppler and power Doppler ultrasound. J Strength Cond Res 31(4): 893-900, 2017-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 4 blindfolded investigators. Measurement values were assessed under resting conditions and twice after foam rolling exercises of the lateral thigh (0 and 30 minutes after 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 after foam rolling exercises compared with baseline (p ≤ 0.05). We detected a relative increase in Vmax of 73.6% (0 minutes) and 52.7% (30 minutes) (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 minutes compared with 0.75 at baseline. Our results may contribute to the understanding of local physiological reactions to self-myofascial release.

Microprobes For Blood Flow Measurements In Tissue And Small Vessels

NASA Astrophysics Data System (ADS)

Oberg, P. A.; Salerud, E. G.

1988-04-01

Laser Doppler flowmetry is a method for the continuous and non-invasive recording of tissue blood flow. The method has already proved to be advantageous in a number of clinical as well as theoretical medical disciplines. In dermatology, plastic- and gastrointestinal surgery laser Doppler measurements have substantially contributed to increase knowledge of microvascular perfusion. In experimental medicine, the method has been used in the study of a great variety of microvascular problems. Spontaneous rhythmical variations, spatial and temporal fluctuations in human skin blood flow are mentioned as examples of problem areas in which new knowledge has been generated. The method has facilitated further investigations of the nature of spongeous bone blood flow, testis and kidney cortex blood flow. Recently we have showed that a variant of the laser Doppler method principle, using a single optical fiber, can be advantageous in deep tissue measurements. With this method laser light is transmitted bidirectionally in a single fiber. The tissue trauma which affects blood flow can be minimized by introducing small diameter fibers (0.1-0.5 mm). A special set-up utilizing the same basic principle has been used for the recording of blood flow in small vessels.

A New Active Cavitation Mapping Technique for Pulsed HIFU Applications – Bubble Doppler

PubMed Central

Li, Tong; Khokhlova, Tatiana; Sapozhnikov, Oleg; Hwang, Joo Ha; Sapozhnikov, Oleg; O’Donnell, Matthew

2015-01-01

In this work, a new active cavitation mapping technique for pulsed high-intensity focused ultrasound (pHIFU) applications termed bubble Doppler is proposed and its feasibility tested in tissue-mimicking gel phantoms. pHIFU therapy uses short pulses, delivered at low pulse repetition frequency, to cause transient bubble activity that has been shown to enhance drug and gene delivery to tissues. The current gold standard for detecting and monitoring cavitation activity during pHIFU treatments is passive cavitation detection (PCD), which provides minimal information on the spatial distribution of the bubbles. B-mode imaging can detect hyperecho formation, but has very limited sensitivity, especially to small, transient microbubbles. The bubble Doppler method proposed here is based on a fusion of the adaptations of three Doppler techniques that had been previously developed for imaging of ultrasound contrast agents – color Doppler, pulse inversion Doppler, and decorrelation Doppler. Doppler ensemble pulses were interleaved with therapeutic pHIFU pulses using three different pulse sequences and standard Doppler processing was applied to the received echoes. The information yielded by each of the techniques on the distribution and characteristics of pHIFU-induced cavitation bubbles was evaluated separately, and found to be complementary. The unified approach - bubble Doppler – was then proposed to both spatially map the presence of transient bubbles and to estimate their sizes and the degree of nonlinearity. PMID:25265178

Modern Diagnostic Techniques for the Assessment of Ocular Blood Flow in Myopia: Current State of Knowledge.

PubMed

Grudzińska, Ewa; Modrzejewska, Monika

2018-01-01

Myopia is the most common refractive error and the subject of interest of various studies assessing ocular blood flow. Increasing refractive error and axial elongation of the eye result in the stretching and thinning of the scleral, choroid, and retinal tissues and the decrease in retinal vessel diameter, disturbing ocular blood flow. Local and systemic factors known to change ocular blood flow include glaucoma, medications and fluctuations in intraocular pressure, and metabolic parameters. Techniques and tools assessing ocular blood flow include, among others, laser Doppler flowmetry (LDF), retinal function imager (RFI), laser speckle contrast imaging (LSCI), magnetic resonance imaging (MRI), optical coherence tomography angiography (OCTA), pulsatile ocular blood flowmeter (POBF), fundus pulsation amplitude (FPA), colour Doppler imaging (CDI), and Doppler optical coherence tomography (DOCT). Many researchers consistently reported lower blood flow parameters in myopic eyes regardless of the used diagnostic method. It is unclear whether this is a primary change that causes secondary thinning of ocular tissues or quite the opposite; that is, the mechanical stretching of the eye wall reduces its thickness and causes a secondary lower demand of tissues for oxygen. This paper presents a review of studies assessing ocular blood flow in myopes.

3D ultrafast ultrasound imaging in vivo.

PubMed

Provost, Jean; Papadacci, Clement; Arango, Juan Esteban; Imbault, Marion; Fink, Mathias; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu

2014-10-07

Very high frame rate ultrasound imaging has recently allowed for the extension of the applications of echography to new fields of study such as the functional imaging of the brain, cardiac electrophysiology, and the quantitative imaging of the intrinsic mechanical properties of tumors, to name a few, non-invasively and in real time. In this study, we present the first implementation of Ultrafast Ultrasound Imaging in 3D based on the use of either diverging or plane waves emanating from a sparse virtual array located behind the probe. It achieves high contrast and resolution while maintaining imaging rates of thousands of volumes per second. A customized portable ultrasound system was developed to sample 1024 independent channels and to drive a 32  ×  32 matrix-array probe. Its ability to track in 3D transient phenomena occurring in the millisecond range within a single ultrafast acquisition was demonstrated for 3D Shear-Wave Imaging, 3D Ultrafast Doppler Imaging, and, finally, 3D Ultrafast combined Tissue and Flow Doppler Imaging. The propagation of shear waves was tracked in a phantom and used to characterize its stiffness. 3D Ultrafast Doppler was used to obtain 3D maps of Pulsed Doppler, Color Doppler, and Power Doppler quantities in a single acquisition and revealed, at thousands of volumes per second, the complex 3D flow patterns occurring in the ventricles of the human heart during an entire cardiac cycle, as well as the 3D in vivo interaction of blood flow and wall motion during the pulse wave in the carotid at the bifurcation. This study demonstrates the potential of 3D Ultrafast Ultrasound Imaging for the 3D mapping of stiffness, tissue motion, and flow in humans in vivo and promises new clinical applications of ultrasound with reduced intra--and inter-observer variability.

Photoacoustic Doppler effect from flowing small light-absorbing particles.

PubMed

Fang, Hui; Maslov, Konstantin; Wang, Lihong V

2007-11-02

From the flow of a suspension of micrometer-scale carbon particles, the photoacoustic Doppler shift is observed. As predicted theoretically, the observed Doppler shift equals half of that in Doppler ultrasound and does not depend on the direction of laser illumination. This new physical phenomenon provides a basis for developing photoacoustic Doppler flowmetry, which can potentially be used for detecting fluid flow in optically scattering media and especially low-speed blood flow of relatively deep microcirculation in biological tissue.

Vibration amplitude sonoelastography lesion imaging using low-frequency audible vibration

NASA Astrophysics Data System (ADS)

Taylor, Lawrence; Parker, Kevin

2003-04-01

Sonoelastography or vibration amplitude imaging is an ultrasound imaging technique in which low-amplitude, low-frequency shear waves, less than 0.1-mm displacement and 1-kHz frequency, are propagated deep into tissue, while real time Doppler techniques are used to image the resulting vibration pattern. Finite-element studies and experiments on tissue-mimicking phantoms verify that a discrete hard inhomogeneity present within a larger region of soft tissue will cause a decrease in the vibration field at its location. This forms the basis for tumor detection using sonoelastography. Real time relative imaging of the vibration field is possible because a vibrating particle will phase modulate an ultrasound signal. The particle's amplitude is directly proportional to the spectral spread of the reflected Doppler echo. Real time estimation of the variance of the Doppler power spectrum at each pixel allows the vibration field to be imaged. Results are shown for phantom lesions, thermal lesions, and 3-D in vitro and 2-D in vivo prostate cancer. MRI and whole mount histology is used to validate the system accuracy.

Colour flow and motion imaging.

PubMed

Evans, D H

2010-01-01

Colour flow imaging (CFI) is an ultrasound imaging technique whereby colour-coded maps of tissue velocity are superimposed on grey-scale pulse-echo images of tissue anatomy. The most widespread use of the method is to image the movement of blood through arteries and veins, but it may also be used to image the motion of solid tissue. The production of velocity information is technically more demanding than the production of the anatomical information, partly because the target of interest is often blood, which backscatters significantly less power than solid tissues, and partly because several transmit-receive cycles are necessary for each velocity estimate. This review first describes the various components of basic CFI systems necessary to generate the velocity information and to combine it with anatomical information. It then describes a number of variations on the basic autocorrelation technique, including cross-correlation-based techniques, power Doppler, Doppler tissue imaging, and three-dimensional (3D) Doppler imaging. Finally, a number of limitations of current techniques and some potential solutions are reviewed.

Causes of Ultrasound Doppler Twinkling Artifact

NASA Astrophysics Data System (ADS)

Leonov, D. V.; Kulberg, N. S.; Gromov, A. I.; Morozov, S. P.; Kim, S. Yu.

2018-01-01

Ultrasound Doppler twinkling artifact is analyzed. It usually appears as a frequent color alteration in the region of hyperechoic objects. Its noiselike spectrum can also be seen in spectral Doppler mode. Physicians use twinkling artifact as a clinical sign for kidney-stone and soft-tissue calculi detection. The advantageous peculiarity of this study is that the experiments were conducted utilizing raw signals obtained from a custom ultrasonic machine and a specially developed phantom. The phantom contained specimens with known qualities, allowing for reproducible and predictable results. The experiments revealed evidence for two physical causes of twinkling artifact, which were associated with two unique Doppler signals. The research laid the foundation for the new reflected-signal model introduced and used throughout this paper.

Predictors of transient left ventricular dysfunction following transcatheter patent ductus arteriosus closure in pediatric age.

PubMed

Agha, Hala Mounir; Hamza, Hala S; Kotby, Alyaa; Ganzoury, Mona E L; Soliman, Nanies

2017-10-01

To evaluate the left ventricular function before and after transcatheter percutaneous patent ductus arteriosus (PDA) closure, and to identify the predictors of myocardial dysfunction post-PDA closure if present. Transcatheter PDA closure; conventional, Doppler, and tissue Doppler imaging; and speckle tracking echocardiography. To determine the feasibility and reliability of tissue Doppler and myocardial deformation imaging for evaluating myocardial function in children undergoing transcatheter PDA closure. Forty-two children diagnosed with hemodynamically significant PDA underwent percutaneous PDA closure. Conventional, Doppler, and tissue Doppler imaging, and speckle-derived strain rate echocardiography were performed at preclosure and at 48 hours, 1 month, and 6 months postclosure. Tissue Doppler velocities of the lateral and septal mitral valve annuli were obtained. Global and regional longitudinal peak systolic strain values were determined using two-dimensional speckle tracking echocardiography. The median age of the patients was 2 years and body weight was 15 kg, with the mean PDA diameter of 3.11 ± 0.99 mm. M-mode measurements (left ventricular end diastolic diameter, left atrium diameter to aortic annulus ratio, ejection fraction, and shortening fraction) reduced significantly early after PDA closure ( p  < 0.001). After 1 month, left ventricular end diastolic diameter and left atrium diameter to aortic annulus ratio continued to decrease, while ejection fraction and fractional shortening improved significantly. All tissue Doppler velocities showed a significant decrease at 48 hours with significant prolongation of global myocardial function ( p  < 0.001) and then were normalized within 1 month postclosure. Similarly, global longitudinal strain significantly decreased at 48 hours postclosure ( p  < 0.001), which also recovered at 1 month follow-up. Preclosure global longitudinal strain showed a good correlation with the postclosure prolongation of the myocardial performance index. Transcatheter PDA closure causes a significant decrease in left ventricular performance early after PDA closure, which recovers completely within 1 month. Preclosure global longitudinal strain can be a predictor of postclosure myocardial dysfunction.

High-frequency dual mode pulsed wave Doppler imaging for monitoring the functional regeneration of adult zebrafish hearts

PubMed Central

Kang, Bong Jin; Park, Jinhyoung; Kim, Jieun; Kim, Hyung Ham; Lee, Changyang; Hwang, Jae Youn; Lien, Ching-Ling; Shung, K. Kirk

2015-01-01

Adult zebrafish is a well-known small animal model for studying heart regeneration. Although the regeneration of scars made by resecting the ventricular apex has been visualized with histological methods, there is no adequate imaging tool for tracking the functional recovery of the damaged heart. For this reason, high-frequency Doppler echocardiography using dual mode pulsed wave Doppler, which provides both tissue Doppler (TD) and Doppler flow in a same cardiac cycle, is developed with a 30 MHz high-frequency array ultrasound imaging system. Phantom studies show that the Doppler flow mode of the dual mode is capable of measuring the flow velocity from 0.1 to 15 cm s−1 with high accuracy (p-value = 0.974 > 0.05). In the in vivo study of zebrafish, both TD and Doppler flow signals were simultaneously obtained from the zebrafish heart for the first time, and the synchronized valve motions with the blood flow signals were identified. In the longitudinal study on the zebrafish heart regeneration, the parameters for diagnosing the diastolic dysfunction, for example, E/Em < 10, E/A < 0.14 for wild-type zebrafish, were measured, and the type of diastolic dysfunction caused by the amputation was found to be similar to the restrictive filling. The diastolic function was fully recovered within four weeks post-amputation. PMID:25505135

Assessment of Impact of Weight Loss on Left and Right Ventricular Functions and Value of Tissue Doppler Echocardiography in Obese Patients.

PubMed

Yuksel, Isa Oner; Akar Bayram, Nihal; Koklu, Erkan; Ureyen, Cagin Mustafa; Kucukseymen, Selcuk; Arslan, Sakir; Bozkurt, Engin

2016-06-01

In our study, we aimed to evaluate the effect of weight loss on left and right ventricular functions in obese patients. Thirty patients with a BMI greater than 30 kg/m(2) and without any exclusion criteria were included in the study. Left ventricular systolic and diastolic functions were assessed with conventional and tissue Doppler echocardiography (TDE). At the end of 3 months, echocardiographic examination was repeated in patients with weight loss for cardiac function evaluation and it was compared to the baseline echocardiographic parameters. At the end of 3 months of weight loss period, conventional Doppler echocardiography revealed an improvement in diastolic functions with an increase in mitral E-wave, a decrease in mitral A-wave and an increase in E/A ratio. Deceleration time and isovolumetric relaxation time were ascertained shortened and Tei index decreased. TDE showed an increase in left ventricular lateral wall systolic wave (Sm) and E-wave velocity (Em). Mitral septal annular isovolumetric acceleration time (IVA), Sm and Em, were found to be increased, whereas Tei index was ascertained reduced. Right ventricular tissue Doppler examination following weight loss revealed an increase in RV- IVA, RV-Sm, and RV-Em, and a decrease in Tei index. We disclosed that left ventricular structural changes and diastolic dysfunction occur in obese patients, and by weight loss, these abnormalities may be reversible which we demonstrated both by conventional and TDE. In addition, obesity might impair RV function as well, and we observed an enhancement in right ventricular functions by weight loss. © 2016, Wiley Periodicals, Inc.

Tissue Doppler imaging and echo-Doppler findings associated with a mitral valve stenosis with an immobile posterior valve leaflet in a bull terrier.

PubMed

Tidholm, A; Nicolle, A P; Carlos, C; Gouni, V; Caruso, J L; Pouchelon, J L; Chetboul, V

2004-04-01

A mitral valve stenosis was diagnosed in a 2-year-old female Bull Terrier by use of two-dimensional (2-D) and M-mode echocardiography, colour-flow imaging and spectral Doppler examinations. Tissue Doppler Imaging was also performed to assess the segmental radial myocardial motion. The mitral valve stenosis was characterized by a decreased mitral orifice area/left ventricle area ratio (0.14), an increased early diastolic flow velocity (E wave = 1.9 m/s), a prolonged pressure half-time (106 ms) and a decreased E-F slope (4.5 cm/s) on pulsed-wave Doppler examination. This mitral stenosis was associated with an immobile posterior leaflet, as seen on 2-D and M-mode echocardiography. Immobility of the posterior mitral leaflet is considered to be a rare finding in humans and, to our knowledge, has not been precisely documented in dogs with mitral valve stenosis.

Usefulness of bedside tissue Doppler echocardiography and B-type natriuretic peptide (BNP) in differentiating congestive heart failure from noncardiac cause of acute dyspnea in elderly patients with a normal left ventricular ejection fraction and permanent, nonvalvular atrial fibrillation: insights from a prospective, monocenter study.

PubMed

Arques, Stephane; Roux, Emmanuel; Sbragia, Pascal; Pieri, Bertrand; Gelisse, Richard; Luccioni, Roger; Ambrosi, Pierre

2007-05-01

The incremental role of bedside tissue Doppler echocardiography and B-type natriuretic peptide (BNP) over the clinical judgment has been recently reported in the emergency diagnosis of congestive heart failure with a normal left ventricular ejection fraction (HFNEF). However, how well does this diagnostic strategy be applicable in the setting of atrial fibrillation is unknown. To investigate the usefulness of bedside tissue Doppler echocardiography and BNP in the emergency diagnosis of HFNEF in elderly patients with permanent, nonvalvular atrial fibrillation. Forty-one consecutive elderly patients with an ejection fraction > or =50% (mean age 84 years; 22 with HFNEF and 19 with noncardiac cause), hospitalized for acute dyspnea at rest, were prospectively enrolled; bedside septal E/Ea and BNP were obtained at admission. By multivariable logistic regression analysis including the clinical judgment of heart failure, E/Ea and BNP, E/Ea (P = 0.014) and BNP (P = 0.018) provided independent diagnostic information. Optimal cutoffs were 13 for E/Ea (area under the ROC curve of 0.846, P < 0.0001; sensitivity 81.8%, specificity 89.5%) and 253 pg/ml for BNP (area under the ROC curve of 0.928, P < 0.0001; sensitivity 86.4%, specificity 89.5%). The concordance between the clinical judgment and BNP concentration at the cutoff of 253 pg/ml correctly classified 24 of 25 patients; E/Ea at the cutoff of 13 correctly classified 14 of the 16 patients with discrepancy. Bedside tissue Doppler echocardiography and BNP provide useful additional diagnostic information over the clinical judgment for the emergency diagnosis of HFNEF in elderly patients with permanent, nonvalvular atrial fibrillation.

Bone tissue phantoms for optical flowmeters at large interoptode spacing generated by 3D-stereolithography

PubMed Central

Binzoni, Tiziano; Torricelli, Alessandro; Giust, Remo; Sanguinetti, Bruno; Bernhard, Paul; Spinelli, Lorenzo

2014-01-01

A bone tissue phantom prototype allowing to test, in general, optical flowmeters at large interoptode spacings, such as laser-Doppler flowmetry or diffuse correlation spectroscopy, has been developed by 3D-stereolithography technique. It has been demonstrated that complex tissue vascular systems of any geometrical shape can be conceived. Absorption coefficient, reduced scattering coefficient and refractive index of the optical phantom have been measured to ensure that the optical parameters reasonably reproduce real human bone tissue in vivo. An experimental demonstration of a possible use of the optical phantom, utilizing a laser-Doppler flowmeter, is also presented. PMID:25136496

A chimaeric-pattern flap design for implantable Doppler surrogate monitoring: a novel placement technique.

PubMed

Kim, Jeong Tae; Ho, Samuel Y M; Kim, Youn Hwan

2014-02-01

Postoperative flap monitoring is a vital aspect of free tissue transfer in order to detect early vascular compromise and to enable early flap salvage. The implantable Doppler monitoring system is one of many monitoring devices used to ensure accuracy and reduce unnecessary flap explorations. However, there are a number of concerns with its use, namely tension on the anastomosis, possible vessel constriction and false-negative detection. This study aimed to alleviate these concerns, by introducing a new method of placing the implantable Doppler probe on the adjacent vessel limb of a chimaeric flap. This is illustrated by a case series of chimaeric free tissue flaps that allow this surrogate placement of the Doppler probe. The flap is raised in a chimaeric fashion, with a main perforator pedicle to the skin or muscle paddle for the main reconstructive purpose and a side branch from the main pedicle going to a smaller adipofascial or muscle flap for monitoring. This branch vascular pedicle leading to the chimaeric tissue is kept sufficiently long to enable placement of the Doppler cuff and prevent turbulence. The probe of a Cook-Swartz implantable Doppler system is placed around the branch pedicle, approximately 5 mm from the branching point, and secured with a vessel clip. This is then secured away from the major vessels of the main free flap. Removal of the probe's crystal and wire is easily done with a single gentle traction on postoperative day 7. Five cases of chimaeric free flaps were performed with this manoeuvre: three thoracodorsal perforator chimaeric flaps for head-and-neck or extremity reconstruction, one latissimus dorsi neuromuscular chimaeric flap for facial reanimation and one digastric lymph node transfer for the treatment of lower limb lymphoedema. The Doppler system showed a low but sustained oscillating flow in all cases indicating vascular patency, with minimal flow interference from other large-calibre vessels. There was no discernible kinking on the anastomosis. There were no complications encountered during probe removal. This postoperative monitoring manoeuvre was done successfully with good results. The monitoring equipment is very sensitive to any flow disturbance due to positional changes in the head-and-neck region or the extremities and is able to detect flow changes in buried flaps postoperatively. Chimaeric flap composition is easier now than before because of perforator-oriented pedicle dissection, and surrogate Doppler monitoring is one more application of the chimaeric flap. This novel chimaeric fashion of implantable Doppler probe placement is a good surrogate measure of flow in the main pedicle. Copyright © 2013. Published by Elsevier Ltd.

Tissue Doppler Imaging in the evaluation of abdominal aortic pulsatility: a useful tool for the neonatologist.

PubMed

Valerio, Enrico; Grison, Alessandra; Capretta, Anna; Golin, Rosanna; Ferrarese, Paola; Bellettato, Massimo

2017-03-01

Sonographic cardiac evaluation of newborns with suspected aortic coarctation (AoC) should tend to demonstrate a good phasic and pulsatile flow and the absence of pressure gradient along a normally conformed aortic arch from the modified left parasternal and suprasternal echocardiographic views; these findings, however, may not necessarily rule out a more distal coarctation in the descending aorta. For this reason, the sonographic exam of newborns with suspected AoC should always include a Doppler evaluation of abdominal aortic blood flow from the subcostal view. Occasionally, however, a clearly pulsatile Doppler flow trace in abdominal aorta may be difficult to obtain due to the bad insonation angle existing between the probe and the vessel. In such suboptimal ultrasonic alignment situation, the use of Tissue Doppler Imaging instead of classic Doppler flow imaging may reveal a preserved aortic pulsatility by sampling the aortic wall motion induced by normal flow. We propose to take advantage of the TDI pattern as a surrogate of a normal pulsatile Doppler flow trace in abdominal aorta when the latter is difficult to obtain due to malalignment with the insonated vessel.

Joint pain and Doppler-detectable bubbles in altitude (Hypobaric) decompression

NASA Technical Reports Server (NTRS)

Powell, Michael R.

1993-01-01

The observation that altitude decompression sickness (DCS) is associated with pain in the lower extremities is not new, although it is not a consistent finding. DCS in divers is generally in the upper body, an effect often attributed to non-loading of the body while immersed. In caisson workers, DCS is reported more in the lower extremities. Surprisingly, many researchers do not mention the location of DCS joint pain, apparently considering it to be random. This is not the case for the tissue ratios encountered in studying decompression associated with simulated EVA. In NASA/JSC tests, altitude DCS generally presented first in either the ankle, knee, or hip (83 percent = 73/88). There was a definite statistical relation between the maximum Spencer precordial Doppler Grade and the incidence of DCS in the extremity, although this is not meant to imply a casual relation between circulating gas bubbles and joint pain. The risk of DCS with Grade 4 was considerably higher than that of Grades 0 to 3. The DCS risk was independent of the 'tissue ratio.' There was a predominance of lower extremity DCS even when exercise was performed with the upper body. The reason for these locations we hypothesize to be attributed to the formation of tissue gas micronuclei from kinetic and tensile forces (stress-assisted nucleation) and are the result of the individuals ambulating in a 1g environment. Additionally, since these showers of Doppler bubbles can persist for hours, it is difficult to imagine that they are emanating solely from tendons and ligaments, the supposed site of joint pain. This follows from Henry's law linking the volume of joint tissue (the solvent) and the solubility coefficient of inert gas; there is volumetrically insufficient connective tissue to produce the prolonged release of gas bubbles. If gas bubbles are spawned and released from connective tissue, their volume is increased by those from muscle tissue. Therefore, the nexus between Doppler-detectable gas bubbles and joint-pain decompression sickness is essentially a statistical, rather than a direct, one.

Changes in cochlear blood flow in mice due to loud sound exposure measured with Doppler optical microangiography and laser Doppler flowmetry.

PubMed

Reif, Roberto; Zhi, Zhongwei; Dziennis, Suzan; Nuttall, Alfred L; Wang, Ruikang K

2013-10-01

In this work we determined the contributions of loud sound exposure (LSE) on cochlear blood flow (CoBF) in an in vivo anesthetized mouse model. A broadband noise system (20 kHz bandwidth) with an intensity of 119 dB SPL, was used for a period of one hour to produce a loud sound stimulus. Two techniques were used to study the changes in blood flow, a Doppler optical microangiography (DOMAG) system; which can measure the blood flow within individual cochlear vessels, and a laser Doppler flowmetry (LDF) system; which averages the blood flow within a volume (a hemisphere of ~1.5 mm radius) of tissue. Both systems determined that the blood flow within the cochlea is reduced due to the LSE stimulation.

Pennation angle dependency in skeletal muscle tissue doppler strain in dynamic contractions.

PubMed

Lindberg, Frida; Öhberg, Fredrik; Granåsen, Gabriel; Brodin, Lars-Åke; Grönlund, Christer

2011-07-01

Tissue velocity imaging (TVI) is a Doppler based ultrasound technique that can be used to study regional deformation in skeletal muscle tissue. The aim of this study was to develop a biomechanical model to describe the TVI strain's dependency on the pennation angle. We demonstrate its impact as the subsequent strain measurement error using dynamic elbow contractions from the medial and the lateral part of biceps brachii at two different loadings; 5% and 25% of maximum voluntary contraction (MVC). The estimated pennation angles were on average about 4° in extended position and increased to a maximal of 13° in flexed elbow position. The corresponding relative angular error spread from around 7% up to around 40%. To accurately apply TVI on skeletal muscles, the error due to angle changes should be compensated for. As a suggestion, this could be done according to the presented model. Copyright © 2011 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Oxygen consumption estimation with combined color doppler ultrasound and photoacoustic microscopy: a phantom study

NASA Astrophysics Data System (ADS)

Jiang, Yan; Harrison, Tyler; Forbrich, Alex; Zemp, Roger J.

2011-03-01

The metabolic rate of oxygen consumption (MRO2) quantifies tissue metabolism, which is important for diagnosis of many diseases. For a single vessel model, the MRO2 can be estimated in terms of the mean flow velocity, vessel crosssectional area, total concentration of hemoglobin (CHB), and the difference between the oxygen saturation (sO2) of blood flowing into and out of the tissue region. In this work, we would like to show the feasibility to estimate MRO2 with our combined photoacoustic and high-frequency ultrasound imaging system. This system uses a swept-scan 25-MHz ultrasound transducer with confocal dark-field laser illumination optics. A pulse-sequencer enables ultrasonic and laser pulses to be interlaced so that photoacoustic and Doppler ultrasound images are co-registered. Since the mean flow velocity can be measured by color Doppler ultrasound, the vessel cross-sectional area can be measured by power Doppler or photoacoustic imaging, and multi-wavelength photoacoustic methods can be used to estimate sO2 and CHB, all of these parameters necessary for MRO2 estimation can be provided by our system. Experiments have been performed on flow phantoms to generate co-registered color Doppler and photoacoustic images. To verify the sO2 estimation, two ink samples (red and blue) were mixed in various concentration ratios to mimic different levels of sO2, and the result shows a good match between the calculated concentration ratios and actual values.

UV laser-induced fluorescence spectroscopy and laser Doppler flowmetry in the diagnostics of alopecia

NASA Astrophysics Data System (ADS)

Skomorokha, Diana P.; Pigoreva, Yulia N.; Salmin, Vladimir V.

2016-04-01

Development of optical biopsy methods has a great interest for medical diagnostics. In clinical and experimental studies it is very important to analyze blood circulation quickly and accurately, thereby laser Doppler flowmetry (LDF) is widely used. UV laser-induced fluorescence spectroscopy (UV LIFS) is express highly sensitive and widely-spread method with no destructive impact, high excitation selectivity and the possibility to use in highly scattering media. The goal of this work was to assess a correlation of UV laser-induced fluorescence spectroscopy and laser Doppler flowmetry parameters, and a possibility to identify or to differentiate various types of pathological changes in tissues according to their autofluorescence spectra. Three groups of patients with diffuse (symptomatic) alopecia, androgenic alopecia, and focal alopecia have been tested. Each groups consisted of not less than 20 persons. The measurements have been done in the parietal and occipital regions of the sculls. We used the original automated spectrofluorimeter to record autofluorescence spectra, and standard laser Doppler flowmeter BLF-21 (Transonic Systems, Inc., USA) to analyze the basal levels of blood circulation. Our results show that UV LIFS accurately distinguishes the zones with different types of alopecia. We found high correlation of the basal levels of blood circulation and the integrated intensity of autofluorescence in the affected tissue.

Contrast-enhanced color Doppler ultrasonography increases diagnostic accuracy for soft tissue tumors.

PubMed

Oebisu, Naoto; Hoshi, Manabu; Ieguchi, Makoto; Takada, Jun; Iwai, Tadashi; Ohsawa, Masahiko; Nakamura, Hiroaki

2014-10-01

Resolution of ultrasonography (US) has undergone marked development. Additionally, a new-generation contrast medium (Sonazoid) used for US is newly available. Contrast-enhanced US has been widely used for evaluating several types of cancer. In the present study, we evaluated the ability of color Doppler US (CDUS) and Sonazoid to differentiate between benign and malignant soft tissue tumors. A total of 180 patients (87 male, 93 female) were enrolled in the present study. The patient ages ranged from 1 to 91 years (mean 58.1±20.0 years). The maximum size, depth, tumor margins, shape, echogenicity and textural pattern were measured on gray-scale images. CDUS was used to evaluate the intratumoral blood flow with and without Sonazoid. Peak systolic flow velocity (Vp), mean flow velocity (Vm), resistivity index (RI) and pulsatility index (PI) of each detected intratumoral artery were automatically calculated with power Doppler US (PDUS). The present study included 118 benign and 62 malignant tumors. Statistical significances were found in size, depth, tumor margin and textural pattern but not in shape or echogenicity on gray-scale images. Before Sonazoid injection, CDUS findings showed 55% sensitivity, 77% specificity and 69% accuracy, whereas contrast-enhanced CDUS showed 87% sensitivity, 68% specificity and 74% accuracy. There were no statistically significant differences between malignant and benign tumors regarding the mean Vp, Vm, RI and PI values determined on PDUS. In conclusion, contrast-enhanced CDUS proved to be a reliable diagnostic tool for detecting malignant potential in soft tissue tumors.

B-mode and Doppler sonography of the mammary glands in dairy goats for mastitis diagnosis.

PubMed

Santos, Vjc; Simplício, K; Sanchez, D; Coutinho, L; Teixeira, P; Barros, F; Almeida, V; Rodrigues, L; Bartlewski, P; Oliveira, M; Feliciano, M; Vicente, W

2015-04-01

This study aimed to evaluate the sonographic characteristics of the udder and teats and to determine the Doppler indexes of mammary artery in healthy and undergoing subclinical and clinical mastitis goats. Thirty animals among Saanen and Alpine Brown goats were arranged in three groups, healthy goats (HG), goats with subclinical mastitis (SMG) and goats with clinical mastitis (CMG). Using the B-mode, the sonographic characteristics (echotexture and echogenicity) and biometry (diameter and area of the udder cistern, diameter and area of the teat cistern and thickness of the teat wall) were evaluated. Using Doppler ultrasonography, the vascular indexes of the mammary artery were obtained. It was observed hyperechogenicity with solid component in the gland cistern when comparing animals with clinical mastitis and healthy mammary tissue. Regarding the echotexture of the breast tissue, there was heterogeneity in the mammary parenchyma on the three groups, for the milk, it was observed homogeneity for animals on HG and SMG and heterogeneity for animals on CMG. Grey-scale quantitative assessment revealed increase in echogenicity (mean value) for all the structures when comparing the three groups. Biometry did not reveal statistical difference between groups, for none of the evaluated structures. Doppler examination of the mammary artery showed the decrease of end diastolic velocity and raise of pulsatility index between groups. The association of B-mode and Doppler ultrasonography is useful for the evaluation of the udder of dairy goats with mastitis. It is a sensitive and specific method for the study of this disease. Doppler mode was unable to establish reliable criteria for diagnosis of subclinical mastitis. Moreover, the quantification of echogenicity is a useful technique for the evaluation of the milk in animals with mastitis; therefore, it is suggested that it can be used as complementary technique for the diagnosis of mastitis in goats. © 2015 Blackwell Verlag GmbH.

Modeling and processing of laser Doppler reactive hyperaemia signals

NASA Astrophysics Data System (ADS)

Humeau, Anne; Saumet, Jean-Louis; L'Huiller, Jean-Pierre

2003-07-01

Laser Doppler flowmetry is a non-invasive method used in the medical domain to monitor the microvascular blood cell perfusion through tissue. Most commercial laser Doppler flowmeters use an algorithm calculating the first moment of the power spectral density to give the perfusion value. Many clinical applications measure the perfusion after a vascular provocation such as a vascular occlusion. The response obtained is then called reactive hyperaemia. Target pathologies include diabetes, hypertension and peripheral arterial occlusive diseases. In order to have a deeper knowledge on reactive hyperaemia acquired by the laser Doppler technique, the present work first proposes two models (one analytical and one numerical) of the observed phenomenon. Then, a study on the multiple scattering between photons and red blood cells occurring during reactive hyperaemia is carried out. Finally, a signal processing that improves the diagnosis of peripheral arterial occlusive diseases is presented.

Does ketogenic diet have any negative effect on cardiac systolic and diastolic functions in children with intractable epilepsy?: One-year follow-up results.

PubMed

Ozdemir, Rahmi; Kucuk, Mehmet; Guzel, Orkide; Karadeniz, Cem; Yilmaz, Unsal; Mese, Timur

2016-10-01

The ketogenic diet (KD) has been referred to as an "effective therapy with side effects" for children with intractable epilepsy. Among the most recognized adverse effects, there are cardiac conduction abnormalities, vascular and myocardial dysfunction. However, very limited and controversial data are available regarding the effects of the KD on cardiac functions. We sought to analyze the mid-term effect of ketogenic diet on cardiac functions in patients with intractable epilepsy who received a ketogenic diet for at least 12months using conventional and relatively new imaging techniques. This prospective study included 61 patients with intractable epilepsy who received ketogenic diet for at least 12months. Clinical examinations, serum carnitine and selenium levels as well as electrocardiographic and echocardiographic examinations were scheduled prior to the procedure and at 1, 3, 6 and 12months. We utilized two-dimensional, M-mode, colored Doppler, spectral Doppler and pulsed wave tissue Doppler imaging techniques to investigate ventricular systolic and diastolic functions of this subgroup of patients. In our study, there was no significant difference after 1year of KD therapy compared to baseline values-except a significantly decreased A wave velocity-in terms of pulse wave Doppler echocardiographic measurements of the diastolic function. The tissue Doppler measurements obtained from the lateral wall of tricuspide and mitral annuli were not different at baseline and at month 12 of the treatment, as well. The ketogenic diet appears to have no disturbing effect on ventricular functions in epileptic children in the midterm. Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Thermal effects of diagnostic ultrasound in an anthropomorphic skull model.

PubMed

Vyskocil, E; Pfaffenberger, S; Kollmann, C; Gleiss, A; Nawratil, G; Kastl, S; Unger, E; Aumayr, K; Schuhfried, O; Huber, K; Wojta, J; Gottsauner-Wolf, M

2012-12-01

Exposure to diagnostic ultrasound (US) can significantly heat biological tissue although conventional routine examinations are regarded as safe. The risk of unwanted thermal effects increases with a high absorption coefficient and extended insonation time. Certain applications of transcranial diagnostic US (TC-US) require prolonged exposure. An anthropomorphic skull model (ASM) was developed to evaluate thermal effects induced by TC-US of different modalities. The objective was to determine whether prolonged continuous TC-US application results in potentially harmful temperature increases. The ASM consists of a human skull with tissue mimicking material and exhibits acoustic and anatomical characteristics of the human skull and brain. Experiments are performed with a diagnostic US device testing four different US modalities: Duplex PW (pulsed wave) Doppler, PW Doppler, color flow Doppler and B-mode. Temperature changes are recorded during 180 minutes of insonation. All measurements revealed significant temperature increases during insonation independent of the US modality. The maximum temperature elevation of + 5.25° C (p < 0.001) was observed on the surface of the skull exposed to duplex PW Doppler. At the bone-brain border a maximum temperature increae of + 2.01 °C (p < 0.001) was noted. Temperature increases within the brain were < 1.23 °C (p = 0.001). The highest values were registered using the duplex PW Doppler modality. TC-US induces significant local heating effects in an ASM. An application duration that extends routine clinical periods causes potentially harmful heating especially in tissue close to bone. TC-US elevates the temperature in the brain mimicking tissue but is not capable of producing harmful temperature increases during routine examinations. However, the risk of thermal injury in brain tissue increases significantly after an exposure time of > 2 hours. © Georg Thieme Verlag KG Stuttgart · New York.

Pulsed and Tissue Doppler Echocardiographic Changes in Hypertensive Crisis with and without End Organ Damage

PubMed Central

Garadah, Taysir; Kassab, Salah; Gabani, Saleh; Abu-Taleb, Ahmed; Abdelatif, Ahmed; Asef, Aysha; Shoroqi, Issa; Jamsheer, Anwer

2011-01-01

Background Hypertensive crisis (HC) is a common medical emergency associated with acute rise in arterial blood pressure that leads to end-organ damage (EOD). Therefore, it is imperative to find markers that may help in the prediction of EOD in acute hypertensive crisis. Aim To assess the clinical presentations on admission; echocardiographic changes of pulsed and tissue Doppler changes in EOD patients compared with no EOD; and the risk of developing end organ damage for clinical and biochemical variables in hypertension crisis. Material and Methods The data of 241 patients with hypertensive crisis with systolic blood pressure (SBP) of >180 mmHg or diastolic blood pressure (DBP) >120 mmHg were extracted from patients files. Patients divided into hypertensive emergency (HE) with EOD, n = 62 and hypertensive urgency (HU) without EOD, n = 179. LV hypertrophy on ECG, echo parameters for wall thickness, left Ventricular mass index (LVMI), Body mass index (BMI), pulse Doppler ratio of early filling velocity E wave to late A wave (E/A) and ratio of E wave velocity to tissue Doppler Em to E wave (E/Em) were evaluated. Serum creatinine, hemoglobin, age, gender, body mass Index (BMI), history of diabetes mellitus, smoking, hypertension, stroke and hyperlipidemia were recorded. Multiple logistic regression analysis was applied for risk prediction of end organ damage of clinical variables. Results Patients with HE compared with HU were significantly older, with a significantly higher SBP on admission, high BMI and LVMI. Further there were significantly higher E/A ratio on Doppler echo and higher E/Em ratio on tissue Doppler echocardiogram. Multiple regression analysis with adjustment for age and sex shows positive predictive value with odds ratio of SBP on admission >220 mmHg of 1.98, serum creatinine > 120 µg/L of 1.43, older age > 60 year of 1.304, obesity (BMI ≥ 30) of 1.9, male gender of 2.26 and left ventricle hypertrophy on ECG of 1.92. The hemoglobin level, history of smoking, hyperlipidemia and DM were with no significant predictive value. The pulsed Doppler E/A ratio was ≥1.6, E/Em > 15, LVMI > 125 gm/m2 in patients with EOD compared with those without. Conclusion In patients presented with hypertensive crisis, the echo indices of E/A ratio and E/Em ratio of tissue Doppler are significantly higher in patients with hypertensive emergency compared to hypertensive urgency. The left ventricle hypertrophy on ECG, high LV mass index of >125 gm/m2, BMI > 30, old age > 60 year, male gender and history of hypertension and stroke were positive predictors of poor outcome and end organ damage. PMID:26949338

Pulsed and Tissue Doppler Echocardiographic Changes in Hypertensive Crisis with and without End Organ Damage.

PubMed

Garadah, Taysir; Kassab, Salah; Gabani, Saleh; Abu-Taleb, Ahmed; Abdelatif, Ahmed; Asef, Aysha; Shoroqi, Issa; Jamsheer, Anwer

2011-01-01

Hypertensive crisis (HC) is a common medical emergency associated with acute rise in arterial blood pressure that leads to end-organ damage (EOD). Therefore, it is imperative to find markers that may help in the prediction of EOD in acute hypertensive crisis. To assess the clinical presentations on admission; echocardiographic changes of pulsed and tissue Doppler changes in EOD patients compared with no EOD; and the risk of developing end organ damage for clinical and biochemical variables in hypertension crisis. The data of 241 patients with hypertensive crisis with systolic blood pressure (SBP) of >180 mmHg or diastolic blood pressure (DBP) >120 mmHg were extracted from patients files. Patients divided into hypertensive emergency (HE) with EOD, n = 62 and hypertensive urgency (HU) without EOD, n = 179. LV hypertrophy on ECG, echo parameters for wall thickness, left Ventricular mass index (LVMI), Body mass index (BMI), pulse Doppler ratio of early filling velocity E wave to late A wave (E/A) and ratio of E wave velocity to tissue Doppler Em to E wave (E/Em) were evaluated. Serum creatinine, hemoglobin, age, gender, body mass Index (BMI), history of diabetes mellitus, smoking, hypertension, stroke and hyperlipidemia were recorded. Multiple logistic regression analysis was applied for risk prediction of end organ damage of clinical variables. Patients with HE compared with HU were significantly older, with a significantly higher SBP on admission, high BMI and LVMI. Further there were significantly higher E/A ratio on Doppler echo and higher E/Em ratio on tissue Doppler echocardiogram. Multiple regression analysis with adjustment for age and sex shows positive predictive value with odds ratio of SBP on admission >220 mmHg of 1.98, serum creatinine > 120 µg/L of 1.43, older age > 60 year of 1.304, obesity (BMI ≥ 30) of 1.9, male gender of 2.26 and left ventricle hypertrophy on ECG of 1.92. The hemoglobin level, history of smoking, hyperlipidemia and DM were with no significant predictive value. The pulsed Doppler E/A ratio was ≥1.6, E/Em > 15, LVMI > 125 gm/m(2) in patients with EOD compared with those without. In patients presented with hypertensive crisis, the echo indices of E/A ratio and E/Em ratio of tissue Doppler are significantly higher in patients with hypertensive emergency compared to hypertensive urgency. The left ventricle hypertrophy on ECG, high LV mass index of >125 gm/m(2), BMI > 30, old age > 60 year, male gender and history of hypertension and stroke were positive predictors of poor outcome and end organ damage.

A multimodal imaging platform with integrated simultaneous photoacoustic microscopy, optical coherence tomography, optical Doppler tomography and fluorescence microscopy

NASA Astrophysics Data System (ADS)

Dadkhah, Arash; Zhou, Jun; Yeasmin, Nusrat; Jiao, Shuliang

2018-02-01

Various optical imaging modalities with different optical contrast mechanisms have been developed over the past years. Although most of these imaging techniques are being used in many biomedical applications and researches, integration of these techniques will allow researchers to reach the full potential of these technologies. Nevertheless, combining different imaging techniques is always challenging due to the difference in optical and hardware requirements for different imaging systems. Here, we developed a multimodal optical imaging system with the capability of providing comprehensive structural, functional and molecular information of living tissue in micrometer scale. This imaging system integrates photoacoustic microscopy (PAM), optical coherence tomography (OCT), optical Doppler tomography (ODT) and fluorescence microscopy in one platform. Optical-resolution PAM (OR-PAM) provides absorption-based imaging of biological tissues. Spectral domain OCT is able to provide structural information based on the scattering property of biological sample with no need for exogenous contrast agents. In addition, ODT is a functional extension of OCT with the capability of measurement and visualization of blood flow based on the Doppler effect. Fluorescence microscopy allows to reveal molecular information of biological tissue using autofluoresce or exogenous fluorophores. In-vivo as well as ex-vivo imaging studies demonstrated the capability of our multimodal imaging system to provide comprehensive microscopic information on biological tissues. Integrating all the aforementioned imaging modalities for simultaneous multimodal imaging has promising potential for preclinical research and clinical practice in the near future.

Method and apparatus for optical Doppler tomographic imaging of fluid flow velocity in highly scattering media

DOEpatents

Nelson, John Stuart; Milner, Thomas Edward; Chen, Zhongping

1999-01-01

Optical Doppler tomography permits imaging of fluid flow velocity in highly scattering media. The tomography system combines Doppler velocimetry with high spatial resolution of partially coherent optical interferometry to measure fluid flow velocity at discrete spatial locations. Noninvasive in vivo imaging of blood flow dynamics and tissue structures with high spatial resolutions of the order of 2 to 10 microns is achieved in biological systems. The backscattered interference signals derived from the interferometer may be analyzed either through power spectrum determination to obtain the position and velocity of each particle in the fluid flow sample at each pixel, or the interference spectral density may be analyzed at each frequency in the spectrum to obtain the positions and velocities of the particles in a cross-section to which the interference spectral density corresponds. The realized resolutions of optical Doppler tomography allows noninvasive in vivo imaging of both blood microcirculation and tissue structure surrounding the vessel which has significance for biomedical research and clinical applications.

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

NASA Astrophysics Data System (ADS)

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.

Patterns of left ventricular diastolic function in Olympic athletes.

PubMed

Caselli, Stefano; Di Paolo, Fernando M; Pisicchio, Cataldo; Pandian, Natesa G; Pelliccia, Antonio

2015-02-01

Whether morphologic left ventricular (LV) changes in elite athletes are associated with altered diastolic properties is undefined. The aim of this study was to investigate LV diastolic properties in a large population of Olympic athletes compared to untrained controls. A total of 1,145 Olympic athletes (61% men), and 154 controls, free of cardiovascular disease, underwent two-dimensional echocardiography, Doppler echocardiography, and Doppler tissue imaging. Athletes had similar E velocities (87 ± 15 vs 89 ± 16 cm/sec, P = .134) but significantly decreased A velocities (47 ± 10 vs 56 ± 12 cm/sec, P < .001) compared with controls, with increased E/A ratios (1.93 ± 0.50 vs 1.63 ± 0.35, P < .001) and values ranging up to 4.8. Isovolumic relaxation (83 ± 13 vs 71 ± 16 msec, P < .001) and deceleration times (203 ± 40 vs 181 ± 36 msec, P < .001) were longer in athletes compared with controls. Doppler tissue imaging e' (13.8 ± 2.2 vs 16.2 ± 3.7 cm/sec, P < .001) and a' (7.2 ± 1.8 vs 8.5 ± 2.1 cm/sec, P < .001) were lower in athletes than in controls, but their ratio was not different between groups; E/e' ratios (6.37 ± 1.2 vs 5.72 ± 1.33, P < .001) were mildly higher in athletes. Subgroup analysis for type of sport showed that endurance athletes had the lowest A and a' velocities and the largest E/A ratios. Gender analysis revealed that men had significantly lower E and A velocities, as well as e', e'/a' ratios, and E/e' ratios (P < .01), compared with women. This study provides normal values for Doppler echocardiographic and Doppler tissue imaging parameters describing diastolic function in elite athletes, which may be implemented as reference values in the clinical assessment of athlete's heart and prove useful in understanding the physiologic limits of cardiac adaptations in athletes. Copyright © 2015 American Society of Echocardiography. All rights reserved.

Echocardiographic Evaluation of Left Atrial Mechanics: Function, History, Novel Techniques, Advantages, and Pitfalls.

PubMed

Leischik, Roman; Littwitz, Henning; Dworrak, Birgit; Garg, Pankaj; Zhu, Meihua; Sahn, David J; Horlitz, Marc

2015-01-01

Left atrial (LA) functional analysis has an established role in assessing left ventricular diastolic function. The current standard echocardiographic parameters used to study left ventricular diastolic function include pulsed-wave Doppler mitral inflow analysis, tissue Doppler imaging measurements, and LA dimension estimation. However, the above-mentioned parameters do not directly quantify LA performance. Deformation studies using strain and strain-rate imaging to assess LA function were validated in previous research, but this technique is not currently used in routine clinical practice. This review discusses the history, importance, and pitfalls of strain technology for the analysis of LA mechanics.

Biventricular and atrial diastolic function assessment using conventional echocardiography and tissue-Doppler imaging in adults with Marfan syndrome.

PubMed

Kiotsekoglou, Anatoli; Moggridge, James C; Bijnens, Bart H; Kapetanakis, Venediktos; Alpendurada, Francisco; Mullen, Michael J; Saha, Samir; Nassiri, Dariush K; Camm, John; Sutherland, George R; Child, Anne H

2009-12-01

Previous studies provided evidence about left ventricular systolic and diastolic dysfunction in adults with Marfan syndrome (MFS). However, in the literature, data on right ventricular and bi-atrial diastolic function are limited. We aimed to investigate whether, in the absence of significant valvular disease, diastolic dysfunction is present not only in both ventricles but also in the atrial cavities. Seventy-two adult unoperated MFS patients and 73 controls without significant differences in age, sex, and body surface area from the patient group were studied using two-dimensional, pulsed, and colour-Doppler and tissue-Doppler imaging (TDI). Biventricular early filling measurements were significantly decreased in MFS patients when compared with controls (P < 0.001). Pulsed TDI early filling measurements obtained from five mitral annular regions and over the lateral tricuspid valve corner were significantly reduced in the patient group (P < 0.001). Indices reflecting atrial function at the reservoir, conduit and contractile phases were also significantly decreased in MFS patients (P < 0.001). This study demonstrated significant biventricular diastolic and biatrial systolic and diastolic dysfunction in MFS patients. Our findings suggest that MFS affects diastolic function independently. Diastolic abnormalities could be attributed to fibrillin-1 deficiency and dysregulation of transforming growth factor-beta activity in the cardiac extracellular matrix.

Assessment of sustained effects of levosimendan and dobutamine on left ventricular systolic functions by using novel tissue Doppler derived indices in patients with advanced heart failure.

PubMed

Oner, Ender; Erturk, Mehmet; Birant, Ali; Kurtar Mansıroglu, Aslı; Akturk, Ibrahim Faruk; Karakurt, Huseyin; Yalcin, Ahmet Arif; Uzun, Fatih; Somuncu, Mustafa Umut; Yildirim, Aydin

2015-01-01

Previous studies comparing levosimendan vs. dobutamine have revealed that levosimendan is better in relieving symptoms. Echocardiographic studies have been done using second measurements immediately following a dobutamine infusion or while it was still being administered. The aim of our study was assessment of sustained effects of 24 h levosimendan and dobutamine infusions on left ventricular systolic functions. A total of 61 patients with acutely decompensated heart failure with New York Heart Association (NYHA) class III or IV symptoms were randomized to receive either levosimendan or dobutamine 2:1 in an open label fashion. Before and 5 days after the initiation of infusions, functional class was assessed, N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) levels and left ventricular ejection fraction (LVEF), mitral inflow peak E and A wave velocity, and E/A ratios were measured; using tissue Doppler imaging, isovolumic myocardial acceleration (IVA), peak myocardial velocity during isovolumic contraction (IVV), peak systolic velocity during ejection period (Sa), early (E') and late (A') diastolic velocities, and E'/A' and E/E' ratios were measured. The NYHA class improved in both groups, but improvements were prominent in the levosimendan group. NT-proBNP levels were significantly reduced in the levosimendan group. Improvements in LVEF and diastolic indices were significant in the levosimendan group. Tissue Doppler-derived systolic indices of IVV and IVA increased significantly in the levosimendan group. Improvements in left ventricular systolic and diastolic functions continue after a levosimendan infusion.

Detecting Subclinical Biventricular Impairment in Scleroderma Patients by Use of Pulsed-Wave Tissue Doppler Imaging

PubMed Central

Can, Ilknur; Onat, Ahmet Mesut; Aytemir, Kudret; Akdogan, Ali; Ureten, Kemal; Kiraz, Sedat; Ertenli, Ihsan; Tokgozoglu, Lale; Oto, Ali

2009-01-01

Systemic scleroderma is a disease that is characterized by excessive fibroblastic activity and collagen deposition in various organs, including the heart. We sought to evaluate the limits of biventricular function as derived noninvasively from pulsed-wave tissue Doppler imaging (TDI) of tricuspid and mitral annular motion in patients who had scleroderma. We enrolled 24 patients with scleroderma (study group; mean age, 49 ± 11 yr; 20 women) and 24 healthy participants (control group; mean age, 51 ± 9 yr; 19 women). Persons with cardiovascular risk factors were excluded. We obtained images by conventional echocardiography and by pulsed-wave TDI, measuring the respective peak systolic velocities (S, Sm) and peak early (E, Em) and late (A, Am) diastolic velocities. Mean Sm, mean Em, and mean Am were averages of the 4 measured sites (anterior, inferior, lateral, and septal). We calculated noninvasive estimates of left ventricular (LV) filling pressure by dividing E velocities (from the mitral inflow) by Em velocities (E/Em ratios). Biventricular regional Sm, regional LV myocardial Em, and ratios of myocardial Em/atrial component velocity (Em/Am) for the LV, and mean Sm, mean Em, and mean Em/mean Am ratios for the LV were significantly lower in the study group. The E/Em ratio was higher in the study group (7.3 ± 2.6 vs 5.2 ± 1.0, P = 0.01). Global LV systolic and diastolic function did not differ between the groups. Tissue Doppler imaging complements conventional echocardiography in detecting subclinical biventricular impairment in patients with scleroderma who have normal global measurements. PMID:19436783

SU-E-J-31: Biodynamic Imaging of Cancer Tissue and Response to Chemotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nolte, D; Turek, J; Childress, M

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 ofmore » 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 progression free survival times. This work is supported by NIH 1R01EB016582 and NSF 1263753-CBET. Nolte, Turek and An have a financial interest in Animated Dynamics, Inc. that will be licensing technology from Purdue University.« less

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.

PubMed

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 < 0.01). Elasticity indexes change in a stepwise pattern with the narrowness of coronary artery, and there was a significant correlation between aortic elasticity and severity of coronary artery by Pearson correlation analysis (P < 0.01). Elasticity indexes of ascending aorta correlate well with severity of coronary stenosis. Elasticity indexes of ascending aorta can serve as predictors for coronary arterial lesion in hypertensive patients.

Right ventricular involvement in patients with inferior myocardial infarction, correlation of electrocardiographic findings with echocardiography data.

PubMed

Javed, Sumbul; Rajani, Ali Raza; Govindaswamy, Pushparani; Radaideh, Ghazi Ahmed; Abubaraka, Harb Ahmed; Qureshi, Tariq Ilyas; Arshad, Hassaan Bin

2017-03-01

To determine the right ventricular involvement in patients with inferior myocardial infarction by echocardiography in relation to electrocardiographic findings. This observational, prospective study was conducted at Rashid Hospital, Dubai, the United Arab Emirates, from January to September 2013, and comprised patients with inferior myocardial infarction. All patients aged above 18 years were included. Right ventricular myocardial infarction was defined by the electrocardiographic criteria of > 1mV ST elevation in V4R-V5R leads. RV infarction was assessed on echocardiography by fractional area change, tricuspid annular plane systolic excursion and tricuspid annular systolic velocity by tissue Doppler imaging. SPSS 21 was used for data analysis. Of the 73 patients, there were 68(93%) men and 5(7%) women. The three modalities used to assess the right ventricular infarction showed right ventricular involvement in 36(49.3%) cases by fractional area change, 28(38.4%) cases by tricuspid annular plane systolic excursion and 31(42.5%) cases by tissue Doppler imaging in patients with inferior myocardial infarction. Tissue Doppler imaging and right ventricular function showed low degree of negative correlation (p=0.16) while the correlation between tricuspid annular plane systolic excursion and right ventricular function showed significant positive correlation (p<0.0001). Assessment of right ventricular infarction by echocardiography helped to diagnose right ventricular infarction in greater number of cases compared to surface electrocardiogram.

Three-dimensional power Doppler sonography in screening for carotid artery disease.

PubMed

Keberle, M; Jenett, M; Beissert, M; Jahns, R; Haerten, R; Hahn, D

2000-01-01

Color Doppler sonography has gained considerable recognition as a noninvasive method to detect carotid artery disease and to assess the degree of carotid artery stenosis. However, results are highly operator-dependent and cannot be presented as survey images. The purpose of this study was to evaluate real-time 3-dimensional (3D) power Doppler sonography as a method for screening for atherosclerosis in the carotid arteries. We prospectively screened 75 patients for carotid artery disease using both conventional color Doppler sonography and 3D power Doppler sonography, and the results from the 2 modalities were compared. A total of 150 common carotid arteries, 150 internal carotid arteries, and 150 external carotid arteries were examined utilizing a 7.5-MHz linear-array transducer combined with tissue harmonic imaging. Color Doppler sonography detected 297 normal or atherosclerotic arteries without stenosis, 57 arteries with mild (1-49%) stenosis, 41 with moderate (50-69%) stenosis, 32 with severe (70-99%) stenosis, and 9 with occlusions. The degree of stenosis determined by color Doppler sonography correlated with that determined by 3D power Doppler sonography (r = 0.982-0.998). Moreover, there was a good correlation between the measurements for both the length of the lesion and its distance from the bulb as determined by the 3D volume surveys and by color Doppler sonography (r = 0.986). The interobserver variability rate was 3.7% +/- 0.5%. Generally, the acquisition and reconstruction of the 3D data took less than 5 minutes. 3D power Doppler sonography is easy to perform and is an accurate method in screening for atherosclerotic lesions of the carotid arteries. Moreover, it provides excellent 3D volume surveys that may be helpful in the planning of surgical treatment. Copyright 2000 John Wiley & Sons, Inc.

[A Comparison Study on Early Damage Detection of Left Ventricular Function Based on Doppler Imaging Method for Children with Tumor].

PubMed

Liu, Ying; Zhang, Haowei; Zhang, Hang

2015-12-01

The early damage detection and evaluation are of great significance in treatment and prognosis to the left ventricular function for children with tumor. In this paper, it is reported that the early damage of the left ventricular function was observed by pulsed wave Doppler (PWD) and tissue Doppler imaging (TDI) in our laboratory. Eighty children half a year to fourteen years old were included in this study. The cardiac function indices in chemotherapy group and control group were measured and compared. The results showed that there was significant difference in mitral and tricuspid annulus flow spectrum between the two groups. Compared with PWD,TDI is more prompt, objective and accurate in detecting early damage of left ventricular function in children with tumor. And TDI is a good method for early identification of ventricular function damage in children with tumor.

Monitoring the impact of pressure on the assessment of skin perfusion and oxygenation using a novel pressure device

NASA Astrophysics Data System (ADS)

Ramella-Roman, Jessica C.; Ho, Thuan; Le, Du; Ghassemi, Pejhman; Nguyen, Thu; Lichy, Alison; Groah, Suzanne

2013-03-01

Skin perfusion and oxygenation is easily disrupted by imposed pressure. Fiber optics probes, particularly those spectroscopy or Doppler based, may relay misleading information about tissue microcirculation dynamics depending on external forces on the sensor. Such forces could be caused by something as simple as tape used to secure the fiber probe to the test subject, or as in our studies by the full weight of a patient with spinal cord injury (SCI) sitting on the probe. We are conducting a study on patients with SCI conducting pressure relief maneuvers in their wheelchairs. This study aims to provide experimental evidence of the optimal timing between pressure relief maneuvers. We have devised a wireless pressure-controlling device; a pressure sensor positioned on a compression aluminum plate reads the imposed pressure in real time and sends the information to a feedback system controlling two position actuators. The actuators move accordingly to maintain a preset value of pressure onto the sample. This apparatus was used to monitor the effect of increasing values of pressure on spectroscopic fiber probes built to monitor tissue oxygenation and Doppler probes used to assess tissue perfusion.

The Short-Term Effects of Ketogenic Diet on Cardiac Ventricular Functions in Epileptic Children.

PubMed

Doksöz, Önder; Çeleğen, Kübra; Güzel, Orkide; Yılmaz, Ünsal; Uysal, Utku; İşgüder, Rana; Çeleğen, Mehmet; Meşe, Timur

2015-09-01

Our primary aim was to determine the short-term effects of a ketogenic diet on cardiac ventricular function in patients with refractory epilepsy. Thirty-eight drug-resistant epileptic patients who were treated with a ketogenic diet were enrolled in this prospective study. Echocardiography was performed on all patients before beginning the ketogenic diet and after the sixth month of therapy. Two-dimensional, M-mode, color flow, spectral Doppler, and pulsed-wave tissue Doppler imaging measurements were performed on all patients. The median age of the 32 patients was 45.5 months, and 22 (57.8%) of them were male. Body weight, height, and body mass index increased significantly at the sixth month of therapy when compared with baseline values (P < 0.05). Baseline variables assessed by conventional M-mode echocardiography showed no significant difference at month 6 (P > 0.05). Doppler flow indices of mitral annulus and tricuspid annulus velocity of patients at baseline and month 6 showed no significant differences (P > 0.05). Tricuspid annular E/A ratio was lower at month 6 (P < 0.05). Although mitral annulus tissue Doppler imaging studies showed no significant difference (P > 0.05), there was a decrease in Ea velocity and Ea/Aa ratio gathered from tricuspid annulus at month 6 compared with baseline (P < 0.05). A 6-month duration ketogenic diet does not impair left ventricular functions in children with refractory epilepsy; however, it may be associated with a right ventricular diastolic dysfunction. Copyright © 2015 Elsevier Inc. All rights reserved.

Evaluation of contrast-enhanced power Doppler imaging for measuring blood flow

NASA Astrophysics Data System (ADS)

Ansaloni, Sara; Arger, Peter H.; Cary, Ted W.; Sehgal, Chandra M.

2005-04-01

Power Doppler ultrasound enhanced by microbubble contrast agent has been used to image tissue vascularity and blood flow for the assessment of antivascular therapies. We have proposed a multigating technique that measures bubble concentration as a function of ultrasound exposure for deriving tumor blood flow and vascularity.1 Techniques using ultrasound contrast agent are known to be sensitive to the choice of imaging parameters like mechanical index and tissue attenuation. In this paper, the roles of mechanical index (MI) and tissue attenuation were evaluated experimentally in a rubber tubing flow phantom connected to a mixing chamber and a variable speed pump. The contrast was injected in the mixing chamber and the flow rate was measured using power Doppler imaging. The measurements were repeated at different MIs (0.1 to 1.3), and at different levels of attenuation, obtained with solutions of glycerol-water (10-20%). True flow was measured by collecting liquid flowing out of the phantom over a fixed duration. At low MI (<0.5), the grayscale and Doppler signal were weak, making these images unsuitable for analysis. At higher MI (> 0.8), there was a well-defined enhancement by contrast agent resulting in reproducible flow measurements at variable MIs. A balance between the number of bubbles destroyed and the echo they generate must be achieved for optimal imaging. The increased attenuation of ultrasound by the overlying medium did not influence the flow measurements.

Stimuli-disassembling gold nanoclusters for diagnosis of early stage oral cancer by optical coherence tomography

NASA Astrophysics Data System (ADS)

Kim, Chang Soo; Ingato, Dominique; Wilder-Smith, Petra; Chen, Zhongping; Kwon, Young Jik

2018-01-01

A key design consideration in developing contrast agents is obtaining distinct, multiple signal changes in diseased tissue. Plasmonic gold nanoparticles (Au NPs) have been developed as contrast agents due to their strong surface plasmon resonance (SPR). This study aims to demonstrate that stimuli-responsive plasmonic Au nanoclusters (Au NCs) can be used as a contrast agent for optical coherence tomography (OCT) in detecting early-stage cancer. Au NPs were clustered via acid-cleavable linkers to synthesize Au NCs that disassemble under mildly acidic conditions into individual Au NPs, simultaneously diminishing SPR effect (quantified by scattering intensity) and increasing Brownian motion (quantified by Doppler variance). The acid-triggered morphological and accompanying optico-physical property changes of the acid-disassembling Au NCs were confirmed by TEM, DLS, UV/Vis, and OCT. Stimuli-responsive Au NCs were applied in a hamster check pouch model carrying early-stage squamous carcinoma tissue. The tissue was visualized by OCT imaging, which showed reduced scattering intensity and increased Doppler variance in the dysplastic tissue. This study demonstrates the promise of diagnosing early-stage cancer using molecularly programmable, inorganic nanomaterial-based contrast agents that are capable of generating multiple, stimuli-triggered diagnostic signals in early-stage cancer.[Figure not available: see fulltext.

Ultrasonically Encoded Photoacoustic Flowgraphy in Biological Tissue

NASA Astrophysics Data System (ADS)

Wang, Lidai; Xia, Jun; Yao, Junjie; Maslov, Konstantin I.; Wang, Lihong V.

2013-11-01

Blood flow speed is an important functional parameter. Doppler ultrasound flowmetry lacks sufficient sensitivity to slow blood flow (several to tens of millimeters per second) in deep tissue. To address this challenge, we developed ultrasonically encoded photoacoustic flowgraphy combining ultrasonic thermal tagging with photoacoustic imaging. Focused ultrasound generates a confined heat source in acoustically absorptive fluid. Thermal waves propagate with the flow and are directly visualized in pseudo color using photoacoustic computed tomography. The Doppler shift is employed to calculate the flow speed. This method requires only acoustic and optical absorption, and thus is applicable to continuous fluid. A blood flow speed as low as 0.24mm·s-1 was successfully measured. Deep blood flow imaging was experimentally demonstrated under 5-mm-thick chicken breast tissue.

Prediabetes and Cardiovascular Parameters in Obese Children and Adolescents

PubMed Central

Eklioğlu, Beray Selver; Atabek, Mehmet Emre; Akyürek, Nesibe; Alp, Hayrullah

2016-01-01

Objective: In this study, our aim was to determine cardiovascular risk and cardiac function in prediabetic obese children and adolescents. Methods: The study was conducted on 198 obese children and adolescents 6-18 years of age. Anthropometric measurements, blood pressure measurements, oral glucose tolerance test, lipid profile, and HbA1c levels of patients were assessed. Prediabetes was defined according to American Diabetes Association criteria. Left ventricular mass index (LVMi), carotid intima-media thickness (c-IMT), and tissue Doppler measurements records were used. Results: LVMi was found to be significantly higher in the prediabetes group (p=0.03). There were no statistically significant differences in right ventricular tissue Doppler measurements between the prediabetic and non-prediabetic groups. Left ventricular tissue Doppler measurements were significantly higher in the prediabetes group: LVEEM (left ventricular E/e ratio) (p=0.04); LVEM (left ventricular myocardial velocity cm/s) (p=0.035). LVMi was found to positively correlate with triglyceride level, diastolic blood pressure, waist circumference, body weight standard deviation score and to negatively correlate with high-density lipoprotein cholesterol (p=0.043, r=0.15; p=0.039, r=0.15; p=0.025, r=0.17; p=0.009, r=0.19; p=0.038, r=-0.15, respectively). LVEM was correlated with glucose (p=0.046, r=0.15) and LVEEM was correlated with systolic blood pressure (p=0.035, r=0.15). In linear regression analysis for clinical cardiovascular risk factors, fasting glucose level was the best predictor of LVEM. Conclusion: In this study, deterioration of cardiac function in prediabetic obese children and adolescents was shown. We recommend determining cardiovascular risk and cardiac dysfunction at early stages in prediabetic obese children and adolescents. PMID:26759114

Prediabetes and Cardiovascular Parameters in Obese Children and Adolescents.

PubMed

Eklioğlu, Beray Selver; Atabek, Mehmet Emre; Akyürek, Nesibe; Alp, Hayrullah

2016-03-05

In this study, our aim was to determine cardiovascular risk and cardiac function in prediabetic obese children and adolescents. The study was conducted on 198 obese children and adolescents 6-18 years of age. Anthropometric measurements, blood pressure measurements, oral glucose tolerance test, lipid profile, and HbA1c levels of patients were assessed. Prediabetes was defined according to American Diabetes Association criteria. Left ventricular mass index (LVMi), carotid intima-media thickness (c-IMT), and tissue Doppler measurements records were used. LVMi was found to be significantly higher in the prediabetes group (p=0.03). There were no statistically significant differences in right ventricular tissue Doppler measurements between the prediabetic and non-prediabetic groups. Left ventricular tissue Doppler measurements were significantly higher in the prediabetes group: LVEEM (left ventricular E/e ratio) (p=0.04); LVEM (left ventricular myocardial velocity cm/s) (p=0.035). LVMi was found to positively correlate with triglyceride level, diastolic blood pressure, waist circumference, body weight standard deviation score and to negatively correlate with high-density lipoprotein cholesterol (p=0.043, r=0.15; p=0.039, r=0.15; p=0.025, r=0.17; p=0.009, r=0.19; p=0.038, r=-0.15, respectively). LVEM was correlated with glucose (p=0.046, r=0.15) and LVEEM was correlated with systolic blood pressure (p=0.035, r=0.15). In linear regression analysis for clinical cardiovascular risk factors, fasting glucose level was the best predictor of LVEM. In this study, deterioration of cardiac function in prediabetic obese children and adolescents was shown. We recommend determining cardiovascular risk and cardiac dysfunction at early stages in prediabetic obese children and adolescents.

Doppler imaging using spectrally-encoded endoscopy

PubMed Central

Yelin, Dvir; Bouma, B. E.; Rosowsky, J. J.; Tearney, G. J.

2009-01-01

The capability to image tissue motion such as blood flow through an endoscope could have many applications in medicine. Spectrally encoded endoscopy (SEE) is a recently introduced technique that utilizes a single optical fiber and miniature diffractive optics to obtain endoscopic images through small diameter probes. Using spectral-domain interferometry, SEE is furthermore capable of three-dimensional volume imaging at video rates. Here we show that by measuring relative spectral phases, this technology can additionally measure Doppler shifts. Doppler SEE is demonstrated in flowing Intralipid phantoms and vibrating middle ear ossicles. PMID:18795020

Diagnostic blood-flow monitoring during therapeutic interventions using color Doppler optical coherence tomography

NASA Astrophysics Data System (ADS)

Yazdanfar, Siavash; Kulkarni, Manish D.; Wong, Richard C. K.; Sivak, Michael J., Jr.; Willis, Joseph; Barton, Jennifer K.; Welch, Ashley J.; Izatt, Joseph A.

1998-04-01

A recently developed modality for blood flow measurement holds high promise in the management of bleeding ulcers. Color Doppler optical coherence tomography (CDOCT) uses low- coherence interferometry and digital signal processing to obtain precise localization of tissue microstructure simultaneous with bi-directional quantitation of blood flow. We discuss CDOCT as a diagnostic tool in the management of bleeding gastrointestinal lesions. Common treatments for bleeding ulcers include local injection of a vasoconstrictor, coagulation of blood via thermal contact or laser treatment, and necrosis of surrounding tissue with a sclerosant. We implemented these procedures in a rat dorsal skin flap model, and acquired CDOCT images before and after treatment. In these studies, CDOCT succeeded in identifying cessation of flow before it could be determined visually. Hence, we demonstrate the diagnostic capabilities of CDOCT in the regulation of bleeding in micron-scale vessels.

Echocardiographic findings in professional hockey players

PubMed Central

Fazel, Poorya; Roberts, Brad J.; Brooks, John

2009-01-01

Tissue Doppler imaging was used to evaluate the physiological and morphological response in athletes whose cardiac system must not only adapt to intense cardiovascular demands but also support sudden, transient changes in cardiac output. A total of 45 professional hockey players with a mean age of 24 years underwent a baseline transthoracic echocardiographic protocol after a typical morning workout; 12 healthy age- and gender-matched controls were evaluated as a means of comparison. The athletes in this study possessed larger left ventricular diastolic and systolic dimensions than the control group (5.5 ± 0.4 vs 4.9 ± 0.4 cm and 3.9 ± 0.4 vs 3.3 ± 0.4 cm, P < 0.0001). The increase in athletes' septal and posterior wall thickness was not substantial, nor was there a significant difference in left ventricular ejection fraction. The athletes demonstrated consistently larger left ventricular end-diastolic volume (196 ± 34 vs 136 ± 23 mL, P < 0.001) and end-systolic volume (87 ± 20 vs 57 ± 12 mL, P < 0.0001). They also had lower annular septal and lateral early diastolic and systolic tissue Doppler velocities compared with the control group. Thus, characteristic myocardial changes previously reported in elite athletes were also represented in professional hockey players. The lower left ventricular tissue Doppler velocities was a relatively unique finding and probably a consequence of lower postexertion preload levels compared with controls who were measured at rest. PMID:19633740

Utilization of laser Doppler flowmetry and tissue spectrophotometry for burn depth assessment using a miniature swine model.

PubMed

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.

Accuracy of tissue Doppler echocardiography in the diagnosis of new-onset congestive heart failure in patients with levels of B-type natriuretic peptide in the midrange and normal left ventricular ejection fraction.

PubMed

Arques, Stephane; Roux, Emmanuel; Sbragia, Pascal; Pieri, Bertrand; Gelisse, Richard; Ambrosi, Pierre; Luccioni, Roger

2006-09-01

Based on the hypothesis that it reflects left ventricular (LV) diastolic pressures, B-type natriuretic peptide (BNP) is largely utilized as first-line diagnostic complement in the emergency diagnosis of congestive heart failure (HF). The incremental diagnostic value of tissue Doppler echocardiography, a reliable noninvasive estimate of LV filling pressures, has been reported in patients with preserved LV ejection fraction and discrepancy between BNP levels and the clinical judgment, however, its clinical validity in such patients in the presence of BNP concentrations in the midrange, which may reflect intermediate, nondiagnostic levels of LV filling pressures, is unknown. 34 patients without history of HF, presenting with acute dyspnea at rest, BNP levels of 100-400 pg/ml and normal LV ejection fraction were prospectively enrolled (17 with congestive HF and 17 with noncardiac cause). Tissue Doppler echocardiography was performed within 3 hours after admission. Unlike BNP (P = 0.78), Boston criteria (P = 0.0129), radiographic pulmonary edema (P = 0.0036) and average E/Ea ratio (P = 0.0032) were predictive of congestive HF by logistic regression analysis. In this clinical setting, radiographic pulmonary edema had a positive predictive value of 80% in the diagnosis of congestive HF. In patients without evidence of radiographic pulmonary edema, average E/Ea > 10 was a powerful predictor of congestive HF (area under the ROC curve of 0.886, P < 0.001, sensitivity 100% and specificity 78.6%). By better reflecting LV filling pressures, bedside tissue Doppler echocardiography accurately differentiates congestive HF from noncardiac cause in dyspneic patients with intermediate, nondiagnostic BNP levels and normal LV ejection fraction.

Utility of Tissue Doppler Imaging in the Echocardiographic Evaluation of Left and Right Ventricular Function in Dogs with Myxomatous Mitral Valve Disease with or without Pulmonary Hypertension.

PubMed

Baron Toaldo, M; Poser, H; Menciotti, G; Battaia, S; Contiero, B; Cipone, M; Diana, A; Mazzotta, E; Guglielmini, C

2016-05-01

In human medicine, right ventricular (RV) functional parameters represent a tool for risk stratification in patients with congestive heart failure caused by left heart disease. Little is known about RV alterations in dogs with left-sided cardiac disorders. To assess RV and left ventricular (LV) function in dogs with myxomatous mitral valve disease (MMVD) with or without pulmonary hypertension (PH). One-hundred and fourteen dogs: 28 healthy controls and 86 dogs with MMVD at different stages. Prospective observational study. Animals were classified as healthy or having MMVD at different stages of severity and according to presence or absence of PH. Twenty-eight morphological, echo-Doppler, and tissue Doppler imaging (TDI) variables were measured and comparison among groups and correlations between LV and RV parameters were studied. No differences were found among groups regarding RV echo-Doppler and TDI variables. Sixteen significant correlations were found between RV TDI and left heart echocardiographic variables. Dogs with PH had significantly higher transmitral E wave peak velocity and higher E/e' ratio of septal (sMV) and lateral (pMV) mitral annulus. These 2 variables were found to predict presence of PH with a sensitivity of 84 and 72%, and a specificity of 71 and 80% at cut-off values of 10 and 9.33 for sMV E/e' and pMV E/e', respectively. No association between variables of RV function and different MMVD stage and severity of PH could be detected. Some relationships were found between echocardiographic variables of right and left ventricular function. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Tei index correlates with tissue Doppler parameters and reflects neurohormonal activation in patients with an abnormal transmitral flow pattern.

PubMed

Greco, Stefania; Troisi, Federica; Brunetti, Natale Daniele; Di Biase, Matteo

2009-10-01

Tei index (TI) is a Doppler parameter which reflects combined systolic and diastolic function. We aimed to study the relationship between TI, both traditional and tissue Doppler imaging (TDI) echocardiographic parameters and neurohormonal profile in outpatients with diastolic dysfunction expressed by an abnormal transmitral flow pattern. A total of 67 consecutive outpatients with diastolic dysfunction (abnormal transmitral flow pattern) were studied; all patients underwent clinical evaluation, blood sampling for B-type natriuretic peptide (BNP) plasma assaying, echocardiography for the determination of left ventricular ejection fraction (LVEF), dP/dt, left atrium (LA) dimensions, longitudinal systolic (S) and diastolic wall velocities (E'and A'), TI measured with Doppler echocardiography, and mitral regurgitation (MR) quantified on a semicontinuous scale. TI values were significantly correlated with BNP levels (r = 0.33; P < 0.01), LVEF (r =-0.56; P < 0.001), dP/dt (r =-0.52; P < 0.01), S (r =-0.45; P < 0.001), E'(r =-0.36; P < 0.01), A'(r =-0.27; P < 0.05), LA volume (r = 0.35; P < 0.01), and MR (P for trend < 0.05). In a multivariate regression analysis, TI was an independent predictor of increased BNP levels (beta= 0.32; P < 0.05), even after correction for potential confounders. ROC analysis showed as values of TI >0.59 identified subjects with combined systolic and diastolic dysfunction with a sensitivity of 73.8% and a specificity of 71.4%. In outpatients with diastolic dysfunction, TI, an easy to perform parameter for global ventricular performance assessment, might be useful in identifying subjects with concomitant systolic impairment and neurohormonal activation.

Cracking the perfusion code?: Laser-assisted Indocyanine Green angiography and combined laser Doppler spectrophotometry for intraoperative evaluation of tissue perfusion in autologous breast reconstruction with DIEP or ms-TRAM flaps.

PubMed

Ludolph, Ingo; Arkudas, Andreas; Schmitz, Marweh; Boos, Anja M; Taeger, Christian D; Rother, Ulrich; Horch, Raymund E; Beier, Justus P

2016-10-01

The aim of this prospective study was to assess the correlation of flap perfusion analysis based on laser-assisted Indocyanine Green (ICG) angiography with combined laser Doppler spectrophotometry in autologous breast reconstruction using free DIEP/ms-TRAM flaps. Between February 2014 and July 2015, 35 free DIEP/ms-TRAM flaps were included in this study. Besides the clinical evaluation of flaps, intraoperative perfusion dynamics were assessed by means of laser-assisted ICG angiography and post-capillary oxygen saturation and relative haemoglobin content (rHb) using combined laser Doppler spectrophotometry. Correlation of the aforementioned parameters was analysed, as well as the impact on flap design and postoperative complications. Flap survival rate was 100%. There were no partial flap losses. In three cases, flap design was based on the angiography, contrary to clinical evaluation and spectrophotometry. The final decision on the inclusion of flap areas was based on the angiographic perfusion pattern. Angiography and spectrophotometry showed a correlation in most of the cases regarding tissue perfusion, post-capillary oxygen saturation and relative haemoglobin content. Laser-assisted ICG angiography is a useful tool for intraoperative evaluation of flap perfusion in autologous breast reconstruction with DIEP/ms-TRAM flaps, especially in decision making in cases where flap perfusion is not clearly assessable by clinical signs and exact determination of well-perfused flap margins is difficult to obtain. It provides an objective real-time analysis of flap perfusion, with high sensitivity for the detection of poorly perfused flap areas. Concerning the topographical mapping of well-perfused flap areas, laser-assisted angiography is superior to combined laser Doppler spectrophotometry. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Development and Application of Multifunctional Optical Coherence Tomography

NASA Astrophysics Data System (ADS)

Zhi, Zhongwei

Microcirculation refers to the functions of capillaries and the neighboring lymphatic vessels. It plays a vital role in the pathophysiology of disorders in many clinical areas including cardiology, dermatology, neurology and ophthalmology, and so forth. It is crucial to develop imaging technologies that can provide both qualitative and quantitative information as to how microcirculation responds to certain injury and/or disease, and its treatment. Optical coherence tomography (OCT) is a non-invasive optical imaging technique for high-resolution cross-sectional imaging of specimens, with many applications in clinical medicine. Current state-of-the-art OCT systems operate in the Fourier domain, using either a broadband light source with a spectrometer, known as spectral domain OCT (SDOCT), or a rapidly tunable laser, known as swept source OCT (SSOCT). The current Fourier domain OCT systems have dramatically improvement in sensitivity, resolution and speed compared to time domain OCT. In addition to the improvement in the OCT system hardware, different methods for functional measurements of tissue beds have been developed and demonstrated. This includes but not limited to, i) Phase-resolved Doppler OCT for quantifying the blood flow, ii) OCT angiography for visualization of microvasculature, iii) Polarization sensitive OCT for measuring the intrinsic optical property/ birefringence of tissue, iv) spectroscopic OCT for measuring blood oxygenation, etc. Functional OCT can provide important clinical information that is not available in the typical intensity based structural OCT images. Among these functional OCT modalities, Doppler OCT and OCT angiography attract great interests as they show high capability for in vivo study of microvascular pathology. By analyzing the Doppler effect of a flowing particle on light frequency, Doppler OCT allows the quantification of the blood flow speed and blood flow rate. The most popular approach for Doppler OCT is achieved through analysis of the phase term in complex OCT signal which termed as Phase-resolved Doppler OCT. However, as limited by the phase noise and motion, Phase-resolved Doppler OCT can only be applied for relative large blood vessels, such as arterioles and venules. On the other hand, in order to visualize the microcirculation network, a number of strategies to enable better contrast of microvasculature components, which we termed OCT angiography, have been introduced during recent years. As a variation of Fourier domain OCT, optical microangiography (OMAG) is one of earliest proposed OCT angiography technique which is capable of generating 3D images of dynamic blood perfusion distribution within microcirculatory tissue beds. The OMAG algorithm works by separating the static and moving elements by high pass filtering on complex valued interferometric data after Fourier transform. Based on the conventional OMAG algorithm, we further developed ultra-high sensitive OMAG (UHS-OMAG) by switching the high-pass filtering from fast scan direction (adjacent A-lines within one B-frame) to slow scan direction (adjacent B-frames), which has a dramatically improved performance for capillary network imaging and analysis. Apart from the microvascular study with current available functional OCT for, visualization of the lymphatic system (lymph nodes and lymphatic vessels) plays a significant role in assessing patients with various malignancies and lymphedema. However, there is a lack of label-free and noninvasive method for lymphangiography. Hence, a cutting edge research to investigate the capability of OCT as a tool for non-invasive and label-free lymphangiography would be highly desired. The objective of my thesis is to develop a multiple-functional SDOCT system to image the microcirculation and quantify the several important parameters of microcirculation within microcirculatory tissue beds, and further apply it for pre-clinical research applications. The multifunctional OCT system provides modalities including structural OCT, OCT angiography, Doppler OCT and Optical lymphangiography, for multi-parametric study of tissue microstructure, blood vessel morphology, blood flow and lymphatic vessel all together. The thesis mainly focus on two parts: first, development of multi-functional OCT/optical microangiography (OMAG) system and methods for volumetric imaging of microvasculature and quantitative measurement of blood flow, and its application for pathological research in ophthalmology on rodent eye models; second, development of ultra-high resolution OCT system and algorithm for simultaneous label free imaging of blood and lymphatic vessel, and its application in wound healing study on mouse ear flap model. Objectives of my research are achieved through the following specific aims: Aim 1: Improve the sensitivity of OMAG for microvasculature imaging; perform volumetric and quantitative imaging of vasculature with combined OMAG and Phase-resolved Doppler OCT for in vivo study of vascular physiology. Aim 2: Develop high speed high resolution OCT system and method for rodent eye imaging. Apply the combined OMAG and Phase-resolved Doppler OCT approach to investigate the impact of elevated intraocular pressure on retinal, choroidal and optic nerve head blood flow in rat eye model, which aids to the better understanding of the mechanism and development of glaucoma. Aim 3: Apply the developed OCT system and ultra-high sensitive OMAG algorithm for noninvasive imaging of retinal morphology and microvasculature in obese mice, which may play an important role in early diagnosis of Diabetic retinopathy. Aim 4: Developing an ultra-high resolution SDOCT system using broadband Supercontinuum light source to achieve ultra-high resolution microvasculature imaging of biological tissue. Aim 5: Develop methods for simultaneous label free optical imaging of blood and lymphatic vessel and demonstrate its capability by monitoring the blood and lymph response to wound healing on mouse ear pinna model.

Can macrocirculation changes predict nonhealing diabetic foot ulcers?

PubMed

Lee, Ye-Na; Kim, Hyon-Surk; Kang, Jeong-A; Han, Seung-Kyu

2014-01-01

Transcutaneous partial oxygen tension (TcpO2) is considered the gold standard for assessment of tissue oxygenation, which is an essential factor for wound healing. The purpose of this study was to evaluate the association between macrocirculation and TcpO2 in persons with diabetes mellitus. Ninety-eight patients with diabetic foot ulcers participated in the study (61 men and 37 women). The subjects had a mean age of 66.6 years (range, 30-83 years) and were treated at the Diabetic Wound Center of Korea University Guro Hospital, Seoul, Republic of Korea. Macrocirculation was evaluated using 2 techniques: computed tomographic angiography and Doppler ultrasound. Macrocirculation scores were based on the patency of the two tibial arteries in 98 patients. Computed tomographic angiography and Doppler ultrasound scores (0-4 points) were given according to intraluminal filling defects and arterial pulse waveform of each vessel, respectively. Tissue oxygenation was measured by TcpO2. Macrocirculation scores were statistically analyzed as a function of the TcpO2. Statistical analysis revealed no significant linear trend between the macrocirculation status and TcpO2. Biavariate analysis using the Fisher exact test, Mantel-Haenszel tests, and McNemar-Bowker tests also found no significant relationship between macrocirculation and TcpO2. Computed tomographic angiography and Doppler ultrasound are not sufficiently reliable substitutes for TcpO2 measurements in regard to determining the optimal treatment for diabetic patients.

Doppler color imaging. Principles and instrumentation.

PubMed

Kremkau, F W

1992-01-01

DCI acquires Doppler-shifted echoes from a cross-section of tissue scanned by an ultrasound beam. These echoes are then presented in color and superimposed on the gray-scale anatomic image of non-Doppler-shifted echoes received during the scan. The flow echoes are assigned colors according to the color map chosen. Usually red, yellow, or white indicates positive Doppler shifts (approaching flow) and blue, cyan, or white indicates negative shifts (receding flow). Green is added to indicate variance (disturbed or turbulent flow). Several pulses (the number is called the ensemble length) are needed to generate a color scan line. Linear, convex, phased, and annular arrays are used to acquire the gray-scale and color-flow information. Doppler color-flow instruments are pulsed-Doppler instruments and are subject to the same limitations, such as Doppler angle dependence and aliasing, as other Doppler instruments. Color controls include gain, TGC, map selection, variance on/off, persistence, ensemble length, color/gray priority. Nyquist limit (PRF), baseline shift, wall filter, and color window angle, location, and size. Doppler color-flow instruments generally have output intensities intermediate between those of gray-scale imaging and pulsed-Doppler duplex instruments. Although there is no known risk with the use of color-flow instruments, prudent practice dictates that they be used for medical indications and with the minimum exposure time and instrument output required to obtain the needed diagnostic information.

Evaluation of left ventricular function by tissue Doppler and speckle-derived strain rate echocardiography after percutaneous ductus closure.

PubMed

Amoogzar, Hamid; Shakiba, Ali Mohammad; Derakhshan, Dorna; Ajami, Gholamhossein; Cheriki, Sirous; Borzouee, Mohammad; Edraki, Mohammad Reza; Mehdizadegan, Nima

2015-01-01

The aim of this study was to evaluate the left ventricular systolic and diastolic function before and after transcatheter percutaneous patent ductus arteriosus (PDA) closure. 21 children (age >6 months old) diagnosed with hemodynamically significant PDA underwent percutaneous PDA closure. Conventional, Doppler and tissue Doppler imaging and speckled-derived strain rate echocardiography were done at pre-closure, 1 day (early) and 1 month (late) post-closure. Mean age of the patients (female/male: 1.3) was 17.54 ± 24.7 months with the mean PDA diameter of 3.6 ± 0.8 mm. Systolic measures (ejection fraction, shortening fraction) reduced significantly early after PDA closure (P < 0.05). After 1 month, both improved significantly; ultimately, after 1 month no change was observed in systolic function measures compared with the pre-closure status. Early and late diastolic flow velocities of mitral (E M and A M) reduced considerably in early and late post-closure time (P < 0.05). Both early tissue Doppler early velocity of lateral mitral annulus (E'M) and early to late velocity ratio (E'M/A'M) of lateral mitral annulus decreased significantly (P = 0.02) in early post-closure. After 1 month, E'M increased considerably. (P = 0.01) but E'M/A'M had an insignificant rise (P > 0.05). E M/E'M ratio did not change in early post-closure but it had a considerable reduction in the subsequent month compared with the pre- and early post-closure (P < 0.001 for both occasions). Global and segmental longitudinal strain measures reduced significantly early after PDA closure (P < 0.05) but it improved remarkably in the subsequent month. Transcatheter PDA closure causes a significant decrease in left ventricular performance early after PDA closure which recovers completely within 1 month. Also PDA size can affect post-closure left ventricular function.

Vessel packaging effect in laser speckle contrast imaging and laser Doppler imaging.

PubMed

Fredriksson, Ingemar; Larsson, Marcus

2017-10-01

Laser speckle-based techniques are frequently used to assess microcirculatory blood flow. Perfusion estimates are calculated either by analyzing the speckle fluctuations over time as in laser Doppler flowmetry (LDF), or by analyzing the speckle contrast as in laser speckle contrast imaging (LSCI). The perfusion estimates depend on the amount of blood and its speed distribution. However, the perfusion estimates are commonly given in arbitrary units as they are nonlinear and depend on the magnitude and the spatial distribution of the optical properties in the tissue under investigation. We describe how the spatial confinement of blood to vessels, called the vessel packaging effect, can be modeled in LDF and LSCI, which affect the Doppler power spectra and speckle contrast, and the underlying bio-optical mechanisms for these effects. As an example, the perfusion estimate is reduced by 25% for LDF and often more than 50% for LSCI when blood is located in vessels with an average diameter of 40  μm, instead of being homogeneously distributed within the tissue. This significant effect can be compensated for only with knowledge of the average diameter of the vessels in the tissue. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

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

PubMed

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

2017-06-21

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 [Formula: see text] 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.

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

NASA Astrophysics Data System (ADS)

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.

Characterizing cardiac dysfunction in fetuses with left congenital diaphragmatic hernia.

PubMed

Cruz-Lemini, Mónica; Valenzuela-Alcaraz, Brenda; Granados-Montiel, Julio; Martínez, Josep M; Crispi, Fátima; Gratacós, Eduard; Cruz-Martínez, Rogelio

2018-03-23

To evaluate cardiac function by conventional echocardiography and tissue Doppler imaging in fetuses with left congenital diaphragmatic hernia (CDH). Conventional echocardiography (myocardial performance index, ventricular filling velocities, and E/A ratios) and tissue Doppler imaging (annular myocardial peak velocities, E/E' and E'/A' ratios) in mitral, septal, and tricuspid annulus were evaluated in a cohort of 31 left-sided CDH fetuses and compared with 75 controls matched for gestational age 2:1. In comparison to controls, CDH fetuses had prolonged isovolumetric time periods (isovolumetric contraction time 35 ms vs 28 ms, P < .001), with higher myocardial performance index (0.49 vs 0.42, P < .001) and tricuspid E/A ratios (0.77 vs 0.72, P = .033). Longitudinal function assessed by tissue Doppler showed signs of impaired relaxation (mitral lateral A' 8.0 vs 10.1 cm/s, P < .001 and an increased mitral lateral E'/A' ratio 0.93 vs 0.78, P < .001) in the CDH fetuses as compared with controls, with preserved systolic function. Left CDH fetuses show echocardiographic signs of diastolic dysfunction, probably secondary to fetal heart compression, maintaining a preserved systolic function. © 2018 John Wiley & Sons, Ltd.

Synergic effects of renin and aldosterone on right ventricular function in hypertension: a tissue Doppler study.

PubMed

Gregori, Mario; Giammarioli, Benedetta; Tocci, Giuliano; Befani, Alberto; Ciavarella, Giuseppino Massimo; Ferrucci, Andrea; Paneni, Francesco

2015-12-01

Right ventricular dysfunction (RVD) is associated with poor cardiovascular outcome. The renin-angiotensin-aldosterone system is involved in alterations of the left ventricular geometry and function. Detrimental effects of the renin-angiotensin-aldosterone system on the right ventricular function are being postulated, but data supporting this assumption are still lacking. The aim of the study was to assess the impact of hyperreninemia, hyperaldosteronism or their combination on right ventricular function in hypertensive individuals. Plasma renin activity (PRA) and plasma aldosterone concentrations (PACs) were measured in 116 hypertensive patients, divided as follows: normal PRA and PAC (n = 38); high PRA and normal PAC (hypereninemia) (n = 26); normal PRA and high PAC (hyperaldosternism) (n = 27); high PRA and PAC (HRA) (n = 25). Echocardiographic evaluation of the left and right ventricles (RV), including tissue Doppler imaging, was performed. RVD was identified by tissue Doppler Imaging-derived Myocardial Performance Index, calculated with a multisegmental approach. Indices of the right ventricular structure and function, as well as the prevalence of RVD, were higher in hyperreninemia and hyperaldosternism groups as compared with the normal group, and a further increase was observed in the HRA patients. Regression models showed a similar risk of RVD in the hyperreninemia and hyperaldosternism patients, regardless of systemic and pulmonary pressure, as well as left ventricular dysfunction. Notably, patients with both hyperreninemia and hyperaldosternism exhibited the strongest association with RVD as compared with patients with only hyperreninemia or hyperaldosternism. Isolated hyperreninemia or hyperaldosternism determines a similar impairment of the right ventricular function, whereas their combination is further detrimental. Renin and aldosterone may represent early biomarkers of right ventricular dysfunction in hypertension.

Real-Time Color-Doppler Guidance of HIFU for the Selective Avoidance or Occlusion of Blood Vessels

NASA Astrophysics Data System (ADS)

Rabkin, Brian A.; Zderic, Vesna; Vaezy, Shahram

2005-03-01

High-intensity focused ultrasound (HIFU) has been shown to effectively occlude blood vessels deep within tissue. The objective of the current study was to synchronize HIFU and color-Doppler ultrasound (US) for the real-time visualization of flow within blood vessels during HIFU treatment. The excitation of the HIFU was synchronized with the color-Doppler imager by collecting the excitation pulses of one of the elements of either a curved array intracavitary (C 9-5) or an intraoperative (CL 10-5) imaging probe. The collected excitation pulse was converted into a TTL-high pulse, which was delayed and gated to time the excitation duration and location of the HIFU pulse with respect to each imaging frame. The single pulse was used to drive a 3.2 MHz concave HIFU transducer (focal length of 3.5 cm, f-number 1) while the US imager was not collecting RF signals from the treatment region of the US image. The feasibility of the system was demonstrated in vivo by the selective ablation of tissue adjacent to, or the occlusion of, large vessels (including the femoral artery) both transcutaneously and interoperatively in the rabbit and pig. For the occlusion of vessels, the HIFU focus was placed immediately distal (with respect to the transducer) to the vessel at a depth of 2-2.5 cm. HIFU was applied at in situ intensities of 1000-2000 W/cm2, at a duty cycle of 50-75%, and a HIFU pulse repetition frequency (set by the US image frame rate) of 6-18 Hz. During each HIFU exposure, the HIFU pulse resulted in color interference bands running vertically within the color-Doppler window. Through the synchronization of the US imager with the HIFU excitation, the location and duration of the interference bands were set outside the treatment region within each image frame. This provided the operator with a clear view of the HIFU treatment site during therapy. Gross assessment showed necrosis of the tissue surrounding the HIFU treated vessel and occlusion of vessels up to 4 mm in diameter after a 30 s HIFU exposure. We have developed a method of synchronizing pulsed HIFU with color-Doppler US imaging for the real-time visualization of flow within blood vessels during HIFU therapy. This provides a means of guiding HIFU therapy for the detection and occlusion of deep vessels, or the selective ablation of tissue surrounding the vessels without vascular occlusion.

Doppler ultrasound compatible plastic material for use in rigid flow models.

PubMed

Wong, Emily Y; Thorne, Meghan L; Nikolov, Hristo N; Poepping, Tamie L; Holdsworth, David W

2008-11-01

A technique for the rapid but accurate fabrication of multiple flow phantoms with variations in vascular geometry would be desirable in the investigation of carotid atherosclerosis. This study demonstrates the feasibility and efficacy of implementing numerically controlled direct-machining of vascular geometries into Doppler ultrasound (DUS)-compatible plastic for the easy fabrication of DUS flow phantoms. Candidate plastics were tested for longitudinal speed of sound (SoS) and acoustic attenuation at the diagnostic frequency of 5 MHz. Teflon was found to have the most appropriate SoS (1376 +/- 40 m s(-1) compared with 1540 m s(-1) in soft tissue) and thus was selected to construct a carotid bifurcation flow model with moderate eccentric stenosis. The vessel geometry was machined directly into Teflon using a numerically controlled milling technique. Geometric accuracy of the phantom lumen was verified using nondestructive micro-computed tomography. Although Teflon displayed a higher attenuation coefficient than other tested materials, Doppler data acquired in the Teflon flow model indicated that sufficient signal power was delivered throughout the depth of the vessel and provided comparable velocity profiles to that obtained in the tissue-mimicking phantom. Our results indicate that Teflon provides the best combination of machinability and DUS compatibility, making it an appropriate choice for the fabrication of rigid DUS flow models using a direct-machining method.

Echocardiographic assessments of longitudinal left ventricular function in healthy English Springer spaniels.

PubMed

Dickson, D; Shave, R; Rishniw, M; Patteson, M

2017-08-01

To establish reference intervals for echocardiographic measures of longitudinal left ventricular function in adult English Springer spaniel (ESS) dogs. This study involved 42 healthy adult ESS. Animals were prospectively recruited from a general practice population in the United Kingdom. Dogs were examined twice, at least 12 months apart, to exclude dogs with progressive cardiac disease. Mitral annular plane systolic excursion, tissue Doppler imaging mitral annular velocities and two-dimensional speckle-tracking echocardiographic left ventricular longitudinal strain and strain rate were measured. Intraoperator and intraobserver variability were examined and reference intervals were calculated. The potential effects of body weight, age and heart rate on these variables were examined. Intraoperator and intraobserver variability was <10% for all parameters except tissue Doppler imaging E' (the peak velocity of early diastolic mitral annular motion as determined by pulsed wave Doppler) and two-dimensional speckle-tracking echocardiographic variables, which were all <20%. Thirty-nine dogs were used to create reference intervals. Significant (but mostly weak) effects of age, heart rate and body weight on were detected. Reference intervals were similar to previously published values in different breeds. Breed specific reference intervals for measures of longitudinal left ventricular function in the ESS are presented. Copyright © 2017 Elsevier B.V. All rights reserved.

Tissue Doppler Imaging can be useful to distinguish pathological from physiological left ventricular hypertrophy: a study in master athletes and mild hypertensive subjects

PubMed Central

Galanti, Giorgio; Toncelli, Loira; Del Furia, Francesca; Stefani, Laura; Cappelli, Brunello; De Luca, Alessio; Vono, Maria Concetta Roberta

2009-01-01

Background Transthoracic echocardiography left ventricular wall thickness is often increased in master athletes and it results by intense physical training. Left Ventricular Hypertrophy can also be due to a constant pressure overload. Conventional Pulsed Wave (PW) Doppler analysis of diastolic function sometimes fails to distinguish physiological from pathological LVH. The aim of this study is to evaluate the role of Pulsed Wave Tissue Doppler Imaging in differentiating pathological from physiological LVH in the middle-aged population. Methods we selected a group of 80 master athletes, a group of 80 sedentary subjects with essential hypertension and an apparent normal diastolic function at standard PW Doppler analysis. The two groups were comparable for increased left ventricular wall thickness and mass index (134.4 ± 19.7 vs 134.5 ± 22.1 gr/m2; p > .05). Diastolic function indexes using the PW technique were in the normal range for both. Results Pulsed Wave TDI study of diastolic function immediately distinguished the two groups. While in master athletes the diastolic TDI-derived parameters remained within normal range (E' 9.4 ± 3.1 cm/sec; E/E' 7.8 ± 2.1), in the hypertensive group these parameters were found to be constantly altered, with mean values and variation ranges always outside normal validated limits (E' 7.2 ± 2.4 cm/sec; E/E' 10.6 ± 3.2), and with E' and E/E' statistically different in the two groups (p < .001). Conclusion Our study showed that the TDI technique can be an easy and validated method to assess diastolic function in differentiating normal from pseudonormal diastolic patterns and it can distinguish physiological from pathological LVH emphasizing the eligibility certification required by legal medical legislation as in Italy. PMID:19845938

Doppler echocardiographic predictors of mortality in female rats after myocardial infarction.

PubMed

Santos, Alexandra Alberta; Helber, Izzo; Flumignan, Ronald L G; Antonio, Ednei L; Carvalho, Antonio C; Paola, Angelo A; Tucci, Paulo J; Moises, Valdir A

2009-03-01

Doppler echocardiogram is useful for the evaluation of anatomical and functional changes in late myocardial infarction (MI) in rats. However, no studies have evaluated the prognostic value of echocardiographic parameters 1 week after MI. Doppler echocardiogram was performed in 84 female Wistar rats 1 week after MI to determine infarction size, left chambers dimensions, fractional area change (FAC) of the left ventricle (LV), mitral inflow and tissue Doppler, myocardial performance index (MPI), and signs of pulmonary hypertension. The 365-day follow-up showed 53.6% mortality rate. Nonsurvivors showed larger (P < .05) MI size and cavity dimensions, poorer diastolic and systolic function, and higher frequency of pulmonary hypertension. Parameters at early stage of MI associated with higher mortality risk by Cox multivariate regression model were FAC or=0.60 (RR 3.49, 95% CI, 1.80-6.76), LV systolic area >or=0.26 cm(2) (RR 4.38, 95% CI, 1.88-10.21), E/E' ratio >or=20.3 (RR 2.12, 95% CI, 1.15-4.34), and E/A ratio associated with FAC (RR 2.99, 95% CI, 1.44-6.18). Some diastolic and systolic Doppler echocardiographic parameters in rats may be able to predict late mortality risk after MI.

The MOST - Monitor for Oxygenation of Surface and Tissue.

DTIC Science & Technology

1995-10-01

CAT Reduce need for ICU, low risk groups Central nursing station Office procedures: Dentistry , Endoscopy Monitoring spinal or epidural narcotics Home...obtainable by using laser Doppler methods (Wickramasinghe et al., 1994; Liepsch et al., 1993; Mendelson, Ochs, 1988). While many parameters beyond oxygenation...blood flow include laser Doppler flowmetry sys- tems which are currently commercially available. These systems measure the velocity of blood particles

L wave in echo Doppler.

PubMed

Kumar, Vipin; Jose, John; Jose, V Jacob

2014-01-01

62-year-old female presented with progressive dyspnea NYHA class III for six months. Echocardiography showed normal left ventricular (LV) systolic function, mild biatrial enlargement, an L wave in pulse wave Doppler at mitral inflow and in M mode echocardiography across mitral valve. Tissue Doppler imaging at medial mitral annulus showed an L' wave in mid diastole in addition to E' and A' wave. An L wave in pulse wave Doppler and M mode echocardiography represents continued pulmonary vein mid diastolic flow through the left atrium in to LV across mitral valve after early rapid filling. Presence of an L' wave in these patients associated with higher E/E' is indicative of advance diastolic dysfunction with elevated filling pressures. Copyright © 2014 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Optical Coherence Tomography for Brain Imaging

NASA Astrophysics Data System (ADS)

Liu, Gangjun; Chen, Zhongping

Recently, there has been growing interest in using OCT for brain imaging. A feasibility study of OCT for guiding deep brain probes has found that OCT can differentiate the white matter and gray matter because the white matter tends to have a higher peak reflectivity and steeper attenuation rate compared to gray matter. In vivo 3D visualization of the layered organization of a rat olfactory bulb with OCT has been demonstrated. OCT has been used for single myelin fiber imaging in living rodents without labeling. The refractive index in the rat somatosensory cortex has also been measured with OCT. In addition, functional extension of OCT, such as Doppler-OCT (D-OCT), polarization sensitive-OCT (PS-OCT), and phase-resolved-OCT (PR-OCT), can image and quantify physiological parameters in addition to the morphological structure image. Based on the scattering changes during neural activity, OCT has been used to measure the functional activation in neuronal tissues. PS-OCT, which combines polarization sensitive detection with OCT to determine tissue birefringence, has been used for the localization of nerve fiber bundles and the mapping of micrometer-scale fiber pathways in the brain. D-OCT, also named optical Doppler tomography (ODT), combines the Doppler principle with OCT to obtain high resolution tomographic images of moving constituents in highly scattering biological tissues. D-OCT has been successfully used to image cortical blood flow and map the blood vessel network for brain research. In this chapter, the principle and technology of OCT and D-OCT are reviewed and examples of potential applications are described.

Trans-skull ultrasonic Doppler system aided by fuzzy logic

NASA Astrophysics Data System (ADS)

Hata, Yutaka; Nakamura, Masato; Yagi, Naomi; Ishikawa, Tomomoto

2012-06-01

This paper describes a trans-skull ultrasonic Doppler system for measuring the blood flow direction in brain under skull. In this system, we use an ultrasonic array probe with the center frequency of 1.0 MHz. The system determines the fuzzy degree of blood flow by Doppler Effect, thereby it locates blood vessel. This Doppler Effect is examined by the center of gravity shift of the frequency magnitudes. In in-vitro experiment, a cow bone was employed as the skull, and three silicon tubes were done as blood vessels, and bubble in water as blood. We received the ultrasonic waves through a protein, the skull and silicon tubes in order. In the system, fuzzy degrees are determined with respect to the Doppler shift, amplitude of the waves and attenuation of the tissues. The fuzzy degrees of bone and blood direction are calculated by them. The experimental results showed that the system successfully visualized the skull and flow direction, compared with the location and flow direction of the phantom. Thus, it detected the flow direction by Doppler Effect under skull, and automatically extracted the region of skull and blood vessel.

Evaluating the effectiveness of rosuvastatin in preventing the progression of diastolic dysfunction in aortic stenosis: A substudy of the aortic stenosis progression observation measuring effects of rosuvastatin (ASTRONOMER) study

PubMed Central

2011-01-01

Background Tissue Doppler imaging (TDI) is a noninvasive echocardiographic method for the diagnosis of diastolic dysfunction in patients with varying degrees of aortic stenosis (AS). Little is known however, on the utility of TDI in the serial assessment of diastolic abnormalities in AS. Objective The aim of the current proposal was to examine whether treatment with rosuvastatin was successful in improving diastolic abnormalities in patients enrolled in the Aortic Stenosis Progression Observation Measuring Effects of Rosuvastatin (ASTRONOMER) study. Methods Conventional Doppler indices including peak early (E) and late (A) transmitral velocities, and E/A ratio were measured from spectral Doppler. Tissue Doppler measurements including early (E') and late (A') velocities of the lateral annulus were determined, and E/E' was calculated. Results The study population included 168 patients (56 ± 13 years), whose AS severity was categorized based on peak velocity at baseline (Group I: 2.5-3.0 m/s; Group II: 3.1-3.5 m/s; Group III: 3.6-4.0 m/s). Baseline and follow-up hemodynamics, LV dimensions and diastolic functional parameters were evaluated in all three groups. There was increased diastolic dysfunction from baseline to follow-up in each of the placebo and rosuvastatin groups. In patients with increasing severity of AS in Groups I and II, the lateral E' was lower and the E/E' (as an estimate of increased left ventricular end-diastolic pressure) was higher at baseline (p < 0.05). However, treatment with rosuvastatin did not affect the progression of diastolic dysfunction from baseline to 3.5 year follow-up between patients in any of the three predefined groups. Conclusion In patients with mild to moderate asymptomatic AS, rosuvastatin did not attenuate the progression of diastolic dysfunction. PMID:21299902

Bubble-Induced Color Doppler Feedback for Histotripsy Tissue Fractionation.

PubMed

Miller, Ryan M; Zhang, Xi; Maxwell, Adam D; Cain, Charles A; Xu, Zhen

2016-03-01

Histotripsy therapy produces cavitating bubble clouds to increasingly fractionate and eventually liquefy tissue using high-intensity ultrasound pulses. Following cavitation generated by each pulse, coherent motion of the cavitation residual nuclei can be detected using metrics formed from ultrasound color Doppler acquisitions. In this paper, three experiments were performed to investigate the characteristics of this motion as real-time feedback on histotripsy tissue fractionation. In the first experiment, bubble-induced color Doppler (BCD) and particle image velocimetry (PIV) analysis monitored the residual cavitation nuclei in the treatment region in an agarose tissue phantom treated with two-cycle histotripsy pulses at [Formula: see text] using a 500-kHz transducer. Both BCD and PIV results showed brief chaotic motion of the residual nuclei followed by coherent motion first moving away from the transducer and then rebounding back. Velocity measurements from both PIV and BCD agreed well, showing a monotonic increase in rebound time up to a saturation point for increased therapy dose. In a second experiment, a thin layer of red blood cells (RBC) was added to the phantom to allow quantification of the fractionation of the RBC layer to compare with BCD metrics. A strong linear correlation was observed between the fractionation level and the time to BCD peak rebound velocity over histotripsy treatment. Finally, the correlation between BCD feedback and histotripsy tissue fractionation was validated in ex vivo porcine liver evaluated histologically. BCD metrics showed strong linear correlation with fractionation progression, suggesting that BCD provides useful quantitative real-time feedback on histotripsy treatment progression.

Bubble-induced Color Doppler Feedback for Histotripsy Tissue Fractionation

PubMed Central

Miller, Ryan M.; Zhang, Xi; Maxwell, Adam; Cain, Charles; Xu, Zhen

2016-01-01

Histotripsy therapy produces cavitating bubble clouds to increasingly fractionate and eventually liquefy tissue using high intensity ultrasound pulses. Following cavitation generated by each pulse, coherent motion of the cavitation residual nuclei can be detected using metrics formed from ultrasound color Doppler acquisitions. In this paper, three experiments were performed to investigate the characteristics of this motion as real-time feedback on histotripsy tissue fractionation. In the first experiment, bubble-induced color Doppler (BCD) and particle image velocimetry (PIV) analysis monitored the residual cavitation nuclei in the treatment region in an agarose tissue phantom treated with 2-cycle histotripsy pulses at > 30 MPa using a 500 kHz transducer. Both BCD and PIV results showed brief chaotic motion of the residual nuclei followed by coherent motion first moving away from the transducer and then rebounding back. Velocity measurements from both PIV and BCD agreed well, showing a monotonic increase in rebound time up to a saturation point for increased therapy dose. In a second experiment, a thin layer of red blood cells (RBC) was added to the phantom to allow quantification of the fractionation of the RBC layer to compare with BCD metrics. A strong linear correlation was observed between the fractionation level and the time to BCD peak rebound velocity over histotripsy treatment. Finally, the correlation between BCD feedback and histotripsy tissue fractionation was validated in ex vivo porcine liver evaluated histologically. BCD metrics showed strong linear correlation with fractionation progression, suggesting that BCD provides useful quantitative real-time feedback on histotripsy treatment progression. PMID:26863659

Tissue Doppler and strain imaging: anything left in the echo-lab?

PubMed Central

Citro, Rodolfo; Bossone, Eduardo; Kuersten, Bettina; Gregorio, Giovanni; Salustri, Alessandro

2008-01-01

Medline research indicates that an increasing number of manuscripts have been published in the last decade claiming, the feasibility and the potential clinical role of tissue Doppler and strain/strain rate imaging. However, despite this amount of scientific evidence, these technologies are still confined to dedicated, high-tech, research-oriented echocardiography laboratories. In this review we have critically evaluated these techniques, analysing their physical principles, the technical problems related to their current clinical application, and the future perspectives. Finally, this review explores the reasons why these technologies are still defined "new technologies" and the impact of their implementation on the current clinical activity of an echocardiography laboratory. PMID:18973677

Tissue Doppler, strain, and strain rate echocardiography for the assessment of left and right systolic ventricular function

PubMed Central

Pellerin, D; Sharma, R; Elliott, P; Veyrat, C

2003-01-01

Tissue Doppler (TDE), strain, and strain rate echocardiography are emerging real time ultrasound techniques that provide a measure of wall motion. They offer an objective means to quantify global and regional left and right ventricular function and to improve the accuracy and reproducibility of conventional echocardiography studies. Radial and longitudinal ventricular function can be assessed by the analysis of myocardial wall velocity and displacement indices, or by the analysis of wall deformation using the rate of deformation of a myocardial segment (strain rate) and its deformation over time (strain). A quick and easy assessment of left ventricular ejection fraction is obtained by mitral annular velocity measurement during a routine study, especially in patients with poor endocardial definition or abnormal septal motion. Strain rate and strain are less affected by passive myocardial motion and tend to be uniform throughout the left ventricle in normal subjects. This paper reviews the underlying principles of TDE, strain, and strain rate echocardiography and discusses currently available quantification tools and clinical applications. PMID:14594870

Speckle tracking evaluation of right ventricular functions in children with sickle cell disease.

PubMed

Tolba, Osama Abd Rab Elrasol; El-Shanshory, Mohamed Ramadan; El-Gamasy, Mohamed Abd Elaziz; El-Shehaby, Walid Ahmed

2017-01-01

Cardiac dysfunction is a risk factor for death in patients with sickle cell disease (SCD). Aim of the work is to evaluate the right ventricular systolic and diastolic functions by tissue Doppler and speckling tracking imaging in children with SCD. Thirty children with SCD and thirty controls were subjected to clinical, laboratory evaluations, and echocardiographic study using GE Vivid 7 (GE Medical System, Horten, Norway with a 3.5-MHz multifrequency transducer) including; Two-dimensional and tissue Doppler echocardiographic study (lateral tricuspid valve annulus peak E' velocity, lateral tricuspid valve annulus peak A' velocity, E'/A' ratio, isovolumetric relaxation time, lateral tricuspid valve annulus S' and septal S' waves and peak longitudinal systolic strain [PLSS] and time to PLSS) were done in six right ventricular segments. There was a significant decrease in right ventricular systolic and diastolic function in patients group when compared to controls. Children with SCD have impaired right ventricular systolic and diastolic functions when compared to healthy children with early evaluation of the systolic dysfunction by speckle tracking imaging technique.

Fetal tissue Doppler imaging in pregnancies complicated with preeclampsia with or without intrauterine growth restriction.

PubMed

Zhou, Qiongjie; Ren, Yunyun; Yan, Yingliu; Chu, Chen; Gui, Yonghao; Li, Xiaotian

2012-11-01

This study's aim was to evaluate the effect of preeclampsia and intrauterine growth restriction (IUGR) on fetal cardiac function, and the relationship of the latter with adverse pregnancy outcomes. We did a cross-sectional study of 132 women with uncomplicated singleton pregnancies, 34 with preeclampsia without IUGR, and 12 with preeclampsia and IUGR. Fetal cardiac structure and function were evaluated using fetal two-dimension ultrasound, pulsed wave Doppler and tissue Doppler imaging (TDI). Data were analyzed by t-tests, ANOVA, Chi-square tests, or Wilcoxon rank-sum test. Compared with the normal pregnancy group, mitral/tricuspid early systolic peak velocity of annulus/late diastolic peak velocity of annulus (Sa) and left ventricular (LV)/right ventricular (RV) early diastolic peak velocity at the annulus (Ea) in TDI decreased in preeclampsia with or without IUGR (P < 0.05). LV/RV Ea underwent a gestational decrease in preeclampsia with or without IUGR (P < 0.05). The changes in mitral/tricuspid Sa and LV Sa associated with preeclampsia were even more pronounced with preterm delivery at less than 34 gestational weeks and stillbirth (P < 0.05). Intrauterine growth restriction influences fetal cardiac function in the presence of preeclampsia, and TDI may be a sensitive and preferable method to detect such changes. Fetal LV/RV Ea is a potential marker for early fetal cardiac diastolic impairment, and mitral/tricuspid Sa and LV Sa may be predictors for adverse pregnancy outcomes. © 2012 John Wiley & Sons, Ltd.

Pulse Doppler ultrasound as a tool for the diagnosis of chronic testicular dysfunction in stallions

PubMed Central

Ortiz-Rodriguez, Jose M.; Anel-Lopez, Luis; Martín-Muñoz, Patricia; Álvarez, Mercedes; Gaitskell-Phillips, Gemma; Anel, Luis; Rodríguez-Medina, Pedro; Peña, Fernando J.

2017-01-01

Testicular function is particularly susceptible to vascular insult, resulting in a negative impact on sperm production and quality of the ejaculate. A prompt diagnosis of testicular dysfunction enables implementation of appropriate treatment, hence improving fertility forecasts for stallions. The present research aims to: (1) assess if Doppler ultrasonography is a good tool to diagnose stallions with testicular dysfunction; (2) to study the relationship between Doppler parameters of the testicular artery and those of sperm quality assessed by flow cytometry and (3) to establish cut off values to differentiate fertile stallions from those with pathologies causing testicular dysfunction. A total of 10 stallions (n: 7 healthy stallions and n: 3 sub-fertile stallions) were used in this study. Two ejaculates per stallion were collected and preserved at 5°C in a commercial extender. The semen was evaluated at T0, T24 and T48h by flow cytometry. Integrity and viability of sperm (YoPro®-1/EthD-1), mitochondrial activity (MitoTracker® Deep Red FM) and the DNA fragmentation index (Sperm Chromatin Structure Assay) were assessed. Doppler parameters were measured at three different locations on the testicular artery (Supratesticular artery (SA); Capsular artery (CA) and Intratesticular artery (IA)). The Doppler parameters calculated were: Resistive Index (RI), Pulsatility Index (PI), Peak Systolic Velocity (PSV), End Diastolic Velocity (EDV), Time Average Maximum Velocity (TAMV), Total Arterial Blood Flow (TABF) and TABF rate. The capsular artery was the most reliable location to carry out spectral Doppler assessment, since blood flow parameters of this artery were most closely correlated with sperm quality parameters. Significant differences in all the Doppler parameters studied were observed between fertile and subfertile stallions (p ≤ 0.05). The principal components analysis assay determined that fertile stallions are characterized by high EDV, TAMV, TABF and TABF rate values (high vascular perfusion). In contrast, subfertile stallions tend to present high values of PI and RI (high vascular resistance). The ROC curves revealed that the best Doppler parameters to predict sperm quality in stallions were: Doppler velocities (PSV, EDV and TAMV), the diameter of the capsular artery and TABF parameters (tissue perfusion parameters). Cut off values were established using a Youden´s Index to identify fertile stallions from stallions with testicular dysfunction. Spectral Doppler ultrasound is a good predictive tool for sperm quality since correlations were determined among Doppler parameters and markers of sperm quality. Doppler ultrasonography could be a valuable diagnostic tool for use by clinical practitioners for the diagnosis of stallions with testicular dysfunction and could be a viable alternative to invasive procedures traditionally used for diagnosis of sub-fertility disorders. PMID:28558006

Intracellular Doppler Signatures of Platinum Sensitivity Captured by Biodynamic Profiling in Ovarian Xenografts

NASA Astrophysics Data System (ADS)

Merrill, Daniel; An, Ran; Sun, Hao; Yakubov, Bakhtiyor; Matei, Daniela; Turek, John; Nolte, David

2016-01-01

Three-dimensional (3D) tissue cultures are replacing conventional two-dimensional (2D) cultures for applications in cancer drug development. However, direct comparisons of in vitro 3D models relative to in vivo models derived from the same cell lines have not been reported because of the lack of sensitive optical probes that can extract high-content information from deep inside living tissue. Here we report the use of biodynamic imaging (BDI) to measure response to platinum in 3D living tissue. BDI combines low-coherence digital holography with intracellular Doppler spectroscopy to study tumor drug response. Human ovarian cancer cell lines were grown either in vitro as 3D multicellular monoculture spheroids or as xenografts in nude mice. Fragments of xenografts grown in vivo in nude mice from a platinum-sensitive human ovarian cell line showed rapid and dramatic signatures of induced cell death when exposed to platinum ex vivo, while the corresponding 3D multicellular spheroids grown in vitro showed negligible response. The differences in drug response between in vivo and in vitro growth have important implications for predicting chemotherapeutic response using tumor biopsies from patients or patient-derived xenografts.

Effect of percutaneous transvenous mitral commissurotomy on left atrial appendage function: an immediate and 6-month follow-up transesophageal Doppler study.

PubMed

Vijayvergiya, Rajesh; Sharma, Rajat; Shetty, Ranjan; Subramaniyan, Anand; Karna, Sunil; Chongtham, Dhanraj

2011-11-01

The left atrial appendage (LAA) is a common site of thrombus formation and is the source of systemic thromboembolism in patients with rheumatic mitral stenosis. LAA contractile dysfunction is a common finding in these patients. The aim of this study was to assess immediate and 6-month follow-up LAA function by transesophageal Doppler echocardiography in patients who underwent percutaneous transvenous mitral commissurotomy (PTMC). Forty-seven consecutive patients with symptomatic critical mitral stenosis who underwent PTMC were enrolled. All had underwent transthoracic and transesophageal echocardiography before, 24 hours after, and 6 months after PTMC. Pulse Doppler velocities of the LAA were measured, including peak early diastolic (E wave), peak late diastolic (A wave), and peak systolic (S wave). The corresponding tissue Doppler velocities of the LAA, including peak early diastolic (E(LAA)), peak late diastolic (A(LAA)), and peak systolic (S(LAA)), were also measured. LAA ejection fraction was measured using the modified Simpson's method. The mean age of the 47 enrolled patients was 31.7 ± 10.26 years. Thirty-eight patients were in sinus rhythm, and the remaining nine were in atrial fibrillation. PTMC was successful in all patients. The pulse Doppler velocities of the LAA at baseline, after PTMC, and at 6-month follow-up were as follows: for the E wave, 15.29 ± 2.26, 17.02 ± 2.25, and 17.97 ± 2.55 cm/sec, respectively (P < .001); for the A wave 22.45 ± 4.11, 24.19 ± 4.21, and 25.99 ± 4.51 cm/sec, respectively (P < .001); and for the S wave, 28.52 ± 4.37, 31.45 ± 5.37, and 33.06 ± 4.99 cm/sec, respectively (P < .001). The corresponding tissue Doppler velocities of LAA were as follows: for E(LAA), 4.65 ± 0.91, 5.28 ± 0.85, and 5.80 ± 0.84 cm/sec, respectively (P < .001); for A(LAA), 6.67 ± 1.12, 7.33 ± 1.17, and 7.88 ± 1.22 cm/sec, respectively (P < .001); and for S(LAA), 4.67 ± 1.12, 5.52 ± 1.18, 6.07 ± 1.11 cm/sec, respectively (P < .001). There was a nonsignificant increase in LAA ejection fraction (48.97 ± 8.14% vs 52.3 ± 13.76% vs 52.11 ± 16.3%, respectively, P = .052). On subgroup analysis between patients in sinus rhythm and those with atrial fibrillation, there was no significant difference for LAA ejection fraction and pulse and tissue Doppler velocities. Very good intraclass correlation of the LAA parameters was also observed for the reproducibility of the data. The present study shows contractile dysfunction of the LAA in patients with critical mitral stenosis, which significantly improved after PTMC, and a further improvement was observed at 6-month follow-up. Favorable 6-month improvements in LAA parameters suggest continuous structural remodeling of the LAA after PTMC, which is clinically attributed to the absence of thromboembolism. Although there was an improvement in LAA function, it was far below the normal range, suggesting a need for continuous long-term monitoring and management of thromboembolism in these patients. Copyright © 2011 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

Investigation of laser Doppler techniques using the Monte Carlo method

NASA Astrophysics Data System (ADS)

Ruetten, Walter; Gellekum, Thomas; Jessen, Katrin

1995-01-01

Laser Doppler techniques are increasingly used in research and clinical applications to study perfusion phenomena in the skin, yet the influences of changing scattering parameters and geometry on the measure of perfusion are not well explored. To investigate these influences, a simulation program based on the Monte Carlo method was developed, which is capable of determining the Doppler spectra caused by moving red blood cells. The simulation model allows for the definition of arbitrary networks of blood vessels with individual velocities. The volume is represented by a voxel tree with adaptive spatial resolution which contains references to the optical properties and is used to store the location dependent photon fluence determined during the simulation. Two evaluation methods for Doppler spectra from biological tissue described in the literate were investigated with the simulation program. The results obtained suggest that both methods give a measure of perfusion nearly proportional to the velocity of the red blood cells. However, simulations done with different geometries of the blood vessels seem to indicate a nonlinear behavior concerning the concentration of red blood cells in the measurement volume. Nevertheless these simulation results may help in the interpretation of measurements obtained from devices using the investigated evaluation methods.

Self-mixing detection of backscattered radiation in a single-mode erbium fibre laser for Doppler spectroscopy and velocity measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dmitriev, A K; Konovalov, A N; Ul'yanov, V A

2014-04-28

We report an experimental study of the self-mixing effect in a single-mode multifrequency erbium fibre laser when radiation backscattered from an external moving object arrives at its cavity. To eliminate resulting chaotic pulsations in the laser, we have proposed a technique for suppressing backscattered radiation through the use of multimode fibre for radiation delivery. The multifrequency operation of the laser has been shown to lead to strong fluctuations of the amplitude of the Doppler signal and a nonmonotonic variation of the amplitude with distance to the scattering object. In spite of these features, the self-mixing signal was detected with amore » high signal-to-noise ratio (above 10{sup 2}) when the radiation was scattered by a rotating disc, and the Doppler frequency shift, evaluated as the centroid of its spectrum, had high stability (0.15%) and linearity relative to the rotation rate. We conclude that the self-mixing effect in this type of fibre laser can be used for measuring the velocity of scattering objects and in Doppler spectroscopy for monitoring the laser evaporation of materials and biological tissues. (control of laser radiation parameters)« less

Nomograms for mitral inflow Doppler and tissue Doppler velocities in Caucasian children.

PubMed

Cantinotti, Massimiliano; Giordano, Raffaele; Scalese, Marco; Murzi, Bruno; Assanta, Nadia; Spadoni, Isabella; Crocetti, Maura; Marotta, Marco; Molinaro, Sabrina; Kutty, Shelby; Iervasi, Giorgio

2016-10-01

Pediatric echocardiographic nomograms for systolic/diastolic functional indices are limited by small sample size and inconsistent methodologies. Our aim was to establish pediatric nomograms for mitral valve (MV) pulsed wave Doppler (PWD) and tissue Doppler imaging (TDI) velocities. We performed PWD/TDI measurements of MV velocities and generated models testing for linear/logarithmic/exponential/square root relationships. Heteroscedasticity was accounted for by White test or Breusch-Pagan test. Age, weight, height, heart rate (HR), and body surface area (BSA) were used as independent variables in different analyses to predict the mean values of each measurement. In all, 904 Caucasian Italian healthy children (age 0 days-17 years; 45.5% females; BSA 0.12-2.12m(2)) were prospectively studied. No individual variable provided equations with an acceptable coefficient of determination (R(2)) and even the inclusion of multiple variables in the model resulted in only a partial amelioration of the R(2). Higher R(2) were obtained for PWD-E deceleration time (0.53), septal (Se') and lateral (Le') MV-TDI e' velocity (Se': 0.54; Le': 0.55). Variability was higher at lower age and BSA. In older children patterns were more reproducible; however, the exclusion of neonates did not substantially improve the final models. The low R(2) hampered building of z-scores and calculation of estimated percentiles. Thus normative data have been presented as observed percentile according to age for all measurements. We report normal ranges for PWD and TDI mitral velocities derived from a large population of Caucasian children. Variability of diastolic patterns especially at lower ages needs to be taken into account. Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Quantitation of stress echocardiography by tissue Doppler and strain rate imaging: a dream come true?

PubMed

Galderisi, Maurizio; Mele, Donato; Marino, Paolo Nicola

2005-01-01

Tissue Doppler (TD) is an ultrasound tool providing a quantitative agreement of left ventricular regional myocardial function in different modalities. Spectral pulsed wave (PW) TD, performed online during the examination, measures instantaneous myocardial velocities. By means of color TD, velocity images are digitally stored for subsequent off-line analysis and mean myocardial velocities are measured. An implementation of color TD includes strain rate imaging (SRI), based on post-processing conversion of regional velocities in local myocardial deformation rate (strain rate) and percent deformation (strain). These three modalities have been applied to stress echocardiography for quantitative evaluation of regional left ventricular function and detection of ischemia and viability. They present advantages and limitations. PWTD does not permit the simultaneous assessment of multiple walls and therefore is not compatible with clinical stress echocardiography while it could be used in a laboratory setting. Color TD provides a spatial map of velocity throughout the myocardium but its results are strongly affected by the frame rate. Both color TD and PWTD are also influenced by overall cardiac motion and tethering from adjacent segments and require reference velocity values for interpretation of regional left ventricular function. High frame rate (i.e. > 150 ms) post-processing-derived SRI can potentially overcome these limitations, since measurements of myocardial deformation have not any significant apex-to-base gradient. Preliminary studies have shown encouraging results about the ability of SRI to detect ischemia and viability, in terms of both strain rate changes and/or evidence of post-systolic thickening. SRI is, however, Doppler-dependent and time-consuming. Further technical refinements are needed to improve its application and introduce new ultrasound modalities to overcome the limitations of the Doppler-derived deformation analysis.

Prognostication of valvular aortic stenosis using tissue Doppler echocardiography: underappreciated importance of late diastolic mitral annular velocity.

PubMed

Poh, Kian-Keong; Chan, Mark Yan-Yee; Yang, Hong; Yong, Quek-Wei; Chan, Yiong-Huak; Ling, Lieng H

2008-05-01

Intact left atrial booster pump function helps maintain cardiac compensation in patients with aortic valve stenosis (AS). Because late diastolic mitral annular (A') velocity reflects left atrial systolic function, we hypothesized that A' velocity correlates with plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) level and clinical outcome in AS. We prospectively enrolled 53 consecutive patients (median age 74 years) with variable degrees of AS, in sinus rhythm, and left ventricular ejection fraction greater than 50%. Indices of valvular stenosis, left ventricular diastolic dysfunction, and mitral annular motion were correlated with plasma NT-proBNP and a composite clinical end point comprising cardiac death and symptom-driven aortic valve replacement. Tissue Doppler echocardiographic parameters, including early diastolic (E') velocity and A' velocity and ratio of early diastolic transmitral (E) to E' velocity (E/E') at the annular septum correlated better with NT-proBNP levels than body surface area-indexed aortic valve area. Eighteen patients had the composite end point, which was univariately predicted by body surface area-indexed aortic valve area, NT-proBNP, and all tissue Doppler echocardiographic indices. This outcome was most strongly predicted by the combination of septal A' velocity and E/E' ratio in bivariate Cox modeling. Septal annular A' velocity less than 9.6 cm/s was associated with significantly reduced event-free survival (Kaplan Meier log rank = 27.3, P < .0001) and predicted the end point with a sensitivity, specificity, and accuracy of 94%, 80%, and 85%, respectively. In patients with AS and normal ejection fraction, annular tissue Doppler echocardiographic indices may better reflect the physiologic consequences of afterload burden on the left ventricle than body surface area-indexed aortic valve area. Lower A' velocity is a predictor of cardiac death and need for valve surgery, suggesting an important role for compensatory left atrial booster pump function.

Improvement of microcirculation and wound healing in vertical ridge augmentation after pre-treatment with self-inflating soft tissue expanders - a randomized study in dogs.

PubMed

Kaner, Dogan; Zhao, Han; Terheyden, Hendrik; Friedmann, Anton

2015-06-01

We investigated the effect of soft tissue expansion (STE) on vertical ridge augmentation with regard to the incidence of wound dehiscences and the impairment of microcirculation in dogs, and the applicability of laser Doppler flowmetry (LDF) to explore the relation between microcirculation and wound healing. Bone defects were created on both mandibular sides in ten beagle dogs by extraction of premolars and removal of bone. Six weeks later, self-filling tissue expanders were implanted in randomly assigned test sites. After 5 weeks of expansion, vertical augmentation was carried out in test and control sites using calvarial onlay grafts side by side with granular biphasic calcium phosphate covered with a resorbable polyethylene glycol membrane. Microcirculation was evaluated with laser Doppler flowmetry (LDF). The incidence of wound dehiscences was evaluated after 2 weeks. The validity of LDF to predict dehiscences was evaluated by construction of receiver operating characteristic (ROC) curves. After augmentation, test sites showed significantly better perfusion than control sites without preceding STE (P = 0.012). Three days after surgery, perfusion was still significantly decreased in control sites (P = 0.005), while microcirculation in test sites had returned to pre-surgical levels. After 2 weeks, healing in test sites was good, whereas eight dehiscences were found in control sites (P = 0.002). ROC curves showed that microcirculation levels immediately after augmentation surgery significantly predicted subsequent wound dehiscences (AUC = 0.799, CI 0.642-0.955, P = 0.006). Laser Doppler flowmetry is suitable for evaluation of soft tissue microcirculation after ridge augmentation. STE reduced the impairment of microcirculation caused by vertical ridge augmentation and decreased the incidence of wound dehiscences in the investigated animal model. © 2014 The Authors. Clinical Oral Implants Research Published by John Wiley & Sons Ltd.

Three-dimensional power doppler ultrasound is useful to monitor the response to treatment in a patient with primary papillary serous carcinoma of the peritoneum.

PubMed

Su, Jen-Min; Huang, Yu-Fang; Chen, Helen H W; Cheng, Ya-Min; Chou, Cheng-Yang

2006-05-01

To date, this is the first report to monitor changes of intratumor vascularization and the response to radiation and Cyberknife therapy in a patient with recurrent primary papillary serous carcinoma of the peritoneum by three dimensional (3D) power Doppler ultrasonography (PDUS). Transvaginal 3D PDUS detected a recurrent presacral tumor with abundant intratumor vascularity. Serial examinations of the tumor volume and serum CA-125 level were studied before, during, and 6 mo after therapy. Meanwhile, the intratumor blood flow was measured and expressed as vascularity indices. All of the tumor volume, intratumor vascularity indices and serum CA-125 level decreased progressively following therapy. A remaining lesion with nearly absent intratumor power Doppler signals suggested a scarring lesion posttreatment. Indeed, CT-guided tissue biopsy confirmed fibrotic change. 3D PDUS is useful to monitor the response to treatments and to differentiate residual tumors from lesions of scarring change posttreatment. It provides more accurate posttreatment information than pelvic computed tomography.

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

PubMed Central

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

2009-01-01

Objective Apply ultrasound (US) imaging techniques to better describe the characteristics of myofascial trigger points (MTrPs) and the immediately adjacent soft tissue. Design Descriptive (exploratory) study. Setting Biomedical research center. Participants 9 subjects meeting Travell and Simons’s criteria for MTrPs in a taut band in the upper trapezius. Interventions (None) Main Outcome Measures MTrPs were evaluated by 1) physical examination, 2) pressure algometry, and 3) three types of ultrasound imaging including grayscale (2D US), vibration sonoelastography (VSE), and Doppler. Methods Four sites in each patient were labeled based on physical examination as either active MTrP (spontaneously-painful, A-MTrP), latent MTrP (non-painful, L-MTrP), or normal myofascial tissue. US examination was performed on each subject by a team blinded to the physical findings. A 12-5 MHz US transducer was used. VSE was performed by color Doppler variance imaging while simultaneously inducing vibrations (~92Hz) with a handheld massage vibrator. Each site was assigned a tissue imaging score (TIS) as follows: 0 = uniform echogenicity and stiffness; 1 = focal hypoechoic region with stiff nodule; 2 = multiple hypoechoic regions with stiff nodules. Blood flow in the neighborhood of MTrPs was assessed using Doppler imaging. Each site was assigned a blood flow waveform score (BFS) as follows: 0 = normal arterial flow in muscle; 1 = elevated diastolic flow; 2 = high-resistance flow waveform with retrograde diastolic flow. Results MTrPs appeared as focal, hypoechoic regions on 2D US, indicating local changes in tissue echogenicity, and as focal regions of reduced vibration amplitude on VSE, indicating a localized stiff nodule. MTrPs were elliptical in shape, with a size of 0.16 ± 0.11 cm2. There were no significant differences in size between A-MTrPs and L-MTrPs. Sites containing MTrPs were more likely to have higher TIS compared to normal myofascial tissue (p<0.002). Small arteries (or enlarged arterioles) near A-MTrPs showed retrograde flow in diastole indicating a highly resistive vascular bed. A-MTrP sites were more likely to have higher BFS compared to L-MTrPs (p<0.021). Conclusions Preliminary findings show that, under the conditions of this investigation, US imaging techniques can be used to distinguish myofascial tissue containing MTrPs from normal myofascial tissue (lacking trigger points). Ultrasound enables visualization and some characterization of MTrPs and adjacent soft tissue. PMID:19887205

Assessment of strain and strain rate by two-dimensional speckle tracking in mice: comparison with tissue Doppler echocardiography and conductance catheter measurements.

PubMed

Ferferieva, V; Van den Bergh, A; Claus, P; Jasaityte, R; La Gerche, A; Rademakers, F; Herijgers, P; D'hooge, J

2013-08-01

This study was designed in order to compare the strain and strain rate deformation parameters assessed by speckle tracking imaging (STI) with those of tissue Doppler imaging (TDI) and conductance catheter measurements in chronic murine models of left ventricular (LV) dysfunction. Twenty-four male C57BL/6J mice were assigned to wild-type (n = 8), myocardial infarction (n = 8) and transaortic constriction (n = 8) groups. Echocardiographic and conductance measurements were simultaneously performed at rest and during dobutamine infusion (5 µg/kg/min) in all animals 10 weeks post-surgery. The LV circumferential strain (Scirc) and the strain rate (SRcirc) were derived from grey scale and tissue Doppler data at frame rates of 224 and 375 Hz, respectively. Scirc and SRcirc by TDI/STI correlated well with the preload recruitable stroke work (PRSW) (r = -0.64 and -0.71 for TDI; r = -0.46 and -0.50 for STI, P < 0.05). Both modalities showed a good agreement with respect to Scirc and SRcirc (r = 0.60 and r = 0.63, P < 0.05). During stress, however, TDI-estimated Scirc and SRcirc values were predominantly higher than those measured by STI (P < 0.05). The similarity of Scirc and SRcirc measurements with respect to the STI/TDI data was examined by the Bland-Altman analysis. In mice, the STI- and TDI-derived strain and strain rate deformation parameters relate closely to intrinsic myocardial function. At low heart rate-to-frame rate ratios (HR/FR), both STI and TDI are equally acceptable for assessing the LV function non-invasively in these animals. At HR/FR (e.g. dobutamine challenge), however, these methods cannot be used interchangeably as STI underestimates S and SR at high values.

Right ventricular diastolic performance in children with pulmonary arterial hypertension associated with congenital heart disease: correlation of echocardiographic parameters with invasive reference standards by high-fidelity micromanometer catheter.

PubMed

Okumura, Kenichi; Slorach, Cameron; Mroczek, Dariusz; Dragulescu, Andreea; Mertens, Luc; Redington, Andrew N; Friedberg, Mark K

2014-05-01

Right ventricular diastolic dysfunction influences outcomes in pulmonary arterial hypertension (PAH), but echocardiographic parameters have not been investigated in relation to invasive reference standards in pediatric PAH. We investigated echocardiographic parameters of right ventricular diastolic function in children with PAH in relation to simultaneously measured invasive reference measures. We prospectively recruited children undergoing a clinically indicated cardiac catheterization for evaluation of PAH and pulmonary vasoreactivity testing. Echocardiography was performed simultaneously with invasive reference measurements by high-fidelity micromanometer catheter. For analysis, patients were divided into shunt and nonshunt groups. Sixteen children were studied. In the group as a whole, significant correlations were found among τ and tricuspid deceleration time, E', E/E', TimeE-E', A wave velocity, and global early and late diastolic strain rate. dp/dt minimum correlated significantly with late diastolic tricuspid annular velocity (A'), tissue Doppler imaging-derived systolic:diastolic duration ratio, and global late diastolic strain rate. End-diastolic pressure correlated significantly with tissue Doppler imaging-derived systolic:diastolic duration ratio. On multivariate analysis, tricuspid deceleration time, TimeE-E', and global early diastolic strain rate were independent predictors of τ, whereas tissue Doppler imaging-derived systolic:diastolic duration ratio was an independent predictor of dp/dt minimum. In general, correlations between echocardiographic and invasive parameters were better in the shunt group than in the nonshunt group. Echocardiography correlates with invasive reference measures of right ventricular diastolic function in children with PAH, although it does not differentiate between early versus late diastolic abnormalities. Newer echocardiographic techniques may have added value to assess right ventricular diastolic dysfunction in this population. © 2014 American Heart Association, Inc.

Current and evolving echocardiographic techniques for the quantitative evaluation of cardiac mechanics: ASE/EAE consensus statement on methodology and indications endorsed by the Japanese Society of Echocardiography.

PubMed

Mor-Avi, Victor; Lang, Roberto M; Badano, Luigi P; Belohlavek, Marek; Cardim, Nuno Miguel; Derumeaux, Genevieve; Galderisi, Maurizio; Marwick, Thomas; Nagueh, Sherif F; Sengupta, Partho P; Sicari, Rosa; Smiseth, Otto A; Smulevitz, Beverly; Takeuchi, Masaaki; Thomas, James D; Vannan, Mani; Voigt, Jens-Uwe; Zamorano, Jose Luis

2011-03-01

Echocardiographic imaging is ideally suited for the evaluation of cardiac mechanics because of its intrinsically dynamic nature. Because for decades, echocardiography has been the only imaging modality that allows dynamic imaging of the heart, it is only natural that new, increasingly automated techniques for sophisticated analysis of cardiac mechanics have been driven by researchers and manufacturers of ultrasound imaging equipment. Several such techniques have emerged over the past decades to address the issue of reader's experience and inter-measurement variability in interpretation. Some were widely embraced by echocardiographers around the world and became part of the clinical routine, whereas others remained limited to research and exploration of new clinical applications. Two such techniques have dominated the research arena of echocardiography: (1) Doppler-based tissue velocity measurements, frequently referred to as tissue Doppler or myocardial Doppler, and (2) speckle tracking on the basis of displacement measurements. Both types of measurements lend themselves to the derivation of multiple parameters of myocardial function. The goal of this document is to focus on the currently available techniques that allow quantitative assessment of myocardial function via image-based analysis of local myocardial dynamics, including Doppler tissue imaging and speckle-tracking echocardiography, as well as integrated back- scatter analysis. This document describes the current and potential clinical applications of these techniques and their strengths and weaknesses, briefly surveys a selection of the relevant published literature while highlighting normal and abnormal findings in the context of different cardiovascular pathologies, and summarizes the unresolved issues, future research priorities, and recommended indications for clinical use.

Current and evolving echocardiographic techniques for the quantitative evaluation of cardiac mechanics: ASE/EAE consensus statement on methodology and indications endorsed by the Japanese Society of Echocardiography.

PubMed

Mor-Avi, Victor; Lang, Roberto M; Badano, Luigi P; Belohlavek, Marek; Cardim, Nuno Miguel; Derumeaux, Geneviève; Galderisi, Maurizio; Marwick, Thomas; Nagueh, Sherif F; Sengupta, Partho P; Sicari, Rosa; Smiseth, Otto A; Smulevitz, Beverly; Takeuchi, Masaaki; Thomas, James D; Vannan, Mani; Voigt, Jens-Uwe; Zamorano, José Luis

2011-03-01

Echocardiographic imaging is ideally suited for the evaluation of cardiac mechanics because of its intrinsically dynamic nature. Because for decades, echocardiography has been the only imaging modality that allows dynamic imaging of the heart, it is only natural that new, increasingly automated techniques for sophisticated analysis of cardiac mechanics have been driven by researchers and manufacturers of ultrasound imaging equipment.Several such technique shave emerged over the past decades to address the issue of reader's experience and inter measurement variability in interpretation.Some were widely embraced by echocardiographers around the world and became part of the clinical routine,whereas others remained limited to research and exploration of new clinical applications.Two such techniques have dominated the research arena of echocardiography: (1) Doppler based tissue velocity measurements,frequently referred to as tissue Doppler or myocardial Doppler, and (2) speckle tracking on the basis of displacement measurements.Both types of measurements lend themselves to the derivation of multiple parameters of myocardial function. The goal of this document is to focus on the currently available techniques that allow quantitative assessment of myocardial function via image-based analysis of local myocardial dynamics, including Doppler tissue imaging and speckle-tracking echocardiography, as well as integrated backscatter analysis. This document describes the current and potential clinical applications of these techniques and their strengths and weaknesses,briefly surveys a selection of the relevant published literature while highlighting normal and abnormal findings in the context of different cardiovascular pathologies, and summarizes the unresolved issues, future research priorities, and recommended indications for clinical use.

Doppler ultrasonography of the pectinis oculi artery in harpy eagles (Harpia harpyja)

PubMed Central

de Moraes, Wanderlei; Ferreira, Thiago A.C.; Somma, André T.; Cubas, Zalmir S.; Moore, Bret A.; Montiani-Ferreira, Fabiano

2017-01-01

Twenty harpy eagles (Harpia harpyja) without systemic or ocular diseases were examined to measure blood velocity parameters of the pectinis oculi artery using Doppler ultrasonography. Pectinate artery resistive index (RI) and pulsatility index (PI) were investigated using ocular Doppler ultrasonography. The mean RI and PI values across all eyes were 0.44±0.10 and 0.62±0.20 respectively. Low RI and PI values found in the harpy eagle´s pectinis oculi artery compared with the American pekin ducks one and other tissue suggest indeed a high metabolic activity in pecten oculi and corroborates the hypothesis of a nutritional function and/or intraocular pressure regulation. PMID:28540254

Characterization of local fluid flow in 3D porous construct characterized by Fourier domain Doppler optical coherence tomography

NASA Astrophysics Data System (ADS)

Bagnaninchi, P. O.; Yang, Y.; El Haj, A.; Hinds, M. T.; Wang, R. K.

2007-02-01

In order to achieve functional tissue with the correct biomechanical properties it is critical to stimulate mechanically the cells. Perfusion bioreactor induces fluid shear stress that has been well characterized for two-dimensional culture where both simulation and experimental data are available. However these results can't be directly translated to tissue engineering that makes use of complex three-dimensional porous scaffold. Moreover, stimulated cells produce extensive extra-cellular matrix (ECM) that alter dramatically the micro-architecture of the constructs, changing the local flow dynamic. In this study a Fourier domain Doppler optical coherent tomography (FD-DOCT) system working at 1300nm with a bandwidth of 50nm has been used to determine the local flow rate inside different types of porous scaffolds used in tissue engineering. Local flow rates can then be linearly related, for Newtonian fluid, to the fluid shear stress occurring on the pores wall. Porous chitosan scaffolds (\\fgr 1.5mm x 3mm) with and without a central 250 μm microchannel have been produced by a freeze-drying technique. This techniques allow us to determine the actual shear stress applied to the cells and to optimise the input flow rate consequently, but also to relate the change of the flow distribution to the amount of ECM production allowing the monitoring of tissue formation.

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

PubMed

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 (CO 2 ) 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.

In Vivo Determination of the Complex Elastic Moduli of Cetacean Head Tissue

DTIC Science & Technology

2012-09-30

and with harvested tissue samples. In vivo testing will be conducted on Navy dolphins . Ultrasound parameters (peak negative pressure, time averaged...A synthetic material was developed which mimicks the ultrasonic properties of living bottlenose dolphin soft tissues. RESULTS 1. System...NIVMS) and with a laser doppler vibrometer (Polytec PDV-100). A variety of pulse drive levels, durations, and bandwidths for both ultrasound

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

PubMed

Walter, Uwe; Niendorf, Thoralf; Graessl, Andreas; Rieger, Jan; Krüger, Paul-Christian; Langner, Sönke; Guthoff, Rudolf F; Stachs, Oliver

2014-05-01

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. • Orbital magnetic resonance and colour Doppler ultrasound real-time fusion imaging is feasible • Fusion imaging combines the spatial and temporal resolution advantages of each modality • Magnetic resonance and ultrasound fusion imaging improves assessment of choroidal melanoma vascularisation.

Effect of local cooling on pro-inflammatory cytokines and blood flow of the skin under surface pressure in rats: feasibility study.

PubMed

Lee, Bernard; Benyajati, Siribhinya; Woods, Jeffrey A; Jan, Yih-Kuen

2014-05-01

The primary purpose of this feasibility study was to establish a correlation between pro-inflammatory cytokine accumulation and severity of tissue damage during local pressure with various temperatures. The secondary purpose was to compare skin blood flow patterns for assessing the efficacy of local cooling on reducing skin ischemia under surface pressure. Eight Sprague-Dawley rats were assigned to two protocols, including pressure with local cooling (Δt = -10 °C) and pressure with local heating (Δt = 10 °C). Pressure of 700 mmHg was applied to the right trochanter area of rats for 3 h. Skin perfusion quantified by laser Doppler flowmetry and TNF-∗ and IL-1β levels were measured. Our results showed that TNF-α concentrations were increased more significantly with local heating than with local cooling under pressure whereas IL-1β did not change. Our results support the notion that weight bearing soft tissue damage may be reduced through temperature modulation and that non-invasive perfusion measurements using laser Doppler flowmetry may be capable of assessing viability. Furthermore, these results show that perfusion response to loading pressure may be correlated with changes in local pro-inflammatory cytokines. These relationships may be relevant for the development of cooling technologies for reducing risk of pressure ulcers. Copyright © 2014 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

A non-invasive method to produce pressure ulcers of varying severity in a spinal cord-injured rat model.

PubMed

Ahmed, A K; Goodwin, C R; Sarabia-Estrada, R; Lay, F; Ansari, A M; Steenbergen, C; Pang, C; Cohen, R; Born, L J; Matsangos, A E; Ng, C; Marti, G P; Abu-Bonsrah, N; Phillips, N A; Suk, I; Sciubba, D M; Harmon, J W

2016-12-01

Experimental study. The objective of this study was to establish a non-invasive model to produce pressure ulcers of varying severity in animals with spinal cord injury (SCI). The study was conducted at the Johns Hopkins Hospital in Baltimore, Maryland, USA. A mid-thoracic (T7-T9) left hemisection was performed on Sprague-Dawley rats. At 7 days post SCI, rats received varying degrees of pressure on the left posterior thigh region. Laser Doppler Flowmetry was used to record blood flow. Animals were killed 12 days after SCI. A cardiac puncture was performed for blood chemistry, and full-thickness tissue was harvested for histology. Doppler blood flow after SCI prior to pressure application was 237.808±16.175 PFUs at day 7. Following pressure application, there was a statistically significant decrease in blood flow in all pressure-applied groups in comparison with controls with a mean perfusion of 118.361±18.223 (P<0.001). White blood cell counts and creatine kinase for each group were statistically significant from the control group (P=0.0107 and P=0.0028, respectively). We have created a novel animal model of pressure ulcer formation in the setting of a SCI. Histological analysis revealed different stages of injury corresponding to the amount of pressure the animals were exposed to with decreased blood flow immediately after the insult along with a subsequent marked increase in blood flow the next day, conducive to an ischemia-reperfusion injury (IRI) and a possible inflammatory response following tissue injury. Following ischemia and hypoxia secondary to microcirculation impairment, free radicals generate lipid peroxidation, leading to ischemic tissue damage. Future studies should be aimed at measuring free radicals during this period of increased blood flow, following tissue ischemia.

Soft-tissue tumor differentiation using 3D power Doppler ultrasonography with echo-contrast medium injection.

PubMed

Chiou, Hong-Jen; Chou, Yi-Hong; Chen, Wei-Ming; Chen, Winby; Wang, Hsin-Kai; Chang, Cheng-Yen

2010-12-01

We aimed to evaluate the ability of 3-dimensional power Doppler ultrasonography to differentiate soft-tissue masses from blood flow and vascularization with contrast medium. Twenty-five patients (mean age, 44.1 years; range, 12-77 years) with a palpable mass were enrolled in this study. Volume data were acquired using linear and convex 3-dimensional probes and contrast medium injected manually by bolus. Data were stored and traced slice by slice for 12 slices. All patients were scanned by the same senior sonologist. The vascular index (VI), flow index (FI), and vascular-flow index (VFI) were automatically calculated after the tumor was completely traced. All tumors were later confirmed by pathology. The study included 8 benign (mean, 36.5 mL; range, 2.4-124 mL) and 17 malignant (mean, 319.4 mL; range, 9.9-1,179.6 mL) tumors. Before contrast medium injection, mean VI, FI and VFI were, respectively, 3.22, 32.26 and 1.07 in benign tumors, and 1.97, 29.33 and 0.67 in malignant tumors. After contrast medium injection, they were, respectively, 20.85, 37.33 and 8.52 in benign tumors, and 40.12, 41.21 and 17.77 in malignant tumors. The mean differences between with and without contrast injection for VI, FI and VFI were, respectively, 17.63, 5.07 and 7.45 in benign tumors, and 38.15, 11.88 and 16.55 in malignant tumors. Tumor volume, VI, FI and VFI were not significantly different between benign and malignant tumors before and after echo-contrast medium injection. However, VI, FI and VFI under self-differentiation (differences between with and without contrast injection) were significantly different between malignant and benign tumors. Three-dimensional power Doppler ultrasound is a valuable tool for differential diagnosis of soft-tissue tumors, especially with the injection of an echo-contrast medium. Copyright © 2010 Elsevier. Published by Elsevier B.V. All rights reserved.

Left ventricular myocardial velocities and deformation indexes in top-level athletes.

PubMed

D'Andrea, Antonello; Cocchia, Rosangela; Riegler, Lucia; Scarafile, Raffaella; Salerno, Gemma; Gravino, Rita; Golia, Enrica; Pezzullo, Enrica; Citro, Rodolfo; Limongelli, Giuseppe; Pacileo, Giuseppe; Cuomo, Sergio; Caso, Pio; Russo, Maria Giovanna; Bossone, Eduardo; Calabrò, Raffaele

2010-12-01

The aim of this study was to define the range of left ventricular (LV) velocities and deformation indexes in highly trained athletes, analyzing potential differences induced by different long-term training protocols. Standard echocardiography, pulsed-wave tissue Doppler echocardiography, and two-dimensional strain echocardiography of the interventricular septum and lateral wall were performed in 370 endurance athletes and 280 power athletes. Using pulsed-wave tissue Doppler, the following parameters of myocardial function were assessed: systolic peak velocities (S(m)), early (E(m)) and late (A(m)) diastolic velocities, and the E(m)/A(m) ratio. By two-dimensional strain echocardiography, peaks of regional systolic strain and LV global longitudinal strain were calculated. LV mass index and ejection fraction did not significantly differ between the two groups. However, power athletes showed an increased sum of wall thicknesses (P < .01) and relative wall thickness, while LV stroke volume and LV end-diastolic diameter (P < .001) were greater in endurance athletes. By pulsed-wave tissue Doppler analysis, E(m) and E(m)/A(m) at both the septal and lateral wall levels were higher in endurance athletes. By two-dimensional strain echocardiography, myocardial deformation indexes were comparable between the two groups. E(m)/A(m) ratios ≥ 1 were found in the overall population, while 90 % of athletes had an E(m) ≥ 16 cm/sec, S(m) ≥ 10 cm/sec, and global longitudinal strain ≤ -16%. Multivariate analyses evidenced independent positive association between Em peak velocity and LV end-diastolic volume (P < .001) and an independent correlation of global longitudinal strain with the sum of LV wall thicknesses (P < .005). This study describes the full spectrum of systolic and diastolic myocardial velocities and deformation indexes in a large population of competitive athletes. Copyright © 2010 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

Evaluation of left ventricular function in obese children without hypertension by a tissue Doppler imaging study.

PubMed

Ghandi, Yazdan; Sharifi, Mehrzad; Habibi, Danial; Dorreh, Fatemeh; Hashemi, Mojtaba

2018-01-01

The prevalence of obesity is increasing worldwide. Obese children without hypertension are becoming an important health challenge. Complications of obesity in adults are well established, but in obese children, cardiac dysfunction has not been reported clinically. The present crosssectional study investigates subclinical systolic and diastolic dysfunction using echocardiographic modalities. Twentyfive youngsters with body mass index (BMI) >30 and 25 healthy children with BMI <25 were assigned into case and control group, respectively. In all participants, complete cardiovascular examination, electrocardiography, and echocardiography were fulfilled. Echocardiography surveys included standard, pulsed wave Doppler (PWD), and tissue Doppler imaging (TDI). SPSS software, version 24. The two groups were matched for age and sex. The resting heart rate and blood pressure were markedly higher in the obese group ( P = 0.0001) though they were within the normal range in either category. Ejection fraction in the two groups was similar. Left ventricular (LV) mass ( P = 0.0001), LV mass index ( P = 0.029), left atrialtoaortic diameter ratio ( P = 0.0001), and LV enddiastolic diameter ( P = 0.008) were significantly greater in the case group, indicating cardiomegaly and subclinical systolic and diastolic dysfunction. Except for the aortic velocity, all PWD variables were considerably lower in the case group, suggesting subclinical diastolic dysfunction. All TDI parameters varied significantly between the two categories. There was a direct correlation between isovolumetric relaxation time and BMI. Obesity in children without hypertension is associated with subclinical systolic and diastolic cardiac dysfunction. We propose the evaluation of blood pressure as well as myocardial performance using PWD and TDI in all obese children without hypertension, regularly.

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

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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.

Applications of Doppler optical coherence tomography

NASA Astrophysics Data System (ADS)

Xu, Zhiqiang

A major development in biomedical imaging in the last decade has been optical coherence tomography (OCT). This technique enables microscale resolution, depth resolved imaging of the detailed morphology of transparent and nontransparent biological tissue in a noncontact and quasi-noninvasive way. In the first part of this dissertation, we will describe the development and the performance of our home-made OCT systems working with different wavelength regions based on free-space and optical fiber Michelson interferometers. The second part will focus on Doppler OCT (DOCT), an important extension of OCT, which enables the simultaneous evaluation of the structural information and of the fluid flow distribution at a localized position beneath the sample surface. Much effort has been spent during the past few years in our laboratory aimed at providing more accurate velocity measurements with an extended dynamic range. We also applied our technique in different research areas such as microfluidics and hemodynamics. Investigations on the optical properties of the biological tissues (such as absorption and scattering) corresponding to different center wavelengths, have been performed in our laboratory. We used a 10 femtosecond Ti:sapphire laser centered at about 810 nm associated with a free-space Michelson interferometer. The infrared sources were centered at about 1310 and 1560 nm with all-fiber interferometers. Comparative studies using three different sources for several in vitro biological tissues based on a graphical method illustrated how the optical properties affect the quality of the OCT images in terms of the penetration depth and backscattering intensity. We have shown the advantage of working with 810-nm emission wavelength for good backscattering amplitude and contrast, while sources emitting at 1570 nm give good penetration depth. The 1330-nm sources provide a good compromise between the two. Therefore, the choice of the source will ultimately determine the longitudinal resolution and the imaging depth for OCT imaging. Doppler OCT is becoming an increasingly popular field of investigation within optical coherence tomography with potentially important applications in cardiovascular and microfluidic research. We have spent some of the effort on searching for accurate and efficient methods for processing the experimental data. We applied the pseudo Wigner time-frequency distribution method to the data processing of Doppler OCT and compared its performance to that of the short-time Fourier transform method, the Hilbert-based phase-resolved method and the autocorrelation method. We concluded that the pseudo Wigner-distribution signal processing method is overall more precise than other often-used methods in Doppler OCT for the analysis of cross-sectional velocity distributions, especially in the high velocity regime. We also discovered the advantage of using the time-domain instead of the frequency domain for Doppler OCT for some applications where precise Doppler-speed metrology is essential. Based on the fact that the obtained local OCT interference signal is almost a single periodic waveform, we have developed a novel, simple and less time-consuming processing method based on the zero-crossing points in an OCT signal for the measurement of the Doppler frequency in a laminar flow. This method was compared to other processing approaches currently used in Doppler OCT. The results show that in the case of laminar flow, the zero-crossing method gives the more precise results, especially in the higher velocity regime with a substantial economy in processing time and an increase in dynamic range which can reach 70 dB. This feature becomes a major advantage in metrology if one wants to measure velocities over several orders of magnitude. We have applied this technique to some real flow models and the preliminary results on flow velocity distributions obtained in the case of a microfluidic circuit and in that of a phantom of a blood vessel stenosis and bifurcation will be described in this thesis. We also proposed the method to successfully obtain the 2D velocity vector map in the phantom models by overlapping the Doppler OCT scalar velocity distributions of different incident angles. This quantitative knowledge of blood velocity profiles in the vessels can provide very important information in studying some cardiovascular diseases such as atherosclerosis. (Abstract shortened by UMI.)

Comparison of NIRS, laser Doppler flowmetry, photoplethysmography, and pulse oximetry during vascular occlusion challenges.

PubMed

Abay, T Y; Kyriacou, P A

2016-04-01

Monitoring changes in blood volume, blood flow, and oxygenation in tissues is of vital importance in fields such as reconstructive surgery and trauma medicine. Near infrared spectroscopy (NIRS), laser Doppler (LDF) flowmetry, photoplethysmography (PPG), and pulse oximetry (PO) contribute to such fields due to their safe and noninvasive nature. However, the techniques have been rarely investigated simultaneously or altogether. The aim of this study was to investigate all the techniques simultaneously on healthy subjects during vascular occlusion challenges. Sensors were attached on the forearm (NIRS and LDF) and fingers (PPG and PO) of 19 healthy volunteers. Different degrees of vascular occlusion were induced by inflating a pressure cuff on the upper arm. The responses of tissue oxygenation index (NIRS), tissue haemoglobin index (NIRS), flux (LDF), perfusion index (PPG), and arterial oxygen saturation (PO) have been recorded and analyzed. Moreover, the optical densities were calculated from slow varying dc PPG, in order to distinguish changes in venous blood volumes. The indexes showed significant changes (p  <  0.05) in almost all occlusions, either venous or over-systolic occlusions. However, differentiation between venous and arterial occlusion by LDF may be challenging and the perfusion index (PI) may not be adequate to indicate venous occlusions. Optical densities may be an additional tool to detect venous occlusions by PPG.

Evaluation of atrial electromechanical conduction delay in case of hemodynamically insignificant rheumatic heart disease: A tissue Doppler study.

PubMed

Cagdas, Metin; Velibey, Yalcin; Guvenc, Tolga Sinan; Gungor, Baris; Guzelburc, Ozge; Calik, Nazmi; Ugur, Murat; Tekkesin, Ahmet Ilker; Gurkan, Kadir; Eren, Mehmet

2015-01-01

Atrial electromechanical delay (AEMD) that reflects delayed conduction may show us the clinical reflection of pathological changes in the atria. The main objective of the present study is to investigate AEMD in patients who had previous rheumatic carditis but without hemodynamically significant valvular disease. A total of 40 patients, previously diagnosed as rheumatic carditis but without significant valvular stenosis/regurgitation and atrial enlargement; and 39 age- and-sex matched controls were enrolled for the present study. Parameters of AEMD (lateral mitral annulus electromechanical delay, septal mitral annulus electromechanical delay and lateral tricuspid annulus electromechanical delay) were measured with tissue Doppler echocardiography and left intra-atrial and inter-atrial conduction times were calculated accordingly. A 24h ambulatory Holter monitoring was used in both groups to detect atrial fibrillation episodes and quantify atrial extrasystoles. Parameters of AEMD, including left intra-atrial and inter-atrial conduction times of subjects in the study group were longer compared to the control group (23.7 ± 7.0 vs. 18.3 ± 6.2). Increased AEMD is observed in patients with previous rheumatic carditis and no significant valvular stenosis/regurgitation and atrial enlargement, which may partly explain the increased incidence of atrial fibrillation observed in these patients.

An Echocardiographic Study of Left Ventricular Size and Cardiac Function in Adolescent Females with Anorexia Nervosa.

PubMed

Escudero, Carolina A; Potts, James E; Lam, Pei-Yoong; De Souza, Astrid M; Mugford, Gerald J; Sandor, George G S

2016-01-01

This retrospective case-control study investigated cardiac dimensions and ventricular function in female adolescents with anorexia nervosa (AN) compared with controls. Echocardiographic measurements of left ventricular (LV) dimensions, LV mass index, left atrial size and cardiac index were made. Detailed measures of systolic and diastolic ventricular function were made including tissue Doppler imaging. Patients were stratified by body mass index ≤10th percentile (AN ≤ 10th) and >10th percentile (AN > 10th). Ninety-five AN patients and 58 controls were included. AN and AN ≤ 10th groups had reduced LV dimensions, LV mass index, left atrial size and cardiac index compared with controls. There were no differences between groups in measures of systolic function. Measures of diastolic tissue Doppler imaging were decreased in AN and AN ≤ 10th. No differences in echocardiographic measurements existed between controls and AN > 10th. Female adolescents with AN have preserved systolic function and abnormalities of diastolic ventricular function. AN ≤ 10th may be a higher risk group. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

Color mapping of one specific velocity of a biological fluid flows with complex geometry using optical coherence tomography

NASA Astrophysics Data System (ADS)

Potlov, A. Yu.; Frolov, S. V.; Proskurin, S. G.

2018-04-01

The method of Doppler color mapping of one specific (previously chosen) velocity in a turbulent flow inside biological tissues using optical coherence tomography is described. The key features of the presented method are: the raw data are separated into three parts, corresponding to the unmoving biological tissue, the positively and negatively directed biological fluid flows; the further independent signal processing procedure yields the structure image and two images of the chosen velocity, which are then normalised, encoded and joined. The described method can be used to obtain in real time the anatomical maps of the chosen velocities in normal and pathological states. The described method can be applied not only in optical coherence tomography, but also in endoscopic and Doppler ultrasonic medical imaging systems.

[Cardiac protection is a clinical evidence].

PubMed

Guarracino, F; Doroni, L; Cariello, C; Baldassarri, R; Vullo, C

2004-05-01

Anaesthetics may have protective effect against myocardial ischemia. We aimed to investigate if sevoflurane administration could exert myocardial protection during following coronary occlusion in patients with coronary artery disease. a). prospective, randomized study. b). University Hospital, cardiac surgical operative theatre. c). 42 patients with coronary artery disease, scheduled to undergo coronary surgery. severe coronary stenosis of anterior descending coronary artery; no collateral flow on angiography; at least two normokinetic segments in the myocardial region supplied by the vessel being bypassed. PATIENTS were randomized to receive (group S) or not (group C) sevoflurane administration for 15 min just before coronary occlusion. d). Transoesophageal Tissue Doppler echocardiographic examination of myocardial systolic and early diastolic velocities in both groups basally and 60 s after coronary occlusion by the surgeon. e). systolic and early diastolic velocities were registered by Tissue Doppler from a long-axis view of the interventricular septum or the anterior wall of the left ventricle. In group C a significant reduction of systolic and diastolic intramyocardial velocities was found during myocardial ischemia due to coronary occlusion. Treatment with sevoflurane before coronary occlusion seem effective in reducing functional myocardial impairment due to ischemia.

In situ monitoring of localized shear stress and fluid flow within developing tissue constructs by Doppler optical coherence tomography

NASA Astrophysics Data System (ADS)

Jia, Yali; Bagnaninchi, Pierre O.; Wang, Ruikang K.

2008-02-01

Mechanical stimuli can be introduced to three dimensional (3D) cell cultures by use of perfusion bioreactor. Especially in musculoskeletal tissues, shear stress caused by fluid flow generally increase extra-cellular matrix (ECM) production and cell proliferation. The relationship between the shear stress and the tissue development in situ is complicated because of the non-uniform pore distribution within the cell-seeded scaffold. In this study, we firstly demonstrated that Doppler optical coherence tomography (DOCT) is capable of monitoring localized fluid flow and shear stress in the complex porous scaffold by examining their variation trends at perfusion rate of 5, 8, 10 and 12 ml/hr. Then, we developed the 3D porous cellular constructs, cell-seeded chitosan scaffolds monitored during several days by DOCT. The fiber based fourier domain DOCT employed a 1300 nm superluminescent diode with a bandwidth of 52 nm and a xyz resolution of 20×20×15 μm in free space. This setup allowed us not only to assess the cell growth and ECM deposition by observing their different scattering behaviors but also to further investigate how the cell attachment and ECM production has the effect on the flow shear stress and the relationship between flow rate and shear stress in the developing tissue construct. The possibility to monitor continuously the constructs under perfusion will easily indicate the effect of flow rate or shear stress on the cell viability and cell proliferation, and then discriminate the perfusion parameters affecting the pre-tissue formation rate growth.

Non-contact photoacoustic tomography with a laser Doppler vibrometer

NASA Astrophysics Data System (ADS)

Xu, Guan; Wang, Cheng; Feng, Ting; Oliver, David E.; Wang, Xueding

2014-03-01

Most concurrent photoacoustic tomography systems are based on traditional ultrasound measurement regime, which requires the contact or acoustic coupling material between the biological tissue and the ultrasound transducer. This study investigates the feasibility of non-contact measurement of photacoustic signals generated inside biomedical tissues by observing the vibrations at the surface of the tissues with a commercial laser Doppler vibrometer. The vibrometer with 0- 2MHz measurement bandwidth and 5 MHz sampling frequency was integrated to a conventional rotational PAT data acquisition system. The data acquisition of the vibrometer was synchronized to the laser illumination from an Nd:YAG laser with output at 532nm. The laser energy was tuned to 17.5mJ per square centimeter. The PA signals were acquired at 120 angular locations uniformly distributed around the scanned objects. The frequency response of the measurement system was first calibrated. 2-inch-diamater cylindrical phantoms containing small rubber plates and biological tissues were afterwards imaged. The phantoms were made from 5% intralipid solution in 10% porcine gelatin to simulate the light scattering in biological tissue and to backscatter the measurement laser from the vibrometer. Time-domain backprojection method was used for the image reconstruction. Experiments with real-tissue phantoms show that with laser illumination of 17.5 mJ/cm2 at 532 nm, the non-contact photoacoustic (PA) imaging system with 15dB detection bandwidth of 2.5 MHz can resolve spherical optical inclusions with dimension of 500μm and multi-layered structure with optical contrast in strongly scattering medium. The experiment results prompt the potential implementation of the non-contact PAT to achieve "photoacoustic camera".

Automated assessment of blood flow in developing embryonic hearts by extending dynamic range of Doppler OCT using a MHz FDML swept laser source (Conference Presentation)

NASA Astrophysics Data System (ADS)

Elahi, Sahar; Thrane, Lars; Rollins, Andrew M.; Jenkins, Michael W.

2017-02-01

Altered hemodynamics in developing embryonic hearts lead to congenital heart diseases, motivating close monitoring of blood flow over several stages of development. Doppler OCT can assess blood flow in tubular hearts, but the maximum velocity increases drastically during the period of cardiac cushion (valve precursors) formation. Therefore, the limited dynamic range of Doppler OCT velocity measurement makes it difficult to conduct longitudinal studies without phase wrapping at high velocities or loss of sensitivity to slow velocities. We have built a high-speed OCT system using an FDML laser (Optores GmbH, Germany) at a sweep rate of 1.68 MHz (axial resolution - 12 μm, sensitivity - 105 dB, phase stability - 17 mrad). The speed of this OCT system allows us to acquire high-density B-scans to obtain an extended velocity dynamic range without sacrificing the frame rate. The extended dynamic range within a frame is achieved by varying the A-scan interval at which the phase difference is found, enabling detection of velocities ranging from tens of microns per second to hundreds of mm per second. The extra lines in a frame can also be utilized to improve the structural and Doppler images via complex averaging. In structural images where presence of blood causes additional scattering, complex averaging helps retrieve features located deeper in the tissue. Moreover, high-density frames can be registered to 4D volumes to determine the orthogonal direction of flow and calculate shear stress. In conclusion, our high-speed OCT system will enable automated Doppler imaging of embryonic hearts in cohort studies.

In Vivo Determination of the Complex Elastic Moduli of Cetacean Head Tissue

DTIC Science & Technology

2013-09-30

of an ultrasonic Doppler vibration measurement system called NVMS developed at Georgia Tech iii. Algorithms have been developed to enable the...magnitude and phase of vibration to be determined as a function of range (tissue depth) along the ultrasonic beam. By measuring the differential phase of...The frequency dependence of the propagation speed is then used to determine the shear loss factor. The elastic properties of tissue phantoms

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

PubMed Central

Sicari, Rosa

2005-01-01

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. PMID:15679889

Non-Invasive Tissue Oxygenation Measurement Systems. Phase 1.

DTIC Science & Technology

1995-10-01

vessels was shown ( in vivo hamster studies) to be a significant factor causing considerable variability in SaO2 in vessels ...shows that trends in blood oxygenation are tracked. The nearly universal applicability and turnkey type measurement capability of pulse oximeters are...approach early in Phase I that might be compatible with laser doppler blood flow measurements. Both methods depend on laser irradiation of the sample

Functional Spectral Domain Optical Coherence Tomography imaging

NASA Astrophysics Data System (ADS)

Bower, Bradley A.

Spectral Domain Optical Coherence Tomography (SDOCT) is a high-speed, high resolution imaging modality capable of structural and functional characterization of tissue microstructure. SDOCT fills a niche between histology and ultrasound imaging, providing non-contact, non-invasive backscattering amplitude and phase from a sample. Due to the translucent nature of the tissue, ophthalmic imaging is an ideal space for SDOCT imaging. Structural imaging of the retina has provided new insights into ophthalmic disease. The phase component of SDOCT images remains largely underexplored, though. While Doppler SDOCT has been explored in a research setting, it has yet to gain traction in the clinic. Other, functional exploitations of the phase are possible and necessary to expand the utility of SDOCT. Spectral Domain Phase Microscopy (SDPM) is an extension of SDOCT that is capable of resolving sub-wavelength displacements within a focal volume. Application of sub-wavelength displacement measurement imaging could provide a new method for non-invasive optophysiological measurement. This body of work encompasses both hardware and software design and development for implementation of SDOCT. Structural imaging was proven in both the lab and the clinic. Coarse phase changes associated with Doppler flow frequency shifts were recorded and a study was conducted to validate Doppler measurement. Fine phase changes were explored through SDPM applications. Preliminary optophysiology data was acquired to study the potential of sub-wavelength measurements in the retina. To remove the complexity associated with in-vivo human retinal imaging, a first principles approach using isolated nerve samples was applied using standard SDPM and a depthencoded technique for measuring conduction velocity. Results from amplitude as well as both coarse and fine phase processing are presented. In-vivo optophysiology using SDPM is a promising avenue for exploration, and projects furthering or extending this body of work are discussed.

Evaluation of left ventricular function in obese children without hypertension by a tissue Doppler imaging study

PubMed Central

Ghandi, Yazdan; Sharifi, Mehrzad; Habibi, Danial; Dorreh, Fatemeh; Hashemi, Mojtaba

2018-01-01

Background: The prevalence of obesity is increasing worldwide. Obese children without hypertension are becoming an important health challenge. Aims: Complications of obesity in adults are well established, but in obese children, cardiac dysfunction has not been reported clinically. Settings and Design: The present crosssectional study investigates subclinical systolic and diastolic dysfunction using echocardiographic modalities. Materials and Methods: Twentyfive youngsters with body mass index (BMI) >30 and 25 healthy children with BMI <25 were assigned into case and control group, respectively. In all participants, complete cardiovascular examination, electrocardiography, and echocardiography were fulfilled. Echocardiography surveys included standard, pulsed wave Doppler (PWD), and tissue Doppler imaging (TDI). Statistical Analysis Used: SPSS software, version 24. Results: The two groups were matched for age and sex. The resting heart rate and blood pressure were markedly higher in the obese group (P = 0.0001) though they were within the normal range in either category. Ejection fraction in the two groups was similar. Left ventricular (LV) mass (P = 0.0001), LV mass index (P = 0.029), left atrialtoaortic diameter ratio (P = 0.0001), and LV enddiastolic diameter (P = 0.008) were significantly greater in the case group, indicating cardiomegaly and subclinical systolic and diastolic dysfunction. Except for the aortic velocity, all PWD variables were considerably lower in the case group, suggesting subclinical diastolic dysfunction. All TDI parameters varied significantly between the two categories. There was a direct correlation between isovolumetric relaxation time and BMI. Conclusions: Obesity in children without hypertension is associated with subclinical systolic and diastolic cardiac dysfunction. We propose the evaluation of blood pressure as well as myocardial performance using PWD and TDI in all obese children without hypertension, regularly. PMID:29440827

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

PubMed

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.

Tissue Doppler-derived E/e' ratio as a parameter for assessing diastolic heart failure and as a predictor of mortality in patients with chronic kidney disease.

PubMed

Kim, Min Keun; Kim, Biro; Lee, Jun Young; Kim, Jae Seok; Han, Byoung-Geun; Choi, Seung Ok; Yang, Jae Won

2013-01-01

Diastolic dysfunction occurs frequently in patients with chronic kidney disease (CKD) and is associated with heart failure (HF) or mortality. We investigated whether the ratio of early diastolic mitral inflow velocity to early diastolic mitral annulus velocity (E/e' ratio), estimated using tissue Doppler imaging, has prognostic value for cardiovascular morbidity and all-cause mortality in patients with CKD. For 186 patients with CKD of stages III to V, we obtained echocardiograms with tissue Doppler imaging. A 5-year follow-up of 136 patients was performed based on hospital records and telephone interviews. The enrolled patients (79 males and 57 females) were categorized into the following CKD subgroups: stage III (n = 25); stage IV (n = 22); and stage V (n = 89). The average follow-up period was 30.45 months and the mean age of the patients was 61.13 years. The mortality rate after 5 years was 60.0%. The causes of death were: sepsis, 21.9%; HF, 16.2%; and sudden death, 15.2%. Age (p = 0.000), increased C-reactive protein level (p = 0.018), and increased E/e' ratio (p = 0.048) were found to correlate with mortality. Age (p = 0.000), decreased ejection fraction (p = 0.003), and increased E/e' ratio (p = 0.045) correlated with cardiovascular event. The E/e' ratio can predict mortality and cardiovascular events in patients with CKD who have diastolic dysfunction.

Bone and gallium scanning in the pre-op evaluation of the infected dysvascular foot

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stewart, C.; Sakimura, I.; Dillon, A.

1984-01-01

The purpose of this study is to determine the value of bone and gallium scans in predicting healing levels in the dysvascular foot with an infection requiring amputation. Healing requires amputation at a level both free of infection and with adequate blood flow. Forty-one such patients had bone and gallium scans and Doppler studies prior to amputation at a level selected by the surgeon. Eight patients required multiple surgeries before healing was obtained. Bone and soft tissue infections were determined from scans and healing levels predicted (SPHL) as the most distal amputation level free from infection: toectomy, Reye's, transmetatarsal, calcanectomy,more » Syme's, below knee. Doppler healing levels (DPHL) were predicted using a standard ischemic index. Doppler alone predicted the final healing level (FHL) in 41% with 59% needing more proximal amputation. Scans alone predicted FHL in 64% with 26% needing more proximal amputation. Ten percent were distal to the SPHL and all healed. These scans showed infection at transition sites between amputation levels, and the more proximal level had been predicted. Using the more proximal of the DPHL and SPHL the FHL was predicted in 78% with another 12% having more proximal amputation for nursing reasons. In 10% amputation was performed between DPHL and SPHL or at the more distal level. In no case was successful surgery performed distal to the more distal SPHL or DPHL. Bone and gallium scans used with Doppler studies are useful in optimizing the choice of amputation level in the infected, dysvascular foot.« less

Absorption and scattering coefficient dependence of laser-Doppler flowmetry models for large tissue volumes.

PubMed

Binzoni, T; Leung, T S; Rüfenacht, D; Delpy, D T

2006-01-21

Based on quasi-elastic scattering theory (and random walk on a lattice approach), a model of laser-Doppler flowmetry (LDF) has been derived which can be applied to measurements in large tissue volumes (e.g. when the interoptode distance is >30 mm). The model holds for a semi-infinite medium and takes into account the transport-corrected scattering coefficient and the absorption coefficient of the tissue, and the scattering coefficient of the red blood cells. The model holds for anisotropic scattering and for multiple scattering of the photons by the moving scatterers of finite size. In particular, it has also been possible to take into account the simultaneous presence of both Brownian and pure translational movements. An analytical and simplified version of the model has also been derived and its validity investigated, for the case of measurements in human skeletal muscle tissue. It is shown that at large optode spacing it is possible to use the simplified model, taking into account only a 'mean' light pathlength, to predict the blood flow related parameters. It is also demonstrated that the 'classical' blood volume parameter, derived from LDF instruments, may not represent the actual blood volume variations when the investigated tissue volume is large. The simplified model does not need knowledge of the tissue optical parameters and thus should allow the development of very simple and cost-effective LDF hardware.

Tissue Pulsatility Imaging of Cerebral Vasoreactivity during Hyperventilation

PubMed Central

Kucewicz, John C.; Dunmire, Barbrina; Giardino, Nicholas D.; Leotta, Daniel F.; Paun, Marla; Dager, Stephen R.; Beach, Kirk W.

2008-01-01

Tissue Pulsatility Imaging (TPI) is an ultrasonic technique that is being developed at the University of Washington to measure tissue displacement or strain due to blood flow over the cardiac and respiratory cycles. This technique is based in principle on plethysmography, an older non-ultrasound technology for measuring expansion of a whole limb or body part due to perfusion. TPI adapts tissue Doppler signal processing methods to measure the “plethysmographic” signal from hundreds or thousands of sample volumes in an ultrasound image plane. This paper presents a feasibility study to determine if TPI can be used to assess cerebral vasoreactivity. Ultrasound data were collected transcranially through the temporal acoustic window from four subjects before, during, and after voluntary hyperventilation. In each subject, decreases in tissue pulsatility during hyperventilation were observed that were statistically correlated with the subject’s end-tidal CO2 measurements. PMID:18336991

Role of color Doppler in differentiation of Graves' disease and thyroiditis in thyrotoxicosis

PubMed Central

Donkol, Ragab Hani; Nada, Aml Mohamed; Boughattas, Sami

2013-01-01

AIM: To evaluate the role of thyroid blood flow assessment by color-flow Doppler ultrasonography in the differential diagnosis of thyrotoxicosis and compare it to technetium pertechnetate thyroid scanning. METHODS: Twenty-six patients with thyrotoxicosis were included in the study. Clinical history was taken and physical examination and thyroid function tests were performed for all patients. Thyroid autoantibodies were measured. The thyroid glands of all patients were evaluated by gray scale ultrasonography for size, shape and echotexture. Color-flow Doppler ultrasonography of the thyroid tissue was performed and spectral flow analysis of both inferior thyroid arteries was assessed. Technetium99 pertechnetate scanning of the thyroid gland was done for all patients. According to thyroid scintigraphy, the patients were divided into two groups: 18 cases with Graves’ disease and 8 cases with Hashimoto’s thyroiditis. All patients had suppressed thyrotropin. The diagnosis of Graves’ disease and Hashimoto’s thyroiditis was supported by the clinical picture and follow up of patients. RESULTS: Peak systolic velocities of the inferior thyroid arteries were significantly higher in patients with Graves’ disease than in patients with thyroiditis (P = 0.004 in the right inferior thyroid artery and P = 0.001 in left inferior thyroid artery). Color-flow Doppler ultrasonography parameters demonstrated a sensitivity of 88.9% and a specificity of 87.5% in the differential diagnosis of thyrotoxicosis. CONCLUSION: Color Doppler flow of the inferior thyroid artery can be used in the differential diagnosis of thyrotoxicosis, especially when there is a contraindication of thyroid scintigraphy by radioactive material in some patients. PMID:23671754

Reliability of laser Doppler, near-infrared spectroscopy and Doppler ultrasound for peripheral blood flow measurements during and after exercise in the heat.

PubMed

Choo, Hui C; Nosaka, Kazunori; Peiffer, Jeremiah J; Ihsan, Mohammed; Yeo, Chow C; Abbiss, Chris R

2017-09-01

This study examined the test-retest reliability of near-infrared spectroscopy (NIRS), laser Doppler flowmetry (LDF) and Doppler ultrasound to assess exercise-induced haemodynamics. Nine men completed two identical trials consisting of 25-min submaximal cycling at first ventilatory threshold followed by repeated 30-s bouts of high-intensity (90% of peak power) cycling in 32.8 ± 0.4°C and 32 ± 5% relative humidity (RH). NIRS (tissue oxygenation index [TOI] and total haemoglobin [tHb]) and LDF (perfusion units [PU]) signals were monitored continuously during exercise, and leg blood flow was assessed by Doppler ultrasound at baseline and after exercise. Cutaneous vascular conductance (CVC; PU/mean arterial pressure (MAP)) was expressed as the percentage change from baseline (%CVC BL ). Coefficients of variation (CVs) as indicators of absolute reliability were 18.7-28.4%, 20.2-33.1%, 42.5-59.8%, 7.8-12.4% and 22.2-30.3% for PU, CVC, %CVC BL , TOI and tHb, respectively. CVs for these variables improved as exercise continued beyond 10 min. CVs for baseline and post-exercise leg blood flow were 17.8% and 10.5%, respectively. CVs for PU, tHb (r 2  = 0.062) and TOI (r 2  = 0.002) were not correlated (P > 0.05). Most variables demonstrated CVs lower than the expected changes (35%) induced by training or heat stress; however, minimum of 10 min exercise is recommended for more reliable measurements.

Etiology of congenital hypothyroidism using thyroglobulin and ultrasound combination.

PubMed

Beltrão, Cristine B; Juliano, Adriana G; Chammas, Maria C; Watanabe, Tomoco; Sapienza, Marcelo T; Marui, Suemi

2010-01-01

Methods currently employed to establish the etiology of congenital hypothyroidism include thyroid ultrasound and scintigraphic exams. Thyroglobulin is a protein almost exclusively secreted by thyroid tissue and indirectly reflects the amount of follicular cells. Even though thyroglobulin is easy to measure, it has been not frequently used because of discordant results to distinguish mainly athyreosis and ectopy (dysgenesis). Knowing the differences in inheritance and prognosis of thyroid dysgenesis and dyshormonogenesis, it is important to define the etiology of CH, combining tools that are easy, fast and available in most medical centers. Our objective was to evaluate and compare color Doppler ultrasound and serum thyroglobulin with radionuclide scan to define the etiology of congenital hypothyroidism. We evaluated 38 children above 3 years-old off-treatment that performed serum thyroglobulin by immunofluorometric assay, color Doppler ultrasound and radionuclide study. On color Doppler ultrasound, 11 patients had athyreosis, 5 ectopic glands, being 1 associated to hemiagenesis. Twenty one had topic thyroid (3 goiters, 10 normal, 8 hypoplastic). Hemiagenesis and cystic lesion were not revealed by radionuclide scan. We observed substantial agreement between color Doppler ultrasound and radionuclide scan (kappa=0.745, p<0.0001). Serum thyroglobulin in athyreosis ranged from <1.0 to 18.7 micro g/L. Patients with ectopic glands showed wider thyroglobulin range (4.5 to 123 micro g/L, median 28.4 micro g/L). Only one patient showed thyroglobulin deficiency. By using color Doppler ultrasound and serum thyroglobulin levels as valuable combined tools, we established the etiology of congenital hypothyroidism limiting excessive and harmful exams in children, like radionuclide scan.

Cyclic reconstruction of 4D retinal blood flow with pulse synchronization

NASA Astrophysics Data System (ADS)

Schmoll, Tilman; Lasser, Theo; Leitgeb, Rainer A.

2009-02-01

Doppler OCT systems allow nowadays to visualize quantitative and qualitative angiographic maps of retinal tissue. We equipped the instrument with a pulse oximeter and recorded the pulse synchronously with the resonant Doppler flow data. Recombination of tomograms according to the heart beat cycles yields full volumes for each cycle instant. We believe such multi-dimensional functional information and the ability to monitor dynamic processes over time to open exciting perspectives that ultimately contribute to a better understanding of retinal physiology and patho-physiology in-vivo.

Accumulation of epicardial fat rather than visceral fat is an independent risk factor for left ventricular diastolic dysfunction in patients undergoing peritoneal dialysis.

PubMed

Lin, Heng-Hsu; Lee, Jen-Kuang; Yang, Chung-Yi; Lien, Yu-Chung; Huang, Jenq-Wen; Wu, Cho-Kai

2013-08-30

Symptoms of heart failure with preserved left ventricular systolic function are common among patients undergoing peritoneal dialysis (PD). Epicardial fat (EpF) is an ectopic fat depot with possible paracrine or mechanical effects on myocardial function. The aim of our current study is to assess the association between EpF and Left ventricular diastolic dysfunction (LVDD) in patients undergoing PD and to clarify the relationships among EpF, inflammation, and LVDD in this population. This was a cross-sectional study of 149 patients with preserved left ventricular systolic function who were undergoing PD. LVDD was diagnosed (according to the European Society of Cardiology guidelines) and EpF thickness measured by echocardiography. The patients without LVDD were used as controls. The serum inflammatory biomarker high-sensitivity C-reactive protein (hsCRP) was measured. The location and amount of adipose tissue were assessed by computed tomography (CT) at the level of the fourth lumbar vertebra. Subjects with LVDD had higher levels of hsCRP, more visceral and peritoneal fat, and thicker EpF (all p < 0.001) than controls. Visceral adipose tissue, hsCRP, and EpF all correlated significantly (p < 0.05) with LVDD. Multivariate regression analysis rendered the relationship between visceral adipose tissue and LVDD insignificant, whereas EpF was the most powerful determinant of LVDD (odds ratio = 2.41, 95% confidence interval = 1.43-4.08, p < 0.01). EpF thickness also correlated significantly with the ratio of transmitral Doppler early filling velocity to tissue Doppler early diastolic mitral annular velocity (E/e'; r = 0.27, p < 0.01). EpF thickness is significantly independently associated with LVDD in patients undergoing PD and may be involved in its pathogenesis.

Accumulation of epicardial fat rather than visceral fat is an independent risk factor for left ventricular diastolic dysfunction in patients undergoing peritoneal dialysis

PubMed Central

2013-01-01

Background Symptoms of heart failure with preserved left ventricular systolic function are common among patients undergoing peritoneal dialysis (PD). Epicardial fat (EpF) is an ectopic fat depot with possible paracrine or mechanical effects on myocardial function. The aim of our current study is to assess the association between EpF and Left ventricular diastolic dysfunction (LVDD) in patients undergoing PD and to clarify the relationships among EpF, inflammation, and LVDD in this population. Methods This was a cross-sectional study of 149 patients with preserved left ventricular systolic function who were undergoing PD. LVDD was diagnosed (according to the European Society of Cardiology guidelines) and EpF thickness measured by echocardiography. The patients without LVDD were used as controls. The serum inflammatory biomarker high-sensitivity C-reactive protein (hsCRP) was measured. The location and amount of adipose tissue were assessed by computed tomography (CT) at the level of the fourth lumbar vertebra. Results Subjects with LVDD had higher levels of hsCRP, more visceral and peritoneal fat, and thicker EpF (all p < 0.001) than controls. Visceral adipose tissue, hsCRP, and EpF all correlated significantly (p < 0.05) with LVDD. Multivariate regression analysis rendered the relationship between visceral adipose tissue and LVDD insignificant, whereas EpF was the most powerful determinant of LVDD (odds ratio = 2.41, 95% confidence interval = 1.43–4.08, p < 0.01). EpF thickness also correlated significantly with the ratio of transmitral Doppler early filling velocity to tissue Doppler early diastolic mitral annular velocity (E/e’; r = 0.27, p < 0.01). Conclusion EpF thickness is significantly independently associated with LVDD in patients undergoing PD and may be involved in its pathogenesis. PMID:24001037

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

NASA Astrophysics Data System (ADS)

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.

Singular value decomposition of received ultrasound signal to separate tissue, blood flow, and cavitation signals

NASA Astrophysics Data System (ADS)

Ikeda, Hayato; Nagaoka, Ryo; Lafond, Maxime; Yoshizawa, Shin; Iwasaki, Ryosuke; Maeda, Moe; Umemura, Shin-ichiro; Saijo, Yoshifumi

2018-07-01

High-intensity focused ultrasound is a noninvasive treatment applied by externally irradiating ultrasound to the body to coagulate the target tissue thermally. Recently, it has been proposed as a noninvasive treatment for vascular occlusion to replace conventional invasive treatments. Cavitation bubbles generated by the focused ultrasound can accelerate the effect of thermal coagulation. However, the tissues surrounding the target may be damaged by cavitation bubbles generated outside the treatment area. Conventional methods based on Doppler analysis only in the time domain are not suitable for monitoring blood flow in the presence of cavitation. In this study, we proposed a novel filtering method based on the differences in spatiotemporal characteristics, to separate tissue, blood flow, and cavitation by employing singular value decomposition. Signals from cavitation and blood flow were extracted automatically using spatial and temporal covariance matrices.

Dentoalveolar growth inhibition induced by bone denudation on palates: a study of two isolated cleft palates with asymmetric scar tissue distribution.

PubMed

Ishikawa, H; Iwasaki, H; Tsukada, H; Chu, S; Nakamura, S; Yamamoto, K

1999-09-01

This report presents two cases of isolated cleft palate with asymmetric distribution of postsurgical scar tissue determined by laser Doppler flowmetry. To determine the effect of mucoperiosteal denudation of the bone on maxillary alveolar growth, the analysis of dentoalveolar structures compared the affected side to the unaffected side of each case. Two Japanese girls with isolated cleft palates were examined. Both subjects had undergone pushback operations (a modified version of the procedure of Wardill) for palatal repair at 18 months of age. Palatal blood flow was examined by laser Doppler flowmetry when the girls were 12 years old to determine the extent of postsurgical scar tissue over the denuded bone. To analyze the maxillary dentoalveolar structures three dimensionally, the whole surface of the upper dental cast was measured and recorded by an optical measuring device when the girls were 7 years old. Analysis via flowmetry showed that the palatal scar tissue area was limited to the anterior tooth region on the right (unaffected) side but extended posteriorly to the premolar region on the left (affected) side in both subjects. The two girls had similar dentoalveolar structures, with the dental and alveolar arches deflected lingually at the deciduous molar area on the affected side. There were no differences in the buccolingual inclination of deciduous molars or in the vertical growth of the alveolar processes between the affected and unaffected sides. In both girls, bone denudation in the premolar region appeared to result in less than 3 mm of displacement of the teeth palatally, with no change in lingual inclination. Any effects of scar tissue on the vertical development of the alveolus were not substantiated.

Technical Note: A new phantom design for routine testing of Doppler ultrasound.

PubMed

Grice, J V; Pickens, D R; Price, R R

2016-07-01

The objective of this project is to demonstrate the principle and operation for a simple, inexpensive, and highly portable Doppler ultrasound quality assurance (QA) phantom intended for routine QA testing. A prototype phantom has been designed, fabricated, and evaluated. The phantom described here is powered by gravity alone, requires no external equipment for operation, and produces a stable fluid velocity useful for quality assurance. Many commercially available Doppler ultrasound testing systems can suffer from issues such as a lengthy setup, prohibitive cost, nonportable size, or difficulty in use. This new phantom design aims to address some of these problems and create a phantom appropriate for assessing Doppler ultrasound stability. The phantom was fabricated using a 3D printer. The basic design of the phantom is to provide gravity-powered flow of a Doppler fluid between two reservoirs. The printed components were connected with latex tubing and then seated in a tissue mimicking gel. Spectral Doppler waveforms were sampled to evaluate variations in the data, and the phantom was evaluated using high frame rate video to find an alternate measure of mean fluid velocity flowing in the phantom. The current system design maintains stable flow from one reservoir to the other for approximately 7 s. Color Doppler imaging of the phantom was found to be qualitatively consistent with laminar flow. Using pulsed spectral Doppler, the average fluid velocity from a sample volume approximately centered in the synthetic vessel was measured to be 56 cm/s with a standard deviation of 3.2 cm/s across 118 measurements. An independent measure of the average fluid velocity was measured to be 51.9 cm/s with a standard deviation of 0.7 cm/s over 4 measurements. The developed phantom provides stable fluid flow useful for frequent clinical Doppler ultrasound testing and attempts to address several obstacles facing Doppler phantom testing. Such an ultrasound phantom can make routine testing more approachable for institutions that wish to initiate a Doppler QA program or complement a previously existing QA program.

[Comparative effects of nebivolol and valsartan on atrial electromechanical coupling in newly diagnosed stage 1 hypertensive patients].

PubMed

Altun, Burak; Acar, Gürkan; Akçay, Ahmet; Sökmen, Abdullah; Kaya, Hakan; Köroğlu, Sedat

2011-10-01

Hypertension is an important cardiovascular risk factor for the development of atrial fibrillation (AF). Increased atrial electromechanical coupling time interval measured by tissue Doppler is accepted as an important factor for prediction of AF development in hypertensive patients. The aim of this study was to compare the effects of valsartan, an angiotensin receptor blocker, and nebivolol, a beta-blocker, on atrial electromechanical coupling in newly diagnosed stage 1 hypertensive patients. The study included 60 newly diagnosed stage 1 hypertensive patients with no other systemic disease. The patients were randomized to receive nebivolol 5 mg (30 patients; 21 women, 9 men; mean age 48.4 ± 11.4 years) and valsartan 160 mg (30 patients; 21 women, 9 men; mean age 49.8 ± 11.3 years). All the patients underwent tissue Doppler echocardiographic examination before and three months after treatment to compare the effects of the two drugs on atrial electromechanical coupling. Baseline blood pressures, electrocardiographic and echocardiographic findings, and atrial electromechanical coupling were similar in both groups (p>0.05). Both drugs significantly reduced blood pressure after treatment, with similar efficacy (p>0.05). Atrial electromechanical coupling time intervals showed significant decreases in both groups. Prolonged interatrial electromechanical time intervals in hypertensives are improved with antihypertensive treatment.

Effect of exercise, heat stress and dehydration on myocardial performance.

PubMed

Fehling, P C; Haller, J M; Lefferts, W K; Hultquist, E M; Wharton, M; Rowland, T W; Smith, D L

2015-06-01

Myocardial dysfunction is a well-documented outcome of extended periods of high cardiac output. Whether similar effects occur during firefighting, an occupation characterized by repeated periods of work compounded by dehydration and heat stress, is uncertain. To investigate the independent and combined effects of moderate heat stress and dehydration on indicators of myocardial performance following intermittent, submaximal treadmill exercise while wearing personal protective equipment (PPE). Twelve aerobically fit young men (age 21.5±2.6 years; maximal oxygen uptake [VO2max] 60.3±4.4ml kg(-1) min(-1)) performed intermittent treadmill walking exercise consisting of three 20min bouts at an intensity of ~40% VO2max separated by two periods of rest in four different conditions in random order: (i) no heat stress-euhydrated, (ii) heat stress-euhydrated (heat stress created by wearing PPE, (iii) no heat stress-dehydrated and (iv) heat stress-dehydrated. We measured core temperature by a telemetric gastrointestinal pill. We determined cardiac variables by standard echocardiographic techniques immediately before and ~30min after exercise. We recorded no significant changes in markers of systolic (ejection fraction, shortening fraction, tissue Doppler-S) or diastolic (mitral peak E velocity, tissue Doppler-E' and E/E') function following exercise in any of the four conditions. In this model of exercise designed to mimic the work, heat stress and dehydration associated with firefighting activities, we observed no negative effects on myocardial inotropic or lusitropic function. © The Author 2015. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Design of a tissue oxygenation monitor and verification on human skin

NASA Astrophysics Data System (ADS)

Liu, Hongyuan; Kohl-Bareis, Matthias; Huang, Xiabing

2011-07-01

We report the design of a tissue oxygen and temperature monitor. The non-invasive, fibre based device monitors tissue haemoglobin (Hb) and oxygen saturation (SO2) and is based on white-light reflectance spectroscopy.Visible light with wavelengths in the 500 - 650nm range is utilized. The spectroscopic algorithm takes into account the tissue scattering and melanin absorption for the calculation of tissue haemoglobin concentration and oxygen saturation. The monitor can probe superficial layers of tissue with a high spatial resolution (mm3) and a high temporal resolution (40 Hz). It provides an accurate measurement with the accuracy of SO2 at 2 % and high reliability with less than 2 % variation of continuous SO2 measurement over 12 hours. It can also form a modular system when used in conjunction with a laser Doppler monitor, enabling simultaneous measurements of Hb, SO2 and blood flow. We found experimentally that the influence of the source-detector separation on the haemoglobin parameters is small. This finding is discussed by Monte Carlo simulations for the depth sensitivity profile. The influence of probe pressure and the skin pigmentation on the measurement parameters are assessed before in vivo experimental data is presented. The combination with laser Doppler flowmetry demonstrates the importance of a measurement of both the haemoglobin and the blood flow parameters for a full description of blood tissue perfusion. This is discussed in experimental data on human skin during cuff occlusion and after hyperemisation by a pharmacological cream. Strong correlation is observed between tissue oxygen (Hb and SO2) and blood flow measurements.

Doppler indices of gas phase formation in hypobaric environments: Time-intensity analysis

NASA Technical Reports Server (NTRS)

Powell, Michael R.

1991-01-01

A semi-quantitative method to analyze decompression data is described. It possesses the advantage that it allows a graded response to decompression rather than the dichotomous response generally employed. A generalized critical volume (C-V), or stoichiometric time-dependent equilibrium model is examined that relates the constant of the equation P sub i equals m P sub f plus b to variable tissue supersaturation and gas washout terms. The effects of the tissue ratio on gas phase formation indicate that a decreased ratio yields fewer individuals with Doppler detectable gas bubbles, but those individuals still present with Spencer Grade 3 or 4. This might indicate a local collapse of tissue saturation. The individuals with Grade 3 or 4 could be at risk for type 2 decompression sickness by transpulmonic arterialization. The primary regulator of the problems of decompression sickness is the reduction of local supersaturation, presumably governed by the presence and number of gas micronuclei. It is postulated that a reduction in these nuclei will favor a low incidence of decompression sickness in microgravity secondary to hypokinesia and adynamia.

Portable duplex ultrasonography: A diagnostic and decision-making tool in reconstructive microsurgery.

PubMed

Gravvanis, Andreas; Karakitsos, Dimitrios; Dimitriou, Vasilios; Zogogiannis, Ioannis; Katsikeris, Nick; Karabinis, Andreas; Tsoutsos, Dimosthenis

2010-07-01

Unidirectional Doppler is a common diagnostic tool by the Reconstructive Microsurgeons; however, it may generate false signals and surely provides less imaging data as compared to duplex ultrasonography. We have reviewed the use of Portable Duplex Ultrasonography (PDU) in 16 patients who underwent complex soft-tissue/bone reconstruction, aiming to determine its role in the design and management of free tissue transfer. According to our data, there were modifications either of the surgical plan and/or of patient's management, based on PDU findings, in 10 out of 16 patients (62.5%). The use of ultrasound directed to subtle modifications in three patients (19%), but to significant changes of the surgical plan in four patients (25%). Also, the use of ultrasound improved significantly the postoperative management in three patients (19%). Thus, significant impact of PDU in patient's treatment was recorded in 44% of cases. Portable ultrasound represents generally available method for preoperative, intraoperative, and postoperative diagnosis and decision-making in free tissue transfer, hence could replace in the near future the unidirectional Doppler in the hands of Microsurgeons. (c) 2010 Wiley-Liss, Inc.

Measurement of subcutaneous adipose tissue blood flow in the morbidly obese using a laser Doppler velocimeter

NASA Astrophysics Data System (ADS)

Klassen, Gerald A.; Paton, Barry E.; Maksym, Geoff; Janigan, David; Perey, Bernard

1992-08-01

Using a laser Doppler velocimeter (LDV) subcutaneous adipose tissue blood flow (AF) was recorded in the upright and supine positions in the upper and lower abdomen in 22 morbidly obese patients before gastroplasty. Age was 42 +/- 3 (mean +/- SEM), weight 135 +/- 7 kg, and body mass index (BMI) 51 +/- 3. Adipose flow expressed as mV was: supine, upper abdomen 647 +/- 23, lower abdomen 604 +/- 24; upright, upper abdomen 621 +/- 27, lower abdomen 607 +/- 29. AF was significantly more in the upper than lower abdomen (supine position) and AF was significantly lower in the lower abdomen upright than the upper abdomen supine. Regression analysis of age indicates that blood flow decreases in the lower abdomen so that in the supine position the difference between upper and lower abdomen AF increases. Similar analysis of BMI did not indicate significant trends. These data indicate that with morbid obesity there is lower tissue blood flow to the lower abdomen. This may explain why such patients may develop areas of painful ischemic necrosis in the dependent region of their anterior abdominal pannus.

New Possibilities of Positron-Emission Tomography

NASA Astrophysics Data System (ADS)

Volobuev, A. N.

2018-01-01

The reasons for the emergence of the angular distribution of photons generated as a result of annihilation of an electron and a positron in a positron-emission tomograph are investigated. It is shown that the angular distribution of the radiation intensity (i.e., the probability of photon emission at different angles) is a consequence of the Doppler effect in the center-of-mass reference system of the electron and the positron. In the reference frame attached to the electron, the angular distribution of the number of emitted photons does not exists but is replaced by the Doppler shift of the frequency of photons. The results obtained in this study make it possible to extend the potentialities of the positron-emission tomograph in the diagnostics of diseases and to obtain additional mechanical characteristics of human tissues, such as density and viscosity.

Evaluation of tissue doppler echocardiography and T2* magnetic resonance imaging in iron load of patients with thalassemia major.

PubMed

Saravi, Mehrdad; Tamadoni, Ahmad; Jalalian, Rozita; Mahmoodi-Nesheli, Hassan; Hojati, Mosatafa; Ramezani, Saeed

2013-01-01

Iron-mediated cardiomyopathy is the main complication of thalassemia major (TM) patients. Therefore, there is an important clinical need in the early diagnosis and risk stratification of patients. The aim of this study was to evaluate the efficacy of tissue doppler imaging (TDI) to study cardiac iron overload in patients with TM using T2* magnetic resonance (MR) as the gold-standard non-invasive diagnostic test. A total of 100 TM patients with the mean age of 19±7 years and 100 healthy controls 18.8±7 years were evaluated. Conventional echocardiography, TDI, and cardiac MRI T2* were performed in all subjects. TDI measures included myocardial systolic (Sm), early (Em) and late (Am) diastolic velocities at basal and middle segments of septal and lateral LV wall. The TM patients were also subgrouped according to those with iron load (T2* ≤ 20 ms) and those without (T2* > 20 ms), and also severe (T2* ≤ 10 ms) versus the non-severe (T2* ≤ 10 ms). Using T2* cardiovascular MR, abnormal myocardial iron load (T2* ≤ 20 ms) was detected in 84% of the patients and among these, 50% (42/84) had severe (T2* ≤ 10 ms) iron load. The mean T2* was 11.6±8.6 ms (5-36.7). A negative linear correlation existed between transfusion period of patients and T2* levels (r = -0.53, p=0.02). The following TDI measures were lower in patients than in controls: basal septal Am (p<0.05), mid-septal Em and Am (p<0.05), basal lateral Am (p<0.05), mid-lateral LV wall Sm (p<0.05) and Am (p<0.05). Tissue doppler imaging is helpful in predicting the presence of myocardial iron load in Thalassemia patients. Therefore, it can be used for screening of thalassemia major patients.

Effects of hypoxia on cochlear blood flow in mice evaluated using Doppler optical microangiography.

PubMed

Dziennis, Suzan; Reif, Roberto; Zhi, Zhongwei; Nuttall, Alfred L; Wang, Ruikang K

2012-10-01

Reduced cochlear blood flow (CoBF) is a main contributor to hearing loss. Studying CoBF has remained a challenge due to the lack of available tools. Doppler optical microangiography (DOMAG), a method to quantify single-vessel absolute blood flow, and laser Doppler flowmetry (LDF), a method for measuring the relative blood flow within a large volume of tissue, were used for determining the changes in CoBF due to systemic hypoxia in mice. DOMAG determined the change in blood flow in the apical turn (AT) with single-vessel resolution, while LDF averaged the change in the blood flow within a large volume of the cochlea (hemisphere with ∼1 to 1.5 mm radius). Hypoxia was induced by decreasing the concentration of oxygen-inspired gas, so that the oxygen saturation was reduced from >95% to ∼80%. DOMAG determined that during hypoxia the blood flow in two areas of the AT near and far from the helicotrema were increased and decreased, respectively. The LDF detected a decrease in blood flow within a larger volume of the cochlea (several turns averaged together). Therefore, the use of DOMAG as a tool for studying cochlear blood flow due to its ability to determine absolute flow values with single-vessel resolution was proposed.

Effects of hypoxia on cochlear blood flow in mice evaluated using Doppler optical microangiography

NASA Astrophysics Data System (ADS)

Dziennis, Suzan; Reif, Roberto; Zhi, Zhongwei; Nuttall, Alfred L.; Wang, Ruikang K.

2012-10-01

Reduced cochlear blood flow (CoBF) is a main contributor to hearing loss. Studying CoBF has remained a challenge due to the lack of available tools. Doppler optical microangiography (DOMAG), a method to quantify single-vessel absolute blood flow, and laser Doppler flowmetry (LDF), a method for measuring the relative blood flow within a large volume of tissue, were used for determining the changes in CoBF due to systemic hypoxia in mice. DOMAG determined the change in blood flow in the apical turn (AT) with single-vessel resolution, while LDF averaged the change in the blood flow within a large volume of the cochlea (hemisphere with ˜1 to 1.5 mm radius). Hypoxia was induced by decreasing the concentration of oxygen-inspired gas, so that the oxygen saturation was reduced from >95% to ˜80%. DOMAG determined that during hypoxia the blood flow in two areas of the AT near and far from the helicotrema were increased and decreased, respectively. The LDF detected a decrease in blood flow within a larger volume of the cochlea (several turns averaged together). Therefore, the use of DOMAG as a tool for studying cochlear blood flow due to its ability to determine absolute flow values with single-vessel resolution was proposed.

Atrial electromechanical conduction delay in patients with neurocardiogenic syncope.

PubMed

Sucu, Murat; Ercan, Suleyman; Uku, Okkes; Davutoglu, Vedat; Altunbas, Gokhan

2014-05-01

We aimed to investigate the presence of atrial electromechanical conduction delay in patients with neurocardiogenic syncope, which was diagnosed with head-up tilt table test (HUTT). A total of 29 patients (mean age: 30.6 ± 15.9 years) with vasovagal syncope, as diagnosed by HUTT, and 23 healthy control subjects (mean age: 34.7 ± 16.3 years) with a negative HUTT were enrolled to the study. Atrial electromechanical conduction delay was defined as the time elapsed from the beginning of the P wave in the electrogardiogram to the beginning of the Am wave in tissue Doppler. There was no statistically significant difference between the groups in terms of interatrial conduction delay, whereas the difference was significant with regard to the right intraatrial electromechanical conduction delay (P < 0.01) and the left intraatrial electromechanical conduction delay (P < 0.0001). There was a negative correlation between the left intraatrial electromechanical conduction delay and the right intraatrial electromechanical conduction delay (r = -0.486, P = 0.001), whereas a positive correlation was present with the interatrial electromechanical conduction delay (r = 0.507, P = 0.001). In this study, the tissue Doppler method revealed that there is left and right intraatrial electromechanical conduction delay in patients with vasovagal syncope. The impact and role of atrial conduction delay as a pathophysiological determinant should be confirmed in further studies. ©2013 Wiley Periodicals, Inc.

Right ventricular systolic function in hypertensive heart failure.

PubMed

Oketona, O A; Balogun, M O; Akintomide, A O; Ajayi, O E; Adebayo, R A; Mene-Afejuku, T O; Oketona, O T; Bamikole, O J

2017-01-01

Heart failure (HF) is a major cause of cardiovascular admissions and hypertensive heart failure (HHF) is the most common cause of HF admissions in sub-Saharan Africa, Nigeria inclusive. Right ventricular (RV) dysfunction is being increasingly recognized in HF and found to be an independent predictor of adverse outcomes in HF. This study aimed to determine the prevalence of RV systolic dysfunction in HHF by several echocardiographic parameters. One hundred subjects with HHF were recruited consecutively into the study along with 50 age and sex-matched controls. All study participants gave written informed consent, and had a full physical examination, blood investigations, 12-lead electrocardiogram, and transthoracic echocardiography. RV systolic function was assessed in all subjects using different methods based on the American Society of Echocardiography guidelines for echocardiographic assessment of the right heart in adults. This included tricuspid annular plane systolic excursion (TAPSE), RV myocardial performance index (MPI), and RV systolic excursion velocity by tissue Doppler (S'). RV systolic dysfunction was found in 53% of subjects with HHF by TAPSE, 56% by RV MPI, and 48% by tissue Doppler systolic excursion S'. RV systolic dysfunction increased with reducing left ventricular ejection fraction (LVEF) in subjects with HHF. A high proportion of subjects with HHF were found to have RV systolic functional abnormalities using TAPSE, RV MPI, and RV S'. Prevalence of RV systolic dysfunction increased with reducing LVEF.

Asymptomatic cardiovascular manifestations in diabetes mellitus: left ventricular diastolic dysfunction and silent myocardial ischemia.

PubMed

Seferović-Mitrović, Jelena P; Lalić, Nebojsa M; Vujisić-Tesić, Bosiljka; Lalić, Katarina; Jotić, Aleksandra; Ristić, Arsen D; Giga, Vojislav; Tesić, Milorad; Milić, Natasa; Lukić, Ljiljana; Milicić, Tanja; Singh, Sandra; Seferović, Petar M

2011-01-01

Several cardiovascular manifestations in patients with diabetes may be asymptomatic. Left ventricular diastolic dysfunction (LVDD) is considered to be the earliest metabolic myocardial lesion in these patients, and can be diagnosed with tissue Doppler echocardiography. Silent myocardial ischemia (SMI) is a characteristic and frequently described form of ischemic heart disease in patients with diabetes. Objective The aim of the study was to assess the prevalence of LVDD and SMI in patients with type 2 diabetes, as well as to compare demographic, clinical, and metabolic data among defined groups (patients with LVDD, patients with SMI and patients with type 2 diabetes, without LVDD and SMI). We investigated 104 type 2 diabetic patients (mean age 55.4 +/- 9.1 years, 64.4% males) with normal blood pressure, prehypertension and arterial hypertension stage I. Study design included basic laboratory assessment and cardiological workup (transthoracic echocardiography and tissue Doppler, as well as the exercise stress echocardiography). LVDD was diagnosed in twelve patients (11.5%), while SMI was revealed in six patients (5.8%). Less patients with LVDD were using metformin, in comparison to other two groups (chi2 =12.152; p=0.002). Values of HDL cholesterol (F=4.515; p=0.013) and apolipoprotein A1 (F=5.128; p= 0.008) were significantly higher in patients with LVDD. The study confirmed asymptomatic cardiovascular complications in 17.3% patients with type 2 diabetes.

Comparison of perioperative outcomes between endoscope-assisted technique and handheld acoustic Doppler for perforator identification in fasciocutaneous flaps.

PubMed

Huang, Jen-Wu; Huang, Chih-Sheng; Shih, Yu-Chung; Perng, Cherng-Kang; Lin, Yi-Ying; Wu, Szu-Hsien

2018-06-01

The endoscopic technique has been utilized to harvest muscle flaps and detect perforators of fasciocutaneous flaps. This study aimed to compare the perioperative outcomes between the endoscope-assisted technique and handheld acoustic Doppler for perforator identification in fasciocutaneous flaps.This retrospective case-control study included patients who underwent fasciocutaneous flap reconstruction for traumatic soft tissue defects. In the case group, perforator identification was assisted by the endoscope-assisted technique. In the control group, age- and sex-matched patients received handheld acoustic Doppler to detect perforators. Perioperative outcomes, flap characteristics, and postoperative complications were compared.There were 12 patients in the case group and 12 in the control group. Compared with the control group, the case group had a significantly shorter length of donor-site wounds (9 cm vs 12 cm, P = .023) and a significantly smaller proportion of patients receiving skin grafting at the donor sites (0% vs 41.7%, P = .037). The case group had a longer operative time, but the difference was not statistically significant (180 minutes vs 150 minutes, P = .367). The amount of blood loss, the time length of postoperative drainage, and complications did not significantly differ between the 2 groups.The endoscope-assisted technique for perforator identification of fasciocutaneous flaps provided less donor-site morbidity and a significantly shorter length of donor-site wounds than the conventional handheld acoustic Doppler, which suggests that this technique could be a valuable alternative when a precise design is indicated.

Comparison of pressure-volume loop and echocardiographic measures of diastolic function in patients with a single-ventricle physiology.

PubMed

Chowdhury, Shahryar M; Butts, Ryan J; Buckley, Jason; Hlavacek, Anthony M; Hsia, Tain-Yen; Khambadkone, Sachin; Baker, G Hamilton

2014-08-01

Echocardiographic measurements of diastolic function have not been validated against invasive pressure-volume loop (PVL) analysis in the single-ventricle population. The authors hypothesized that echocardiographic measures of diastolic function would correlate with PVL indices of diastolic function in patients with a single-ventricle physiology. The conductance-derived PVL measures of diastolic function included the isovolumic relaxation time constant (τ), the maximum rate of ventricular pressure decline (peak -dP/dt), and a measure of passive diastolic stiffness (μ). The echocardiographic measures included Doppler inflow patterns of the dominant atrioventricular valve (DAVV), tissue Doppler velocities (TDI) at the lateral (ventricular free wall) component of the DAVV annulus, and the TDI-derived isovolumic relaxation time (IVRT'). The correlation between PVL and echocardiographic measures was examined. The study enrolled 13 patients at various stages of surgical palliation. The median age of the patients was 3 years (range 3 months to 19 years). τ correlated well with Doppler E:A (r = 0.832; p = 0.005), lateral E:E' (r = 0.747; p = 0.033), and IVRT' (r = 0.831; p = 0.001). Peak -dP/dt also was correlated with IVRT' (r = 0.609; p = 0.036), and μ also was correlated with IVRT' (r = 0.884; p = 0.001). This study represents the first-ever comparison of diastolic echocardiographic and PVL indices in a single-ventricle population. The findings show that Doppler E:A, lateral E:E', and IVRT' correlate well with PVL measures of diastolic function. This study supports further validation of echocardiographic measures of diastolic function versus PVL measures of diastolic function in the single-ventricle population.

Prognostic value of systolic mitral annular velocity measured with Doppler tissue imaging in patients with chronic heart failure caused by left ventricular systolic dysfunction

PubMed Central

Nikitin, N P; Loh, P H; de Silva, R; Ghosh, J; Khaleva, O Y; Goode, K; Rigby, A S; Alamgir, F; Clark, A L; Cleland, J G F

2006-01-01

Objective To assess the prognostic value of various conventional and novel echocardiographic indices in patients with chronic heart failure (CHF) caused by left ventricular (LV) systolic dysfunction. Methods 185 patients with a mean (SD) age of 67 (11) years with CHF and LV ejection fraction < 45% despite optimal pharmacological treatment were prospectively enrolled. The patients underwent two dimensional echocardiography with tissue harmonic imaging to assess global LV systolic function and obtain volumetric data. Transmitral flow was assessed with conventional pulse wave Doppler. Systolic (Sm), early, and late diastolic mitral annular velocities were measured with the use of colour coded Doppler tissue imaging. Results During a median follow up of 32 months (range 24–38 months in survivors), 34 patients died and one underwent heart transplantation. Sm velocity (hazard ratio (HR) 0.648, 95% confidence interval (CI) 0.463 to 0.907, p  =  0.011), diastolic arterial pressure (HR 0.965, 95% CI 0.938 to 0.993, p  =  0.015), serum creatinine (HR 1.006, 95% CI 1.001 to 1.011, p  =  0.023), LV ejection fraction (HR 0.945, 95% CI 0.899 to 0.992, p  =  0.024), age (HR 1.035, 95% CI 1.000 to 1.071, p  =  0.052), LV end systolic volume index (HR 1.009, 95% CI 0.999 to 1.019, p  =  0.067), and restrictive pattern of transmitral flow (HR 0.543, 95% CI 0.278 to 1.061, p  =  0.074) predicted the outcome of death or transplantation on univariate analysis. On multivariate analysis, only Sm velocity (HR 0.648, 95% CI 0.460 to 0.912, p  =  0.013) and diastolic arterial pressure (HR 0.966, 95% CI 0.938 to 0.994, p  =  0.016) emerged as independent predictors of outcome. Conclusions In patients with CHF and LV systolic dysfunction despite optimal pharmacological treatment, the strongest independent echocardiographic predictor of prognosis was Sm velocity measured with quantitative colour coded Doppler tissue imaging. PMID:16251233

Corrected tetralogy of Fallot: comparison of tissue doppler imaging and velocity-encoded MR for assessment of performance and temporal activation of right ventricle.

PubMed

van der Hulst, Annelies E; Roest, Arno A W; Delgado, Victoria; Kroft, Lucia J M; Holman, Eduard R; Blom, Nico A; Bax, Jeroen J; de Roos, Albert; Westenberg, Jos J M

2011-07-01

To compare velocity-encoded (VE) magnetic resonance (MR) imaging with tissue Doppler imaging to assess right ventricular (RV) peak systolic velocities and timing of velocities in patients with corrected tetralogy of Fallot and healthy subjects. Local institutional review board approval was obtained; patients or their parents gave informed consent. Thirty-three patients (20 male, 13 female; median age, 12 years; interquartile range [IQR], 11-15 years; age range, 8-18 years) and 19 control subjects (12 male, seven female; median age, 14 years; IQR, 12-16 years; age range, 8-18 years) underwent VE MR imaging and tissue Doppler imaging. Peak systolic velocity and time to peak systolic velocity (percentage of cardiac cycle) were assessed at the RV free wall (RVFW) and RV outflow tract (RVOT). Data were analyzed by using linear regression, paired and unpaired tests, and Bland-Altman plots. Good correlation and agreement between the two techniques were observed. For peak systolic velocity at RVFW, r = 0.95 (mean difference, -0.4 cm/sec, P < .01), and at RVOT, r = 0.95 (mean difference, -0.4 cm/sec, P = .02). For timing at RVFW, r = 0.94 (mean difference, -0.2%, P = .44), and at RVOT, r = 0.89 (mean difference, -0.5%, P = .01). Peak systolic velocity was reduced in patients with corrected tetralogy of Fallot (at RVFW, median was 8.2 cm/sec [IQR, 6.4-9.7 cm/sec] vs 12.4 cm/sec [IQR, 10.8-13.8 cm/sec], P < .01; at RVOT, 4.7 cm/sec [IQR, 4.1-7.2 cm/sec] vs 10.2 cm/sec [IQR, 8.7-11.2 cm/sec], P < .01). The time delay between RVFW and RVOT was observed, which was significantly shorter in patients with corrected tetralogy of Fallot (median, 5.9% [IQR, 4.9%-7.4%] vs 8.4% [IQR, 6.6%-12.4%], P < .01). VE MR imaging and tissue Doppler imaging enable assessment of RV systolic performance and timing of velocities at the RVFW and RVOT in patients with corrected tetralogy of Fallot. Both techniques can be used interchangeably to clinically assess velocities and timing of velocities of the RV.

Early Detection of Subclinical Uremic Cardiomyopathy Using Two-Dimensional Speckle Tracking Echocardiography.

PubMed

Hassanin, Noha; Alkemary, Alkhateeb

2016-04-01

Overhydration has a deleterious effect on cardio myocytes. This study was designated to evaluate left ventricular (LV) systolic and diastolic dysfunction in patients with various stages of chronic kidney disease (CKD) using conventional, tissue Doppler and two-dimensional speckle tracking echocardiography (2DSTE). Forty controls and 90 CKD patients, aged 49.3 ± 14 years old, were enrolled in the study. Patients were divided into 3 groups depending on their glomerular filtration rate. Group 1 (≥60 mL/min per 1.73 m(2) ), group 2 (≤60 mL/min per 1.73 m(2) ), and group 3 (≤60 mL/min per 1.73 m(2) and on regular dialysis for at least 12 months). Pulsed-Doppler and tissue Doppler studies were used to estimate LV filling pressure E/E'. Using 2DSTE, circumferential, radial, and longitudinal functions of the LV have been measured. LV longitudinal systolic strain, early, and late diastolic strain rates were significantly reduced in CKD patients (-16.9 ± 3.8%, 1.6 ± 0.5%, and 1.3 ± 0.4% in CKD vs. -22.5 ± 0.6%, 2.3 ± 0.2%, and 1.9 ± 0.1% in controls, P < 0.001 for all), and no difference was observed in terms of the circumferential LV functions (-22.4 ± 1.7 vs. -22.5 ± 1.4, P = 0.567). Severity of the kidney dysfunction appears to parallel with the rise of E/E' significantly (P < 0.001). In CKD, although the longitudinal and radial systolic functions were reduced, LV ejection fraction may remain within normal limits due to the preservation of the circumferential functions. Early detection of uremic cardiomyopathy might provide useful information for the risk stratification and decide the proper dialysis therapy in these patients. © 2015, Wiley Periodicals, Inc.

Effect of well-controlled gestational diabetes on left ventricular diastolic dysfunction in neonates.

PubMed

Ghandi, Yazdan; Habibi, Danial; Nasri, Khadijeh; Alinejad, Saeed; Taherahmad, Hassan; Arjmand Shabestari, Ali; Nematinejad, Ali

2018-06-17

There are some evidences supporting the relation between gestational diabetes mellitus (GDM) and diastolic dysfunction. The aim of our study was to investigate the effect of well-controlled GDM on morphological and functional myocardium. We designed a prospective cross-sectional study to evaluate left ventricular (LV) diastolic function of 60 neonates born from mothers with well-controlled GDM (case group) on days of 3-5 after birth. The infants of diabetic mothers (IDM) group were divided into two groups: diabetic mothers treated only with diet (class A) and group of mothers on medical therapy by insulin or metformin (class B). Traditional echocardiography and pulsed-wave Doppler (PWD), tissue Doppler imaging (TDI) were performed for all the neonates. The study group consisted of 60 neonates as males (M) = 32, (0.53%) and females (F) = 28, (0.46%). Using M-mode echocardiography, interventricular septum thickness (IVS), and LV mass were significantly higher in IDM than control group (p = .0001). The PWD showed both a significantly more peak mitral flow at early diastolic wave (E) and an early filling deceleration time (E-DT) (p = .0001). Tissue Doppler echocardiography parameters A' (cm/s) (p = .0001), E' (cm/s) (p = .002), and E'/A' ratio (p = .0001), left ventricular myocardial performance index (LVMPI), and isovolumetric relaxation time (IVRT) were outstandingly different between the two groups (p = .0001, respectively). Evaluating the GDM group mothers of class A and class B, no significant difference was noted in PWD or TDI parameters compared with the healthy ones. It seems that neonates of mothers with well-controlled GDM are still at increased risk of cardiac hypertrophy, subclinical diastolic dysfunction, and impaired left ventricular relaxation. This can be interpreted that focusing only on glycemic control is not enough to prevent cardiac dysfunction.

High-sensitive cardiac Troponin T is superior to echocardiography in predicting 1-year mortality in patients with SIRS and shock in intensive care.

PubMed

Bergenzaun, Lill; Ohlin, Hans; Gudmundsson, Petri; Düring, Joachim; Willenheimer, Ronnie; Chew, Michelle S

2012-09-24

Left ventricular (LV) dysfunction is well documented in the critically ill. We assessed 1-year mortality in relation to cardiac biomarkers and LV function parameters by echocardiography in patients with shock. A prospective, observational, cohort study of 49 patients. B-natriuretic peptide (BNP), high-sensitive troponin T (hsTNT) and transthoracic echocardiography (TTE) were assessed within 12 h of study inclusion. LV systolic function was measured by ejection fraction (LVEF), mean atrioventricular plane displacement (AVPDm), peak systolic tissue Doppler velocity imaging (TDIs) and velocity time integral in the LV outflow tract (LVOT VTI). LV diastolic function was evaluated by transmitral pulsed Doppler (E, A, E/A, E-deceleration time), tissue Doppler indices (é, á, E/é) and left atrial volume (La volume). APACHE II (Acute Physiology and Chronic Health Evaluation) and SOFA (Sequential Organ Failure Assessment) scores were calculated. hsTNT was significantly higher in non-survivors than in survivors (60 [17.0-99.5] vs 168 [89.8-358] ng/l, p = 0.003). Other univariate predictors of mortality were APACHE II (p = 0.009), E/é (p = 0.023), SOFA (p = 0.024) and age (p = 0.031). Survivors and non-survivors did not differ regarding BNP (p = 0.26) or any LV systolic function parameter (LVEF p = 0.87, AVPDm p = 0.087, TDIs p = 0.93, LVOT VTI p = 0.18). Multivariable logistic regression analysis identified hsTNT (p = 0.010) as the only independent predictor of 1-year mortality; adjusted odds ratio 2.0 (95% CI 1.2- 3.5). hsTNT was the only independent predictor of 1-year mortality in patients with shock. Neither BNP nor echocardiographic parameters had an independent prognostic value. Further studies are needed to establish the clinical significance of elevated hsTNT in patients in shock.

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

NASA Astrophysics Data System (ADS)

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.

Optical coherence tomography for the quantitative study of cerebrovascular physiology

PubMed Central

Srinivasan, Vivek J; Atochin, Dmitriy N; Radhakrishnan, Harsha; Jiang, James Y; Ruvinskaya, Svetlana; Wu, Weicheng; Barry, Scott; Cable, Alex E; Ayata, Cenk; Huang, Paul L; Boas, David A

2011-01-01

Doppler optical coherence tomography (DOCT) and OCT angiography are novel methods to investigate cerebrovascular physiology. In the rodent cortex, DOCT flow displays features characteristic of cerebral blood flow, including conservation along nonbranching vascular segments and at branch points. Moreover, DOCT flow values correlate with hydrogen clearance flow values when both are measured simultaneously. These data validate DOCT as a noninvasive quantitative method to measure tissue perfusion over a physiologic range. PMID:21364599

The use of laser Doppler imaging as an aid in clinical management decision making in the treatment of vesicant burns.

PubMed

Brown, R F; Rice, P; Bennett, N J

1998-12-01

Vesicants are a group of chemicals recognised, under the terms of the Chemical Weapons Convention, as potential chemical warfare agents whose prime effect on the skin is to cause burns and blistering. Experience of the clinical management of these injuries is not readily available and therefore an accurate assessment of the severity of the lesion and extent of tissue involvement is an important factor when determining the subsequent clinical management strategy for such lesions. This study was performed to assess the use of laser Doppler imaging (LDI) as a noninvasive means of assessing wound microvascular perfusion following challenge with the vesicant agents (sulphur mustard or lewisite) by comparing the images obtained with histopathological analysis of the lesion. Large white pigs were challenged with sulphur mustard (1.91 mg cm(-2)) or lewisite (0.3 mg.cm(-2)) vapour for periods of up to 6 h At intervals of between 1 h and 7 days following vesicant challenge, LDI images were acquired and samples for routine histopathology were taken. The results from this study suggest that LDI was: (i) a simple, reproducible and noninvasive means of assessing changes in tissue perfusion, and hence tissue viability, in developing and healing vesicant burns; (ii) the LDI images correlates well with histopathological assessment of the resulting lesions and the technique was sufficiently sensitive enough to discriminate between skin lesions of different aetiology. These attributes suggest that LDI would be a useful investigative tool that could aid clinical management decision making in the early treatment of vesicant agent-induced skin burns.

Combined use of Doppler OCT and en face OCT functions for discrimination of an aneurysm in the lamina cribrosa from a disc hemorrhage.

PubMed

Holló, Gábor

2015-12-01

In addition to retinal nerve fiber layer thickness measurements, the recently introduced AngioVue optical coherence tomography (OCT) offers corresponding layer-by-layer Doppler OCT and en face OCT functions, for simultaneous evaluation of perfusion and structure of the optic nerve head. We investigated the clinical usefulness of combined use of Doppler and en face Fourier-domain OCT functions of the AngioVue Fourier-domain OCT for discrimination of a disc hemorrhage and a disc hemorrhage-like atypical vessel structure located deep in the lamina cribrosa. We present our findings with AngioVue OCT on a disc hemorrhage and a spatially related retinal nerve fiber layer bundle defect in a glaucomatous eye (case 1). Both alterations were detected on en face OCT images without any Doppler OCT signal. We also report on an aneurysm suggestive for a disc hemorrhage on clinical examination and disc photography in a treated ocular hypertensive eye (case 2). The aneurysm was within the lamina cribrosa tissue at the border of the cup and the neuroretinal rim. This vascular structure produced strong Doppler signals but no structurally detectable signs on the en face OCT images. Combined evaluation of corresponding Doppler OCT and en face OCT images enables ophthalmologists to easily separate true disc hemorrhages from disc hemorrhage-like deep vascular structures. This is of clinical significance in preventing unnecessary intensification of pressure-lowering treatment in glaucoma.

Effects of exercise training on systo-diastolic ventricular dysfunction in patients with hypertension: an echocardiographic study with tissue velocity and strain imaging evaluation.

PubMed

Leggio, Massimo; Mazza, Andrea; Cruciani, Giancarlo; Sgorbini, Luca; Pugliese, Marco; Bendini, Maria Grazia; Severi, Paolo; Jesi, Anna Patrizia

2014-07-01

There is a lack of detailed data regarding the effect of exercise training in pharmacologically treated hypertensive patients. Therefore, the aim of this study was to evaluate the effects of exercise training on left and right ventricular morphologic and functional parameters by means of conventional echocardiography and sensitive new echocardiographic techniques including tissue Doppler velocity and strain imaging, that were performed in pharmacologically treated hypertensive patients at baseline and at the end of a specific exercise training protocol for primary prevention of cardiovascular disease. We selected 116 pharmacologically treated hypertensive patients who completed the exercise training protocol. All patients underwent a clinical history and examination; transthoracic echocardiography and exercise testing were performed at baseline and at the end of the exercise training protocol. Conventional echocardiography revealed a mild degree of diastolic dysfunction without significant differences or variations from baseline to the end of the exercise training protocol. In contrast, tissue Doppler velocity and strain imaging measurements demonstrated and highlighted the positive influence of exercise training: for both left and right ventricle myocardial early peak diastolic velocities (Em), the ratio of myocardial early-late peak diastolic velocity (Em/Am), myocardial peak systolic velocities (Sm) and peak strain and strain rate values significantly increased at the end of the exercise training protocol, suggesting a relationship between exercise capacity and both left and right ventricular systo-diastolic function. Our study, by means of newer more sensitive echocardiographic techniques, clearly demonstrated the positive impact of exercise training on both left and right ventricular systo-diastolic function, in terms of adjunctive subclinical improvement, in pharmacologically treated hypertensive patients.

Evaluation of blood microcirculation parameters by combined use of laser Doppler flowmetry and videocapillaroscopy methods

NASA Astrophysics Data System (ADS)

Volkov, M. V.; Kostrova, D. A.; Margaryants, N. B.; Gurov, I. P.; Erofeev, N. P.; Dremin, V. V.; Zharkikh, E. V.; Zherebtsov, E. A.; Kozlov, I. O.; Dunaev, A. V.

2017-03-01

Laser Doppler flowmetry (LDF) is widely used for diagnosing blood microcirculation diseases. It is well known that the Doppler shift of laser radiation scattered by moving red blood cells (RBC) can be assessed through analyzing photocurrent produced by a photodetector. LDF signal contains information about regulating blood flow rhythms: myogenic, cardiac, nervous and endothelial. The method of videocapillaroscopy (VCS) allows local capillary blood flow velocity evaluation and, using video data processing algorithms, is able to assess RBC velocity changes into capillary. We present the results of simultaneous investigations of changes in tissue perfusion of the distal phalanx of human finger by the LDF as well as changes in capillary blood flow velocity in the nail bed evaluated by the VCS method during arterial occlusion test. The experimental results confirmed the correspondence between blood perfusion and blood flow velocity.

Laser Doppler flowmetry evaluation of gingival recovery response after laser treatment

NASA Astrophysics Data System (ADS)

Todea, Carmen; Cânjǎu, Silvana; Dodenciu, Dorin; Miron, Mariana I.; Tudor, Anca; Bǎlǎbuc, Cosmin

2013-06-01

This study was performed in order to evaluate in vivo the applicability of Laser Doppler Flowmetry (LDF) in recording the gingival blood flow and to assess the changes of gingival blood flow following gingival reshaping performed with Er:YAG and 980 nm diode lasers. The LDF evaluation was performed on 20 anterior teeth, which underwent reshaping of gingiva, corresponding to 5 female patients (4 anterior teeth/patient), aged between 20 and 35. One part of the mouth was treated with Er:YAG laser (LP, VLP modes, 140 - 250 mJ, 10 - 20 Hz, using cylindrical sapphire tips) and other part with 980 nm diode laser (CW, 4 W, contact mode and saline solution cooling). The gingival blood flow was monitored using a MoorLab laser Doppler equipment (Moor Instruments Ltd., Axminster, UK) with a straight optical probe, MP3b, 10 mm. The data were processed using statistical analysis software SPSS v16.0.1. The investigation showed an evident decrease in perfusion for both areas in comparison with the baseline values 24 hours after treatment. The microvascular blood flow increased significantly after 7 days in both areas but mostly in diode area (p<0.001). After 14 days for the Er:YAG area the blood perfusion returned to the initial value. The results in diode area remained at a high level after 14 days. Both lasers proved efficiency in the surgical treatment of gingival tissue. Moreover, Laser Doppler Flowmetry is adequate for recording changes in gingival blood flow following periodontal surgery.

Noninvasive Doppler Tissue Measurement of Pulmonary Artery Compliance in Children with Pulmonary Hypertension

PubMed Central

Dyer, Karrie; Lanning, Craig; Das, Bibhuti; Lee, Po-Feng; Ivy, D. Dunbar; Valdes-Cruz, Lilliam; Shandas, Robin

2007-01-01

Background We have shown previously that input impedance of the pulmonary vasculature provides a comprehensive characterization of right ventricular afterload by including compliance. However, impedance-based compliance assessment requires invasive measurements. Here, we develop and validate a noninvasive method to measure pulmonary artery (PA) compliance using ultrasound color M-mode (CMM) Doppler tissue imaging (DTI). Methods Dynamic compliance (Cdyn) of the PA was obtained from CMM DTI and continuous wave Doppler measurement of the tricuspid regurgitant velocity. Cdyn was calculated as: [(Ds − Dd)/(Dd × Ps)] × 104; where Ds = systolic diameter, Dd = diastolic diameter, and Ps = systolic pressure. The method was validated both in vitro and in 13 patients in the catheterization laboratory, and then tested on 27 pediatric patients with pulmonary hypertension, with comparison with 10 age-matched control subjects. Cdyn was also measured in an additional 13 patients undergoing reactivity studies. Results Instantaneous diameter measured using CMM DTI agreed well with intravascular ultrasound measurements in the in vitro models. Clinically, Cdyn calculated by CMM DTI agreed with Cdyn calculated using invasive techniques (23.4 ± 16.8 vs 29.1 ± 20.6%/100 mm Hg; P = not significant). Patients with pulmonary hypertension had significantly lower peak wall velocity values and lower Cdyn values than control subjects (P < .01). Cdyn values followed an exponentially decaying relationship with PA pressure, indicating the nonlinear stress–strain behavior of these arteries. Reactivity in Cdyn agreed with reactivity measured using impedance techniques. Conclusion The Cdyn method provides a noninvasive means of assessing PA compliance and should be useful as an additional measure of vascular reactivity subsequent to pulmonary vascular resistance in patients with pulmonary hypertension. PMID:16581479

Noninvasive Doppler tissue measurement of pulmonary artery compliance in children with pulmonary hypertension.

PubMed

Dyer, Karrie; Lanning, Craig; Das, Bibhuti; Lee, Po-Feng; Ivy, D Dunbar; Valdes-Cruz, Lilliam; Shandas, Robin

2006-04-01

We have shown previously that input impedance of the pulmonary vasculature provides a comprehensive characterization of right ventricular afterload by including compliance. However, impedance-based compliance assessment requires invasive measurements. Here, we develop and validate a noninvasive method to measure pulmonary artery (PA) compliance using ultrasound color M-mode (CMM) Doppler tissue imaging (DTI). Dynamic compliance (C(dyn)) of the PA was obtained from CMM DTI and continuous wave Doppler measurement of the tricuspid regurgitant velocity. C(dyn) was calculated as: [(D(s) - D(d))/(D(d) x P(s))] x 10(4); where D(s) = systolic diameter, D(d) = diastolic diameter, and P(s) = systolic pressure. The method was validated both in vitro and in 13 patients in the catheterization laboratory, and then tested on 27 pediatric patients with pulmonary hypertension, with comparison with 10 age-matched control subjects. C(dyn) was also measured in an additional 13 patients undergoing reactivity studies. Instantaneous diameter measured using CMM DTI agreed well with intravascular ultrasound measurements in the in vitro models. Clinically, C(dyn) calculated by CMM DTI agreed with C(dyn) calculated using invasive techniques (23.4 +/- 16.8 vs 29.1 +/- 20.6%/100 mm Hg; P = not significant). Patients with pulmonary hypertension had significantly lower peak wall velocity values and lower C(dyn) values than control subjects (P < .01). C(dyn) values followed an exponentially decaying relationship with PA pressure, indicating the nonlinear stress-strain behavior of these arteries. Reactivity in C(dyn) agreed with reactivity measured using impedance techniques. The C(dyn) method provides a noninvasive means of assessing PA compliance and should be useful as an additional measure of vascular reactivity subsequent to pulmonary vascular resistance in patients with pulmonary hypertension.

Addition of rituximab to chop does not increase the risk of cardiotoxicity in patients with non-Hodgkin's lymphoma.

PubMed

Kilickap, Saadettin; Yavuz, Bunyamin; Aksoy, Sercan; Sahiner, Levent; Dincer, Murat; Harputluoglu, Hakan; Erman, Mustafa; Aytemir, Kudret; Tokgozoglu, Lale; Barista, Ibrahim

2008-01-01

The addition of rituximab to doxorubicin-containing standard chemotherapy significantly improves response to therapy and reduces the risk of death in B-cell non-Hodgkin's lymphoma (NHL) patients. However, the impact of this approach on doxorubicin-induced cardiotoxicity has not been elucidated. Patients who had been planned to receive CHOP or rituximab plus CHOP (R-CHOP) combination chemotherapy with a diagnosis of NHL were included in the study. In all patients, systolic and diastolic parameters were measured by using conventional and pulsed-wave tissue Doppler echocardiography, which is more sensitive than conventional lead-dependent techniques, both before and in the sixth month of therapy. There were 28 (M/F; 14/14) patients on CHOP and 33 (M/F; 16/17) patients on R-CHOP. Median age in CHOP and R-CHOP was 49 and 50 years (P = 0.44), respectively. Cumulative doxorubicin doses were 280 and 286 mg/m(2) on CHOP and R-CHOP (P = 0.65), respectively. None of the patients developed clinically evident congestive heart failure. Parameters of systolic function such as LVEF and FS did not significantly change in any patients. In both arms, tissue Doppler parameters of diastolic function such as lateral E and septal E velocity of mitral annulus decreased significantly after therapy (P < 0.001). However, the decrease in diastolic function was similar in both arms (P > 0.05). Conventional Doppler echocardiography yielded consistent findings. Both CHOP and R-CHOP cause diastolic dysfunction in the early period following their administration. The addition of rituximab to CHOP chemotherapy does not significantly increase the risk of doxorubicin-induced cardiotoxicity during this period.

Hypercholesterolemia and Myocardial function evaluated via Tissue Doppler Imaging

PubMed Central

2009-01-01

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 < 0.01). Myocardial cholesterol content was also higher in group 3 compared to group 2 (0.10 ± 0.04 vs. 0.06 mg/dl ± 0.02; p = 0.05). There was significant correlation between S', E'/A', E/E' and serum cholesterol (r2 = 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. PMID:19943937

A brief history of ultrasound in rheumatology: where we were.

PubMed

Grassi, Walter; Filippucci, Emilio

2014-01-01

Ultrasonography in the '70s was a well-known and widely used method within several medical specialties but not in rheumatology. Initial development of the field was led by radiologists who mainly investigated the potential of ultrasound in the assessment of large joints. In the late '80s, the first studies supporting the role of ultrasound in the detection of soft tissue changes and bone erosions in the hands of patients with rheumatoid arthritis were published. In the '90s, the dramatic improvement of spatial resolution due to the new generation high frequency probes opened up new avenues for the exploration of otherwise undetectable anatomical details. Ultrasound research during this period was enhanced by the growing use of colour Doppler and power Doppler and by the first prototypes of three dimensional ultrasound. Over the last 10 years, the buzz words in ultrasound research in rheumatology have been standardisation, early diagnosis and therapy monitoring.

Power Doppler of the urethra in continent or incontinent, pre- and postmenopausal women.

PubMed

Jármy-Di Bella, Z I; Girão, M J; Sartori, M F; Di Bella Júnior, V; Lederman, H M; Baracat, E C; Lima, G R

2000-06-01

Urethral pressure should exceed bladder pressure, both at rest and on stress, for urinary continence to occur. A decrease in urethral pressure is a major factor explaining the pathogenesis of urinary incontinence. A number of elements, such as smooth and striated periurethral muscles, and connective, vascular and elastic tissues, contribute to urethral pressure. The periurethral vessels are influenced by hormonal changes during the menstrual cycle, during pregnancy and postmenopause. We studied the periurethral vessels in 97 women, 57 of whom were incontinent and 40 continent, using power color Doppler velocimetry. The number of periurethral vessels, systolic peak, minimum diastolic values, pulsatility and resistance indexes, as well as systolic-diastolic ratio, were assessed. Statistically significant differences were found between incontinent women in the premenopausal period and those in the postmenopausal period, regarding the number of periurethral vessels, systolic peak, minimum diastolic values, pulsatility and resistance indexes.

Differential diagnosis between benign and malignant soft tissue tumors utilizing ultrasound parameters.

PubMed

Morii, Takeshi; Kishino, Tomonori; Shimamori, Naoko; Motohashi, Mitsue; Ohnishi, Hiroaki; Honya, Keita; Aoyagi, Takayuki; Tajima, Takashi; Ichimura, Shoichi

2018-01-01

Preoperative discrimination between benign and malignant soft tissue tumors is critical for the prevention of excess application of magnetic resonance imaging and biopsy as well as unplanned resection. Although ultrasound, including power Doppler imaging, is an easy, noninvasive, and cost-effective modality for screening soft tissue tumors, few studies have investigated reliable discrimination between benign and malignant soft tissue tumors. To establish a modality for discrimination between benign and malignant soft tissue tumors using ultrasound, we extracted the significant risk factors for malignancy based on ultrasound information from 40 malignant and 56 benign pathologically diagnosed soft tissue tumors and established a scoring system based on these risk factors. The maximum size, tumor margin, and vascularity evaluated using ultrasound were extracted as significant risk factors. Using the odds ratio from a multivariate regression model, a scoring system was established. Receiver operating characteristic analyses revealed a high area under the curve value (0.85), confirming the accuracy of the scoring system. Ultrasound is a useful modality for establishing the differential diagnosis between benign and malignant soft tissue tumors.

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

NASA Technical Reports Server (NTRS)

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 deviation, particularly when combined, appear to be sensitive in predicting the risk for developing childhood HCM. Large-scale, prospective studies are needed to confirm this hypothesis.

Assessment of atrial electromechanical delay and P-wave dispersion in patients with psoriasis.

PubMed

Yildiz, Abdulkadir; Ucmak, Derya; Oylumlu, Mustafa; Akkurt, Meltem Z; Yuksel, Murat; Akil, Mehmet Ata; Acet, Halit; Polat, Nihat; Aydin, Mesut; Bilik, M Zihni

2014-10-01

In this study, we sought to evaluate atrial electromechanical properties and conduction homogeneity by tissue Doppler imaging and electrocardiography in patients with psoriasis. Thirty-four patients with psoriasis and 30 age- and gender-matched healthy controls were included in the study. Atrial electromechanical coupling intervals were assessed by means of tissue Doppler echocardiography and P-wave dispersion (Pd) was calculated from electrocardiogram. A total of 64 subjects (33 male) with a mean age of 36.8 ± 11.9 years were included in the study. Basal characteristics were similar between 2 groups. Intra-atrial (15 ± 7 ms vs. 12 ± 5 ms, P = 0.009) and inter-atrial (28 ± 7 ms vs. 23 ± 7 ms, P = 0.002) electromechanical delays were significantly higher in patients with psoriasis compared with control groups. P-maximum (112 ± 16 ms vs. 103 ± 8 ms, P = 0.006) and Pd (35 ± 9 ms vs. 20 ± 6 ms, P < 0.001) were also prolonged in patients with psoriasis. This study demonstrated that atrial electromechanical coupling intervals and P-wave dispersion were prolonged in patients with psoriasis, which may cause an increased risk of atrial fibrillation in this patient group. © 2014, Wiley Periodicals, Inc.

Modelling and characterisation of a ultrasound-actuated needle for improved visibility in ultrasound-guided regional anaesthesia and tissue biopsy.

PubMed

Kuang, Y; Hilgers, A; Sadiq, M; Cochran, S; Corner, G; Huang, Z

2016-07-01

Clear needle visualisation is recognised as an unmet need for ultrasound guided percutaneous needle procedures including regional anaesthesia and tissue biopsy. With inadequate needle visibility, these procedures may result in serious complications or a failed operation. This paper reports analysis of the modal behaviour of a previously proposed ultrasound-actuated needle configuration, which may overcome this problem by improving needle visibility in colour Doppler imaging. It uses a piezoelectric transducer to actuate longitudinal resonant modes in needles (outer diameter 0.8-1.2mm, length>65mm). The factors that affect the needle's vibration mode are identified, including the needle length, the transducer's resonance frequency and the gripping position. Their effects are investigated using finite element modelling, with the conclusions validated experimentally. The actuated needle was inserted into porcine tissue up to 30mm depth and its visibility was observed under colour Doppler imaging. The piezoelectric transducer is able to generate longitudinal vibration with peak-to-peak amplitude up to 4μm at the needle tip with an actuating voltage of 20Vpp. Actuated in longitudinal vibration modes (distal mode at 27.6kHz and transducer mode at 42.2kHz) with a drive amplitude of 12-14Vpp, a 120mm needle is delineated as a coloured line in colour Doppler images, with both needle tip and shaft visualised. The improved needle visibility is maintained while the needle is advanced into the tissue, thus allowing tracking of the needle position in real time. Moreover, the needle tip is highlighted by strong coloured artefacts around the actuated needle generated by its flexural vibration. A limitation of the technique is that the transducer mode requires needles of specific lengths so that the needle's resonance frequency matches the transducer. This may restrict the choice of needle lengths in clinical applications. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

In Vivo Determination of the Complex Elastic Moduli of Cetacean Head Tissue

DTIC Science & Technology

2009-09-30

remotely generated elastic waves can be detected remotely using a modified version of an ultrasonic Doppler vibration measurement system called NIVMS...developed at Georgia Techiii. Algorithms are being developed to enable the magnitude and phase of vibration to be determined, as well as the range (tissue...depth) along the ultrasonic beam at which the vibration is being measured. By measuring the amplitude and arrival time of the shear wave at two

[Features of the periodontal pathology at patients with metabolic syndrome].

PubMed

Ermolaeva, L A; Shishkin, A N; Sheveleva, N A; Penkovoi, E A; Sheveleva, M A; Sokolovich, N A; Khabarova, O V; Mihailova, E S

2016-01-01

The purpose of this article is to familiarize readers on the relationship between metabolic syndrome and periodontitis, as well as common pathogenetic processes underlying these diseases. The data of modern researches, devoted to the correlation of lesions of periodontal and systemic diseases associated with metabolic syndrome. In the article analyzed also the data of the original study of the interaction of periodontitis and metabolic syndrome, which also used special methods of examination like Doppler ultrasound microcirculatory vasculature of the periodontal tissues and ultrasound densitometry. The possible methods of diagnostics of a condition of periodontal tissues in patients with metabolic syndrome are considered. Conclusions about the relationship of each component of metabolic syndrome with periodontitis are made.

High-Resolution Tissue Doppler Imaging of the Zebrafish Heart During Its Regeneration

PubMed Central

Su, Ta-Han; Shih, Cho-Chiang

2015-01-01

Abstract 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. PMID:25517185

Diastolic dysfunction is associated with insulin resistance, but not with aldosterone level in normotensive offspring of hypertensive families.

PubMed

Zizek, Bogomir; Poredos, Pavel; Trojar, Andrej; Zeljko, Tadej

2008-01-01

We investigated left ventricular (LV) morphology and function in association with insulin level/insulin resistance (IR) and aldosterone level in normotensive offspring of subjects with essential hypertension (familial trait, FT). The study encompassed 76 volunteers of whom 44 were normotensive with FT (aged 28-39 years) and 32 age-matched controls without FT. LV mass and function were measured using conventional echocardiography and tissue Doppler imaging. LV diastolic function was reported as peak septal annular velocities (E(m) and E(m)/A(m) ratio) in tissue Doppler imaging. Fasting insulin and aldosterone were determined. In subjects with FT, the LV mass was higher than in controls (92.14 +/- 24.02 vs. 70.08 +/- 20.58 g; p < 0.001). The study group had a worse LV diastolic function than control subjects (lower E(m) and E(m)/A(m) ratio; p < 0.001). In subjects with FT, the E(m)/A(m) ratio was independently associated with IR (partial p = 0.029 in multivariate model, R(2) = 0.51), but not with LV mass. The aldosterone level was comparable in both groups. In normotensive individuals with FT, LV morphological and functional abnormalities were found. LV dysfunction but not an increase in LV mass is associated with IR. The aldosterone level is probably not responsible for the development of early hypertensive heart disease. (c) 2008 S. Karger AG, Basel.

Maternal Serum Endocan Concentration in Pregnancies Complicated by Intrauterine Growth Restriction.

PubMed

Szpera-Gozdziewicz, Agata; Kosicka, Katarzyna; Gozdziewicz, Tomasz; Krzyscin, Mariola; Wirstlein, Przemyslaw; Siemiatkowska, Anna; Glowka, Franciszek; Wender-Ozegowska, Ewa; Breborowicz, Grzegorz H

2018-01-01

Endocan plays a role in the development of vascular tissue in health and disease and is an indicator of endothelial cells activation and angiogenesis. Therefore, this study aimed to investigate the relationship between maternal endocan serum level and intrauterine growth restriction (IUGR) as well as ultrasound Doppler flow measurements indicating placental insufficiency. This study included a group of women with IUGR (n = 37) and a group of healthy pregnant women (controls, n = 37). The endocan serum concentrations were assessed using commercially available enzyme-linked immunosorbent assay kit. Every woman underwent an ultrasound examination with Doppler flow measurements of the uterine arteries, umbilical vessels, and fetal middle cerebral artery. We used the cerebroplacental ratio (CPR) to determine placental insufficiency. We found significant differences in median (interquartile) endocan serum level (pg/mL) between study and control groups (464 [374-532] vs 339 [189-496], respectively; P < .001). The endocan serum level correlated neither with umbilical cord blood gases nor with Apgar score. Ultrasound Doppler findings revealed significant differences in middle cerebral artery pulsatility index (PI), umbilical artery PI, CPR, as well as mean uterine arteries PI between IUGR group and controls. In the study group, we found significant correlations between the serum endocan and CPR ( R = 0.56, P < .001) as well as between serum endocan and mean uterine arteries PI ( R = 0.46, P = .006). Endocan is likely involved in the pathogenesis of IUGR in pregnant women and possibly is a useful marker of endothelial dysfunction in these cases.

Propagating Neural Source Revealed by Doppler Shift of Population Spiking Frequency

PubMed Central

Zhang, Mingming; Shivacharan, Rajat S.; Chiang, Chia-Chu; Gonzalez-Reyes, Luis E.

2016-01-01

Electrical activity in the brain during normal and abnormal function is associated with propagating waves of various speeds and directions. It is unclear how both fast and slow traveling waves with sometime opposite directions can coexist in the same neural tissue. By recording population spikes simultaneously throughout the unfolded rodent hippocampus with a penetrating microelectrode array, we have shown that fast and slow waves are causally related, so a slowly moving neural source generates fast-propagating waves at ∼0.12 m/s. The source of the fast population spikes is limited in space and moving at ∼0.016 m/s based on both direct and Doppler measurements among 36 different spiking trains among eight different hippocampi. The fact that the source is itself moving can account for the surprising direction reversal of the wave. Therefore, these results indicate that a small neural focus can move and that this phenomenon could explain the apparent wave reflection at tissue edges or multiple foci observed at different locations in neural tissue. SIGNIFICANCE STATEMENT The use of novel techniques with an unfolded hippocampus and penetrating microelectrode array to record and analyze neural activity has revealed the existence of a source of neural signals that propagates throughout the hippocampus. The source itself is electrically silent, but its location can be inferred by building isochrone maps of population spikes that the source generates. The movement of the source can also be tracked by observing the Doppler frequency shift of these spikes. These results have general implications for how neural signals are generated and propagated in the hippocampus; moreover, they have important implications for the understanding of seizure generation and foci localization. PMID:27013678

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

PubMed

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.

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

PubMed

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.

Effects of sedation on echocardiographic variables of left atrial and left ventricular function in healthy cats.

PubMed

Ward, Jessica L; Schober, Karsten E; Fuentes, Virginia Luis; Bonagura, John D

2012-10-01

Although sedation is frequently used to facilitate patient compliance in feline echocardiography, the effects of sedative drugs on echocardiographic variables have been poorly documented. This study investigated the effects of two sedation protocols on echocardiographic indices in healthy cats, with special emphasis on the assessment of left atrial size and function, as well as left ventricular diastolic performance. Seven cats underwent echocardiography (transthoracic two-dimensional, spectral Doppler, color flow Doppler and tissue Doppler imaging) before and after sedation with both acepromazine (0.1 mg/kg IM) and butorphanol (0.25 mg/kg IM), or acepromazine (0.1 mg/kg IM), butorphanol (0.25 mg/kg IM) and ketamine (1.5 mg/kg IV). Heart rate increased significantly following acepromazine/butorphanol/ketamine (mean±SD of increase, 40±26 beats/min) and non-invasive systolic blood pressure decreased significantly following acepromazine/butorphanol (mean±SD of decrease, 12±19 mmHg). The majority of echocardiographic variables were not significantly different after sedation compared with baseline values. Both sedation protocols resulted in mildly decreased left ventricular end-diastolic dimension and mildly increased left ventricular end-diastolic wall thickness. This study therefore failed to demonstrate clinically meaningful effects of these sedation protocols on echocardiographic measurements, suggesting that sedation with acepromazine, butorphanol and/or ketamine can be used to facilitate echocardiography in healthy cats.

Full-field high-speed laser Doppler imaging system for blood-flow measurements

NASA Astrophysics Data System (ADS)

Serov, Alexandre; Lasser, Theo

2006-02-01

We describe the design and performance of a new full-field high-speed laser Doppler imaging system developed for mapping and monitoring of blood flow in biological tissue. The total imaging time for 256x256 pixels region of interest is 1.2 seconds. An integrating CMOS image sensor is utilized to detect Doppler signal in a plurality of points simultaneously on the sample illuminated by a divergent laser beam of a uniform intensity profile. The integrating property of the detector improves the signal-to-noise ratio of the measurement, which results in high-quality flow-images provided by the system. The new technique is real-time, non-invasive and the instrument is easy to use. The wide range of applications is one of the major challenges for a future application of the imager. High-resolution high-speed laser Doppler perfusion imaging is a promising optical technique for diagnostic and assessing the treatment effect of the diseases such as e.g. atherosclerosis, psoriasis, diabetes, skin cancer, allergies, peripheral vascular diseases, skin irritancy and wound healing. We present some biological applications of the new imager and discuss the perspectives for the future implementations of the imager for clinical and physiological applications.

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

PubMed Central

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

2014-01-01

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

Two-dimensional strain profiles in patients with physiological and pathological hypertrophy and preserved left ventricular systolic function: a comparative analyses.

PubMed

Afonso, Luis; Kondur, Ashok; Simegn, Mengistu; Niraj, Ashutosh; Hari, Pawan; Kaur, Ramanjit; Ramappa, Preeti; Pradhan, Jyotiranjan; Bhandare, Deepti; Williams, Kim A; Zalawadiya, Sandip; Pinheiro, Aurelio; Abraham, Theodore P

2012-01-01

This study was designed to examine the utility of two-dimensional strain (2DS) or speckle tracking imaging to typify functional adaptations of the left ventricle in variant forms of left ventricular hypertrophy (LVH). Cross-sectional study. Urban tertiary care academic medical centres. A total of 129 subjects, 56 with hypertrophic cardiomyopathy (HCM), 34 with hypertensive left ventricular hypertrophy (H-LVH), 27 professional athletes with LVH (AT-LVH) and 12 healthy controls in sinus rhythm with preserved left ventricular systolic function. Conventional echocardiographic and tissue Doppler examinations were performed in all study subjects. Bi-dimensional acquisitions were analysed to map longitudinal systolic strain (automated function imaging, AFI, GE Healthcare, Waukesha, Wisconsin, USA) from apical views. Subjects with HCM had significantly lower regional and average global peak longitudinal systolic strain (GLS-avg) compared with controls and other forms of LVH. Strain dispersion index, a measure of regional contractile heterogeneity, was higher in HCM compared with the rest of the groups. On receiver operator characteristics analysis, GLS-avg had excellent discriminatory ability to distinguish HCM from H-LVH area under curve (AUC) (0.893, p<0.001) or AT-LVH AUC (0.920, p<0.001). Tissue Doppler and LV morphological parameters were better suited to differentiate the athlete heart from HCM. 2DS (AFI) allows rapid characterisation of regional and global systolic function and may have the potential to differentiate HCM from variant forms of LVH.

Tissue viability imaging: microvascular response to vasoactive drugs induced by iontophoresis.

PubMed

Henricson, Joakim; Nilsson, Anders; Tesselaar, Erik; Nilsson, Gert; Sjöberg, Folke

2009-09-01

When one is studying the physiology of the cutaneous microcirculation there is a need for relevant non-invasive and versatile techniques. In this study we used a new optical device, the tissue viability imager (TiVi), to map changes in cutaneous microvascular concentrations of red blood cells during iontophoresis of vasoactive substances (noradrenaline (NA) and phenylephrine (Phe) for vasoconstriction and acetylcholine (ACh) and sodium nitroprusside (SNP) for vasodilatation). We aimed to present data both individually and pooled, using a four-variable logistic dose response model that is commonly used in similar in vitro vascular studies. The accuracy of the TiVi was also investigated by calculating the coefficient of variation and comparing it with similar tests previously done using laser Doppler imaging. Tests were also performed using the TiVi and LDPI simultaneously to further compare the two methods. Results showed that the TiVi is capable of quantifying vascular responses to iontophorised noradrenaline and phenylephrine without the need to increase background flow first. Fitting the TiVi data to the dose response model resulted in ED(50)-values with narrow confidence intervals and acceptable r(2) values. Mean ED(50)-values for the TiVi did not differ significantly from similar values obtained using laser Doppler. Results further seem to suggest that when the blood perfusion increases during vasodilatation in skin the initial phase relies mainly on an increase in red blood cell concentration whereas the further perfusion increase is due to an increase in red blood cell velocity.

Ultrastructural and cellular basis for the development of abnormal myocardial mechanics during the transition from hypertension to heart failure.

PubMed

Shah, Sanjiv J; Aistrup, Gary L; Gupta, Deepak K; O'Toole, Matthew J; Nahhas, Amanda F; Schuster, Daniel; Chirayil, Nimi; Bassi, Nikhil; Ramakrishna, Satvik; Beussink, Lauren; Misener, Sol; Kane, Bonnie; Wang, David; Randolph, Blake; Ito, Aiko; Wu, Megan; Akintilo, Lisa; Mongkolrattanothai, Thitipong; Reddy, Mahendra; Kumar, Manvinder; Arora, Rishi; Ng, Jason; Wasserstrom, J Andrew

2014-01-01

Although the development of abnormal myocardial mechanics represents a key step during the transition from hypertension to overt heart failure (HF), the underlying ultrastructural and cellular basis of abnormal myocardial mechanics remains unclear. We therefore investigated how changes in transverse (T)-tubule organization and the resulting altered intracellular Ca(2+) cycling in large cell populations underlie the development of abnormal myocardial mechanics in a model of chronic hypertension. Hearts from spontaneously hypertensive rats (SHRs; n = 72) were studied at different ages and stages of hypertensive heart disease and early HF and were compared with age-matched control (Wistar-Kyoto) rats (n = 34). Echocardiography, including tissue Doppler and speckle-tracking analysis, was performed just before euthanization, after which T-tubule organization and Ca(2+) transients were studied using confocal microscopy. In SHRs, abnormalities in myocardial mechanics occurred early in response to hypertension, before the development of overt systolic dysfunction and HF. Reduced longitudinal, circumferential, and radial strain as well as reduced tissue Doppler early diastolic tissue velocities occurred in concert with T-tubule disorganization and impaired Ca(2+) cycling, all of which preceded the development of cardiac fibrosis. The time to peak of intracellular Ca(2+) transients was slowed due to T-tubule disruption, providing a link between declining cell ultrastructure and abnormal myocardial mechanics. In conclusion, subclinical abnormalities in myocardial mechanics occur early in response to hypertension and coincide with the development of T-tubule disorganization and impaired intracellular Ca(2+) cycling. These changes occur before the development of significant cardiac fibrosis and precede the development of overt cardiac dysfunction and HF.

Semiquantitative Evaluation of Extrasynovial Soft Tissue Inflammation in the Shoulders of Patients with Polymyalgia Rheumatica and Elderly-Onset Rheumatoid Arthritis by Power Doppler Ultrasound.

PubMed

Suzuki, Takeshi; 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.

The use of contrasted transvaginal sonography in the diagnosis of gynecologic diseases: a preliminary study.

PubMed

Testa, Antonia Carla; Ferrandina, Gabriella; Fruscella, Erika; Van Holsbeke, Caroline; Ferrazzi, Enrico; Leone, Francesco P G; Arduini, Domenico; Exacoustos, Caterina; Bokor, Daniela; Scambia, Giovanni; Timmerman, Dirk

2005-09-01

The purpose of this study was to evaluate the efficacy of a new contrast-dedicated ultrasound technology, contrast-tuned imaging (CnTI), implemented on an endovaginal probe and using the second-generation contrast agent SonoVue (Bracco International BV, Amsterdam, the Netherlands), compared with the standard ultrasound examination in different gynecologic diseases. Eighty-nine patients were enrolled in the study in 4 different clinical centers. The study included 40 patients with uncertain pelvic adnexal masses, 10 patients with pelvic masses indicative of recurrences of gynecologic tumors, 26 patients with uterine pathologic features, and 13 patients with cervical lesions. Application of CnTI technology after the SonoVue injection gave a picture of the intralesional microvascularization dramatically different from that obtained during color Doppler examination. Of the 40 pelvic masses, 15 (37.5%) were considered benign and 25 (62.5%) were considered malignant at B-mode and color Doppler examinations. Contrast-enhanced sonography showed no intralesional contrast perfusion in 11 (73%) of 15 cases, and all these were benign at final diagnosis. Of the 4 (27%) cases that had perfusion, 2 were malignant. Conversely, of the 25 cases with positive findings at color Doppler examination and therefore expected to show the appearance of contrast tissue-filling morphologic characteristics, 13 (52%) were malignant at final diagnosis. For evaluation of uterine pathologic features, the CnTI-SonoVue technology did not appear to be superior to the B-mode and color Doppler examinations; however, for the evaluation of cervical cancer, CnTI-SonoVue technology revealed a better definition of the margins of the neoplastic lesions in 4 (40%) of 10 cases. In the evaluation of uncertain pelvic masses, the CnTI technology led to an improvement in the ability of the practitioner to differentiate benign from malignant adnexal lesions.

Analysis of the individual risk of altitude decompression sickness under repeated exposures

NASA Technical Reports Server (NTRS)

Kumar, K. Vasantha; Horrigan, David J.; Waligora, James M.; Gilbert, John H.

1991-01-01

In a case-control study, researchers examined the risk of decompression sickness (DCS) in individual subjects with higher number of exposures. Of the 126 subjects, 42 showed one or more episodes of DCS. Examination of the exposure-DCS relationship by odds ratio showed a linear relationship. Stratification analysis showed that sex, tissue ratio, and the presence of Doppler microbubbles were cofounders of this risk. A higher number of exposures increased the risk of DCS in this analysis.

Power and color Doppler ultrasound settings for inflammatory flow: impact on scoring of disease activity in patients with rheumatoid arthritis.

PubMed

Torp-Pedersen, Søren; Christensen, Robin; Szkudlarek, Marcin; Ellegaard, Karen; D'Agostino, Maria Antonietta; Iagnocco, Annamaria; Naredo, Esperanza; Balint, Peter; Wakefield, Richard J; Torp-Pedersen, Arendse; Terslev, Lene

2015-02-01

To determine how settings for power and color Doppler ultrasound sensitivity vary on different high- and intermediate-range ultrasound machines and to evaluate the impact of these changes on Doppler scoring of inflamed joints. Six different types of ultrasound machines were used. On each machine, the factory setting for superficial musculoskeletal scanning was used unchanged for both color and power Doppler modalities. The settings were then adjusted for increased Doppler sensitivity, and these settings were designated study settings. Eleven patients with rheumatoid arthritis (RA) with wrist involvement were scanned on the 6 machines, each with 4 settings, generating 264 Doppler images for scoring and color quantification. Doppler sensitivity was measured with a quantitative assessment of Doppler activity: color fraction. Higher color fraction indicated higher sensitivity. Power Doppler was more sensitive on half of the machines, whereas color Doppler was more sensitive on the other half, using both factory settings and study settings. There was an average increase in Doppler sensitivity, despite modality, of 78% when study settings were applied. Over the 6 machines, 2 Doppler modalities, and 2 settings, the grades for each of 7 of the patients varied between 0 and 3, while the grades for each of the other 4 patients varied between 0 and 2. The effect of using different machines, Doppler modalities, and settings has a considerable influence on the quantification of inflammation by ultrasound in RA patients, and this must be taken into account in multicenter studies. Copyright © 2015 by the American College of Rheumatology.

P1033Echocardiographic predictive model of new-onset postoperative atrial fibrillation after abdominal surgery.

PubMed

Demirevska, L; Gotchev, D

2016-12-01

and purpose: Postoperative atrial fibrillation (POAF) is a frequent complication post high-risk abdominal surgery in elderly patients. This study aimed to develop a predictive model of POAF based on preoperative transthoracic echocardiography (TTE) findings in these patients. We conducted a prospective study of 300 consecutive patients, age ≥ 65 years (mean age 72±6 years, 61% men), who underwent high-risk abdominal surgery under general anesthesia. Preoperative TTE was performed in all patients, including tissue Doppler imaging (TDI). We measured the time interval between the onset of the P-wave on ECG and a point of the peak-A wave on TDI from the lateral mitral annulus (PA lateral) and septal mitral annulus (PA septal). Left atrial (LA) dyssynchrony was measured by subtracting the PA septal from PA lateral. Right ventricular systolic pressure was estimated by using the tricuspid regurgitation jet (TRJ) Doppler velocity method. The primary endpoint was the occurance of new-onset POAF. Thirty-seven (12%) patients developed POAF. Multiple echocardiographic parameters were measured and tested in different combinations. The final model included the following variables with cutoff points predictive of POAF: PA lateral > 139 ms (69% sensitivity, 92% specificity), LA dyssynchrony > 35 ms (78% sensitivity, 89% specificity), and TRJ Doppler velocity >2.6 m/s (89% sensitivity, 64% specificity). A value of 0 was assigned when the result was below the cutoff point and a value of 1 if above the cutoff point. Coding of these three variables in the following order: PA lateral- TRJ Doppler- left atrial dyssynchrony can predict the probability of POAF. The model showed a postive predictive value of 79% and a negative predictive value of 95%. A model using three echocardiographic variables: PA lateral, LA dyssynchrony and TRJ Doppler velocity, can predict the incidence of POAF after high-risk abdominal surgery. The model can be used preoperatively to identify high-risk patients that would need aggressive prophylactic treatment. PA lateral >139 ms-TRJ Doppler velocity >2.6 m/s-LA dyssynchrony >35 msProbability of POAF0- 0- 0; 0- 1- 0No0- 0- 1; 0- 1- 1; 1- 0- 0; 1- 0- 1; 1- 1- 0; 1- 1- 1Yes. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: Journals.permissions@oup.com.

Light-induced fluorescence for pulpal diagnosis

NASA Astrophysics Data System (ADS)

Ebihara, Arata; Liaw, Lih-Huei L.; Krasieva, Tatiana B.; Wilder-Smith, Petra B. B.

2001-04-01

A direct non-histological means of pulpal diagnosis remains elusive to clinical practice. Clinical vitality testing remains limited to electric, thermal criteria, or laser Doppler flowmetry. The goal of these investigations was to determine the feasibility of using light-induced fluorescence as a non-invasive modality for pulpal evaluation. Such a capability would, for example, permit expanded use of pulpotomy/pulpectomy techniques. Clinically healthy and diseased human extirpated pulpal tissues were used in this study. After excision, they were rapidly frozen and standard cryosections prepared. Measurement of tissue excitation/emission characteristics was performed using spectrographic analysis. A low-light level fluorescence microscopy system was then used to image autofluorescence localization and intensity at optimal excitation/detection parameters. Excitation/detection parameters used in this study included 405/605, 405/635, 405/670, 440/550, and 440/635. Autofluorescence intensities in healthy tissues were significantly stronger than those in diseased tissues at optimal parameters. It is postulated that autofluorescence characteristics are related to pathology- related structural changes in the pulp. This work provides the basis for further investigation into the relation between autofluorescence, histology and clinical symptoms.

Destructive effect of HIFU on rabbit embedded endometrial carcinoma tissues and their vascularities

PubMed Central

Guan, Liming; Xu, Gang

2017-01-01

Objectives To evaluate damage effect of High-intensity focused ultrasound on early stage endometrial cancer tissues and their vascularities. Materials and Methods Rabbit endometrial cancer models were established via tumor blocks implantation for a prospective control study. Ultrasonic ablation efficacy was evaluated by pathologic and imaging changes. The target lesions of experimental rabbits before and after ultrasonic ablation were observed after autopsy. The slides were used for hematoxylin-eosin staining, elastic fiber staining and endothelial cell staining; the slides were observed by optical microscopy. One slide was observed by electron microscopy. Then the target lesions of experimental animals with ultrasonic ablation were observed by vascular imaging, one group was visualized by digital subtract angiography, one group was quantified by color Doppler flow imaging, and one group was detected by dye perfusion. SPSS 19.0 software was used for statistical analyses. Results Histological examination indicated that High-intensity focused ultrasound caused the tumor tissues and their vascularities coagulative necrosis. Tumor vascular structure components including elastic fiber, endothelial cells all were destroyed by ultrasonic ablation. Digital subtract angiography showed tumor vascular shadow were dismissed after ultrasonic ablation. After ultrasonic ablation, gray-scale of tumor nodules enhanced in ultrasonography, tumor peripheral and internal blood flow signals disappeared or significantly reduced in color Doppler flow imaging. Vascular perfusion performed after ultrasonic ablation, tumor vessels could not filled by dye liquid. Conclusion High-intensity focused ultrasound as a noninvasive method can destroy whole endometrial cancer cells and their supplying vascularities, which maybe an alternative approach of targeted therapy and new antiangiogenic strategy for endometrial cancer. PMID:28121624

Destructive effect of HIFU on rabbit embedded endometrial carcinoma tissues and their vascularities.

PubMed

Guan, Liming; Xu, Gang

2017-03-21

To evaluate damage effect of High-intensity focused ultrasound on early stage endometrial cancer tissues and their vascularities. Rabbit endometrial cancer models were established via tumor blocks implantation for a prospective control study. Ultrasonic ablation efficacy was evaluated by pathologic and imaging changes. The target lesions of experimental rabbits before and after ultrasonic ablation were observed after autopsy. The slides were used for hematoxylin-eosin staining, elastic fiber staining and endothelial cell staining; the slides were observed by optical microscopy. One slide was observed by electron microscopy. Then the target lesions of experimental animals with ultrasonic ablation were observed by vascular imaging, one group was visualized by digital subtract angiography, one group was quantified by color Doppler flow imaging, and one group was detected by dye perfusion.SPSS 19.0 software was used for statistical analyses. Histological examination indicated that High-intensity focused ultrasound caused the tumor tissues and their vascularities coagulative necrosis. Tumor vascular structure components including elastic fiber, endothelial cells all were destroyed by ultrasonic ablation. Digital subtract angiography showed tumor vascular shadow were dismissed after ultrasonic ablation. After ultrasonic ablation, gray-scale of tumor nodules enhanced in ultrasonography, tumor peripheral and internal blood flow signals disappeared or significantly reduced in color Doppler flow imaging. Vascular perfusion performed after ultrasonic ablation, tumor vessels could not filled by dye liquid. High-intensity focused ultrasound as a noninvasive method can destroy whole endometrial cancer cells and their supplying vascularities, which maybe an alternative approach of targeted therapy and new antiangiogenic strategy for endometrial cancer.

Invasive and noninvasive assessment of pulmonic regurgitation: clinical, angiographic, phonocardiographic, echocardiographic, and Doppler ultrasound correlations.

PubMed

Chandraratna, P A; Wilson, D; Imaizumi, T; Ritter, W S; Aronow, W S

1982-06-01

Three patients with pulmonic regurgitation and no evidence of pulmonary hypertension were investigated. These patients had low pitched diastolic murmurs which increased on inspiration, evidence of connective tissue disease as manifested by lax joints and hyperextensible skin, and marked hilar dance which extended up to the peripheral vessels. Suprasternal echocardiography revealed dilatation and increased systolic expansion of the right pulmonary artery (RPA) (25% and 28%, respectively) in two patients; the third patient had a normal RPA dimension in diastole and a marked increase in diameter (88%) in systole. Thus, these three patients demonstrated hyperdistensibility of the RPA. The spectral signal from the pulsed doppler echocardiograph showed evidence of turbulent blood flow in diastole (wide dispersion of the dots) in the right ventricular outflow tract in all three patients. This pattern was indicative of pulmonic regurgitation. In summary, the combined use of echocardiography and Doppler ultrasound is useful in the evaluation of patients with pulmonic regurgitation.

Assessment of Spectral Doppler in Preclinical Ultrasound Using a Small-Size Rotating Phantom

PubMed Central

Yang, Xin; Sun, Chao; Anderson, Tom; Moran, Carmel M.; Hadoke, Patrick W.F.; Gray, Gillian A.; Hoskins, Peter R.

2013-01-01

Preclinical ultrasound scanners are used to measure blood flow in small animals, but the potential errors in blood velocity measurements have not been quantified. This investigation rectifies this omission through the design and use of phantoms and evaluation of measurement errors for a preclinical ultrasound system (Vevo 770, Visualsonics, Toronto, ON, Canada). A ray model of geometric spectral broadening was used to predict velocity errors. A small-scale rotating phantom, made from tissue-mimicking material, was developed. True and Doppler-measured maximum velocities of the moving targets were compared over a range of angles from 10° to 80°. Results indicate that the maximum velocity was overestimated by up to 158% by spectral Doppler. There was good agreement (<10%) between theoretical velocity errors and measured errors for beam-target angles of 50°–80°. However, for angles of 10°–40°, the agreement was not as good (>50%). The phantom is capable of validating the performance of blood velocity measurement in preclinical ultrasound. PMID:23711503

Computed estimates of maximum temperature elevations in fetal tissues during transabdominal pulsed Doppler examinations.

PubMed

Bly, S H; Vlahovich, S; Mabee, P R; Hussey, R G

1992-01-01

Measured characteristics of ultrasonic fields were obtained in submissions from manufacturers of diagnostic ultrasound equipment for devices operating in pulsed Doppler mode. Simple formulae were used with these data to generate upper limits to fetal temperature elevations, delta Tlim, during a transabdominal pulsed Doppler examination. A total of 236 items were analyzed, each item being a console/transducer/operating-mode/intended-use combination, for which the spatial-peak temporal-average intensity, ISPTA, was greater than 500 mW cm-2. The largest calculated delta Tlim values were approximately 1.5, 7.1 and 8.7 degrees C for first-, second- and third-trimester examinations, respectively. The vast majority of items yielded delta Tlim values which were less than 1 degree C in the first trimester. For second- and third-trimester examinations, where heating of fetal bone determines delta Tlim, most delta Tlim values were less than 4 degrees C. The clinical significance of the results is discussed.

Functional optical coherence tomography: principles and progress

NASA Astrophysics Data System (ADS)

Kim, Jina; Brown, William; Maher, Jason R.; Levinson, Howard; Wax, Adam

2015-05-01

In the past decade, several functional extensions of optical coherence tomography (OCT) have emerged, and this review highlights key advances in instrumentation, theoretical analysis, signal processing and clinical application of these extensions. We review five principal extensions: Doppler OCT (DOCT), polarization-sensitive OCT (PS-OCT), optical coherence elastography (OCE), spectroscopic OCT (SOCT), and molecular imaging OCT. The former three have been further developed with studies in both ex vivo and in vivo human tissues. This review emphasizes the newer techniques of SOCT and molecular imaging OCT, which show excellent potential for clinical application but have yet to be well reviewed in the literature. SOCT elucidates tissue characteristics, such as oxygenation and carcinogenesis, by detecting wavelength-dependent absorption and scattering of light in tissues. While SOCT measures endogenous biochemical distributions, molecular imaging OCT detects exogenous molecular contrast agents. These newer advances in functional OCT broaden the potential clinical application of OCT by providing novel ways to understand tissue activity that cannot be accomplished by other current imaging methodologies.

Functional Optical Coherence Tomography: Principles and Progress

PubMed Central

Kim, Jina; Brown, William; Maher, Jason R.; Levinson, Howard; Wax, Adam

2015-01-01

In the past decade, several functional extensions of optical coherence tomography (OCT) have emerged, and this review highlights key advances in instrumentation, theoretical analysis, signal processing and clinical application of these extensions. We review five principal extensions: Doppler OCT (DOCT), polarization-sensitive OCT (PS-OCT), optical coherence elastography (OCE), spectroscopic OCT (SOCT), and molecular imaging OCT. The former three have been further developed with studies in both ex vivo and in vivo human tissues. This review emphasizes the newer techniques of SOCT and molecular imaging OCT, which show excellent potential for clinical application but have yet to be well reviewed in the literature. SOCT elucidates tissue characteristics, such as oxygenation and carcinogenesis, by detecting wavelength-dependent absorption and scattering of light in tissues. While SOCT measures endogenous biochemical distributions, molecular imaging OCT detects exogenous molecular contrast agents. These newer advances in functional OCT broaden the potential clinical application of OCT by providing novel ways to understand tissue activity that cannot be accomplished by other current imaging methodologies. PMID:25951836

Application of optical non-invasive methods to diagnose the state of the lower limb tissues in patients with diabetes mellitus

NASA Astrophysics Data System (ADS)

Zharkikh, E. V.; Dremin, V. V.; Filina, M. A.; Makovik, I. N.; Potapova, E. V.; Zherebtsov, E. A.; Zherebtsova, A. I.; Dunaev, A. V.

2017-11-01

The paper shows the possibility of assessing the functional state of microcirculatory-tissue systems of patients with diabetes mellitus by laser Doppler flowmetry (LDF), diffuse reflectance spectroscopy (DRS) and fluorescence spectroscopy (FS) methods. A review of the existing non-invasive optical technologies used to assess the state of microcirculation and oxygen metabolism in tissues of patients with diabetes is conducted. A series of experimental studies involving 76 patients with diabetes and 46 healthy volunteers was carried out. A wavelet analysis of LDF-grams was used to evaluate the adaptive changes of microcirculation during the temperature tests. The obtained data revealed that the proposed methodology in the form of combined use of several diagnostic technologies (LDF, FS and DRS) allows us to detect the presence or absence of trophic disorders and to evaluate adaptation processes during thermal tests.

Advanced Doppler radar physiological sensing technique for drone detection

NASA Astrophysics Data System (ADS)

Yoon, Ji Hwan; Xu, Hao; Garcia Carrillo, Luis R.

2017-05-01

A 24 GHz medium-range human detecting sensor, using the Doppler Radar Physiological Sensing (DRPS) technique, which can also detect unmanned aerial vehicles (UAVs or drones), is currently under development for potential rescue and anti-drone applications. DRPS systems are specifically designed to remotely monitor small movements of non-metallic human tissues such as cardiopulmonary activity and respiration. Once optimized, the unique capabilities of DRPS could be used to detect UAVs. Initial measurements have shown that DRPS technology is able to detect moving and stationary humans, as well as largely non-metallic multi-rotor drone helicopters. Further data processing will incorporate pattern recognition to detect multiple signatures (motor vibration and hovering patterns) of UAVs.

SHEAR WAVE DISPERSION MEASURES LIVER STEATOSIS

PubMed Central

Barry, Christopher T.; Mills, Bradley; Hah, Zaegyoo; Mooney, Robert A.; Ryan, Charlotte K.; Rubens, Deborah J.; Parker, Kevin J.

2012-01-01

Crawling waves, which are interfering shear wave patterns, can be generated in liver tissue over a range of frequencies. Some important biomechanical properties of the liver can be determined by imaging the crawling waves using Doppler techniques and analyzing the patterns. We report that the dispersion of shear wave velocity and attenuation, that is, the frequency dependence of these parameters, are strongly correlated with the degree of steatosis in a mouse liver model, ex vivo. The results demonstrate the possibility of assessing liver steatosis using noninvasive imaging methods that are compatible with color Doppler scanners and, furthermore, suggest that liver steatosis can be separated from fibrosis by assessing the dispersion or frequency dependence of shear wave propagations. PMID:22178165

Temporal Doppler Effect and Future Orientation: Adaptive Function and Moderating Conditions.

PubMed

Gan, Yiqun; Miao, Miao; Zheng, Lei; Liu, Haihua

2017-06-01

The objectives of this study were to examine whether the temporal Doppler effect exists in different time intervals and whether certain individual and environmental factors act as moderators of the effect. Using hierarchical linear modeling, we examined the existence of the temporal Doppler effect and the moderating effect of future orientation among 139 university students (Study 1), and then the moderating conditions of the temporal Doppler effect using two independent samples of 143 and 147 university students (Studies 2 and 3). Results indicated that the temporal Doppler effect existed in all of our studies, and that future orientation moderated the temporal Doppler effect. Further, time interval perception mediated the relationship between future orientation and the motivation to cope at long time intervals. Finally, positive affect was found to enhance the temporal Doppler effect, whereas control deprivation did not influence the effect. The temporal Doppler effect is moderated by the personality trait of future orientation and by the situational variable of experimentally manipulated positive affect. We have identified personality and environmental processes that could enhance the temporal Doppler effect, which could be valuable in cases where attention to a future task is necessary. © 2016 Wiley Periodicals, Inc.

Wavelet-analysis of gastric microcirculation in rats with ulcer bleedings

NASA Astrophysics Data System (ADS)

Pavlov, A. N.; Semyachkina-Glushkovskaya, O. V.; Pavlova, O. N.; Bibikova, O. A.; Kurths, J.

2013-10-01

Nitric oxide (NO) plays an important role in regulation of central and peripheral circulation in normal state and during hemorrhagic stress. Because the impaired gastric mucosal blood flow is the major cause of gastroduodenal lesions including ulcer bleeding (UB), we study in this work the NO-ergic mechanism responsible for regulation of this blood flow. Our study is performed in rats with a model of stress-induced UB using laser Doppler flowmetry (LDF) that characterizes the rate of blood flow by measuring a Doppler shift of the laser beam scattered by the moving red blood cells. Numerical analysis of LDF-data is based on the discrete wavelet-transform (DWT) using Daubechies wavelets aiming to quantify influences of NO on the gastric microcirculation. We show that the stress-induced UB is associated with an increased level of NO in the gastric tissue and a stronger vascular sensitivity to pharmacological modulation of NO-production by L-NAME. We demonstrate that wavelet-based analyses of NO-dependent regulation of gastric microcirculation can provide an effective endoscopic diagnostics of a risk of UB.

Prognostic accuracy of cerebroplacental ratio and middle cerebral artery Doppler for adverse perinatal outcome: systematic review and meta‐analysis

PubMed Central

De Boer, M. A.; Heymans, M. W.; Schoonmade, L. J.; Bossuyt, P. M. M.; Mol, B. W. J.; De Groot, C. J. M.; Bax, C. J.

2018-01-01

ABSTRACT Objective Doppler ultrasonographic assessment of the cerebroplacental ratio (CPR) and middle cerebral artery (MCA) is widely used as an adjunct to umbilical artery (UA) Doppler to identify fetuses at risk of adverse perinatal outcome. However, reported estimates of its accuracy vary considerably. The aim of this study was to review systematically the prognostic accuracies of CPR and MCA Doppler in predicting adverse perinatal outcome, and to compare these with UA Doppler, in order to identify whether CPR and MCA Doppler evaluation are of added value to UA Doppler. Methods PubMed, EMBASE, the Cochrane Library and ClinicalTrials.gov were searched, from inception to June 2016, for studies on the prognostic accuracy of UA Doppler compared with CPR and/or MCA Doppler in the prediction of adverse perinatal outcome in women with a singleton pregnancy of any risk profile. Risk of bias and concerns about applicability were assessed using the QUADAS‐2 (Quality Assessment of Diagnostic Accuracy Studies‐2) tool. Meta‐analysis was performed for multiple adverse perinatal outcomes. Using hierarchal summary receiver–operating characteristics meta‐regression models, the prognostic accuracy of CPR vs MCA Doppler was compared indirectly, and CPR and MCA Doppler vs UA Doppler compared directly. Results The search identified 4693 articles, of which 128 studies (involving 47 748 women) were included. Risk of bias or suboptimal reporting was detected in 120/128 studies (94%) and substantial heterogeneity was found, which limited subgroup analyses for fetal growth and gestational age. A large variation was observed in reported sensitivities and specificities, and in thresholds used. CPR outperformed UA Doppler in the prediction of composite adverse outcome (as defined in the included studies) (P < 0.001) and emergency delivery for fetal distress (P = 0.003), but was comparable to UA Doppler for the other outcomes. MCA Doppler performed significantly worse than did UA Doppler in the prediction of low Apgar score (P = 0.017) and emergency delivery for fetal distress (P = 0.034). CPR outperformed MCA Doppler in the prediction of composite adverse outcome (P < 0.001) and emergency delivery for fetal distress (P = 0.013). Conclusion Calculating the CPR with MCA Doppler can add value to UA Doppler assessment in the prediction of adverse perinatal outcome in women with a singleton pregnancy. However, it is unclear to which subgroup of pregnant women this applies. The effectiveness of the CPR in guiding clinical management needs to be evaluated in clinical trials. © 2017 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology. PMID:28708272

Ultrasonography with color Doppler and power Doppler in the diagnosis of periapical lesions

PubMed Central

Goel, Sumit; Nagendrareddy, Suma Gundareddy; Raju, Manthena Srinivasa; Krishnojirao, Dayashankara Rao Jingade; Rastogi, Rajul; Mohan, Ravi Prakash Sasankoti; Gupta, Swati

2011-01-01

Aim: To evaluate the efficacy of ultrasonography (USG) with color Doppler and power Doppler applications over conventional radiography in the diagnosis of periapical lesions. Materials and Methods: Thirty patients having inflammatory periapical lesions of the maxillary or mandibular anterior teeth and requiring endodontic surgery were selected for inclusion in this study. All patients consented to participate in the study. We used conventional periapical radiographs as well as USG with color Doppler and power Doppler for the diagnosis of these lesions. Their diagnostic performances were compared against histopathologic examination. All data were compared and statistically analyzed. Results: USG examination with color Doppler and power Doppler identified 29 (19 cysts and 10 granulomas) of 30 periapical lesions accurately, with a sensitivity of 100% for cysts and 90.91% for granulomas and a specificity of 90.91% for cysts and 100% for granulomas. In comparison, conventional intraoral radiography identified only 21 lesions (sensitivity of 78.9% for cysts and 45.4% for granulomas and specificity of 45.4% for cysts and 78.9% for granulomas). There was definite correlation between the echotexture of the lesions and the histopathological features except in one case. Conclusions: USG imaging with color Doppler and power Doppler is superior to conventional intraoral radiographic methods for diagnosing the nature of periapical lesions in the anterior jaws. This study reveals the potential of USG examination in the study of other jaw lesions. PMID:22223940

Intraoperative Vascular Neuromonitoring in Patients with Subarachnoid Hemorrhage: A Pilot Study Using Combined Laser-Doppler Spectrophotometry.

PubMed

Schmitz, Emilija; Bischoff, Barbara; Wolf, Dennis; Schmitt, Hubert J; Eyupoglu, Ilker Y; Roessler, Karl; Buchfelder, Michael; Sommer, Björn

2017-11-01

Intraoperative monitoring of cerebral microcirculation in patients with subarachnoid hemorrhage (SAH) may predict the postoperative neurologic outcome. In this pilot study, we examined the value of a novel noninvasive real-time measurement technique for detecting changes in local microcirculation. We used the O2C (Oxygen to see) laser-Doppler spectrophotometry system in 14 patients with Hunt & Hess grade 2-5 SAH who underwent microsurgical cerebral aneurysm clipping. A subdural probe recorded capillary venous oxygenation (SO 2 ), relative hemoglobin concentration, blood cell velocity, and blood flow at a tissue depth of 7 mm. Data were recorded immediately before dural closure. We also recorded somatosensory evoked potentials (SEPs) with median and tibial nerve stimulation. Results were compared with neurologic performance, as measured on the modified Rankin Scale, at the day of discharge from the hospital and 12 months thereafter. Patient functional outcomes after discharge and 12 months were correlated with pathological decreased flow and increased SO 2 values. In 6 of 8 patients, microcirculatory monitoring parameters indicated ischemia during surgery, as shown by electrophysiological SEP changes and infarction detected on the postoperative computed tomography (CT) scan. Pathological SEP results correlated closely with infarct demarcation as seen on CT. Our results indicate the potential benefit of intraoperative combined laser-Doppler flowmetry and spectrophotometry for predicting postoperative clinical outcomes in this small patient sample. Larger-cohort testing is needed to verify our findings and show the possible merits of this novel method. Copyright © 2017 Elsevier Inc. All rights reserved.

Combined use of serum MCP-1/IL-10 ratio and uterine artery Doppler index significantly improves the prediction of preeclampsia.

PubMed

Cui, Shihong; Gao, Yanan; Zhang, Linlin; Wang, Yuan; Zhang, Lindong; Liu, Pingping; Liu, Ling; Chen, Juan

2017-10-01

Monocyte chemotactic protein-1 (MCP-1, or CCL2) is a member of the chemokine subfamily involved in recruitment of monocytes in inflammatory tissues. IL-10 is a key regulator for maintaining the balance of anti-inflammatory and pro-inflammatory milieu at the feto-maternal interface. Doppler examination has been routinely performed for the monitoring and management of preeclampsia patients. This study evaluates the efficiency of these factors alone, or in combination, for the predication of preeclampsia. The serum levels of MCP-1 and IL-10 in 78 preeclampsia patients and 143 age-matched normal controls were measured. The Doppler ultrasonography was performed and Artery Pulsatility Index (PI) and Resistance Index (RI) were calculated for the same subjects. It was found that while the second-trimester serum MCP-1, IL-10, MCP-1/IL-10 ratio, PI, and RI showed some power in predicting preeclampsia, the combination of MCP-1/IL-10 and PI and RI accomplishes the highest efficiency, achieving an AUC of 0.973 (95% CI, 0.000-1.000, P<0.001), a sensitivity of 94%, and a specificity of 80%. The use of MCP-1/IL-10 ratio in combination with ultrasound findings appears to provide a promising modality for predicting preeclampsia. Future studies using a larger sample can be conducted to construct an algorithm capable of quantitative assessment on the risk of preeclampsia. Copyright © 2016 Elsevier B.V. All rights reserved.

Sonoelastography in the musculoskeletal system: Current role and future directions.

PubMed

Winn, Naomi; Lalam, Radhesh; Cassar-Pullicino, Victor

2016-11-28

Ultrasound is an essential modality within musculoskeletal imaging, with the recent addition of elastography. The elastic properties of tissues are different from the acoustic impedance used to create B mode imaging and the flow properties used within Doppler imaging, hence elastography provides a different form of tissue assessment. The current role of ultrasound elastography in the musculoskeletal system will be reviewed, in particular with reference to muscles, tendons, ligaments, joints and soft tissue tumours. The different ultrasound elastography methods currently available will be described, in particular strain elastography and shear wave elastography. Future directions of ultrasound elastography in the musculoskeletal system will also be discussed.

Post-operative monitoring of free muscle transfers by Laser Doppler Imaging: A prospective study.

PubMed

Tschumi, Christian; Seyed Jafari, S Morteza; Rothenberger, Jens; Van de Ville, Dimitri; Keel, Marius; Krause, Fabian; Shafighi, Maziar

2015-10-01

Despite different existing methods, monitoring of free muscle transfer is still challenging. In the current study we evaluated our clinical setting regarding monitoring of such tissues, using a recent microcirculation-imaging camera (EasyLDI) as an additional tool for detection of perfusion incompetency. This study was performed on seven patients with soft tissue defect, who underwent reconstruction with free gracilis muscle. Beside standard monitoring protocol (clinical assessment, temperature strips, and surface Doppler), hourly EasyLDI monitoring was performed for 48 hours. Thereby a baseline value (raised flap but connected to its vascular bundle) and an ischaemia perfusion value (completely resected flap) were measured at the same point. The mean age of the patients, mean baseline value, ischaemia value perfusion were 48.00 ± 13.42 years, 49.31 ± 17.33 arbitrary perfusion units (APU), 9.87 ± 4.22 APU, respectively. The LDI measured values in six free muscle transfers were compatible with hourly standard monitoring protocol, and normalized LDI values significantly increased during time (P < 0.001, r = 0.412). One of the flaps required a return to theatre 17 hours after the operation, where an unsalvageable flap loss was detected. All normalized LDI values of this flap were under the ischaemia perfusion level and the trend was significantly descending during time (P < 0.001, r = -0.870). Due to the capability of early detection of perfusion incompetency, LDI may be recommended as an additional post-operative monitoring device for free muscle flaps, for early detection of suspected failing flaps and for validation of other methods. © 2015 Wiley Periodicals, Inc.

Assessment of left ventricular function using pulsed tissue Doppler imaging in healthy dogs and dogs with spontaneous mitral regurgitation.

PubMed

Teshima, Kenji; Asano, Kazushi; Sasaki, Yukie; Kato, Yuka; Kutara, Kenji; Edamura, Kazuya; Hasegawa, Atsuhiko; Tanaka, Shigeo

2005-12-01

Pulsed tissue Doppler imaging (pulsed TDI) has been demonstrated to be useful for the estimation of left ventricular (LV) systolic and diastolic functions in various human cardiac diseases. The objectives of this study were to investigate the relationship between pulsed TDI and LV function by using cardiac catheterization in healthy dogs and to evaluate the clinical usefulness of pulsed TDI in dogs with spontaneous mitral regurgitation (MR). The peak early diastolic velocity (E'), peak atrial systolic velocity (A'), and peak systolic velocity (S') were detectable in the velocity profiles of the mitral annulus in all the dogs. In the healthy dogs, S' and E' were correlated with LV peak +dP/dt and -dP/dt, respectively. E' was lower in dogs with MR than in dogs without cardiac diseases. E/E' in the MR dogs with decompensated heart failure was significantly increased in comparison with those with compensated heart failure. The sensitivity and specificity of the E/E' cutoff value of 13.0 for identifying decompensated heart failure were 80% and 83%, respectively. In addition, E/E' was significantly correlated with the ratio of left atrial to aortic diameter. These findings suggest that canine pulsed TDI can be applied clinically for estimation of cardiac function and detection of cardiac decompensation and left atrial volume overload in dogs with MR.

Tissue vibration pulsatility for arterial bleeding detection using Doppler ultrasound.

PubMed

Xie, Zhiyong; Kim, Eung-Hun; Kim, Yongmin

2009-01-01

Trauma is the number one cause of death among Americans between 1 and 44 years old, and exsanguination due to internal bleeding resulting from arterial injuries is a major factor in trauma deaths. We have evaluated the feasibility of using tissue vibration pulsatility in arterial bleeding detection. Eight femoral arteries from four juvenile pigs were punctured transcutaneously with a 6 or 9-French catheter. Also, 11 silicone vessels wrapped with turkey breast were placed in a pulsatile flow phantom and penetrated with an 18-gauge needle. The tissue vibration pulsatility was derived as a ratio of the maximum spectral energy from 200 to 2500 Hz of tissue vibration in systole over a baseline value in diastole. Then, the tissue vibration pulsatility index (TVPI) was defined as the maximum tissue vibration pulsatility value for each experimental condition. Both in vitro and in vivo results showed that the TVPI from injured vessels is significantly higher (p<0.005) than that of intact vessels. In addition, we constructed the 2D map of tissue vibration pulsatility during in vitro studies and found that it could be used for spatial localization of the puncture site. Our preliminary results indicate that the tissue vibration pulsatility may be useful for detecting arterial bleeding and localizing the bleeding site.

Medical ultrasound: imaging of soft tissue strain and elasticity

PubMed Central

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

2011-01-01

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

Real-time, high-resolution ultrasonography of the vocal folds--a prospective pilot study in patients before and after thyroidectomy.

PubMed

Dedecjus, Marek; Adamczewski, Zbigniew; Brzeziński, Jan; Lewiński, Andrzej

2010-09-01

The aim of the study was to evaluate the functionality of vocal folds (VF) by real-time, high-resolution ultrasonography (US) and to correlate the imaged features to results of laryngological examination (LE). The study group comprised 50 patients (41 females and nine males), qualified to thyroidectomy. All the patients had LE and US examination before and 2 days, 2 months, and 3 months after the surgery. We used high-resolution US imaging to identify VFs and, subsequently, a pulsed Doppler and Doppler gate to quantify the tissue displacement velocity in the vibrating VF section. LE revealed unilateral VF paralysis in two patients. VF dysfunction was diagnosed in other four subjects. In simultaneously performed US examination, changes in VF displacement velocity (VFDV) were observed in ten patients. In two subjects, VFDV was below 30 cm/s- patients with VF paralysis, diagnosed in LE. In a further eight cases, we observed VFDV decrease by 50%, comparing to preoperative values. Both US-imaging and LE, performed after the 3-month follow-up, confirmed the transitional character of the above-mentioned pathologies. US imaging of the VFs correlated with LE results, while being a minimally invasive, easily reproducible, and inexpensive method of examining VF functionality. Thanks to many recording options, it may soon become a perfect tool for an early identification of postoperative VF dysfunction with its later monitoring. To our knowledge, it is the first application of US and Doppler gate modes for VFDF quantification; however, an analysis on a larger group of patients is necessary to standardize the technique.

Two-dimensional color tissue Doppler imaging detects myocardial dysfunction before occurrence of hypertrophy in a young Maine Coon cat.

PubMed

Chetboul, Valerie; Sampedrano, Carolina Carlos; Gouni, Vassiliki; Nicolle, Audrey P; Pouchelon, Jean-Louis

2006-01-01

A 20-month-old healthy male Maine Coon cat was referred for a cardiovascular evaluation. Physical examination and electrocardiogram were normal. The end-diastolic subaortic interventricular septal thickness (6 mm; reference range: < or = 6mm) and the mitral flow late diastolic velocity (0.89 m/s; reference range: 0.2-0.8m/s) were within the upper ranges. However, M-mode echocardiography did not reveal any sign of hypertrophic cardiomyopathy (HCM). Tissue Doppler imaging (TDI) identified a marked left ventricular free wall dysfunction characterized by decreased myocardial velocities in early diastole, increased myocardial velocities in late diastole and the presence of postsystolic contractions both at the base and the apex for the longitudinal motion. One year later, the diagnosis of HCM was confirmed by conventional echocardiography and the cat died suddenly 2 months later. This report demonstrates for the first time in spontaneous HCM the sensitivity of TDI for early diagnosis of myocardial dysfunction and suggests that TDI should form part of the screening techniques for early diagnosis of feline HCM.

3D motion and strain estimation of the heart: initial clinical findings

NASA Astrophysics Data System (ADS)

Barbosa, Daniel; Hristova, Krassimira; Loeckx, Dirk; Rademakers, Frank; Claus, Piet; D'hooge, Jan

2010-03-01

The quantitative assessment of regional myocardial function remains an important goal in clinical cardiology. As such, tissue Doppler imaging and speckle tracking based methods have been introduced to estimate local myocardial strain. Recently, volumetric ultrasound has become more readily available, allowing therefore the 3D estimation of motion and myocardial deformation. Our lab has previously presented a method based on spatio-temporal elastic registration of ultrasound volumes to estimate myocardial motion and deformation in 3D, overcoming the spatial limitations of the existing methods. This method was optimized on simulated data sets in previous work and is currently tested in a clinical setting. In this manuscript, 10 healthy volunteers, 10 patient with myocardial infarction and 10 patients with arterial hypertension were included. The cardiac strain values extracted with the proposed method were compared with the ones estimated with 1D tissue Doppler imaging and 2D speckle tracking in all patient groups. Although the absolute values of the 3D strain components assessed by this new methodology were not identical to the reference methods, the relationship between the different patient groups was similar.

Can tissue spectrophotometry and laser Doppler flowmetry help to identify patients at risk for wound healing disorders after neck dissection?

PubMed

Rohleder, Nils H; Flensberg, Sandra; Bauer, Florian; Wagenpfeil, Stefan; Wales, Craig J; Koerdt, Steffen; Wolff, Klaus D; Hölzle, Frank; Steiner, Timm; Kesting, Marco R

2014-03-01

Microcirculation and oxygen supply in cervical skin were measured with an optical, noninvasive method in patients with or without radiotherapy before neck dissection. The course of wound healing was monitored after the surgical procedure to identify predictive factors for postoperative wound healing disorders. Tissue spectrophotometry and laser Doppler flowmetry were used to determine capillary oxygen saturation, hemoglobin concentration, blood flow, and blood velocity at 2-mm and 8-mm depths in the cervical skin of 91 patients before neck dissection in a maxillofacial unit of a university hospital in Munich, Germany. Parameters were evaluated for differences between patients with irradiation (24) and without (67) and patients with wound healing disorders (25) and without (66) (univariate or multivariate statistical analyses). Velocity at 2 mm was lower in irradiated skin (P = .016). Flow at 2 mm was higher in patients with wound healing disorders (P = .018). High flow values could help to identify patients at risk for cervical wound healing disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

Photoacoustic tomography and sensing in biomedicine

PubMed Central

Li, Changhui; Wang, Lihong V.

2010-01-01

Photoacoustics has been broadly studied in biomedicine, for both human and small animal tissues. Photoacoustics uniquely combines the absorption contrast of light or radio frequency waves with ultrasound resolution. Moreover, it is non-ionizing and non-invasive, and is the fastest growing new biomedical method, with clinical applications on the way. This article provides a brief review of recent developments in photoacoustics in biomedicine, from basic principles to applications. The emphasized areas include the new imaging modalities, hybrid detection methods, photoacoustic contrast agents, and the photoacoustic Doppler effect, as well as translational research topics. PMID:19724102

Coronary flow reserve is associated with tissue ischemia and is an additive predictor of intensive care unit mortality to traditional risk scores in septic shock.

PubMed

Ikonomidis, Ignatios; Makavos, George; Nikitas, Nikitas; Paraskevaidis, Ioannis; Diamantakis, Argyris; Kopterides, Petros; Theodorakopoulou, Maria; Parissis, John; Lekakis, John; Armaganidis, Apostolos; Dimopoulou, Ioanna

2014-03-01

Reduced coronary velocity flow reserve (CFR) is associated with poor outcome in patients with cardiovascular disease. We investigated whether CFR is associated with tissue ischemia and acidosis, impaired myocardial deformation and adverse outcome in patients with septic shock. In 70 mechanically-ventilated patients with septic shock, we examined: a) S' and E' mitral annular velocities using tissue Doppler imaging (TDI), b) CFR of the left anterior descending artery after adenosine infusion using transesophageal Doppler echocardiography and c) lactate, pyruvate and glycerol in tissue by means of a microdialysis (MD) catheter inserted into the subcutaneous adipose tissue as markers of tissue ischemia and acidosis. SOFA and APACHE II prognostic scores and mortality in the intensive care unit (ICU) were recorded. Reduced CFR, S' and E' as well as increased E/E' correlated with increased SOFA, APACHE II and MD lactate to pyruvate ratio (p<0.05 for all correlations). Impaired TDI markers also correlated with increased MD glycerol (p<0.05). Reduced CFR correlated with decreased E' (p<0.05). CFR was 1.8 ± 0.42 in non-survivors (n=34) versus 2.08 ± 0.44 in survivors (p=0.007). A CFR<1.90 predicted mortality with sensitivity of 70% and specificity of 69% (area under the curve 77%; p=0.003). CFR had an additive value to APACHE (chi-square change: 4.358, p=0.03) and SOFA (chi-square change: 3.692, p=0.04) for the prediction of mortality. Tissue ischemia and acidosis is a common pathophysiological link between decreased CFR and impaired LV myocardial deformation in septic shock. CFR is an additive predictor of ICU mortality to traditional risk scores in septic shock. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Assessment of cerebral blood flow with magnetic resonance imaging in children with sickle cell disease: A quantitative comparison with transcranial Doppler ultrasonography.

PubMed

Croal, Paula L; Leung, Jackie; Kosinski, Przemyslaw; Shroff, Manohar; Odame, Isaac; Kassner, Andrea

2017-11-01

Transcranial Doppler ultrasonography (TCD) is a clinical tool for stratifying ischemic stroke risk by identifying abnormal elevations in blood flow velocity (BFV) in the middle cerebral artery (MCA). However, TCD is not effective at screening for subtle neurologic injury such as silent cerebral infarcts. To better understand this disparity, we compared TCD measures of BFV with tissue-level cerebral blood flow (CBF) using arterial spin-labeling MRI in children with and without sickle cell disease, and correlated these measurements against clinical hematologic measures of disease severity. TCD and MRI assessment were performed in 13 pediatric sickle cell disease patients and eight age-matched controls. Using MRI measures of MCA diameter and territory weight, TCD measures of BFV in the MCA [cm/s] were converted into units of CBF [ml min -1 100 g -1 ] for comparison. There was no significant association between TCD measures of BFV in the MCA and corresponding MRI measures of CBF in patients ( r  =   .28, p  =   .39) or controls ( r  =   .10, p  =   .81). After conversion from BFV into units of CBF, a strong association was observed between TCD and MRI measures ( r  =   .67, p  =   .017 in patients, r  =   .86, p  =   .006 in controls). While BFV in the MCA showed a lack of correlation with arterial oxygen content, an inverse association was observed for CBF measurements. This study demonstrates that BFV in the MCA cannot be used as a surrogate marker for tissue-level CBF in children with sickle cell disease. Therefore, TCD alone may not be sufficient for understanding and predicting subtle pathophysiology in this population, highlighting the potential clinical value of tissue-level CBF.

Optical guidance for stereotactic brain tumor biopsy procedures: preliminary clinical evaluation (Conference Presentation)

NASA Astrophysics Data System (ADS)

Haj-Hosseini, Neda; Richter, Johan; Milos, Peter; Hallbeck, Martin; Wârdell, Karin

2017-02-01

In the routine of stereotactic biopsy on suspected tumors located deep in the brain or patients with multiple lesions, tissue samples are harvested to determine the type of malignancy. Biopsies are taken from pre-calculated positions based on the preoperative radiologic images susceptible to brain shift. In such cases the biopsy procedure may need to be repeated leading to a longer operation time. To provide guidance for targeting diagnostic tumor tissue and to avoid vessel rupture on the insertion path of the tumor, an application specific fiber optic probe was developed. The setup incorporated spectroscopy for 5-aminolevulinic acid induced protopophyrin IX (PpIX) fluorescence in the tumor and laser Doppler for measuring microvascular blood flow which recorded backscattered light (TLI) at 780 nm and blood perfusion. The recorded signals were compared to the histopathologic diagnosis of the tissue samples (n=16) and to the preoperative radiologic images. All together 146 fluorescence and 276 laser Doppler signals were recorded along 5 trajectories in 4 patients. On all occasions strong PpIX fluorescence peaks were visible during real-time guidance. Comparing the gliotic tumor marginal zone with the tumor, the PpIX (51 vs. 528 a.u., [0-1790], p < 0.05) was higher and TLI (2.9 vs. 2.0 a.u., [0-4.1], p < 0.05) was lower in tumor. The autofluorescence (104 vs.70 a.u., [0-442], p > 0.05) and blood perfusion (8.3 vs. 17 a.u., [0-254], p > 0.05) were not significantly different. In conclusion, the optical guidance probe made real-time tumor detection and vessel tracking possible during the stereotactic biopsy procedures. Moreover, the fluorescence and blood perfusion in the tumor could be studied at controlled positions in the brain and the tumor.

The blood perfusion and NADH/FAD content combined analysis in patients with diabetes foot

NASA Astrophysics Data System (ADS)

Dremin, Victor V.; Sidorov, Victor V.; Krupatkin, Alexander I.; Galstyan, Gagik R.; Novikova, Irina N.; Zherebtsova, Angelina I.; Zherebtsov, Evgeny A.; Dunaev, Andrey V.; Abdulvapova, Zera N.; Litvinova, Karina S.; Rafailov, Ilya E.; Sokolovski, Sergei G.; Rafailov, Edik U.

2016-03-01

Skin blood microcirculation and the metabolism activity of tissue were examined on the patients with type 2 diabetes. Laser Doppler flowmetry (LDF) with 1064 nm laser light source and fluorescence spectroscopy (FS) with excitation light of 365 nm and 450 nm have been used to monitor the blood perfusion and the content of coenzymes NADH and FAD. Concluding, the proposed combined LDF and tissue FS approach allows to identify the significant violations in the blood microcirculation and metabolic activity for type 2 diabetes patients.

Assessment of left atrial mechanical functions and atrial electromechanical delay in Juvenile idiopathic arthritis by tissue Doppler echocardiography.

PubMed

El Eraky, Azza Z; Handoka, Nesrin M; Ghaly, Mona Sayed; Nasef, Samah Ismail; Eldahshan, Nahed A; Ibrahim, Ahmed M; Shalaby, Sherein

2016-11-24

Juvenile idiopathic arthritis (JIA) is a systemic chronic inflammatory disease. Studies using tissue Doppler imaging (TDI) for the evaluation of cardiac functions of children with JIA are limited. Thus, this study was conducted to evaluate Left ventricular function, left atrial mechanical functions and atrial electromechanical delay in JIA. This study was carried out as a across sectional study. A total of 34 patients with active JIA and 34 controls were included. Atrial electromechanical delay and left atrial (LA) mechanical functions in addition to systolic and diastolic left ventricular (LV) functions were measured by using conventional echocardiography and TDI. Assessment of disease activity was done using Juvenile arthritis disease activity score (JADAS-27). JIA patients had abnormal atrial electromechanical coupling as established from prolonged lateral mitral annulus (PA lateral), septal mitral annulus (PA septum), inter-atrial and intra-atrial electromechanical delays compared with healthy controls. Left ventricular filling abnormalities were found characterized by a reduced E/A ratio (1.07 ± 0.56 vs. 1.48 ± 0.16, p = 0.01). E/Em was significantly higher in patients with JIA (7.58 ± 1.79 vs. 4.74 ± 1.45, p = 0.003) denoting impaired diastolic function. Left atrial mechanical functions assessment showed significantly decreased LA passive emptying fraction, increased LA active emptying fraction and LA total emptying volume in JIA patients (p = 0.01, p = 0.01, p = 0.03 respectively). Atrial electromechanical coupling intervals, and LA mechanical functions were impaired which can be considered as an early form of subclinical cardiac involvement in JIA patients. Significant diastolic functional abnormalities exist in JIA.

The Prevalence of Stages of Heart Failure in Primary Care: A Population-Based Study.

PubMed

Jorge, Antonio Lagoeiro; Rosa, Maria Luiza G; Martins, Wolney A; Correia, Dayse Mary S; Fernandes, Luiz Claudio M; Costa, Jean A; Moscavitch, Samuel D; Jorge, Bruno Afonso L; Mesquita, Evandro T

2016-02-01

Planning strategies to prevent heart failure (HF) in developing countries require epidemiologic data in primary care. The purpose of this study was to estimate the prevalence of HF stages and their phenotypes, HF with preserved ejection fraction (HFPEF), and HF with reduced EF (HFREF) and to determine B-type natriuretic peptide (BNP) levels to identify HF in the adult population. This is a cross-sectional study including 633 individuals, aged ≥45 years, who were randomly selected and registered in a primary care program of a medium-sized city in Brazil. All participants were underwent clinical evaluations, BNP measurements, electrocardiograms, and tissue Doppler echocardiography in a single day. The participants were classified as stage 0 (healthy, 11.7%), stage A (risk factors, 36.6%), stage B (structural abnormalities, 42.7%), or stage C (symptomatic HF, 9.3%). Among patients with HF, 59% presented with HFPEF and 41% presented with HFREF. The mean BNP levels were 20 pg/mL(-1) in stage 0, 20 pg/mL(-1) in stage A, 24 pg/mL(-1) in stage B, 93 pg/mL(-1) in HFPEF, and 266 pg/mL(-1) in HFREF. The cutoff BNP level with optimal sensitivity (92%) and specificity (91%) to identify HF was 42 pg/mL(-1). The present study demonstrated a high prevalence of individuals at risk for HF and the predominance of HFPEF in a primary care setting. The clinical examination, along with BNP and tissue Doppler echocardiography, may facilitate early detection of stages A and B HF and allow implementation of interventions aimed at preventing progression to symptomatic HF. Copyright © 2015 Elsevier Inc. All rights reserved.

High Serum Phosphorus Level Is Associated with Left Ventricular Diastolic Dysfunction in Peritoneal Dialysis Patients.

PubMed

Ye, Min; Tian, Na; Liu, Yanqiu; Li, Wei; Lin, Hong; Fan, Rui; Li, Cuiling; Liu, Donghong; Yao, Fengjuan

We initiated this study to explore the relationships of serum phosphorus level with left ventricular ultrasound features and diastolic function in peritoneal dialysis (PD) patients. 174 patients with end-stage renal disease (ESRD) receiving PD were enrolled in this retrospective observational study. Conventional echocardiography examination and tissue Doppler imaging (TDI) were performed in each patient. Clinical information and laboratory data were also collected. Analyses of echocardiographic features were performed according to phosphorus quartiles groups. And multivariate regression models were used to determine the association between serum phosphorus and Left ventricular diastolic dysfunction (LVDD). With the increase of serum phosphorus levels, patients on PD showed an increased tissue Doppler-derived E/e' ratio of lateral wall (P < 0.001), indicating a deterioration of left ventricular diastolic function. Steady growths of left atrium and left ventricular diameters as well as increase of left ventricular muscle mass were also observed across the increasing quartiles of phosphorus, while left ventricular ejection fraction remained normal. In a multivariate analysis, the regression coefficient for E/e' ratio in the highest phosphorus quartile was almost threefold higher relative to those in the lowest quartile group. And compared with patients in the lowest phosphorus quartile (<1.34 mmol/L) those in the highest phosphorus quartile (>1.95 mmol/L) had a more than fivefold increased odds of E/e' ratio >15. Our study showed an early impairment of left ventricular diastolic function in peritoneal dialysis patients. High serum phosphorus level was independently associated with greater risk of LVDD in these patients. Whether serum phosphorus will be a useful target for prevention or improvement of LVDD remains to be proved by further studies.

[Venous Doppler color echography: importance and inconveniences].

PubMed

Laroche, J P; Dauzat, M; Muller, G; Janbon, C

1993-01-01

Color Doppler is a technique which performs a real-time opacification of the vascular system with blue indicating reverse flow and red indicating forward flow (directional color coding). In venous pathology, the use of color Doppler improves significantly the anatomical evaluation of the inferior vena cava, the iliac vein, the deep femoral vein, and the sural system. Color Doppler facilitates the study of deep venous thrombosis (providing useful information to differentiate ancient from most recent thrombus) and also the study of post-thrombotic conditions (assessment of reverse flow, repermeation phenomena). Finally, color Doppler produces a better insight for the study of varicose veins, especially with regard to mapping, identification of communicante veins, and study of the external saphenous vein.

A new method for the noninvasive determination of abdominal muscle feedforward activity based on tissue velocity information from tissue Doppler imaging.

PubMed

Mannion, A F; Pulkovski, N; Schenk, P; Hodges, P W; Gerber, H; Loupas, T; Gorelick, M; Sprott, H

2008-04-01

Rapid arm movements elicit anticipatory activation of the deep-lying abdominal muscles; this appears modified in back pain, but the invasive technique used for its assessment [fine-wire electromyography (EMG)] has precluded its widespread investigation. We examined whether tissue-velocity changes recorded with ultrasound (M-mode) tissue Doppler imaging (TDI) provided a viable noninvasive alternative. Fourteen healthy subjects rapidly flexed, extended, and abducted the shoulder; recordings were made of medial deltoid (MD) surface EMG and of fine-wire EMG and TDI tissue-velocity changes of the contralateral transversus abdominis, obliquus internus, and obliquus externus. Muscle onsets were determined by blinded visual analysis of EMG and TDI data. TDI could not distinguish between the relative activation of the three muscles, so in subsequent analyses only the onset of the earliest abdominal muscle activity was used. The latter occurred <50 ms after the onset of medial deltoid EMG (i.e., was feedforward) and correlated with the corresponding EMG onsets (r = 0.47, P < 0.0001). The mean difference between methods was 20 ms and was likely explained by electromechanical delay; limits of agreement were wide (-40 to +80 ms) but no greater than those typical of repeated measurements using either technique. The between-day standard error of measurement of the TDI onsets (examined in 16 further subjects) was 16 ms. TDI yielded reliable and valid measures of the earliest onset of feedforward activity within the anterolateral abdominal muscle group. The method can be used to assess muscle dysfunction in large groups of back-pain patients and may also be suitable for the noninvasive analysis of other deep-lying or small/thin muscles.

Transesophageal color Doppler evaluation of obstructive lesions using the new "Quasar" technology.

PubMed

Fan, P; Nanda, N C; Gatewood, R P; Cape, E G; Yoganathan, A P

1995-01-01

Due to the unavoidable problem of aliasing, color flow signals from high blood flow velocities cannot be measured directly by conventional color Doppler. A new technology termed Quantitative Un-Aliased Speed Algorithm Recognition (Quasar) has been developed to overcome this limitation. Employing this technology, we used transesophageal color Doppler echocardiography to investigate whether the velocities detected by the Quasar would correlate with those obtained by continuous-wave Doppler both in vitro and in vivo. In the in vitro study, a 5.0 MHz transesophageal transducer of a Kontron Sigma 44 color Doppler flow system was used. Fourteen different peak velocities calculated and recorded by color Doppler-guided continuous-wave Doppler were randomly selected. In the clinical study, intraoperative transesophageal echocardiography was performed using the same transducer 18 adults (13 aortic valve stenosis, 2 aortic and 2 mitral stenosis, 2 hypertrophic obstructive cardiomyopathy and 1 mitral valve stenosis). Following each continuous-wave Doppler measurement, the Quasar was activated, and a small Quasar marker was placed in the brightest area of the color flow jet to obtain the maximum mean velocity readout. The maximum mean velocities measured by Quasar closely correlated with maximum peak velocities obtained by color flow guided continuous-wave Doppler in both in vitro (0.53 to 1.65 m/s, r = 0.99) and in vivo studies (1.50 to 6.01 m/s, r = 0.97). We conclude that the new Quasar technology can accurately measure high blood flow velocities during transesophageal color Doppler echocardiography. This technique has the potential of obviating the need for continuous-wave Doppler.

Bone surface enhancement in ultrasound images using a new Doppler-based acquisition/processing method.

PubMed

Yang, Xu; Tang, Songyuan; Tasciotti, Ennio; Righetti, Raffaella

2018-01-17

Ultrasound (US) imaging has long been considered as a potential aid in orthopedic surgeries. US technologies are safe, portable and do not use radiations. This would make them a desirable tool for real-time assessment of fractures and to monitor fracture healing. However, image quality of US imaging methods in bone applications is limited by speckle, attenuation, shadow, multiple reflections and other imaging artifacts. While bone surfaces typically appear in US images as somewhat 'brighter' than soft tissue, they are often not easily distinguishable from the surrounding tissue. Therefore, US imaging methods aimed at segmenting bone surfaces need enhancement in image contrast prior to segmentation to improve the quality of the detected bone surface. In this paper, we present a novel acquisition/processing technique for bone surface enhancement in US images. Inspired by elastography and Doppler imaging methods, this technique takes advantage of the difference between the mechanical and acoustic properties of bones and those of soft tissues to make the bone surface more easily distinguishable in US images. The objective of this technique is to facilitate US-based bone segmentation methods and improve the accuracy of their outcomes. The newly proposed technique is tested both in in vitro and in vivo experiments. The results of these preliminary experiments suggest that the use of the proposed technique has the potential to significantly enhance the detectability of bone surfaces in noisy ultrasound images.

Bone surface enhancement in ultrasound images using a new Doppler-based acquisition/processing method

NASA Astrophysics Data System (ADS)

Yang, Xu; Tang, Songyuan; Tasciotti, Ennio; Righetti, Raffaella

2018-01-01

Ultrasound (US) imaging has long been considered as a potential aid in orthopedic surgeries. US technologies are safe, portable and do not use radiations. This would make them a desirable tool for real-time assessment of fractures and to monitor fracture healing. However, image quality of US imaging methods in bone applications is limited by speckle, attenuation, shadow, multiple reflections and other imaging artifacts. While bone surfaces typically appear in US images as somewhat ‘brighter’ than soft tissue, they are often not easily distinguishable from the surrounding tissue. Therefore, US imaging methods aimed at segmenting bone surfaces need enhancement in image contrast prior to segmentation to improve the quality of the detected bone surface. In this paper, we present a novel acquisition/processing technique for bone surface enhancement in US images. Inspired by elastography and Doppler imaging methods, this technique takes advantage of the difference between the mechanical and acoustic properties of bones and those of soft tissues to make the bone surface more easily distinguishable in US images. The objective of this technique is to facilitate US-based bone segmentation methods and improve the accuracy of their outcomes. The newly proposed technique is tested both in in vitro and in vivo experiments. The results of these preliminary experiments suggest that the use of the proposed technique has the potential to significantly enhance the detectability of bone surfaces in noisy ultrasound images.

Evaluation of atrial electromechanical delay and left atrial mechanical function in patients with obstructive sleep apnea : Cardiac involvement in patients with OSA.

PubMed

Karabag, Turgut; Aydin, Mustafa; Altin, Remzi; Dogan, Sait M; Cil, Cem; Buyukuysal, Cagatay; Sayin, Muhammet R

2012-07-01

The aim of this study was to evaluate atrial electromechanical delay measured by tissue Doppler imaging and left atrial mechanical function in patients with obstructive sleep apnea (OSA). Fourty-seven moderate-to-severe OSA patients who were newly diagnosed by polysomnography (Apnea-hypopnea index ≥ 15 events/h, 32 males, mean age 49.4 ± 11.5) and 30 patients who had no OSA in polysomnography (Apnea-hypopnea index < 5 events/h, 21 males, mean age 45.4 ± 9.1) were included in the study. Using tissue Doppler, diastolic functions, atrial electromechanical coupling were measured from the lateral mitral, septal, and tricuspid annulus. Inter, intra, and left atrial electromechanical delay were calculated (lateral-tricuspid, septum-tricuspid, lateral-septal). Left atrial volumes (maximal, minimal, and presystolic) were measured by the method of discs in the apical four-chamber view and were indexed to body surface area. Mechanical function parameters of the left atrium were also calculated. Interatrial, intraatrial, and left atrial electromechanical delays were significantly higher in the OSA group compared to the control group. Passive emptying fraction was significantly decreased, volume at the beginning of atrial systole and active emptying volume were significantly increased in OSA patients compared to the controls. The apnea-hypopnea index was significantly associated with interatrial and intraatrial electromechanical delay, passive emptying fraction, and conduit volume. Electromechanical delay was markedly prolonged and left atrial electromechanical function was impaired in untreated OSA patients. These impairments worsen with increasing severity of OSA.

Atrial conduction times and left atrial mechanical functions and their relation with diastolic function in prediabetic patients.

PubMed

Gudul, Naile Eris; Karabag, Turgut; Sayin, Muhammet Rasit; Bayraktaroglu, Taner; Aydin, Mustafa

2017-03-01

The aim of this study was to investigate atrial conduction times and left atrial mechanical functions, the noninvasive predictors of atrial fibrillation, in prediabetic patients with impaired fasting glucose (IFG) and impaired glucose tolerance (IGT). Study included 59 patients (23 males, 36 females; mean age 52.5 ± 10.6 years) diagnosed with IFG or IGT by the American Diabetes Association criteria, and 43 healthy adults (22 males, 21 females; mean age 48.5 ± 12.1 years). Conventional and tissue Doppler echocardiography were performed. The electromechanical delay parameters were measured from the onset of the P wave on the surface electrocardiogram to the onset of the atrial systolic wave on tissue Doppler imaging from septum, lateral, and right ventricular annuli. The left atrial volumes were calculated by the disk method. Left atrial mechanical functions were calculated. The mitral E/A and E'/A' ratios measured from the lateral and septal annuli were significantly lower in the prediabetics compared to the controls. The interatrial and left atrial electromechanical delay were significantly longer in prediabetic group compared to the controls. Left atrial active emptying volume (LAAEV) and fraction (LAAEF) were significantly higher in the prediabetics than the controls. LAAEV and LAAEF were significantly correlated with E/A, lateral and septal E'/A'. In the prediabetic patients, the atrial conduction times and P wave dispersion on surface electrocardiographic were longer before the development of overt diabetes. In addition, the left atrial mechanical functions were impaired secondary to a deterioration in the diastolic functions in the prediabetic patients.

Comparative study evaluating the role of color Doppler sonography and computed tomography in predicting chest wall invasion by lung tumors.

PubMed

Sripathi, Smiti; Mahajan, Abhishek

2013-09-01

To analyze qualitative and quantitative parameters of lung tumors by color Doppler sonography, determine the role of color Doppler sonography in predicting chest wall invasion by lung tumors using spectral waveform analysis, and compare color Doppler sonography and computed tomography (CT) for predicting chest wall invasion by lung tumors. Between March and September 2007, 55 patients with pleuropulmonary lesions on chest radiography were assessed by grayscale and color Doppler sonography for chest wall invasion. Four patients were excluded from the study because of poor acoustic windows. Quantitative and qualitative sonographic examinations of the lesions were performed using grayscale and color Doppler imaging. The correlation between the color Doppler and CT findings was determined, and the final outcomes were correlated with the histopathologic findings. Of a total of 51 lesions, 32 were malignant. Vascularity was present on color Doppler sonography in 28 lesions, and chest wall invasion was documented in 22 cases. Computed tomography was performed in 24 of 28 evaluable malignant lesions, and the findings were correlated with the color Doppler findings for chest wall invasion. Of the 24 patients who underwent CT, 19 showed chest wall invasion. The correlation between the color Doppler and CT findings revealed that color Doppler sonography had sensitivity of 95.6% and specificity of 100% for assessing chest wall invasion, whereas CT had sensitivity of 85.7% and specificity of 66.7%. Combined qualitative and quantitative color Doppler sonography can predict chest wall invasion by lung tumors with better sensitivity and specificity than CT. Although surgery is the reference standard, color Doppler sonography is a readily available, affordable, and noninvasive in vivo diagnostic imaging modality that is complementary to CT and magnetic resonance imaging for lung cancer staging.

Cardiac structure and function and dependency in the oldest old.

PubMed

Leibowitz, David; Jacobs, Jeremy M; Stessman-Lande, Irit; Cohen, Aharon; Gilon, Dan; Ein-Mor, Eliana; Stessman, Jochanan

2011-08-01

To examine the association between cardiac function and activities of daily living (ADLs) in an age-homogenous, community-dwelling population born in 1920 and 1921. Cross-sectional analysis of a prospective cohort study. Community-dwelling elderly population. Participants were recruited from the Jerusalem Longitudinal Cohort Study, which has followed an age-homogenous cohort of Jerusalem residents born in 1920 and 1921. Four hundred eighty-nine of the participants (228 male, 261 female) from the most recent set of data collection in 2005 and 2006 underwent echocardiography at their place of residence in addition to structured interviews and physical examination. A home-based comprehensive assessment was performed to assess health and functional status, including performance of ADLs. Dependence was defined as needing assistance with one or more basic ADLs. Standard echocardiographic assessment of cardiac structure and function, including ejection fraction (EF) and diastolic function as assessed using early diastolic mitral annular tissue velocity measurements obtained using tissue Doppler, was performed. Of the participants with limitation in at least one ADL, significantly more had low EF (< 55%) than the group that was independent (52.6 % vs 39.1%; P=.01). In addition, participants with dependence in ADL had higher left ventricular mass index (LVMI) (129.3 vs 119.7 g/m²) and left atrial volume index (LAVI) (41.3 vs 36.7 mL/m²). There were no differences between the groups in percentage of participants with impaired diastolic function or average ratio of early diastolic transmitral flow velocity to early diastolic mitral annular tissue velocity (11.5 vs 11.8; P=.64). In this age-homogenous cohort of the oldest old, high LVMI and LAVI and indices of systolic but not diastolic function as assessed according to Doppler were associated with limitations in ADLs. © 2011, Copyright the Authors. Journal compilation © 2011, The American Geriatrics Society.

Influence of detomidine on atrial fibrillation cycle length measured by intracardiac electrogram recording and by colour tissue Doppler imaging in horses.

PubMed

Decloedt, A; de Clercq, D; van der Vekens, N; Verheyen, T; Ven, S; van Loon, G

2016-01-01

Shortening of atrial fibrillation cycle length (AFCL) is a marker of atrial electrical remodelling due to atrial fibrillation (AF). To investigate the effect of administration of detomidine on AFCL measured invasively from an intra-atrial electrogram (AFCLEGM) and noninvasively by tissue Doppler imaging (AFCLTDI). We hypothesised that detomidine would have no effect on AFCL but would improve the ease of TDI measurements and facilitate noninvasive AFCL determination. Prospective clinical study. Measurements were performed before and after i.v. administration of 7.5 μg/kg bwt detomidine in 33 episodes of AF in 32 horses (582 ± 64 kg bwt, 10 ± 3 years old) referred for electrical cardioversion. The AFCLEGM was measured from a right atrial intracardiac electrogram. The AFCLTDI was measured from atrial colour tissue velocity curves in 5 atrial wall regions. Mean AFCLEGM and AFCLTDI without and with sedation were compared using a repeated-measures linear mixed model with Bonferroni correction for multiple comparisons and calculation of the Bland-Altman mean bias and limits of agreement between AFCLEGM and AFCLTDI. The mean AFCL was significantly increased after sedation, but this increase was very small (mean difference +4 ms). For AFCLTDI measurements, sedation significantly improved the quality of the atrial myocardial velocity curves and the number of AF cycles that could be measured per cardiac cycle. The Bland-Altman bias between AFCLEGM without sedation and AFCLTDI with sedation ranged from -18 to +15 ms depending on wall region. Bland-Altman limits of agreement were similar between AFCLEGM without sedation and AFCLTDI without and with sedation. Therefore, noninvasive AFCLTDI measurements with sedation can be used to estimate the atrial fibrillatory rate. Sedation facilitates noninvasive AFCL measurements but causes a slight increase in AFCL. Noninvasive AFCL measurements can be used as an indicator of atrial electrical remodelling, to study AF pathophysiology and to investigate the effect of anti-arrhythmic drugs. © 2014 EVJ Ltd.

Is Doppler ultrasound useful for evaluating gestational trophoblastic disease?

PubMed

Lin, Lawrence H; Bernardes, Lisandra S; Hase, Eliane A; Fushida, Koji; Francisco, Rossana P V

2015-12-01

Doppler ultrasound is a non-invasive method for evaluating vascularization and is widely used in clinical practice. Gestational trophoblastic neoplasia includes a group of highly vascularized malignancies derived from placental cells. This review summarizes data found in the literature regarding the applications of Doppler ultrasound in managing patients with gestational trophoblastic neoplasia. The PubMed/Medline, Web of Science, Cochrane and LILACS databases were searched for articles published in English until 2014 using the following keywords: "Gestational trophoblastic disease AND Ultrasonography, Doppler." Twenty-eight articles met the inclusion criteria and were separated into the 4 following groups according to the aim of the study. (1) Doppler ultrasound does not seem to be capable of differentiating partial from complete moles, but it might be useful when evaluating pregnancies in which a complete mole coexists with a normal fetus. (2) There is controversy in the role of uterine artery Doppler velocimetry in the prediction of development of gestational trophoblastic neoplasia. (3) Doppler ultrasound is a useful tool in the diagnosis of gestational trophoblastic neoplasia because abnormal myometrial vascularization and lower uterine artery Doppler indices seem to be correlated with invasive disease. (4) Lower uterine artery Doppler indices in the diagnosis of gestational trophoblastic neoplasia are associated with methotrexate resistance and might play a role in prognosis. Several studies support the importance of Doppler ultrasound in the management of patients with gestational trophoblastic neoplasia, particularly the role of Doppler velocimetry in the prediction of trophoblastic neoplasia and the chemoresistance of trophoblastic tumors. Doppler findings should be used as ancillary tools, along with human chorionic gonadotropin assessment, in the diagnosis of gestational trophoblastic neoplasia.

Analysis and prediction of Doppler noise during solar conjunctions

NASA Technical Reports Server (NTRS)

Berman, A. L.; Rockwell, S. T.

1975-01-01

The results of a study of Doppler data noise during solar conjunctions were presented. During the first half of 1975, a sizeable data base of Doppler data noise (estimates) for the Pioneer 10, Pioneer 11, and Helios 1 solar conjunctions was accumulated. To analyze this data, certain physical assumptions are made, leading to the development of a geometric parameter ("ISI") which correlates strongly with Doppler data noise under varying sun-earth-spacecraft geometries. Doppler noise models are then constructed from this parameter, resulting in the newfound ability to predict Doppler data noise during solar conjunctions, and hence to additionally be in a position to validate Doppler data acquired during solar conjunctions.

Interobserver agreement on the echocardiographic parameters that estimate right ventricular systolic function in the early postoperative period of cardiac surgery.

PubMed

Olmos-Temois, S G; Santos-Martínez, L E; Álvarez-Álvarez, R; Gutiérrez-Delgado, L G; Baranda-Tovar, F M

2016-11-01

To know the variability of transthoracic echocardiographic parameters that assess right ventricular systolic function by analyzing interobserver agreement in the early postoperative period of cardiovascular surgery. To assess the feasibility of these echocardiographic measurements. A cross-sectional study, double-blind pilot study was carried out from May 2011 to February 2013. Cardiovascular postoperative critical care at the National Institute of Cardiology "Ignacio Chávez", Mexico City, Mexico. Consecutive, non-probabilistic sampling. Fifty-six patients were studied in the postoperative period of cardiac surgery. The first echocardiographic parameters were obtained between 6-8hours after cardiac surgery, followed by blinded second measurements. Tricuspid annular plane systolic excursion (TAPSE), tricuspid annular peak systolic velocity on tissue Doppler imaging (VSPAT), diameters and right ventricular outflow area, tract fractional shortening. The agreement was analyzed by the Bland-Altman method, and its magnitude was assessed by the intraclass correlation coefficient (95% confidence interval). Both observers evaluated TAPSE and VSPAT in 48 patients (92%). The average TAPSE was 11.68±4.53mm (range 4-27mm). Right ventricular systolic dysfunction was observed in 41 cases (85%) and normal TAPSE in 7 patients (15%). The average difference and its limits according to TAPSE were -0.917±2.95 (-6.821, 4.988), with a magnitude of 0.725 (0.552, 0.837); the tricuspid annular peak systolic velocity on tissue Doppler imaging was -0.001±0.015 (-0.031, 0.030), and its magnitude 0.825 (0.708, 0.898), respectively. VSPAT and TAPSE were estimated by both observers in 92% of the patients, these parameters exhibiting the lowest interobserver variability. Copyright © 2016 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

Abbreviated right-sided heart echocardiogram and the STOP-Bang questionnaire-a useful relationship for preoperative patient evaluation?

PubMed

Evans, Rebecca E; Zimmerman, Joshua; Shishido, Sonia; Heath, Elise; Bledsoe, Amber; Johnson, Ken

2016-05-01

The aims of this study were to (1) explore the incidence of right-sided heart dysfunction (RHD) and STOP-Bang questionnaire responses consistent with obstructive sleep apnea (OSA) and (2) assess the relationship between patients with STOP-Bang questionnaire responses consistent with OSA and echocardiographic findings suggestive of RHD. Observational study. Tertiary academic center preoperative clinic. Two hundred patients presenting for elective surgery to the University of Utah preoperative clinic. Abbreviated transthoracic right-sided echocardiogram and STOP-Bang questionnaire. Tricuspid annular plane systolic excursion, tissue Doppler-derived tricuspid lateral annular systolic velocity (S'), and the tricuspid inflow E wave to tricuspid annular tissue Doppler e' wave ratio (E/e') for the presence of RHD, as well as responses to STOP-Bang questionnaire. A total of 140 echocardiograms were analyzed after exclusion of participants with incomplete STOP-Bang questionnaires and inadequate images. Thirty-five patients (25%) reported 5 or more positive responses to the STOP-Bang questionnaire. Forty-six patients (35%) had abnormal right-sided heart measurements. Of the 35 patients with STOP-Bang scores 5 or greater, 11 (31%) had evidence of RHD. No correlation was observed between STOP-Bang scores and the echocardiography metrics of RHD. This preliminary study suggests that there are numerous sources of RHD, among one of which is sleep apnea, and/or the STOP-Bang questionnaire is not a sensitive tool for predicting RHD. We conclude that although the STOP-Bang questionnaire is easy to implement in a preoperative clinical setting, it is not useful in identifying patients at risk for RHD. Copyright © 2015 Elsevier Inc. All rights reserved.

Diagnostic Accuracy of B-mode USG and Doppler Scan for Ovarian Lesions

PubMed Central

Agarwal, Vinish Kumar

2016-01-01

Introduction Ultrasonography (USG) is considered as the primary imaging modality for confirmation of ovarian mass and to differentiate them in to benign or malignant. Aim The present study was conducted with the aim to evaluate accuracy of B- mode USG and Doppler scan (Colour Doppler + Spectral Doppler) for ovarian lesions. Materials and Methods The patients included in the study were from those referred with either palpable adnexal mass or incidentally detected adnexal masses. Total 250 women were evaluated by USG, Doppler scan. Only fifty patients who had true ovarian mass intraoperatively and on histopathology were included in study, rest masses were excluded. Study parameters were morphological indexing on B- Mode USG, flow study, vessel arrangement, and vessel morphology and vessel location in Colour Doppler and resistive index and pulsatility index in spectral Doppler. Results Total 50 women were included in present study. Out of these 46% were pre-menopausal while 54% were menopaused women, 66.7% of post-menopausal women had malignant ovarian masses compared to 8.7% of premenopausal. Sensitivity, specificity, positive predictive value and negative predictive value of B-Mode USG for ovarian masses were 94.44%, 48.15%, 54.84% and 92.86% respectively, with p-value = 0.007, while sensitivity, specificity, positive predictive value and negative predictive value of Doppler scan were 85%, 90%, 85% and 90% respectively, with p-value = 0.0001. Conclusion USG and its different techniques are accepted as the primary imaging modality for early stage diagnosis of an ovarian malignancy. Statistical analysis suggests that Doppler Scan (Colour + Spectral) was more accurate (88%) than B-Mode USG (67%), but author is in view that both of these modalities should be used in conjunction to screen the ovarian lesions. PMID:27790544

Real-time, high-resolution ultrasonography of the vocal folds—a prospective pilot study in patients before and after thyroidectomy

PubMed Central

Adamczewski, Zbigniew; Brzeziński, Jan; Lewiński, Andrzej

2010-01-01

Purpose The aim of the study was to evaluate the functionality of vocal folds (VF) by real-time, high-resolution ultrasonography (US) and to correlate the imaged features to results of laryngological examination (LE). Methods The study group comprised 50 patients (41 females and nine males), qualified to thyroidectomy. All the patients had LE and US examination before and 2 days, 2 months, and 3 months after the surgery. We used high-resolution US imaging to identify VFs and, subsequently, a pulsed Doppler and Doppler gate to quantify the tissue displacement velocity in the vibrating VF section. Results LE revealed unilateral VF paralysis in two patients. VF dysfunction was diagnosed in other four subjects. In simultaneously performed US examination, changes in VF displacement velocity (VFDV) were observed in ten patients. In two subjects, VFDV was below 30 cm/s— patients with VF paralysis, diagnosed in LE. In a further eight cases, we observed VFDV decrease by 50%, comparing to preoperative values. Both US-imaging and LE, performed after the 3-month follow-up, confirmed the transitional character of the above-mentioned pathologies. Conclusions US imaging of the VFs correlated with LE results, while being a minimally invasive, easily reproducible, and inexpensive method of examining VF functionality. Thanks to many recording options, it may soon become a perfect tool for an early identification of postoperative VF dysfunction with its later monitoring. To our knowledge, it is the first application of US and Doppler gate modes for VFDF quantification; however, an analysis on a larger group of patients is necessary to standardize the technique. PMID:20640934

Determinants of diastolic myocardial tissue Doppler velocities: influences of relaxation and preload.

PubMed

Firstenberg, M S; Greenberg, N L; Main, M L; Drinko, J K; Odabashian, J A; Thomas, J D; Garcia, M J

2001-01-01

Myocardial tissue Doppler echocardiography (TDE) has been proposed as a tool for the assessment of diastolic function. Controversy exists regarding whether TDE measurements are influenced by preload. In this study, left ventricular volume and high-fidelity pressures were obtained in eight closed-chest dogs during intermittent caval occlusion. The time constant of isovolumic ventricular relaxation (tau) was altered with varying doses of dobutamine and esmolol. Peak early diastolic myocardial (E(m)) and transmitral (E) velocities were measured before and after preload reduction. The relative effects of changes in preload and relaxation were determined for E(m) and compared with their effects on E. The following results were observed: caval occlusion significantly decreased E (DeltaE = 16.4 +/- 3.3 cm/s, 36.6 +/- 13.7%, P < 0.01) and E(m) (DeltaE(m) = 1. 3 +/- 0.4 cm/s, 32.5 +/- 26.1%, P < 0.01) under baseline conditions. However, preload reduction was similar for E under all lusitropic conditions (P = not significant), but these effects on E(m) decreased with worsening relaxation. At tau < 50 ms, changes in E(m) with preload reduction were significantly greater (DeltaE(m) = 2.8 +/- 0.6 cm/s) than at tau = 50-65 ms (DeltaE(m) = 1.2 +/- 0.2 cm/s) and at tau >65 ms (DeltaE(m) = 0.5 +/- 0.1 cm/s, P < 0.05). We concluded that TDE E(m) is preload dependent. However, this effect decreases with worsening relaxation.

Fundamentals of diagnostic ultrasonography.

PubMed

Noce, J P

1990-01-01

Diagnostic ultrasonography uses acoustical waves in the frequency range of 1 to 20 MHz. These waves obey Snell's law of reflection and refraction, which are rules ordinary to wave behavior. In ultrasound, the analogy to momentum is acoustic impedance. The acoustic impedance, Z, is equal to the density, p, times velocity, v. The ultrasound transducer converts electrical energy into ultrasound energy and vice versa. The transducer usually consists of a piezoelectric crystal composed of such ceramic materials as barium titanate, lead titanate, zirconate, or lead metaniobate. Five basic ultrasonic scanning modes play the major roles in clinical applications. A-mode, or amplitude-mode, scanning measures the tissue discontinuity along the scan axis. B-mode scanning produces a two-dimensional image of the tissue under study by combining A-mode signals from various directions through mechanical transducer scanning. M-mode, or time motion scanning, is an extension of the A-mode approach in which a single stationary transducer is used. The depth of the echo is displayed on the vertical axis; the brightness of the oscilloscope display is modulated by the echo amplitude. Real-time scanning, or rapid B-scanning, techniques provide continuous data acquisition at a rate sufficient to give the impression of the instantaneous motion of moving structures. Doppler scanning relies on the presence of motion. The Doppler effect occurs when there is relative motion between the source of sound and the receiver of the sound, causing a change in the detected frequency of the sound source.

B-mode and power Doppler ultrasonography of the equine suspensory ligament branches: A descriptive study on 13 horses.

PubMed

Rabba, Silvia; Grulke, Sigrid; Verwilghen, Denis; Evrard, Laurence; Busoni, Valeria

2018-03-01

Ultrasonography is routinely used to achieve the diagnosis of equine suspensory ligament desmopathy. In human medicine, power Doppler ultrasonography has also been found to be useful for the diagnosis of tendon/ligament injuries. The aim of this prospective, pilot study was to assess the presence or absence of power Doppler signal in suspensory ligament branches and compare B-mode findings with power Doppler findings in suspensory ligament branches of lame and non-lame limbs. Thirteen horses were used (eight lame horses, with lameness related to pain in the suspensory ligament branches, and five non-lame horses). Ten lame limbs and 24 sound limbs were assessed by B-mode and power Doppler ultrasonography. The severity of power Doppler signal was scored by two independent readers. The B-mode ultrasonographic examination revealed abnormalities in branches of lame limbs and in branches of sound limbs. Suspensory ligament branches that were considered normal in B-mode showed no power Doppler signal. However, power Doppler signal was detected in suspensory ligament branches that were abnormal in B-mode, both in lame and sound limbs. Power Doppler scores were subjectively higher in suspensory ligament branches of lame limbs and in branches with more severe B-mode changes. Findings supported the use of power Doppler as an adjunctive diagnostic test for lame horses with suspected suspensory desmopathy. © 2018 American College of Veterinary Radiology.

Power Doppler evaluation of joint effusions: investigation in a rabbit model.

PubMed

Strouse, P J; DiPietro, M A; Teo, E L; Doi, K; Chrisp, C E

1999-08-01

To study the power Doppler findings of septic arthritis and noninfectious synovitis in an animal model. The right knees of 10 rabbits were inoculated with an aqueous suspension of Staphylococcus aureus. The right knees of 5 rabbits were injected with talc suspension. The right knees of 5 rabbits were injected with saline. All 20 left knees were injected with saline. Serial power Doppler images were obtained using constant-imaging parameters. Images were reviewed by blinded observers who assessed for increased power Doppler signal. All 10 knees inoculated with S. aureus developed septic arthritis. Each infected rabbit knee demonstrated increased signal on power Doppler on at least one examination, ranging from 1-6 days after inoculation. Only 23 of 45 examinations of infected knees were unequivocally positive by power Doppler on examinations performed 1 to 6 days after inoculation. No knee with talc synovitis demonstrated increased power Doppler signal. No control knee demonstrated increased power Doppler signal. Increased power Doppler signal may be seen with septic arthritis; however, its intensity and timing may vary from subject to subject. A normal power Doppler examination does not exclude septic arthritis.

Adaptation of laser-Doppler flowmetry to measure cerebral blood flow in the fetal sheep.

PubMed

Lan, J; Hunter, C J; Murata, T; Power, G G

2000-09-01

The purpose of this study was to devise a means to use laser-Doppler flowmetry to measure cerebral perfusion before birth. The method has not been used previously, largely because of intrauterine movement artifacts. To minimize movement artifacts, a probe holder was molded from epoxy putty to the contour of the fetal skull. A curved 18-gauge needle was embedded in the holder. At surgery, the holder, probe, and skull were fixed together with tissue glue. Residual signals were recorded after fetal death and after maternal death 1 h later. These averaged <5% of baseline flow signals, indicating minimal movement artifact. To test the usefulness of the method, cerebral flow responses were measured during moderate fetal hypoxia induced by giving the ewes approximately 10% oxygen in nitrogen to breathe. As fetal arterial PO(2) decreased from 21.1 +/- 0.5 to 10.7 +/- 0.4 Torr during a 30-min period, cerebral perfusion increased progressively to 56 +/- 8% above baseline. Perfusion then returned to baseline levels during a 30-min recovery period. These responses are quantitatively similar to those spot observations that have been recorded earlier using labeled microspheres. We conclude that cerebral perfusion can be successfully measured by using laser-Doppler flowmetry with the unanesthetized, chronically prepared fetal sheep as an experimental model. With this method, relative changes of perfusion from a small volume of the ovine fetal brain can be measured on a continuous basis, and movement artifacts can be reduced to 5% of measured flow values.

Using a laser-Doppler flowmetry to measure pulsatile microcirculation on the kidney in rats

NASA Astrophysics Data System (ADS)

Jan, Ming-Yie; Chao, Pin-Tsun; Hsu, Tse-Lin; Wang, Yuh-Yin L.; Wang, Wei-Kung

2001-10-01

Although Laser Doppler flowmetery (LDF) been extensively used in measurement of microvascular blood flow of different tissues. However, due to some physiological vibrations, fast oscillations of the renal cortical flux (RCF) are hard to be measured. In the study, a commercial 3mW 780nm Laser Doppler flowmetery, with a single fiber and a de-vibration holder, was used to measure the pulsatile RCF in rats. Considering the fast response due to the heart rate of rats, the time constant (TC) was set to 0.05 second and thus the frequency response is up to 20Hz. Furthermore, a calibration standard and a static blood sample were also measured as the references without the pulsatile driving force. In order not to perturb the RCF with tiny momentum, the applying force that the fiber exerted on the renal surface was controlled below 100 dyne. To enhance the signal to noise ratio (SNR), an averaged periodogram was used to estimate the frequency components of the pulsatile microcirculation. It is found that the dominating fast oscillation of RCF is pulsatile and its harmonic components are directly correlated with those of the heartbeat (correlation coefficient =0.999, P<0.001, n=17). The result shows that, in the kidney, the pulsatile RCF is the dominating component of microcirculation oscillation and driven by the fast propagating blood pressure. This technique could be further utilized to analyze the pharmacological effect and hemodynamic parameters on renal function.

Measurement of ciliary beat frequency using Doppler optical coherence tomography.

PubMed

Lemieux, Bryan T; Chen, Jason J; Jing, Joseph; Chen, Zhongping; Wong, Brian J F

2015-11-01

Measuring ciliary beat frequency (CBF) is a technical challenge and difficult to perform in vivo. Doppler optical coherence tomography (D-OCT) is a mesoscopic noncontact imaging modality that provides high-resolution tomographic images and detects micromotion simultaneously in living tissues. In this work we used D-OCT to measure CBF in ex vivo tissue as the first step toward translating this technology to clinical use. Fresh ex vivo samples of rabbit tracheal mucosa were imaged using both D-OCT and phase-contrast microscopy (n = 5). The D-OCT system was designed and built to specification in our lab (1310-nm swept source vertical-cavity surface-emitting laser [VCSEL], 6-μm axial resolution). The samples were placed in culture and incubated at 37°C. A fast Fourier transform was performed on the D-OCT signal recorded on the surface of the samples to gauge CBF. High-speed digital video of the epithelium recorded via phase-contrast microscopy was analyzed to confirm the CBF measurements. The D-OCT system detected Doppler signal at the epithelial layer of ex vivo rabbit tracheal samples suggestive of ciliary motion. CBF was measured at 9.36 ± 1.22 Hz using D-OCT and 9.08 ± 0.48 Hz using phase-contrast microscopy. No significant differences were found between the 2 methods (p > 0.05). D-OCT allows for the quantitative measurement of CBF without the need to resolve individual cilia. Furthermore, D-OCT technology can be incorporated into endoscopic platforms that allow clinicians to readily measure CBF in the office and provide a direct measurement of mucosal health. © 2015 ARS-AAOA, LLC.

Doppler effect of subluminal and superluminal sources in eight dimensions

NASA Astrophysics Data System (ADS)

Chandola, H. C.; Rajput, B. S.

1984-06-01

The study of the relativistic Doppler effect of subliminal and superluminal sources has been undertaken in the eight-dimensional space. It has been shown that correct Doppler shifts are obtained in the external spaces of these sources and the conformal correspondence between Doppler effect curves holds in case of approaching and receeding sources but not in the transverse case.

Which is Superior, Doppler Velocimetry or Non-stress Test or Both in Predicting the Perinatal Outcome of High-Risk Pregnancies.

PubMed

Subramanian, Vijaya; Venkat, Janani; Dhanapal, Mohana

2016-10-01

To analyze which is superior, Doppler velocimetry or non-stress test or both by means of categorization into four groups and comparing the prediction of perinatal outcome in high-risk pregnancies like anemia, hypertensive disorders of pregnancies. This was a prospective study conducted at the Department of Obstetrics and Gynaecology, ISO KGH, Madras Medical College, Chennai, in the year 2014. Two hundred high-risk pregnancies like anemia, hypertensive disorders of pregnancy were included in the study. They were examined systematically, and Doppler velocimetry and non-stress test were done. The main vessels studied by Doppler were umbilical artery and middle cerebral artery, and the indices were calculated. The results of the non-stress test were interpreted as reactive and non-reactive. Based on the results of Doppler and non-stress test, the 200 cases were categorized into four groups and the results were analyzed. Among the 200 cases of high-risk pregnancies, those with a normal Doppler study and a reactive non-stress test had good perinatal outcome. When both were abnormal, there was a higher percentage of adverse outcome as compared to that of either Doppler alone being abnormal or non-stress test alone being non-reactive. It was also found that abnormal Doppler but with a reactive non-stress test had the advantage of prolonging the pregnancy and bringing a better outcome indicating that non-stress test is surely a good test of well-being. When Doppler was normal, but non-stress test was non-reactive, there was an increase in the rate of cesarean section. Each method of fetal surveillance reflects different aspect of maternal and fetal pathophysiology. Hence, combining these will help to bring out better perinatal outcome.

Peroneal perforator pedicle propeller flap for lower leg soft tissue defect reconstruction: Clinical applications and treatment of venous congestion

PubMed Central

Liu, Yiyang; Zhang, Chun; Guo, Qiaofeng; Huang, Wenhua; Wong, Kelvin Kian Loong; Chang, Shimin

2017-01-01

Objective To describe the characteristics of the perforator vessel in the peroneal artery of the lower leg and to explore the use of perforator pedicle propeller flaps to repair soft tissue defects in the lower leg, heel and foot. Methods This retrospective study enrolled patients with soft tissue defects of the distal lower leg, heel and foot who underwent surgery using peroneal perforator-based propeller flaps. The peroneal artery perforators were identified preoperatively by colour duplex Doppler ultrasound. The flap was designed based on the preoperatively-identified perforator location, with the posterior border of the fibula employed as an axis, and the perforator vessel as the pivot point of rotation. Patients were followed-up to determine the outcomes. Results The study analysed 36 patients (mean age, 39.7 years). The majority of the soft tissue defects were on the heel (20; 55.6%). The donor-site of the flap was closed in 11 patients by direct suturing and skin grafting was undertaken in 25 patients. Postoperative complications included venous congestion (nine patients), which was managed with delayed wound coverage and bleeding therapy. All wounds were eventually cured and the flaps were cosmetically acceptable. Conclusions The peroneal perforator pedicle propeller flap is an appropriate choice to repair soft tissue defects of the distal limbs. PMID:28345420

Peroneal perforator pedicle propeller flap for lower leg soft tissue defect reconstruction: Clinical applications and treatment of venous congestion.

PubMed

Shen, Lifeng; Liu, Yiyang; Zhang, Chun; Guo, Qiaofeng; Huang, Wenhua; Wong, Kelvin Kian Loong; Chang, Shimin

2017-06-01

Objective To describe the characteristics of the perforator vessel in the peroneal artery of the lower leg and to explore the use of perforator pedicle propeller flaps to repair soft tissue defects in the lower leg, heel and foot. Methods This retrospective study enrolled patients with soft tissue defects of the distal lower leg, heel and foot who underwent surgery using peroneal perforator-based propeller flaps. The peroneal artery perforators were identified preoperatively by colour duplex Doppler ultrasound. The flap was designed based on the preoperatively-identified perforator location, with the posterior border of the fibula employed as an axis, and the perforator vessel as the pivot point of rotation. Patients were followed-up to determine the outcomes. Results The study analysed 36 patients (mean age, 39.7 years). The majority of the soft tissue defects were on the heel (20; 55.6%). The donor-site of the flap was closed in 11 patients by direct suturing and skin grafting was undertaken in 25 patients. Postoperative complications included venous congestion (nine patients), which was managed with delayed wound coverage and bleeding therapy. All wounds were eventually cured and the flaps were cosmetically acceptable. Conclusions The peroneal perforator pedicle propeller flap is an appropriate choice to repair soft tissue defects of the distal limbs.

An airport wind shear detection and warning system using Doppler radar: A feasibility study

NASA Technical Reports Server (NTRS)

Mccarthy, J.; Blick, E. F.; Elmore, K. L.

1981-01-01

A feasibility study was conducted to determine whether ground based Doppler radar could measure the wind along the path of an approaching aircraft with sufficient accuracy to predict aircraft performance. Forty-three PAR approaches were conducted, with 16 examined in detail. In each, Doppler derived longitudinal winds were compared to aircraft measured winds; in approximately 75 percent of the cases, the Doppler and aircraft winds were in acceptable agreement. In the remaining cases, errors may have been due to a lack of Doppler resolution, a lack of co-location of the two sampling volumes, the presence of eddy or vortex like disturbances within the pulse volume, or the presence of point targets in antenna side lobes. It was further concluded that shrouding techniques would have reduced the side lobe problem. A ground based Doppler radar operating in the optically clear air, provides the appropriate longitudinal winds along an aircraft's intended flight path.

[Parenchymal complications of the transplanted kidney: the role of color-Doppler imaging].

PubMed

Granata, Antonio; Clementi, Silvia; Clementi, Anna; Di Pietro, Fabio; Scarfia, Viviana R; Insalaco, Monica; Aucella, Filippo; Prencipe, Michele; Fiorini, Fulvio; Sicurezza, Elvia

2012-01-01

Kidney transplantation is the treatment of choice for end-stage renal disease, given the better quality of life of transplanted patients when compared to patients on maintenance dialysis. In spite of surgical improvements and new immunosuppressive regimens, part of the transplanted grafts still develop chronic dysfunction. Ultrasonography, both in B-mode and with Doppler ultrasound, is an important diagnostic tool in case of clinical conditions which might impair kidney function. Even though ultrasonography is considered fundamental in the diagnosis of vascular and surgical complications of the transplanted kidney, its role is not fully understood in case of parenchymal complications of the graft. The specificity of Doppler ultrasound is low both in case of acute complications such as acute tubular necrosis, drug toxicity and acute rejection, and in case of chronic conditions such as chronic allograft nephropathy. Single determinations of resistance indices present low diagnostic accuracy, which is higher in case of successive measurements performed during the follow-up of the graft. Modern techniques including tissue pulsatility index, maximal fractional area and contrast-enhanced ultrasound increase the diagnostic power of ultrasonography in case of parenchymal complications of the transplanted kidney.

Artifacts in Sonography - Part 3.

PubMed

Bönhof, Jörg A; McLaughlin, Glen

2018-06-01

As a continuation of parts 1 1 and 2 2, this article discusses artifacts as caused by insufficient temporal resolution, artifacts in color and spectral Doppler sonography, and information regarding artifacts in sonography with contrast agents. There are artifacts that occur in B-mode sonography as well as in Doppler imaging methods and sonography with contrast agents, such as slice thickness artifacts and bow artifacts, shadows, mirroring, and artifacts due to refraction that appear, for example, as double images, because they are based on the same formation mechanisms. In addition, there are artifacts specific to Doppler sonography, such as the twinkling artifact, and method-based motion artifacts, such as aliasing, the ureteric jet, and due to tissue vibration. The artifacts specific to contrast mode include echoes from usually highly reflective structures that are not contrast bubbles ("leakage"). Contrast agent can also change the transmitting signal so that even structures not containing contrast agent are echogenic ("pseudoenhancement"). While artifacts can cause problems regarding differential diagnosis, they can also be useful for determining the diagnosis. Therefore, effective use of sonography requires both profound knowledge and skilled interpretation of artifacts. © Georg Thieme Verlag KG Stuttgart · New York.

Depth discrimination in acousto-optic cerebral blood flow measurement simulation

NASA Astrophysics Data System (ADS)

Tsalach, A.; Schiffer, Z.; Ratner, E.; Breskin, I.; Zeitak, R.; Shechter, R.; Balberg, M.

2016-03-01

Monitoring cerebral blood flow (CBF) is crucial, as inadequate perfusion, even for relatively short periods of time, may lead to brain damage or even death. Thus, significant research efforts are directed at developing reliable monitoring tools that will enable continuous, bed side, simple and cost-effective monitoring of CBF. All existing non invasive bed side monitoring methods, which are mostly NIRS based, such as Laser Doppler or DCS, tend to underestimate CBF in adults, due to the indefinite effect of extra-cerebral tissues on the obtained signal. If those are to find place in day to day clinical practice, the contribution of extra-cerebral tissues must be eliminated and data from the depth (brain) should be extracted and discriminated. Recently, a novel technique, based on ultrasound modulation of light was developed for non-invasive, continuous CBF monitoring (termed ultrasound-tagged light (UTL or UT-NIRS)), and shown to correlate with readings of 133Xe SPECT and laser Doppler. We have assembled a comprehensive computerized simulation, modeling this acousto-optic technique in a highly scattering media. Using the combination of light and ultrasound, we show how depth information may be extracted, thus distinguishing between flow patterns taking place at different depths. Our algorithm, based on the analysis of light modulated by ultrasound, is presented and examined in a computerized simulation. Distinct depth discrimination ability is presented, suggesting that using such method one can effectively nullify the extra-cerebral tissues influence on the obtained signals, and specifically extract cerebral flow data.

Ad hoc posterior tibial vessels perforator propeller flaps for the reconstruction of lower third leg soft- tissue defects.

PubMed

Balakrishnan, Thalaivirithan Margabandu; Ramkumar, Jayagosh; Jaganmohan, Janardhanan

2017-01-01

Lower third leg soft tissue defects with anatomical and pathological constraints are posing formidable challenges to reconstructive surgeon. This retrospective study was conducted to assess the effectiveness of ad hoc posterior tibial vessels perforator-propeller flaps for the reconstruction of small and medium sized soft tissue defects in the lower third leg. 22 patients (16 were males and 6 were females) were involved in this study between period of January 2012 and December 2016.We followed the protocol of initial non delineating exploratory incision made to find out single best perforator in all patients. All the defects in leg reconstructed with adhoc posterior tibial vessel propeller flaps. All 22 flaps survived well. All in an average of 13 months follow up period, had pain free walking, with minimal scarring and acceptable aesthesis at the reconstruction sites with no need for any secondary procedure. With inability of preoperatively dopplering the perforators in the lower third leg region, the exploratory posterior nondelineating incision was used in all cases to secure the single best perforator for the propeller flaps. Thus adhoc posterior tibial vessel propeller flaps are dependable, easily adoptable for the reconstruction of soft tissue defects of the lower third leg region.

Ad hoc posterior tibial vessels perforator propeller flaps for the reconstruction of lower third leg soft- tissue defects

PubMed Central

Balakrishnan, Thalaivirithan Margabandu; Ramkumar, Jayagosh; Jaganmohan, Janardhanan

2017-01-01

Introduction: Lower third leg soft tissue defects with anatomical and pathological constraints are posing formidable challenges to reconstructive surgeon. Aim: This retrospective study was conducted to assess the effectiveness of ad hoc posterior tibial vessels perforator-propeller flaps for the reconstruction of small and medium sized soft tissue defects in the lower third leg. Patients and Methods: 22 patients (16 were males and 6 were females) were involved in this study between period of January 2012 and December 2016.We followed the protocol of initial non delineating exploratory incision made to find out single best perforator in all patients. All the defects in leg reconstructed with adhoc posterior tibial vessel propeller flaps. Results: All 22 flaps survived well. All in an average of 13 months follow up period, had pain free walking, with minimal scarring and acceptable aesthesis at the reconstruction sites with no need for any secondary procedure. Conclusion: With inability of preoperatively dopplering the perforators in the lower third leg region, the exploratory posterior nondelineating incision was used in all cases to secure the single best perforator for the propeller flaps. Thus adhoc posterior tibial vessel propeller flaps are dependable, easily adoptable for the reconstruction of soft tissue defects of the lower third leg region. PMID:29618863

[Proteomic analysis of myocardial hypertrophy induced by left kidney artery coarctation in rats].

PubMed

Lv, Yuan-yuan; Sun, Biao; Ma, Ji-zheng

2009-05-01

To identify the expression of proteins in cardiomyocytes in rats with left kidney artery coarctation. 16 male SD rats were separated into 2 groups (n=8): 2 kidney 1 Clip group (2K1C) and sham operation group (SO). The postoperational 8th week, after examination by normal doppler and tissue doppler echocardiography, the extracted proteins from cardiomyocytes were isolated by two-dimensional gel electrophoresis with staining. The gel images were acquired by scanner and 2-DE analysis software. Different spots observed on two 2D gels were selected and identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Overall, 21 protein spots showed significant difference, and 14 out of which were identified. Kidney artery coactation-induced cardiac hypertrophy displays different expression of proteins in cardiomyocytes.

Gastrointestinal Impedance Spectroscopy to Detect Hypoperfusion During Hemorrhage.

PubMed

Bloch, Andreas; Kohler, Andreas; Posthaus, Horst; Berger, David; Santos, Laura; Jakob, Stephan; Takala, Jukka; Haenggi, Matthias

2017-08-01

Changes in tissue impedance (Ω) have been proposed as early signs of impaired tissue perfusion. We hypothesized that hemorrhage may induce early changes in alimentary tract tissue impedance and that these can be detected by impedance spectroscopy. We evaluated impedance spectroscopy in an acute hemorrhage model in pigs. Twenty anesthetized pigs were randomized to stepwise hemorrhage to mean arterial blood pressure (MAP) targets of 60 mm Hg, 50 mm Hg, 45 mm Hg, and 40 mm Hg, followed by retransfusion in two steps, or control (n = 10 each). In the end, 500 mL of enteral nutrition was administered in both groups. Ω in four sites (sublingually, esophagus, stomach, proximal jejunum) and cardiac output (Qtot thermodilution), superior mesenteric artery blood flow (QSMA; Doppler ultrasound), and jejunal mucosal blood flow (LDF; laser Doppler) were measured. The bleeding (total volume 838 ± 185 mL; mean ± SD) resulted in progressive hypotension (actual MAP 65 ± 3 mm Hg, 59 ± 4 mm Hg, 55 ± 5 mm Hg, and 46 ± 6 mm Hg) and decrease in Qtot, QSMA, and mucosal LDF. Bleeding did not change Ω in any of the monitoring sites. Retransfusion restored the blood flows to at least baseline levels, again without change in Ω. Enteral nutrition did not alter Ω or any of the blood flows.Five animals (three in the hemorrhage group, two in the control group) had histologically proven acute gastric focal necrosis at the site of It transducer. Gastrointestinal impedance spectroscopy does not detect early changes in tissue perfusion during progressive hemorrhage or retransfusion. Ω spectroscopy is unlikely to provide any additional information of hypovolemia-induced early changes in gastrointestinal perfusion.

Blue Laser Light Increases Perfusion of a Skin Flap Via Release of Nitric Oxide from Hemoglobin

PubMed Central

Mittermayr, Rainer; Osipov, Anatoly; Piskernik, Christina; Haindl, Susanne; Dungel, Peter; Weber, Carina; Vladimirov, Yuri A; Redl, Heinz; Kozlov, Andrey V

2007-01-01

It has recently been shown that nitrosyl complexes of hemoglobin (NO-Hb) are sensitive to low-level blue laser irradiation, suggesting that laser irradiation can facilitate the release of biologically active nitric oxide (NO), which can affect tissue perfusion. The aim of this study was to evaluate the therapeutic value of blue laser irradiation for local tissue perfusion after surgical intervention. Blood was withdrawn from a rat, exposed to NO and infused back to the same rat or used for in vitro experiments. In vitro, an increase of NO-Hb levels (electron paramagnetic resonance spectroscopy) up to 15 μM in rat blood did not result in the release of detectable amounts of NO (NO selective electrode). Blue laser irradiation of NO-Hb in blood caused decomposition of NO-Hb complexes and release of free NO. Systemic infusion of NO-Hb in rats affected neither systemic circulation (mean arterial pressure) nor local tissue perfusion (Doppler blood flow imaging system). In contrast, a clear enhancement of local tissue perfusion was observed in epigastric flap when elevated NO-Hb levels in blood were combined with local He-Cd laser irradiation focused on the left epigastric artery. The enhancement of regional tissue perfusion was not accompanied by any detectable changes in systemic circulation. This study demonstrates that blue laser irradiation improves local tissue perfusion in a controlled manner stimulating NO release from NO-Hb complexes. PMID:17515954

Assessment of left ventricular functions and myocardial iron load with tissue Doppler and speckle tracking echocardiography and T2* MRI in patients with β-thalassemia major.

PubMed

Ari, Mehmet Emre; Ekici, Filiz; Çetin, İbrahim İlker; Tavil, Emine Betül; Yaralı, Neşe; Işık, Pamir; Hazırolan, Tuncay; Tunç, Bahattin

2017-03-01

The purpose of this study is to determine early myocardial dysfunction in β-thalassemia major (BTM) patients. Where the myocardial dysfunction cannot be detected by conventional echocardiography, it could be detected by tissue Doppler imaging (TDI) or speckle tracking echocardiography (STE). In this study, we analyzed 60 individuals, 30 of whom were BTM patients and the other 30 of whom were the control group. T2* magnetic resonance imaging (MRI) was used to measure cardiac iron deposition. The myocardial functions were evaluated by conventional echocardiography, TDI and STE. When basal lateral left ventricular and basal septal wall TDI values were compared between the patient group and control group, only isovolumic contraction time values were significantly longer in the patients. The global circumferential strain was significantly lower in the patients. When evaluated as segmental, longitudinal strain values of basal inferoseptum and circumferential strain values of anteroseptum, anterior, and inferolateral segments were significantly lower in the patients. In the patients, global longitudinal and circumferential strains in the group who had pathological T2* values were significantly lower than the group who did not. In addition, circumferential strain values in anteroseptum, anterolateral, inferior, and inferoseptum segments were significantly lower in the patients with T2* values<20 ms than those with T2* values≥20 ms. Although T2* MRI is the most sensitive test detecting myocardial iron load, TDI and STE can be used for screening myocardial dysfunction. The abnormal strain values, especially circumferential, may be detected as the first finding of abnormal iron load and related to T2* values. © 2017, Wiley Periodicals, Inc.

DDD(R)-pacing, but not AAI(R)-pacing induces left ventricular desynchronization in patients with sick sinus syndrome: tissue-Doppler and 3D echocardiographic evaluation in a randomized controlled comparison.

PubMed

Albertsen, Andi Eie; Nielsen, Jens Cosedis; Poulsen, Steen Hvitfeldt; Mortensen, Peter Thomas; Pedersen, Anders Kirstein; Hansen, Peter Steen; Jensen, Henrik Kjaerulf; Egeblad, Henrik

2008-02-01

Increasing evidence from randomized trials and experimental studies indicates that right ventricular (RV) pacing may induce congestive heart failure. We studied regional left ventricular (LV) dyssynchrony and global LV function in 50 consecutive patients with sick sinus syndrome (SSS) randomized to either atrial pacing [AAI(R)] or dual chamber RV-pacing [DDD(R)]. Fifty consecutive patients were randomized to AAI(R) or DDD(R)-pacing. Tissue-Doppler imaging was used to quantify LV dyssynchrony in terms of number of segments with delayed longitudinal contraction (DLC). Left ventricular ejection fraction (LVEF) was measured using three-dimensional echocardiography. Dyssynchrony was more pronounced in the DDD(R)-group than in the AAI(R)-group at the 12 months follow-up (P < 0.05). This reflected a significant increase of dyssynchrony in the DDD(R)-group from baseline to the 12 months follow-up (1.3 +/- 1 to 2.1 +/- 1 segments displaying DLC per patient), P < 0.05. No change was observed in the AAI(R)-group (1.6 +/- 2 to 1.3 +/- 2 segments displaying DLC per patient, NS). No difference in LVEF, NYHA or NT-proBNP was observed between AAI(R)- and DDD(R)-mode after 12 months of pacing although LVEF decreased significantly in the DDD(R)-group from baseline (63.1 +/- 8%) to the 12 months follow-up (59.3 +/- 8%, P < 0.05), while LVEF remained unchanged in the AAI(R)-group (61.5 +/- 11% at baseline vs. 62.3 +/- 7% after 12 months, NS. In patients with SSS, DDD(R)-pacing but not AAI(R)-pacing induces significant LV desynchronization and reduction of LVEF.

Prevalence and factors related to left ventricular systolic dysfunction in asymptomatic patients with rheumatoid arthritis. A prospective tissue Doppler echocardiography study.

PubMed

Cioffi, Giovanni; Viapiana, Ombretta; Ognibeni, Federica; Dalbeni, Andrea; Gatti, Davide; Adami, Silvano; Mazzone, Carmine; Faganello, Giorgio; Di Lenarda, Andre; Rossini, Maurizio

2015-11-01

Patients with rheumatoid arthritis (RA) have a high risk for cardiovascular disease due to a chronic inflammatory state, accelerated atherosclerosis, and changes in left ventricular (LV) geometry. These conditions predispose patients to LV systolic dysfunction (LVSD). In this study we assessed whether RA is a condition associated with LVSD, and analyzed the prevalence and factors associated with LVSD in patients with RA. Echocardiographic and clinical data from 198 patients with RA without presence or history of symptoms of cardiac disease were compared with 198 non-RA controls matched for cardiovascular risk factors. LVSD was identified with tissue Doppler echocardiography (TDE) when mitral annular peak systolic velocity (S') was < 9.0 cm/s. Patients with RA were 61 ± 12 years old and 71 % were female (disease duration 14 ± 10 years). LVSD was found in 89 patients with RA (45 %). By multiple regression analysis including both RA patients and controls, RA emerged as an independent condition associated with LVSD (exp β 3.89; CI: 1.87-8.08) together with higher E/E' ratio (index of LV diastolic function) and diabetes mellitus. For the 198 patients with RA, the variables associated with LVSD were higher E/E' ratio and systolic blood pressure. Almost half of asymptomatic RA patients without history of cardiac disease have subclinical LVSD easily detectable with TDE. RA is closely related to LVSD. A higher degree of LV diastolic dysfunction and systolic blood pressure are associated with LVSD in these patients, whose risk for cardiovascular events could be better defined using such information in the asymptomatic stage of cardiac disease.

Three-Dimensional Right Ventricular Strain Versus Volume Quantification in Heart Transplant Recipients in Relation to Pulmonary Artery Pressure.

PubMed

Sade, Leyla Elif; Kozan, Hatice; Eroglu, Serpil; Pirat, Bahar; Aydinalp, Alp; Sezgin, Atilla; Muderrisoglu, Haldun

2017-02-01

Residual pulmonary hypertension challenges the right ventricular function and worsens the prognosis in heart transplant recipients. The complex geometry of the right ventricle complicates estimation of its function with conventional transthoracic echocardiography. We evaluated right ventricular function in heart transplant recipients with the use of 3-dimensional echocardiography in relation to systolic pulmonary artery pressure. We performed 32 studies in 26 heart transplant patients, with 6 patients having 2 studies at different time points with different pressures and thus included. Right atrial volume, tricuspid annular plane systolic excursion, peak systolic annular velocity, fractional area change, and 2-dimensional speckle tracking longitudinal strain were obtained by 2-dimensional and tissue Doppler imaging. Three-dimensional right ventricular volumes, ejection fraction, and 3-dimensional right ventricular strain were obtained from the 3-dimensional data set by echocardiographers. Systolic pulmonary artery pressure was obtained during right heart catheterization. Overall mean systolic pulmonary artery pressure was 26 ± 7 mm Hg (range, 14-44 mmHg). Three-dimensional end-diastolic (r = 0.75; P < .001) and end-systolic volumes (r = 0.55; P = .001)correlated well with systolic pulmonary artery pressure. Right ventricular ejection fraction and right atrium volume also significantly correlated with systolic pulmonary artery pressure (r = 0.49 and P = .01 for both). However, right ventricular 2- and 3-dimensional strain, tricuspid annular plane systolic excursion, and tricuspid annular velocity did not. The effects of pulmonary hemodynamic burden on right ventricular function are better estimated by a 3-dimensional volume evaluation than with 3-dimensional longitudinal strain and other 2-dimensional and tissue Doppler measurements. These results suggest that the peculiar anatomy of the right ventricle necessitates 3-dimensional volume quantification in heart transplant recipients in relation to residual pulmonary hypertension.

[The effectiveness of romifidine on myocardial function in horses with and without heart disease, evaluated with M-mode echocardiography and PW-tissue Doppler imaging].

PubMed

Nagel, Deborah; Gehlen, Heidrun

2013-01-01

The aim of this study was to evaluate to what extent the myocardial function in horses (measured by PW-tissue Doppler = PW-TDI) is affected during a sedation with romifidine (0.04 mg/kg, i. v.), particularly in case of an accompanying heart disease. Based on an echo- and electrocardiographic examination, a total of 45 horses was subdivided into group 1 (no heart disease), group 2 (heart disease without increased heart dimensions) and group 3 (heart disease with increased heart dimensions). Heart rate (HF), M-mode- (FS%) and TDI-measurements were performed before and after the application of romifidine. The velocities of the radial myocardial movement in the left and right ventricular wall were evaluated using PW-TDI. The TDI parameters included the isovolumic contraction (IVC), the systolic (S) as well as the early (E) and late diastolic maximal velocity (A). After the application of romifidine HF and FS were significantly decreased in all groups. IVC, S and E, determined by PW-TDI were also significantly decreased in both ventricular walls. A significant difference between groups was shown for the isovolumic contraction in the left ventricular wall. This was observed distinctly more in horses with heart disease and increased heart dimensions compared to horses with heart disease but no increased heart dimensions. The results of the study indicate that PW-TDI is a suitable imaging technique to analyse the effects of romifidine on equine myocardial function. The major percentage change after application of romifidine for TDI measurements compared to the M-mode parameters indicate that the parameter myocardial velocity measured with TDI appeared to be the most sensitive parameter to document romifidine--induced changes on the myocardium.

Doppler Optical Coherence Tomography

NASA Astrophysics Data System (ADS)

Chen, Zhongping; Zhang, Jun

Noninvasive techniques for imaging in vivo blood flow are of great value to biomedical research and clinical diagnostics where many diseases have a vascular etiology or component. In ophthalmology, many diseases involve disturbances in ocular blood flow, including diabetic retinopathy, low tension glaucoma, anterior ischemic optic neuritis, and macular degeneration. Simultaneous imaging of tissue structure and blood flow could provide critical information for early diagnosis of ocular diseases.

Extended dynamic range of Doppler OCT by application of a new method to high density B-scans using a MHz FDML swept laser source (Conference Presentation)

NASA Astrophysics Data System (ADS)

Elahi, Sahar; Thrane, Lars; Rollins, Andrew M.; Jenkins, Michael W.

2017-02-01

The limited dynamic range of optical coherence tomography (OCT) Doppler velocity measurements makes it difficult to conduct experiments on samples requiring a large dynamic range without phase wrapping at high velocities or loss of sensitivity at slow velocities. Hemodynamics and wall motion undergo significant increases in velocity as the embryonic heart develops. Experimental studies indicate that altered hemodynamics in early-stage embryonic hearts can lead to congenital heart diseases (CHDs), motivating close monitoring of blood flow over several stages of development. We have built a high-speed OCT system using an FDML laser (Optores GmbH, Germany) at a sweep rate of 1.68 MHz (axial resolution - 12 μm, sensitivity - 105 dB, phase stability - 17 mrad). The speed of this OCT system allows us to acquire high-density B-scans to obtain an extended velocity dynamic range without sacrificing the frame rate (100 Hz). The extended dynamic range within a frame is achieved by varying the A-scan interval at which the phase difference is found, enabling detection of velocities ranging from tens of microns per second to hundreds of millimeters per second. The extra lines in a frame can also be utilized to improve the structural and Doppler images via complex averaging. In structural images where the presence of blood causes additional scattering, complex averaging helps retrieve features located deeper in the tissue. Moreover, high-density frames can be registered to 4D volumes to determine the orthogonal direction of flow for calculating shear stress as well as estimating the cardiac output. In conclusion, high density B-scans acquired by our high-speed OCT system enable image enhancement and direct measurement of biological parameters in cohort studies.

Quantified elasticity mapping of ocular tissue using acoustic radiation force optical coherence elastography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Qu, Yueqiao; He, Youmin; Zhang, Yi; Ma, Teng; Zhu, Jiang; Miao, Yusi; Dai, Cuixia; Silverman, Ronald; Humayun, Mark S.; Zhou, Qifa; Chen, Zhongping

2017-02-01

Age-related macular degeneration and keratoconus are two ocular diseases occurring in the posterior and anterior eye, respectively. In both conditions, the mechanical elasticity of the respective tissues changes during the early onset of disease. It is necessary to detect these differences and treat the diseases in their early stages to provide proper treatment. Acoustic radiation force optical coherence elastography is a method of elasticity mapping using confocal ultrasound waves for excitation and Doppler optical coherence tomography for detection. We report on an ARF-OCE system that uses modulated compression wave based excitation signals, and detects the spatial and frequency responses of the tissue. First, all components of the system is synchronized and triggered such that the signal is consistent between frames. Next, phantom studies are performed to validate and calibrate the relationship between the resonance frequency and the Young's modulus. Then the frequency responses of the anterior and posterior eye are detected for porcine and rabbit eyes, and the results correlated to the elasticity. Finally, spatial elastograms are obtained for a porcine retina. Layer segmentation and analysis is performed and correlated to the histology of the retina, where five distinct layers are recognized. The elasticities of the tissue layers will be quantified according to the mean thickness and displacement response for the locations on the retina. This study is a stepping stone to future in-vivo animal studies, where the elastic modulus of the ocular tissue can be quantified and mapped out accordingly.

Accuracy of three-dimensional multislice view Doppler in diagnosis of morbid adherent placenta

PubMed Central

Abdel Moniem, Alaa M.; Ibrahim, Ahmed; Akl, Sherif A.; Aboul-Enen, Loay; Abdelazim, Ibrahim A.

2015-01-01

Objective To detect the accuracy of the three-dimensional multislice view (3D MSV) Doppler in the diagnosis of morbid adherent placenta (MAP). Material and Methods Fifty pregnant women at ≥28 weeks gestation with suspected MAP were included in this prospective study. Two dimensional (2D) trans-abdominal gray-scale ultrasound scan was performed for the subjects to confirm the gestational age, placental location, and findings suggestive of MAP, followed by the 3D power Doppler and then the 3D MSV Doppler to confirm the diagnosis of MAP. Intraoperative findings and histopathology results of removed uteri in cases managed by emergency hysterectomy were compared with preoperative sonographic findings to detect the accuracy of the 3D MSV Doppler in the diagnosis of MAP. Results The 3D MSV Doppler increased the accuracy and predictive values of the diagnostic criteria of MAP compared with the 3D power Doppler. The sensitivity and negative predictive value (NPV) (79.6% and 82.2%, respectively) of crowded vessels over the peripheral sub-placental zone to detect difficult placental separation and considerable intraoperative blood loss in cases of MAP using the 3D power Doppler was increased to 82.6% and 84%, respectively, using the 3D MSV Doppler. In addition, the sensitivity, specificity, and positive predictive value (PPV) (90.9%, 68.8%, and 47%, respectively) of the disruption of the uterine serosa-bladder interface for the detection of emergency hysterectomy in cases of MAP using the 3D power Doppler was increased to 100%, 71.8%, and 50%, respectively, using the 3D MSV Doppler. Conclusion The 3D MSV Doppler is a useful adjunctive tool to the 3D power Doppler or color Doppler to refine the diagnosis of MAP. PMID:26401104

An Observational Study of a Prefrontal Convective Rainband Using Tamex Single-and Dual-Doppler Data

DTIC Science & Technology

1991-01-01

integration from the surface. Other Doppler studies, e.g., Chong and Testud (1983), Lin et al. 37 (1986), etc, also showed similiar results. 4.3 Variational...Atmos. Sci., 39, 258- 279. Chong, M., and J. Testud , 1983: Three-Dimensional Wind Field Analysis from Dual-Doppler Radar Data. Part III: The Boundary

Non-invasive diagnostic methods in dentistry

NASA Astrophysics Data System (ADS)

Todea, Carmen

2016-03-01

The paper, will present the most important non-invasive methods for diagnostic, in different fields of dentistry. Moreover, the laser-based methods will be emphasis. In orthodontics, 3D laser scanners are increasingly being used to establish database for normative population and cross-sectional growth changes but also to asses clinical outcomes in orthognatic surgical and non-surgical treatments. In prevention the main methods for diagnostic of demineralization and caries detection in early stages are represented by laser fluorescence - Quantitative Light Florescence (QLF); DiagnoDent-system-655nm; FOTI-Fiberoptic transillumination; DIFOTI-Digital Imaging Fiberoptic transillumination; and Optical Coherence Tomography (OCT). In odontology, Laser Doppler Flowmetry (LDF) is a noninvasive real time method used for determining the tooth vitality by monitoring the pulp microcirculation in traumatized teeth, fractured teeth, and teeth undergoing different conservative treatments. In periodontology, recently study shows the ability of LDF to evaluate the health of gingival tissue in periodontal tissue diseases but also after different periodontal treatments.

Effect of intraoperative transesophageal Doppler-guided fluid therapy versus central venous pressure-guided fluid therapy on renal allograft outcome in patients undergoing living donor renal transplant surgery: a comparative study.

PubMed

Srivastava, Divya; Sahu, Sandeep; Chandra, Abhilash; Tiwari, Tanmay; Kumar, Sanjay; Singh, P K

2015-12-01

Transesophageal Doppler (TED)-guided intraoperative fluid therapy has shown to noninvasively optimize intravascular volume and reduce postoperative morbidity. The aim of this study was to compare the effects of Doppler-guided intraoperative fluid administration and central venous pressure (CVP)-guided fluid therapy on renal allograft outcome and postoperative complications. A prospective nonrandomized active controlled study was conducted on end-stage renal disease patients scheduled for living donor renal transplant surgery. 110 patients received intraoperative fluid guided by corrected flow time (FTc) and variation in stroke volume values obtained by continuous TED monitoring. Data of 104 patients in whom intraoperative fluid administration was guided by CVP values were retrospectively obtained for a control. The amount of intraoperative fluid given in the study group (12.20 ± 4.24 ml/kg/h) was significantly lower than in the controls (22.21 ± 4.67 ml/kg/h). The amount of colloid used was also significantly less and fewer recipients were seen to require colloid (69 vs 85%). The mean arterial pressures were comparable throughout. CVP reached was 7.18 ± 3.17 mmHg in the study group. It was significantly higher in the controls (13.42 ± 3.12 mmHg). The postoperative graft function and rate of dysfunction were comparable. Side-effects like postoperative dyspnoea (4.8 vs 0%) and tissue edema (9.6 vs 2.7%) were higher in the controls. FTc-guided intraoperative fluid therapy achieved the same rate of immediate graft function as CVP-guided fluid therapy but used a significantly less amount of fluid. The incidence of postoperative complications related to fluid overload was also reduced. The use of TED may replace invasive central line insertions in the future.

Noninvasive assessment of testicular torsion in rabbits using frequency-domain near-infrared spectroscopy: prospects for pediatric urology

NASA Astrophysics Data System (ADS)

Hallacoglu, Bertan; Matulewicz, Richard S.; Paltiel, Harriet J.; Padua, Horacio; Gargollo, Patricio; Cannon, Glenn; Alomari, Ahmad; Sassaroli, Angelo; Fantini, Sergio

2009-09-01

We present a quantitative near-IR spectroscopy study of the absolute values of oxygen saturation of hemoglobin before and after surgically induced testicular torsion in adult rabbits. Unilateral testicular torsions (0, 540, or 720 deg) on experimental testes and contralateral sham surgery on control testes are performed in four adult rabbits. A specially designed optical probe for measurements at multiple source-detector distances and a commercial frequency-domain tissue spectrometer are used to measure absolute values of testicular hemoglobin saturation. Our results show: (1) a consistent baseline absolute tissue hemoglobin saturation value of 78+/-5%, (2) a comparable tissue hemoglobin saturation of 77+/-6% after sham surgery, and (3) a significantly lower tissue hemoglobin saturation of 36+/-2% after 540- and 720-deg testicular torsion surgery. Our findings demonstrate the feasibility of performing frequency-domain, multidistance near-IR spectroscopy for absolute testicular oximetry in the assessment of testicular torsion. We conclude that near-IR spectroscopy has potential to serve as a clinical diagnostic and monitoring tool for the assessment of absolute testicular hemoglobin desaturation caused by torsion, with the possibility of serving as a complement to conventional color and spectral Doppler ultrasonography.

Laser Doppler diagnostics for orthodontia

NASA Astrophysics Data System (ADS)

Ryzhkova, Anastasia V.; Lebedeva, Nina G.; Sedykh, Alexey V.; Ulyanov, Sergey S.; Lepilin, Alexander V.; Kharish, Natalia A.

2004-06-01

The results of statistical analysis of Doppler spectra of intensity fluctuations of light, scattered from mucous membrane of oral cavity of healthy volunteers and patients, abused by the orthodontic diseases, are presented. Analysis of Doppler spectra, obtained from tooth pulp of patients, is carried out. New approach to monitoring of blood microcirculation in orthodontics is suggested. Influence of own noise of Doppler measuring system on formation of the output signal is studied.

Analysis of airborne Doppler lidar, Doppler radar and tall tower measurements of atmospheric flows in quiescent and stormy weather

NASA Technical Reports Server (NTRS)

Bluestein, H. B.; Doviak, R. J.; Eilts, M. D.; Mccaul, E. W.; Rabin, R.; Sundara-Rajan, A.; Zrnic, D. S.

1986-01-01

The first experiment to combine airborne Doppler Lidar and ground-based dual Doppler Radar measurements of wind to detail the lower tropospheric flows in quiescent and stormy weather was conducted in central Oklahoma during four days in June-July 1981. Data from these unique remote sensing instruments, coupled with data from conventional in-situ facilities, i.e., 500-m meteorological tower, rawinsonde, and surface based sensors, were analyzed to enhance understanding of wind, waves and turbulence. The purposes of the study were to: (1) compare winds mapped by ground-based dual Doppler radars, airborne Doppler lidar, and anemometers on a tower; (2) compare measured atmospheric boundary layer flow with flows predicted by theoretical models; (3) investigate the kinematic structure of air mass boundaries that precede the development of severe storms; and (4) study the kinematic structure of thunderstorm phenomena (downdrafts, gust fronts, etc.) that produce wind shear and turbulence hazardous to aircraft operations. The report consists of three parts: Part 1, Intercomparison of Wind Data from Airborne Lidar, Ground-Based Radars and Instrumented 444 m Tower; Part 2, The Structure of the Convective Atmospheric Boundary Layer as Revealed by Lidar and Doppler Radars; and Part 3, Doppler Lidar Observations in Thunderstorm Environments.

[Effect of cupping on hemodynamic levels in the regional sucked tissues in patients with lumbago].

PubMed

Tang, Xiao; Xiao, Xue-Hua; Zhang, Guo-Qing

2012-10-01

To observe hemodynamic changes in the local sucked tissue of lower back undergoing negative pressure after cupping in patients with lumbago. Twenty-two lumbago outpatients were recruited in the present study and 32 sucked tissues accepted measurements. The cupping was applied to the tenderpoint of the patients' lower back for 10 min by using a glass-mug (5 cm in diameter). Hemodynamic indexes [peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistance index (RI)] of the sucked skin and subcutaneous tissues at the lower back were detected before and after cupping by using a color Doppler flow imaging. After cupping intervention at the lower back, the PSV [(14.2 +/- 1.8) cm/s] and EDV [(5.5 +/- 0.7) cm/s] levels were increased significantly in comparison with those [(5.9 +/- 0.9) and (1.9 +/- 0.3) cm/s] before cupping (P < 0.01), while RI was reduced evidently after cupping (0.61 +/- 0.05 vs 0.68 +/- 0.06, P < 0.01), suggesting an increase of the regional blood flow. Cupping therapy can increase the peak systolic velocity and end-diastolic velocity and lower vascular resistance of the subcutaneous arterioles in the regional tissue, which may contribute to its effect in relieving lumbago.

Feasibility of transabdominal Doppler sonography for studying uterine blood flow characteristics in cycling gilts.

PubMed

Herlta, Catherine; Starka, Rosa; Sigmarsson, Haukur L; Kauffold, Johannes

2018-06-01

To test for the feasibility of transabdominal Doppler sonography (color, power, pulse wave) to define uterine perfusion characteristics throughout the estrous cycle in gilts. A total of 15 gilts were synchronized for estrus and scanned in their following spontaneous cycle while being restrained in a purpose-designed mobile crate. To define uterine perfusion characteristics, vessels in between and within uterine cross-sections were imaged and recorded as video sequences to be analyzed by PixelFlux® software for perfused area (Amix), blood flow velocity (vmix) and intensity (Imix) as well as resistance (RIvmix) and pulsatility index (PIvmix). Color Doppler sonography proved to be the only feasible technique, as it was less affected by animal movements than power and pulse wave sonography. As determined by color Doppler sonography, all five parameters determined showed specific patterns through the estrous cycle, i. e. Amix, vmix, Imix were high in proestrus, decreased in estrus and remained low in midestrus and most parts of diestrus; RIvmix and PIvmix with inversely paralleled patterns. This study has demonstrated that transabdominal color Doppler but not power and pulse wave Doppler sonography is feasible to be performed in crate-restrained gilts for studying uterine perfusion characteristics during the estrous cycle, and that changes of uterine perfusion over the course of the estrous cycle can be clearly followed by color Doppler sonography. Results encourage the use of color Doppler sonography for studying i. e. uterine capacity or uterus related infertility such as for cases of clinically unapparent endometritis. Schattauer GmbH.

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

NASA Technical Reports Server (NTRS)

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.;

Localization of needle tip with color doppler during pericardiocentesis: In vitro validation and initial clinical application

NASA Technical Reports Server (NTRS)

Armstrong, G.; Cardon, L.; Vilkomerson, D.; Lipson, D.; Wong, J.; Rodriguez, L. L.; Thomas, J. D.; Griffin, B. P.

2001-01-01

This study evaluates a new device that uses color Doppler ultrasonography to enable real-time image guidance of the aspirating needle, which has not been possible until now. The ColorMark device (EchoCath Inc, Princeton, NJ) induces high-frequency, low-amplitude vibrations in the needle to enable localization with color Doppler. We studied this technique in 25 consecutive patients undergoing pericardiocentesis, and in vitro, in a urethane phantom with which the accuracy of color Doppler localization of the needle tip was compared with that obtained by direct measurement. Tip localization was excellent in vitro; errors axial to the ultrasound beam (velocity Doppler -0.13 +/- 0.90 mm, power Doppler -0.05 +/- 1.7 mm) were less than lateral errors (velocity -0.36 +/- 1.8 mm, power -0.02 +/- 2.8 mm). In 18 of 25 patients, the needle was identified and guided into the pericardial space with the ColorMark technique, and it allowed successful, uncomplicated drainage of fluid. Initial failures were the result of incorrect settings on the echocardiographic machine and inappropriate combinations of the needle puncture site and imaging window. This study demonstrates a novel color Doppler technique that is highly accurate at localizing a needle tip. The technique is feasible for guiding pericardiocentesis. Further clinical validation of this technique is required.

Pulse Oximeter Derived Blood Pressure Measurement in Patients With a Continuous Flow Left Ventricular Assist Device.

PubMed

Hellman, Yaron; Malik, Adnan S; Lane, Kathleen A; Shen, Changyu; Wang, I-Wen; Wozniak, Thomas C; Hashmi, Zubair A; Munson, Sarah D; Pickrell, Jeanette; Caccamo, Marco A; Gradus-Pizlo, Irmina; Hadi, Azam

2017-05-01

Currently, blood pressure (BP) measurement is obtained noninvasively in patients with continuous flow left ventricular assist device (LVAD) by placing a Doppler probe over the brachial or radial artery with inflation and deflation of a manual BP cuff. We hypothesized that replacing the Doppler probe with a finger-based pulse oximeter can yield BP measurements similar to the Doppler derived mean arterial pressure (MAP). We conducted a prospective study consisting of patients with contemporary continuous flow LVADs. In a small pilot phase I inpatient study, we compared direct arterial line measurements with an automated blood pressure (ABP) cuff, Doppler and pulse oximeter derived MAP. Our main phase II study included LVAD outpatients with a comparison between Doppler, ABP, and pulse oximeter derived MAP. A total of five phase I and 36 phase II patients were recruited during February-June 2014. In phase I, the average MAP measured by pulse oximeter was closer to arterial line MAP rather than Doppler (P = 0.06) or ABP (P < 0.01). In phase II, pulse oximeter MAP (96.6 mm Hg) was significantly closer to Doppler MAP (96.5 mm Hg) when compared to ABP (82.1 mm Hg) (P = 0.0001). Pulse oximeter derived blood pressure measurement may be as reliable as Doppler in patients with continuous flow LVADs. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

MicroV Technology to Improve Transcranial Color Coded Doppler Examinations.

PubMed

Malferrari, Giovanni; Pulito, Giuseppe; Pizzini, Attilia Maria; Carraro, Nicola; Meneghetti, Giorgio; Sanzaro, Enzo; Prati, Patrizio; Siniscalchi, Antonio; Monaco, Daniela

2018-05-04

The purpose of this review is to provide an update on technology related to Transcranial Color Coded Doppler Examinations. Microvascularization (MicroV) is an emerging Power Doppler technology which can allow visualization of low and weak blood flows even at high depths, thus providing a suitable technique for transcranial ultrasound analysis. With MicroV, reconstruction of the vessel shape can be improved, without any overestimation. Furthermore, by analyzing the Doppler signal, MicroV allows a global image of the Circle of Willis. Transcranial Doppler was originally developed for the velocimetric analysis of intracranial vessels, in particular to detect stenoses and the assessment of collateral circulation. Doppler velocimetric analysis was then compared to other neuroimaging techniques, thus providing a cut-off threshold. Transcranial Color Coded Doppler sonography allowed the characterization of vessel morphology. In both Color Doppler and Power Doppler, the signal overestimated the shape of the intracranial vessels, mostly in the presence of thin vessels and high depths of study. In further neurosonology technology development efforts, attempts have been made to address morphology issues and overcome technical limitations. The use of contrast agents has helped in this regard by introducing harmonics and subtraction software, which allowed better morphological studies of vessels, due to their increased signal-to-noise ratio. Having no limitations in the learning curve, in time and contrast agent techniques, and due to its high signal-to-noise ratio, MicroV has shown great potential to obtain the best morphological definition. Copyright © 2018 by the American Society of Neuroimaging.

Improved measurement of vibration amplitude in dynamic optical coherence elastography

PubMed Central

Kennedy, Brendan F.; Wojtkowski, Maciej; Szkulmowski, Maciej; Kennedy, Kelsey M.; Karnowski, Karol; Sampson, David D.

2012-01-01

Abstract: Optical coherence elastography employs optical coherence tomography (OCT) to measure the displacement of tissues under load and, thus, maps the resulting strain into an image, known as an elastogram. We present a new improved method to measure vibration amplitude in dynamic optical coherence elastography. The tissue vibration amplitude caused by sinusoidal loading is measured from the spread of the Doppler spectrum, which is extracted using joint spectral and time domain signal processing. At low OCT signal-to-noise ratio (SNR), the method provides more accurate vibration amplitude measurements than the currently used phase-sensitive method. For measurements performed on a mirror at OCT SNR = 5 dB, our method introduces <3% error, compared to >20% using the phase-sensitive method. We present elastograms of a tissue-mimicking phantom and excised porcine tissue that demonstrate improvements, including a 50% increase in the depth range of reliable vibration amplitude measurement. PMID:23243565

Postnatal Anthropometric and Body Composition Profiles in Infants with Intrauterine Growth Restriction Identified by Prenatal Doppler

PubMed Central

Mazarico, E.; Martinez-Cumplido, R.; Díaz, M.; Sebastiani, G.; Ibáñez, L.; Gómez-Roig, M. D.

2016-01-01

Introduction Infant anthropometry and body composition have been previously assessed to gauge the impact of intrauterine growth restriction (IUGR) at birth, but the interplay between prenatal Doppler measurements and postnatal development has not been studied in this setting. The present investigation was performed to assess the significance of prenatal Doppler findings relative to postnatal anthropometrics and body composition in IUGR newborns over the first 12 months of life. Patients and Methods Consecutive cases of singleton pregnancies with suspected IUGR were prospectively enrolled over 12 months. Fetal biometry and prenatal Doppler ultrasound examinations were performed. Body composition was assessed by absorptiometry at ages 10 days, and at 4 and12 months. Results A total of 48 pregnancies qualifying as IUGR were studied. Doppler parameters were normal in 26 pregnancies. The remaining 22 deviated from normal, marked by an Umbilical Artery Pulsatility Index (UA-PI) >95th centil or Cerebro-placental ratio (CPR) <5th centile. No significant differences emerged when comparing anthropometry and body composition at each time point, in relation to Doppler findings. Specifically, those IUGR newborns with and without abnormal Doppler findings had similar weight, length, body mass index, lean and fat mass, and bone mineral content throughout the first 12 months of life. In a separate analysis, when comparing IUGR newborns by Doppler (abnormal UA-PI vs. abnormal CPR), anthropometry and body composition did not differ significantly. Conclusions Infants with IUGR maintain a pattern of body composition during the first year of life that is independent of prenatal Doppler findings. Future studies with larger sample sizes and correlating with hormonal status are warranted to further extend the phenotypic characterization of the various conditions now classified under the common label of IUGR. PMID:26938993

Evaluation of Trastuzumab-induced early cardiac dysfunction using two-dimensional Strain Echocardiography.

PubMed

Emren, Sadik Volkan; Tuluce, Selcen Yakar; Levent, Fatih; Tuluce, Kamil; Kalkan, Toygar; Yildiz, Yasar; Alacacioğlu, Ahmet; Kucukzeybek, Yüksel; Akyol, Murat; Salman, Tarık

2015-12-01

Trastuzumab, a chemotherapeutic agent used in the treatment of breast cancer. has been shown to induce subclinical left ventricular (LV) dysfunction during a three to six month period as evidenced by strain echocardiographic examination without any change occurring in the ejection fraction of LV. The present study evaluated the presence of subclinical LV dysfunction using strain echocardiography 1 day and 7 days after the initiation of trastuzumab therapy. The patients with breast cancer receiving adjuvant trastuzumab therapy underwent 2-dimensional, tissue Doppler, and strain echocardiographic examination at baseline and 1 day and 7 days after therapy. LV global longitudinal strain (GLS), global circumferential strain (GCS) values, and other echocardiographic parameters were calculated. A total of 40 females, mean age 50+/-10 years, were evaluated. Of these patients, 97% received anthracycline and 73% received radiotherapy before the initiation of trastuzumab therapy. No change was observed in any of the echocardiographic parameters 1 day after the initiation of trastuzumab therapy (p>0.05). The LV ejection fraction, tissue Doppler parameters, and GCS values did not show any changes 7 days after the initiation of therapy, whereas significant decreases were observed in GLS value (19.2+/-4.0% vs. 17.2+/-3.4, p=0.001) and systolic annular velocity of the lateral LV wall (S' velocity) (10.5+/-3.2 vs. 8.6+/-2.2, p=0.002). Trastuzumab therapy is associated with subclinical LV dysfunction as early as 7 days after initiation of the therapy as evidenced by the decreases in GLS value of LV and systolic annular velocity of the lateral LV wall.

Natriuretic Peptide and Clinical Evaluation in the Diagnosis of Heart Failure Hemodynamic Profile: Comparison with Tissue Doppler Echocardiography.

PubMed

Almeida Junior, Gustavo Luiz Gouvêa de; Clausell, Nadine; Garcia, Marcelo Iorio; Esporcatte, Roberto; Rangel, Fernando Oswaldo Dias; Rocha, Ricardo Mourilhe; Beck-da-Silva, Luis; Silva, Fabricio Braga da; Gorgulho, Paula de Castro Carvalho; Xavier, Sergio Salles

2018-03-01

Physical examination and B-type natriuretic peptide (BNP) have been used to estimate hemodynamics and tailor therapy of acute decompensated heart failure (ADHF) patients. However, correlation between these parameters and left ventricular filling pressures is controversial. This study was designed to evaluate the diagnostic accuracy of physical examination, chest radiography (CR) and BNP in estimating left atrial pressure (LAP) as assessed by tissue Doppler echocardiogram. Patients admitted with ADHF were prospectively assessed. Diagnostic characteristics of physical signs of heart failure, CR and BNP in predicting elevation (> 15 mm Hg) of LAP, alone or combined, were calculated. Spearman test was used to analyze the correlation between non-normal distribution variables. The level of significance was 5%. Forty-three patients were included, with mean age of 69.9 ± 11.1years, left ventricular ejection fraction of 25 ± 8.0%, and BNP of 1057 ± 1024.21 pg/mL. Individually, all clinical, CR or BNP parameters had a poor performance in predicting LAP ≥ 15 mm Hg. A clinical score of congestion had the poorest performance [area under the receiver operating characteristic curve (AUC) 0.53], followed by clinical score + CR (AUC 0.60), clinical score + CR + BNP > 400 pg/mL (AUC 0.62), and clinical score + CR + BNP > 1000 pg/mL (AUC 0.66). Physical examination, CR and BNP had a poor performance in predicting a LAP ≥ 15 mm Hg. Using these parameters alone or in combination may lead to inaccurate estimation of hemodynamics.

Doppler Assessment of Diastolic Function Reflect the Severity of Injury in Rats With Chronic Heart Failure.

PubMed

Sanchez, Pablo; Lancaster, Jordan J; Weigand, Kyle; Mohran, Saffie-Alrahman Ezz-Eldin; Goldman, Steven; Juneman, Elizabeth

2017-10-01

For chronic heart failure (CHF), more emphasis has been placed on evaluation of systolic as opposed to diastolic function. Within the study of diastology, measurements of left ventricular (LV) longitudinal myocardial relaxation have the most validation. Anterior wall radial myocardial tissue relaxation velocities along with mitral valve inflow (MVI) patterns are applicable diastolic parameters in the differentiation between moderate and severe disease in the ischemic rat model of CHF. Myocardial tissue relaxation velocities correlate with traditional measurements of diastolic function (ie, hemodynamics, Tau, and diastolic pressure-volume relationships). Male Sprague-Dawley rats underwent left coronary artery ligation or sham operation. Echocardiography was performed at 3 and 6 weeks after coronary ligation to evaluate LV ejection fraction (EF) and LV diastolic function through MVI patterns (E, A, and E/A) and Doppler imaging of the anterior wall (e' and a'). The rats were categorized into moderate or severe CHF according to their LV EF at 3 weeks postligation. Invasive hemodynamic measurements with solid-state pressure catheters were obtained at the 6-week endpoint. Moderate (N = 20) and severe CHF (N = 22) rats had significantly (P < .05) different EFs, hemodynamics, and diastolic pressure-volume relationships. Early diastolic anterior wall radial relaxation velocities as well as E/e' ratios separated moderate from severe CHF and both diastolic parameters had strong correlations with invasive hemodynamic measurements of diastolic function. Radial anterior wall e' and E/e' can be used for serial assessment of diastolic function in rats with moderate and severe CHF. Copyright © 2017 Elsevier Inc. All rights reserved.

Assessment of regional systolic and diastolic myocardial function using tissue Doppler and strain imaging in dogs with dilated cardiomyopathy.

PubMed

Chetboul, Valérie; Gouni, Vassiliki; Sampedrano, Carolina Carlos; Tissier, Renaud; Serres, François; Pouchelon, Jean-Louis

2007-01-01

Tissue Doppler Imaging (TDI) or strain (St) imaging could provide sensitive indices for early detection and treatment follow-up of canine dilated cardiomyopathy (DCM). Analysis of TDI and St features in dogs with overt DCM is a prerequisite before using these new criteria in prospective screenings of predisposed families or in clinical trials. Radial and longitudinal right and left myocardial motion, assessed by TDI and St variables, is altered in dogs with DCM. Case records for 26 dogs; 14 with DCM and 12 healthy controls of comparable age and weight were reviewed. A retrospective analysis was conducted of conventional echocardiography, 2-dimensional color TDI, and St imaging data. The DCM group was characterized by decreases in radial and longitudinal systolic velocity gradients of the left ventricular free wall (LVFW), radial and longitudinal absolute values of peak systolic St of the LVFW, and longitudinal systolic right ventricular (RV) velocities (all P < .001 versus control) associated with longitudinal postsystolic contraction waves in 7/14 dogs. Early diastolic LVFW velocities also were decreased for longitudinal (P < .01) and radial (P < .05) motions. All radial LVFW, longitudinal basal LVFW, and RV systolic velocities were negatively correlated with heart rate (P < .01). LV contractility along both the short and long axes is impaired in dogs with spontaneous DCM, as is systolic RV and diastolic LVFW function. These myocardial alterations are associated with an inverse force-frequency relationship. Studies now are needed to determine the comparative sensitivity of TDI and St variables for the early detection of canine DCM.

Doppler flowmetry in preeclampsia.

PubMed

Zahumensky, J

2009-01-01

The purpose of this study was to summarize the new published data on the Doppler flowmetry in preeclampsia. We summarize the new published data on the Doppler flowmetry in uteroplacental, fetoplacental and fetal circulation in preeclampsia. The present review summarized the results of clinical research on the Doppler flowmetry in the screening of risk of preclampsia, in the diagnosis of preclampsia and in the fetal risk in preclampsia (Ref. 19). Full Text (Free, PDF) www.bmj.sk.

Optimized doppler optical coherence tomography for choroidal capillary vasculature imaging

NASA Astrophysics Data System (ADS)

Liu, Gangjun; Qi, Wenjuan; Yu, Lingfeng; Chen, Zhongping

2011-03-01

In this paper, we analyzed the retinal and choroidal blood vasculature in the posterior segment of the human eye with optimized color Doppler and Doppler variance optical coherence tomography. Depth-resolved structure, color Doppler and Doppler variance images were compared. Blood vessels down to capillary level were able to be obtained with the optimized optical coherence color Doppler and Doppler variance method. For in-vivo imaging of human eyes, bulkmotion induced bulk phase must be identified and removed before using color Doppler method. It was found that the Doppler variance method is not sensitive to bulk motion and the method can be used without removing the bulk phase. A novel, simple and fast segmentation algorithm to indentify retinal pigment epithelium (RPE) was proposed and used to segment the retinal and choroidal layer. The algorithm was based on the detected OCT signal intensity difference between different layers. A spectrometer-based Fourier domain OCT system with a central wavelength of 890 nm and bandwidth of 150nm was used in this study. The 3-dimensional imaging volume contained 120 sequential two dimensional images with 2048 A-lines per image. The total imaging time was 12 seconds and the imaging area was 5x5 mm2.

The metabolic syndrome is associated with a higher resistance to intravenous thrombolysis for acute ischemic stroke in women than in men.

PubMed

Arenillas, Juan F; Sandoval, Patricio; Pérez de la Ossa, Natalia; Millán, Mónica; Guerrero, Cristina; Escudero, Domingo; Dorado, Laura; López-Cancio, Elena; Castillo, José; Dávalos, Antoni

2009-02-01

The metabolic syndrome (MetS) might confer a higher resistance to intravenous thrombolysis in acute middle cerebral artery (MCA) ischemic stroke. MetS increases the risk of stroke in women to a greater extent than in men. We aimed to investigate whether there might be sex differences in the impact of MetS on the response to intravenous thrombolysis for acute MCA ischemic stroke. We prospectively studied consecutive ischemic stroke patients, treated with intravenous tissue-type plasminogen activator according to SITS-MOST criteria, with an MCA occlusion on prebolus transcranial Doppler examination. Resistance to thrombolysis was defined as the absence of complete MCA recanalization 24 hours after tissue-type plasminogen activator infusion by transcranial Doppler criteria. MetS was diagnosed according to the criteria established by the American Heart Association/National Heart, Lung, and Blood Institute 2005 statement. A total of 125 patients (75 men, 50 women; mean age, 67.6+/-11 years) were included. MetS was diagnosed in 76 (61%) patients. Resistance to clot lysis at 24 hours was observed in 53 (42%) patients. Two multivariate-adjusted, logistic-regression models identified that MetS was associated with a higher resistance to tissue-type plasminogen activator, independently of other significant baseline variables (odds ratio=9.8; 95% CI, 3.5 to 27.8; P=0.0001) and of the individual components of the MetS. The MetS was associated with a significantly higher odds of resistance to thrombolysis in women (odds ratio=17.5; 95% CI, 1.9 to 163.1) than in men (odds ratio=5.1; 95% CI, 1.6 to 15.6; P for interaction=0.0004). The effect of MetS on the resistance to intravenous thrombolysis for acute MCA ischemic stroke appears to be more pronounced in women than in men.

Validation of continuous-wave Doppler echocardiographic measurements of mitral and tricuspid prosthetic valve gradients: a simultaneous Doppler-catheter study.

PubMed

Wilkins, G T; Gillam, L D; Kritzer, G L; Levine, R A; Palacios, I F; Weyman, A E

1986-10-01

For patients with stenotic native valves, the modified Bernoulli equation (delta P = 4V2) may be applied to Doppler-measured transvalvular velocities to yield an accurate estimate of transvalvular gradients. Although it would be useful if the same approach could be used for those with stenotic prosthetic valves, no previous study has validated the Doppler technique in this setting. We therefore recorded simultaneous continuous-wave Doppler flow profiles and transvalvular manometric gradients in 12 catheterized patients in whom all atrial and ventricular pressures were directly measured (transseptal left atrial catheterization and transthoracic ventricular puncture were performed where necessary). A total of 13 prostheses were studied: 11 mitral (seven porcine, three Starr-Edwards, and one Björk-Shiley) and two tricuspid (one porcine and one Björk-Shiley). The Doppler-determined mean gradient was calculated as the mean of the instantaneous gradients (delta P = 4V2) at 10 msec intervals throughout diastole. The correlation of simultaneous Doppler (DMG) and manometric mean gradients (MG) for the whole group (n = 13) demonstrated a highly significant relationship (MG = 1.07 DMG + 0.28; r = .96, p = .0001). The correlation was equally good for porcine valves alone (n = 8) (MG = 1.06 DMG + 0.55; r = .96, p = .001) and for mechanical valves alone (n = 5) (MG = 1.06 DMG - 0.04; r = .93, p = .02). In a subset of patients without regurgitation (n = 8), prosthetic valve areas were estimated by two Doppler methods originally described by Holen and Hatle, as well as by the invasive Gorlin method. As expected from theoretical considerations, a close correlation was not demonstrated between results of the Gorlin method and those of either Hatle's Doppler method (r = .65, fp = NS) or Holen's method (r = .14, p = NS). Comparison of the results of the two Doppler methods yielded a somewhat closer correlation (r = .73, p less than or equal to .05). These results suggest that in patients with disk-occluder, ball-occluder, and porcine prosthetic valves, Doppler estimates of transvalvular gradients are virtually identical to those obtained invasively.

Evaluation of transcatheter arterial embolization therapy on hepatocellular carcinomas using contrast-enhanced harmonic power Doppler sonography: comparison with CT, power Doppler sonography, and dynamic MRI.

PubMed

Shima, Toshihide; Mizuno, Masayuki; Otsuji, Hideaki; Mizuno, Chiemi; Obata, Hirozumi; Park, Hyohun; Nakajo, Shinobu; Okanoue, Takeshi

2005-09-01

The aim of this study was to assess and compare the sensitivity of power Doppler sonography, contrast-enhanced sonography, plain computed tomography (CT), and dynamic magnetic resonance imaging (MRI) for detecting hepatocellular carcinoma (HCC) nodules incompletely treated with transcatheter arterial embolization (TAE). A total of 63 unresectable HCC nodules were examined in this study. The HCCs were treated with TAE. All patients underwent plain CT, power Doppler sonography, contrast-enhanced harmonic power Doppler sonography, and dynamic MRI 1 week after TAE. The sensitivity of each modality to incompletely treated HCC nodules was compared. Detection of the residual viable HCC on angiography or tumor biopsy was regarded as the gold standard for the diagnosis of incomplete treatment. Twenty-four nodules (38%) were diagnosed as incompletely treated. The sensitivities of plain CT, power Doppler sonography, contrast-enhanced harmonic power Doppler sonography, and dynamic MRI to these incompletely treated nodules were 42% (10/24), 46% (11/24), 88% (21/24), and 79% (19/24), respectively. Eighty percent (19 nodules) of the 24 incompletely treated nodules were located within a depth of less than 8 cm. The sensitivities of plain CT, power Doppler sonography, contrast-enhanced harmonic power Doppler sonography, and dynamic MRI to these superficial incompletely treated nodules were 37% (7/19), 53% (10/19), 100% (19/19), and 74% (14/19), respectively. In contrast, the sensitivities of each modality to deeply located nodules were 60% (3/5), 20% (1/5), 40% (2/5), and 100% (5/5), respectively. Plain CT and power Doppler sonography had a low sensitivity to HCC nodules incompletely treated with TAE. Except for those that were deeply located, contrast-enhanced harmonic sonography showed the highest sensitivity in detecting incompletely treated HCC nodules.

Effect of Mitral Annular Calcium on Left Ventricular Diastolic Parameters.

PubMed

Codolosa, Jose N; Koshkelashvili, Nikoloz; Alnabelsi, Talal; Goykhman, Igor; Romero-Corral, Abel; Pressman, Gregg S

2016-03-01

Assessment of left ventricular (LV) diastolic function by Doppler flow imaging and tissue Doppler is an integral part of the echocardiographic examination. Mitral annular calcium (MAC) is frequently encountered on echocardiography. The aim of this study was to assess the impact of MAC, quantitatively measured by computed tomography scan, on echocardiographic LV diastolic parameters. We included 155 patients aged ≥65 years. Computed tomography reconstructions of the mitral annulus were created, and calcium identified and quantified by Agatston technique. Calcium locations were assigned using an overlaid template depicting the annular segments in relation to surrounding anatomic structures. Echocardiographic assessment of diastolic function was performed in standard fashion. Mean age was 77 years; 49% were men; and 43% were black. Patients with MAC had lower septal e' (p = 0.003), lateral e' (p = 0.04), and average e' (p = 0.01) compared with those without MAC. They also had a higher E-wave velocity (p = 0.01) and E/e' ratio (p <0.001). When evaluated by severity of MAC, and after adjustment for multiple clinical factors, there was a graded (inverse) relation between MAC severity and septal e' (p = 0.01), lateral e' (p = 0.01), and average e' (p = 0.01). In conclusion, LV diastolic parameters, as measured by Doppler echocardiography, are altered in the presence of MAC. This could be due to direct effects of MAC on annular function or might reflect truly reduced diastolic function. Interpretation of diastolic parameters in patients with MAC should be performed with caution. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparative Evaluation of Advanced and Conventional Diagnostic Aids for Endodontic Management of Periapical Lesions, An in Vivo Study

PubMed Central

Singh, Smita; Arora, Saurabh; Sandhu, Amneet Kaur; Dhingra, Ravneet

2015-01-01

Aim: To evaluate efficacy of Colour Doppler ultrasonography (CDUSG), direct digital radiography (DDR) and conventional radiography (CR) in diagnosis of periapical lesions and to clinically correlate treatment plan of periapical diseases. Materials and Methods: Thirty patients which were diagnosed with periapical lesions in anterior region by using both conventional and digital radiography were examined using colour doppler ultrasound imaging at the site of lesion. The images of each lesion were analysed by two endodontists and by an expert oral radiologist. A tentative differential diagnosis was agreed upon, based on certain principles discussed in article, then a diagnosis between cyst, granuloma and mixed lesions was made. Periapical lesions diagnosed as mixed lesions by colour doppler ultrasonography (CDUSG) were treated non-surgically whereas other periapical lesions were treated surgically. Tissues obtained during endodontic surgery were processed and examined for histopathological findings, and compared with the diagnosis made by ultrasound images. Statistical analysis was done with Chi-Square test and using one-way-Anova. Results: The periapical lesions which were diagnosed as granuloma by ultrasonographic findings, was confirmed by the results of histopathological examination in all 16 surgically treated cases. The lesions in rest of the 14 cases which showed vascularity and were diagnosed as mixed lesions by ultrasonography, were treated non-surgically and had a favourable prognosis. Conclusion: CR and DDR facilitate diagnosis of the presence of periapical disease, but do not provide and information of its nature. CDUSG imaging facilitates accurate information on the pathological nature of the lesion and hence can lead to predictable treatment planning. PMID:25738075

Protective effects of a selective neutrophil elastase inhibitor (sivelestat) on lipopolysaccharide-induced acute dysfunction of the pulmonary microcirculation.

PubMed

Inoue, Yoshiaki; Seiyama, Akitoshi; Tanaka, Hiroshi; Ukai, Isao; Akimau, Pavel; Nishino, Masato; Shimazu, Takeshi; Sugimoto, Hisashi

2005-08-01

The purpose of this study was to evaluate the effect of a neutrophil elastase inhibitor, sivelestat, on lipopolysaccharide-induced acute lung injury through analysis of hemodynamic changes in the pulmonary microcirculation. Randomized animal study. Medical school laboratory. Twenty-seven Wistar rats (15 rats for microspectroscopic observations, 12 rats for measurements of neutrophil elastase activity and wet-to-dry ratio). Thoracosternotomy was performed on male Wistar rats under continuous anesthesia and mechanical ventilation. Rats were divided into three groups (n = 5 each groups) on the basis of the reagent used: lipopolysaccharide group (100 microg/kg lipopolysaccharide intravenously), sivelestat group (10 mg/kg sivelestat; 100 microg/kg lipopolysaccharide intravenously), and control group (saline only, intravenously). We measured morphologic changes and hemodynamic variables, including tissue blood flow, erythrocyte velocity, erythrocyte count, thickness of interalveolar septa, and leukocyte adhesion in the pulmonary microcirculation, with a video-rate (33 msec/frame) dual-spot microspectroscopy system (DSMSS) and a laser-Doppler flowmeter. Blood-free wet-to-dry ratio and neutrophil elastase activity in bronchoalveolar lavage fluid, serum, and supernatant of lung homogenate were measured in another set of experiments (n = 4 for each group). Sixty minutes after lipopolysaccharide administration, severe thickening of the interalveolar septa was observed in the lipopolysaccharide but not the sivelestat group. In the lipopolysaccharide group, DSMSS measurements of erythrocyte velocity and hemoglobin oxygenation in single capillaries were decreased significantly (vs. control p < .05, vs. sivelestat p < .01), whereas tissue blood flow and erythrocyte velocity measurements from laser-Doppler flowmeter were increased significantly (vs. control p < .05, vs. sivelestat p < .01). The number of adherent leukocytes was increased significantly in the lipopolysaccharide group at 30, 45, and 60 mins after lipopolysaccharide administration (vs. control p < .01, vs. sivelestat p < .05). The number of adherent leukocytes did not increase in the sivelestat group. The wet-to-dry ratio was significantly higher in the lipopolysaccharide group than in control (p < .05) and sivelestat (p < .05) groups. Neutrophil elastase activities in the bronchoalveolar lavage fluid, serum, and lung tissue were all significantly lower in the sivelestat group than in the lipopolysaccharide group (p < .05). Lipopolysaccharide induces leukocyte adhesion in the pulmonary microcirculation, resulting in decreased tissue hemoglobin oxygen and alveolar and interstitial edema. The selective neutrophil elastase inhibitor sivelestat reduces neutrophil elastase activity and attenuates acute changes in the pulmonary microcirculation.

Peripheral arteriovenous fistula as vascular access for long-term chemotherapy.

PubMed

Kovalyov, Oleksiy O; Kostyuk, Oleksandr G; Tkachuk, Tetyana V

To provide long-term vascular access in clinical oncology peripheral forearm veins (up to 95% of patients in Ukraine), central venous access and "complete implanted vascular systems" are used most often. Many oncology patients have contraindications to catheterization of superior vena cava. Besides, exploitation of central veins is associated with potential technical and infectious complications. The aim - to study short-term and long-term results of arteriovenous fistula exploitation as vascular access for continuous anticancer therapy. Peripheral venous bed status in 41 oncology patients taking long-term chemotherapy treatment is analyzed in the article. Doppler sonography, morphologic and immune histochemical analyses were used in the study. Doppler sonography found qualitative and quantitative changes in forearm veins at different time periods after initiation of chemotherapy in the majority of patients. The major morphologic manifestations of venous wall damage were chemical phlebitis, local or extended hardening of venous wall, venous thrombosis and extravasations with necrosis and subsequent paravasal tissue sclerosis. Alternative vascular access created in 12 patients completely met the adequacy criteria (safety, multiple use, longevity, realization of the designed therapy program). The conclusion was made about inapplicability of forearm veins for long-term administration of cytostatic agents. If it is impossible to use central veins, arteriovenous fistula can become an alternative vascular access.

The effect of three different surgical techniques for colon anastomosis on regional postoperative microperfusion: Laser Doppler Flowmetry study in pigs.

PubMed

Kaska, Milan; Blazej, Slavomir; Turek, Zdenek; Ryska, Ales; Jegorov, Boris; Radochova, Vera; Bezouska, Jan; Paral, Jiri

2018-01-01

The optimal surgical approach to reconnecting bowel ends safely after resection is of great importance. This project is focused on assessment of the perianastomotic microcirculation quality in the short postoperative period when using three different anastomosis techniques in experimental animal. The experimental study involved 27 young female domestic pigs divided into three subgroups of 9 animals according to each surgical method of anastomosis construction in the sigmoid colon region: by manual suture, by stapler, or by gluing. Blood microcirculation in the anastomosis region was monitored using Laser Doppler Flowmetry (LDF). Anastomosis healing was evaluated by macroscopic and histological examination. Evaluation of the microcirculation in the anastomosis region showed the smallest decrease in perfusion values in animals reconstructed by suturing (Δ= -38.01%). A significantly more profound drop was observed postoperatively after stapling or gluing (Δ= -52.42% and Δ= -59.53%, respectively). All performed anastomoses healed without any signs of tissue and function pathology. Sewing, stapling, and gluing techniques for bowel anastomosis each have a different effect on regional microcirculation during 120 min. postoperatively. Nevertheless, the final results of anastomosis healing were found without of any pathology in all experimental animals managed by above mentioned anastomotic techniques.

Ultrasound-mediated microbubble enhancement of radiation therapy studied using three-dimensional high-frequency power Doppler ultrasound.

PubMed

Kwok, Sheldon J J; El Kaffas, Ahmed; Lai, Priscilla; Al Mahrouki, Azza; Lee, Justin; Iradji, Sara; Tran, William Tyler; Giles, Anoja; Czarnota, Gregory J

2013-11-01

Tumor responses to high-dose (>8 Gy) radiation therapy are tightly connected to endothelial cell death. In the study described here, we investigated whether ultrasound-activated microbubbles can locally enhance tumor response to radiation treatments of 2 and 8 Gy by mechanically perturbing the endothelial lining of tumors. We evaluated vascular changes resulting from combined microbubble and radiation treatments using high-frequency 3-D power Doppler ultrasound in a breast cancer xenograft model. We compared treatment effects and monitored vasculature damage 3 hours, 24 hours and 7 days after treatment delivery. Mice treated with 2 Gy radiation and ultrasound-activated microbubbles exhibited a decrease in vascular index to 48 ± 10% at 24 hours, whereas vascular indices of mice treated with 2 Gy radiation alone or microbubbles alone were relatively unchanged at 95 ± 14% and 78 ± 14%, respectively. These results suggest that ultrasound-activated microbubbles enhance the effects of 2 Gy radiation through a synergistic mechanism, resulting in alterations of tumor blood flow. This novel therapy may potentiate lower radiation doses to preferentially target endothelial cells, thus reducing effects on neighboring normal tissue and increasing the efficacy of cancer treatments. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Low-frequency high-definition power Doppler in visualizing and defining fetal pulmonary venous connections.

PubMed

Liu, Lin; He, Yihua; Li, Zhian; Gu, Xiaoyan; Zhang, Ye; Zhang, Lianzhong

2014-07-01

The use of low-frequency high-definition power Doppler in assessing and defining pulmonary venous connections was investigated. Study A included 260 fetuses at gestational ages ranging from 18 to 36 weeks. Pulmonary veins were assessed by performing two-dimensional B-mode imaging, color Doppler flow imaging (CDFI), and low-frequency high-definition power Doppler. A score of 1 was assigned if one pulmonary vein was visualized, 2 if two pulmonary veins were visualized, 3 if three pulmonary veins were visualized, and 4 if four pulmonary veins were visualized. The detection rate between Exam-1 and Exam-2 (intra-observer variability) and between Exam-1 and Exam-3 (inter-observer variability) was compared. In study B, five cases with abnormal pulmonary venous connection were diagnosed and compared to their anatomical examination. In study A, there was a significant difference between CDFI and low-frequency high-definition power Doppler for the four pulmonary veins observed (P < 0.05). The detection rate of each pulmonary vein when employing low-frequency high-definition power Doppler was higher than that when employing two-dimensional B-mode imaging or CDFI. There was no significant difference between the intra- and inter-observer variabilities using low-frequency high-definition power Doppler display of pulmonary veins (P > 0.05). The coefficient correlation between Exam-1 and Exam-2 was 0.844, and the coefficient correlation between Exam-1 and Exam-3 was 0.821. In study B, one case of total anomalous pulmonary venous return and four cases of partial anomalous pulmonary venous return were diagnosed by low-frequency high-definition power Doppler and confirmed by autopsy. The assessment of pulmonary venous connections by low-frequency high-definition power Doppler is advantageous. Pulmonary venous anatomy can and should be monitored during fetal heart examination.

A novel decision tree approach based on transcranial Doppler sonography to screen for blunt cervical vascular injuries.

PubMed

Purvis, Dianna; Aldaghlas, Tayseer; Trickey, Amber W; Rizzo, Anne; Sikdar, Siddhartha

2013-06-01

Early detection and treatment of blunt cervical vascular injuries prevent adverse neurologic sequelae. Current screening criteria can miss up to 22% of these injuries. The study objective was to investigate bedside transcranial Doppler sonography for detecting blunt cervical vascular injuries in trauma patients using a novel decision tree approach. This prospective pilot study was conducted at a level I trauma center. Patients undergoing computed tomographic angiography for suspected blunt cervical vascular injuries were studied with transcranial Doppler sonography. Extracranial and intracranial vasculatures were examined with a portable power M-mode transcranial Doppler unit. The middle cerebral artery mean flow velocity, pulsatility index, and their asymmetries were used to quantify flow patterns and develop an injury decision tree screening protocol. Student t tests validated associations between injuries and transcranial Doppler predictive measures. We evaluated 27 trauma patients with 13 injuries. Single vertebral artery injuries were most common (38.5%), followed by single internal carotid artery injuries (30%). Compared to patients without injuries, mean flow velocity asymmetry was higher for single internal carotid artery (P = .003) and single vertebral artery (P = .004) injuries. Similarly, pulsatility index asymmetry was higher in single internal carotid artery (P = .015) and single vertebral artery (P = .042) injuries, whereas the lowest pulsatility index was elevated for bilateral vertebral artery injuries (P = .006). The decision tree yielded 92% specificity, 93% sensitivity, and 93% correct classifications. In this pilot feasibility study, transcranial Doppler measures were significantly associated with the blunt cervical vascular injury status, suggesting that transcranial Doppler sonography might be a viable bedside screening tool for trauma. Patient-specific hemodynamic information from transcranial Doppler assessment has the potential to alter patient care pathways to improve outcomes.

Power Doppler flow mapping and four-dimensional ultrasound for evaluating tubal patency compared with laparoscopy.

PubMed

Soliman, Amr A; Shaalan, Waleed; Abdel-Dayem, Tamer; Awad, Elsayed Elbadawy; Elkassar, Yasser; Lüdders, Dörte; Malik, Eduard; Sallam, Hassan N

2015-12-01

To study the accuracy of four-dimensional (4D) ultrasound and power Doppler flow mapping in detecting tubal patency in women with sub-/infertility, and compare it with laparoscopy and chromopertubation. A prospective study. The study was performed in the outpatient clinic and infertility unit of a university hospital. The sonographic team and laparoscopic team were blinded to the results of each other. Women aged younger than 43 years seeking medical advice due to primary or secondary infertility and who planned to have a diagnostic laparoscopy performed, were recruited to the study after signing an informed consent. All of the recruited patients had power Doppler flow mapping and 4D hysterosalpingo-sonography by injecting sterile saline into the fallopian tubes 1 day before surgery. Registering Doppler signals, while using power Doppler, both at the tubal ostia and fimbrial end and the ability to demonstrate the course of the tube especially the isthmus and fimbrial end, while using 4D mode, was considered a patent tube. Out of 50 recruited patients, 33 women had bilateral patent tubes and five had unilateral patent tubes as shown by chromopertubation during diagnostic laparoscopy. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for two-dimensional power Doppler hysterosalpingography were 94.4%, 100%, 100%, 89.2%, and 96.2%, respectively and for 4D ultrasound were 70.4%, 100%, 100%, 70.4%, and 82.6%, respectively. Four-dimensional saline hysterosalpingography has acceptable accuracy in detecting tubal patency, but is surpassed by power Doppler saline hysterosalpingography. Power Doppler saline hysterosalpingography could be incorporated into the routine sub-/infertility workup. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

High-sensitivity detection and monitoring of microcirculation using cutaneous and catheter probes for Doppler optical coherence tomography

NASA Astrophysics Data System (ADS)

Yang, Victor X.; Gordon, M. L.; Qi, B.; Yue, E. Seng; Tang, S.; Bisland, Stuart K.; Pekar, J.; Lo, S.; Marcon, Norman E.; Wilson, B.; Vitkin, Alex

2003-07-01

Background: Currently clinical Doppler ultrasound cannot detect microvascular blood flow and it is difficult to provide depth discrimination using laser Doppler flowmetry. Doppler optical coherence tomography (DOCT) is a novel technique for noninvasive subsurface imaging of microcirculation and tissue structure. Aims: To design handheld and catheter-based DOCT probes for clinical cutaneous and endoscopic imaging. To develop signal processing techniques for real-time detection and quantification of microvascular blood flow. Methods: A DOCT system, with interchangeable cutaneous and catheter probes, was developed. The axial spatial resolution was 10 μm, and the velocity resolution was 20 μm/s, using a 1300 nm broadband infrared light. The system achieved real-time imaging with frame rates up to 32 Hz at 512 x 256 pixels per frame. We used the system to detect microcirculation in human skin and rat esophagus, and to monitor microvascular responses to photodynamic therapy (PDT) in a rat tumor model. Results: We present experimental results from in vivo DOCT imaging of microcirculation in human skin arterio-venous malformations (AVM), normal rat esophagus, and a rat gliosarcoma PDT model. In the PDT model, we followed microvascular responses to PDT and observed differences in the microcirculation during and after therapy, which can have important implications for PDT dosimetry and treatment optimization. Conclusions: To our knowledge, this is the first demonstration of endoscopic catheter-based DOCT detection of microcirculation in vivo. In addition, AVM can be detected using handheld cutaneous DOCT probes under clinical settings. DOCT may serve as a real-time monitoring tool for PDT dosimetry, especially for vascular targeting photosensitizers.

Left atrial strain: a new parameter for assessment of left ventricular filling pressure.

PubMed

Cameli, Matteo; Mandoli, Giulia Elena; Loiacono, Ferdinando; Dini, Frank Lloyd; Henein, Michael; Mondillo, Sergio

2016-01-01

In order to obtain accurate diagnosis, treatment and prognostication in many cardiac conditions, there is a need for assessment of left ventricular (LV) filling pressure. While systole depends on ejection function of LV, diastole and its disturbances influence filling function and pressures. The commonest condition that represents the latter is heart failure with preserved ejection fraction in which LV ejection is maintained, but diastole is disturbed and hence filling pressures are raised. Significant diastolic dysfunction results in raised LV end-diastolic pressure, mean left atrial (LA) pressure and pulmonary capillary wedge pressure, all referred to as LV filling pressures. Left and right heart catheterization has traditionally been used as the gold standard investigation for assessing these pressures. More recently, Doppler echocardiography has taken over such application because of its noninvasive nature and for being patient friendly. A number of indices are used to achieve accurate assessment of filling pressures including: LV pulsed-wave filling velocities (E/A ratio, E wave deceleration time), pulmonary venous flow (S wave and D wave), tissue Doppler imaging (E' wave and E/E' ratio) and LA volume index. LA longitudinal strain derived from speckle tracking echocardiography (STE) is also sensitive in estimating intracavitary pressures. It is angle-independent, thus overcomes Doppler limitations and provides highly reproducible measures of LA deformation. This review examines the application of various Doppler echocardiographic techniques in assessing LV filling pressures, in particular the emerging role of STE in assessing LA pressures in various conditions, e.g., HF, arterial hypertension and atrial fibrillation.

The Place of Nailfold Capillaroscopy Among Instrumental Methods for Assessment of Some Peripheral Ischaemic Syndromes in Rheumatology.

PubMed

Lambova, Sevdalina N

2016-01-01

Micro- and macrovascular pathology is a frequent finding in a number of common rheumatic diseases. Secondary Raynaud's phenomenon (RP) is among the most common symptoms in systemic sclerosis and several other systemic autoimmune diseases including a broad differential diagnosis. It should be also differential from other peripheral vascular syndromes such as embolism, thrombosis, etc., some of which lead to clinical manifestation of the blue toe syndrome. The current review discusses the instrumental methods for vascular assessments. Nailfold capillaroscopy is the only method among the imaging techniques that can be used for morphological assessment of the nutritive capillaries in the nailfold area. Laser-Doppler flowmetry and laser-Doppler imaging are methods for functional assessment of microcirculation, while thermography and plethysmography reflect both blood flow in peripheral arteries and microcirculation. Doppler ultrasound and angiography visualize peripheral arteries. The choice of the appropriate instrumental method is guided by the clinical presentation. The main role of capillaroscopy is to provide differential diagnosis between primary and secondary RP. In rheumatology, capillaroscopic changes in systemic sclerosis have been recently defined as diagnostic. The appearance of abnormal capillaroscopic pattern inherits high positive predictive value for the development of a connective tissue disease that is higher than the predictive value of antinuclear antibodies. In cases of abrupt onset of peripheral ischaemia, clinical signs of critical ischaemia, unilateral or lower limb involvement, Doppler ultrasound and angiography are indicated. The most common causes for such clinical picture that may be referred to rheumatologic consultation are the antiphospholipid syndrome, mimickers of vasculitides such as atherosclerosis with cholesterol emboli, and neoplasms.

Ultrasonic and optical evaluation of surgical implant materials and devices. A durability study of pericardial bioprostheses

NASA Technical Reports Server (NTRS)

Schuster, P. R.

1984-01-01

Laser Doppler Anemometry (LDA) and accelerated fatigue testing were used in an attempt to assess the durability of two cardiac value bioprostheses. The LDA system was used to monitor the function of the cardiac valves over time. This was done through flow characterization in an aortic flow chamber, designed to closely simulate in vivo conditions, both in the near vicinity (sinuses of valsalva region) and also somewhat downstream (aortic region) from the values. The accelerated fatigue tester was operated by opening and closing the valves at a rate of 1300 R.P.M., about 18 x the normal rate. The results from the two test valves indicate a definite change in the flow characteristics downstream from the valve after certain accelerated test intervals. The high velocity cross-sectional flow area seems to increase over time in use, causing a decrease in the peak velocity. The tissue became more flaccid in certain areas, and tears were apparent at about 9.4 million cycles for the Ionescu-Shiley valve and at 24 million cycles for the Carpentier-Edwards valve. The use of Doppler ultrasound as a technique for monitoring the function of bioprostheses over time in vivo is also discussed.

Increased mitral valve regurgitation and myocardial hypertrophy in two dogs with long-term pimobendan therapy.

PubMed

Tissier, R; Chetboul, V; Moraillon, R; Nicolle, A; Carlos, C; Enriquez, B; Pouchelon, J-L

2005-01-01

The aim of this article is to describe original adverse effects in two dogs chronically treated with the inodilator pimobendan. We report a German shepherd (i.e., dog 1) and a poodle (i.e., dog 2) that were referred to our cardiology unit after receiving pimobendan for 10 and 5 mo, respectively. In both dogs, conventional echo-Doppler examination demonstrated mitral valve regurgitation and myocardial hypertrophy. Tissue Doppler imaging (TDI) was performed in the first case and revealed an abnormal relaxation phase. After the first examination, pimobendan administration was stopped in both cases and dogs were re-examined 3 and 1 mo later, respectively. Mitral valve regurgitation assessed by echocardiography decreased in both dogs, and the systolic heart murmur disappeared in dog 1. Importantly, most echocardiographic and TDI parameters tended to normalize in dog 1, suggesting, at least partial reversal of both myocardial hypertrophy and relaxation abnormality produced during inodilator therapy. This is the first report to describe an increase in mitral regurgitation under clinical conditions in dogs treated with pimobendan. We also suggest that pimobendan may induce ventricular hypertrophy. However, prospective studies are needed to confirm this observation.

Introducing a Mobile-Connected Umbilical Doppler Device (UmbiFlow™) into a Primary Care Maternity Setting: Does This Reduce Unnecessary Referrals to Specialised Care? Results of a Pilot Study in Kraaifontein, South Africa.

PubMed

Mufenda, Josef; Gebhardt, Stefan; van Rooyen, Rita; Theron, Gerhard

2015-01-01

UmbiFlow™ is a mobile-connected Doppler device that utilises a continuous waveform to measure resistance in the umbilical artery. The main aim of this pilot study was to determine whether the use of UmbiFlow™ for umbilical artery Doppler in patients with a suspected decreased symphysis fundal (SF) growth could safely lead to a decreased number of patients requiring referral to a more specialised level of care. A secondary aim of the study was to evaluate the effectiveness of UmbiFlow™ Doppler as a screening tool for concealed placental insufficiency in late bookers by using a single screening cut-off value that will be abnormal for any gestation >28 weeks. The cohort comprised two groups of patients: The first group included all follow-up patients with suspected intra-uterine growth restriction (a decreased symphysis-fundus measurement based on serial assessment) who underwent on-site UmbiFlow™Doppler testing performed by the midwife directly after the clinical examination. The second group included late bookers, where gestation was uncertain; but estimated >28 weeks based on clinical grounds. This group was comprised of unselected patients who report to antenatal care late for the first time and received an UmbiFlow™Doppler test for concealed placental insufficiency. UmbiFlow™Doppler could reduce the number of false referrals to hospital by 55%. A single UmbiFlow™Doppler test in late bookers appeared to identify a group of women at moderate risk of lower birth weight babies.

Local microcirculation disorders in uterus under laser tissue welding and their influence in the healing process

NASA Astrophysics Data System (ADS)

Kozlov, Valentine I.; Skobelkin, Oleg K.; Fatkullin, Ildar; Terman, Oleg A.; Chizhov, Gennadii; Gabidullina, Rushania

1994-12-01

To study the possibility of using Nd:YAG laser to weld the tissues of the uterus experiments in rats and dogs have been conducted. With the biomicroscopy and the laser Doppler flowmetry we have evaluated the microcirculation in the uterus wall under traditional suture and laser welding suture. As a model of the wound, the dissection of serosa and muscles of the organ wall have been used. In laser welding suture we have welded the zone of tissue about 1 mm3 with the laser (power density 270 W/cm2). Histological control has been fulfilled on various phases of the healing process. The investigation of the uterus wall demonstrates that there are zones of microcirculation disorders in tissues: (1) the zone of coagulation of microvessels and adjacent tissues (about 100 micrometers ); (2) the zone of stasis (150 - 200 micrometers ); (3) the zone of reactive-destructive changes of microvessels (300 micrometers ), (4) the zone of malfunctional microcirculatory changes (600 micrometers ). The coagulation of microvessels changes the character of inflammation and the healing process, decreases the exudation phase and the leucocyte infiltration of tissues, and accelerates the capillary growth. In contrast with traditional suture, in the case of laser welding suture the edema and hemorrhagic signs are less expressed. The complete restoration of microcirculation under laser welding suture has been observed by the fourteenth day of the healing process. Under the traditional suture method normalization of tissue nutritious blood flow has been achieved by 21 days.

Doppler waveform study as indicator of change of portal pressure after administration of octreotide

PubMed Central

Haider, Shahbaz; Hussain, Qurban; Tabassum, Sumera; Hussain, Bilal; Durrani, Muhammad Rasheed; Ahmed, Fayyaz

2016-01-01

Objective: To estimate the effect of portal pressure lowering drug ‘octreotide’, by observing the Doppler waveform before and after the administration of intravenous bolus of octreotide and thus to assess indirectly its efficacy to lower the portal pressure. Methods: This quassi experimental study was carried out in Medical Department in collaboration with Radiology Department of Jinnah Postgraduate Medical Center Karachi Pakistan from September 10, 2015 to February 5, 2016. Cases were selected from patients admitted in Medical Wards and those attending Medical OPD. Diagnosis of cirrhosis was confirmed by Clinical Examination and Lab & Imaging investigation in Medical Department. Doppler waveform study was done by experienced radiologist in Radiology Department before and after administration of octreotide. Doppler signals were obtained from the right hepatic vein. Waveform tracings were recorded for five seconds and categorized as ‘monophasic’, ‘biphasic’ and ‘triphasic’. Waveform changes from one waveform to other were noted and analyzed. Results: Significant change i.e. from ‘monophasic’ to ‘biphasic’ or ‘biphasic’ to ‘triphasic’ was seen in 56% cases while ‘monophasic’ to ‘triphasic’ was seen in 20% cases. No change was seen in 24% cases. Improvement in waveform reflects lowering of portal vein pressure. Conclusion: Non invasive Hepatic vein Doppler waveform study showed improvement in Doppler waveform after administration of octreotide in 76% cases. Doppler waveform study has the potential of becoming non invasive ‘follow up tool’ of choice for assessing portal pressure in patients having variceal bleed due to portal hypertension. PMID:27648043

A Comparative Study on Quantitative Assessment of Blood Flow and Vascularization in Polycystic Ovary Syndrome Patients and Normal Women Using Three-Dimensional Power Doppler Ultrasonography.

PubMed

Garg, Nitasha; Khaira, Harkiran Kaur; Kaur, Manjot; Sinha, Smita

2018-04-01

To compare the quantitative assessment of blood flow and vascularization of ovaries in polycystic ovary syndrome patients and normal women using three-dimensional power Doppler ultrasonography. This cross-sectional quantitative study was conducted on women of reproductive age group (15-45 years) attending Gynaecology OPD AIMSR, Bathinda, Punjab. Thirty women were enrolled in polycystic ovarian syndrome (PCOS) group and 30 healthy women in control group. Women were categorized as polycystic ovary syndrome according to Rotterdam's criteria. The women with PCOS underwent transvaginal USG Doppler on day 6 of the cycle using 3D power Doppler USG equipment (GE Voluson E8), and vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were measured. The mean values of VI, FI and VFI measured by power Doppler ultrasonography were significantly increased ( P value = 0.000) in women with PCOS when compared with healthy women. This study suggests that blood flow and vascularization measured by 3D power Doppler ultrasonography in ovaries of polycystic ovary syndrome patients were significantly more than the ovaries of normal women.

The uses of two-dimensional Doppler echocardiographic techniques preoperatively and postoperatively in a ventricular septal defect caused by penetrating trauma.

PubMed

Goldman, A P; Kotler, M N; Goldberg, S E; Parameswaran, R; Parry, W

1985-12-01

Doppler echocardiography was used to determine the site and size of a ventricular septal defect in a patient with a penetrating wound of the heart. Additional physiological measurements by Doppler study, including pulmonary artery pressure and degree of left-to-right shunting, were helpful in deciding on surgical closure of the defect as the definitive therapy in this patient. Associated intracardiac defects (e.g., mitral or tricuspid regurgitation) can be excluded by Doppler echocardiography.

Echocardiography for cardiac resynchronization therapy: recommendations for performance and reporting--a report from the American Society of Echocardiography Dyssynchrony Writing Group endorsed by the Heart Rhythm Society.

PubMed

Gorcsan, John; Abraham, Theodore; Agler, Deborah A; Bax, Jeroen J; Derumeaux, Genevieve; Grimm, Richard A; Martin, Randy; Steinberg, Jonathan S; Sutton, Martin St John; Yu, Cheuk-Man

2008-03-01

Echocardiography plays an evolving and important role in the care of heart failure patients treated with biventricular pacing, or cardiac resynchronization therapy (CRT). Numerous recent published reports have utilized echocardiographic techniques to potentially aide in patient selection for CRT prior to implantation and to optimized device settings afterwards. However, no ideal approach has yet been found. This consensus report evaluates the contemporary applications of echocardiography for CRT including relative strengths and technical limitations of several techniques and proposes guidelines regarding current and possible future clinical applications. Principal methods advised to qualify abnormalities in regional ventricular activation, known as dyssynchrony, include longitudinal velocities by color-coded tissue Doppler and the difference in left ventricular to right ventricular ejection using routine pulsed Doppler, or interventricular mechanical delay. Supplemental measures of radial dynamics which may be of additive value include septal-to-posterior wall delay using M-mode in patients with non-ischemic disease with technically high quality data, or using speckle tracking radial strain. A simplified post-CRT screening for atrioventricular optimization using Doppler mitral inflow velocities is also proposed. Since this is rapidly changing field with new information being added frequently, future modification and refinements in approach are anticipated to continue.

Comparison of the Diagnostic Performance of Power Doppler Ultrasound and a New Microvascular Doppler Ultrasound Technique (AngioPLUS) for Differentiating Benign and Malignant Breast Masses.

PubMed

Jung, Hae Kyoung; Park, Ah Young; Ko, Kyung Hee; Koh, Jieun

2018-03-12

This study was performed to compare the diagnostic performance of power Doppler ultrasound (US) and a new microvascular Doppler US technique (AngioPLUS; SuperSonic Imagine, Aix-en-Provence, France) for differentiating benign and malignant breast masses. Power Doppler US and AngioPLUS findings were available in 124 breast masses with confirmed pathologic results (benign, 80 [64.5%]; malignant, 44 [35.5%]). The diagnostic performance of each tool was calculated to distinguish benign from malignant masses using a receiver operating characteristic curve analysis and compared. The area under the curve showed that AngioPLUS was superior to power Doppler US in differentiating benign from malignant breast masses, but the difference was not statistically significant. © 2018 by the American Institute of Ultrasound in Medicine.

Antiinflammatory effect of BPC 157 on experimental periodontitis in rats.

PubMed

Keremi, B; Lohinai, Z; Komora, P; Duhaj, S; Borsi, K; Jobbagy-Ovari, G; Kallo, K; Szekely, A D; Fazekas, A; Dobo-Nagy, C; Sikiric, P; Varga, G

2009-12-01

The pentadecapeptide BPC 157 has been shown to have anti-inflammatory and wound healing effects on multiple target tissues and organs. The purpose of the present study was to investigate the effect of BPC 157 on inflammation and bone resorption in experimental periodontitis in rats. First the acute effect of BPC was tested on gingival blood flow by laser doppler flowmetry. Then periodontitis was produced by a silk ligature placed around the lower left first molar. Rats were treated with BPC 157 (once daily for 12 days) or vehicle. At day 13, the gingivomucosal tissues encircling the molars were removed on both sides. Inflammation was assessed by Evans blue plasma extravasation technique and by histology. Alveolar bone loss was analyzed by microCT. BPC 157 had no effect on gingivomucosal blood flow. Twelve day ligature caused a significantly increased Evans blue extravasation in the gingivomucosal tissue, histological signs of inflammation, and alveolar bone destruction. BPC 157 treatment significantly reduced both plasma extravasation, histological alterations and alveolar bone resorption. In conclusion, systemic application of BPC 157 does not alter blood circulation in healthy gingiva. Chronic application of the peptide has potent antiinflammatory effects on periodontal tissues in ligature induced periodontitis in rats. Taken together, this proof of concept study suggests that BPC 157 may represent a new peptide candidate in the treatment of periodontal disease.

Determining the appropriate number and duration of leech therapy in congested tissues using tissue spectrophotometry and laser Doppler flowmetry.

PubMed

Rothenberger, Jens; Petersen, Wiebke; Schaller, Hans-Eberhard; Held, Manuel

2016-11-01

A universal protocol determining the number of leeches and their application time does not exist. The aim of this study, therefore, is to quantify perfusion dynamics in venous congested tissues after leech application to get more detailed information about changes due to leech-induced skin microcirculation and to evaluate the usability of the Oxygen to See (O2C) device in terms of determining the appropriate number of leeches and the duration of therapy. Twelve patients with the need for leech therapy participated in the study. Perfusion dynamics of the congested tissue was assessed using the O2C device, which determines blood flow (BF), the relative amount of hemoglobin (rHB), and the oxygen saturation (SO2). Measurements were carried out before leech application and on various intervals like 10 minutes, one hour, and three hours after leech application. The leech application effectuated after 10 minutes a nonsignificant perfusion improvement, which further increased after one hour with a significant reduction of the relative amount of hemoglobin and a significant increase of blood flow and oxygen saturation (BF= +56.7%; rHB= -25.5%; SO2= +53.7%). After three hours, the values returned to the levels before leech administration. In two cases, in which further administration of leeches within the measurement period was necessary, no substantial perfusion changes were obtained. The results of this study forms a more precise pattern of microcirculatory changes of leech therapy in congested tissues. According to our measurements a venous drainage improvement can be expected in congested tissue one hour after leech administration. The O2C seems to be a useful method to determine the appropriate number and duration of leech therapy. © 2016 by the Wound Healing Society.

Echocardiographic evaluation of left ventricular diastolic dysfunction in subclinical hypothyroidism: A case-control study.

PubMed

Malhotra, Yuthika; Kaushik, Rajeev Mohan; Kaushik, Reshma

2017-08-01

To study the prevalence of left ventricular diastolic dysfunction (LVDD) in patients with subclinical hypothyroidism (SCH) and the response of LVDD to L-thyroxine therapy. This cross-sectional case-control study with one longitudinal arm included 67 patients with SCH attending a tertiary care hospital in Uttarakhand, India, and 67 age- and sex-matched healthy controls. LVDD was assessed by 2D, pulsed-wave Doppler (PWD), continuous wave Doppler (CWD), and tissue Doppler echocardiography (TDE). Patients with LVDD received L-thyroxine therapy with reassessment for LVDD 6 months later. SCH patients had a higher prevalence of LVDD than controls (13.43% versus 1.49%; p = 0.017). LVDD showed a significant association with gender (p = 0.004) and serum FT4 (p = 0.001). E velocity, E' velocity, A' velocity, iso-volumetric relaxation time (IVRT), E/A, and E'/A' ratios were significantly lower, while A velocity, deceleration time (DT), E/E' ratio, left atrial (LA) volume index, and peak tricuspid regurgitation (TR) velocity were significantly higher in cases than controls (p < 0.05 each). The E/A ratio correlated significantly with age, serum very low-density lipoprotein (VLDL), triglycerides (TG), thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and high-density lipoprotein (HDL) (p < 0.05 each). E' velocity correlated significantly with age, serum total cholesterol, VLDL, and TG (p < 0.05 each), DT with serum total cholesterol (p = 0.047), and LA volume index with age (p = 0.021). Age (p = 0.016) and serum HDL (p = 0.029) were independent predictors of E/A ratio. Gender was an independent predictor for LVDD (p = 0.003). Echocardiographic indices for LVDD showed significant improvement after 6 months of L-thyroxine therapy (p < 0.05 each). LVDD occurs commonly in SCH patients. It can be detected timely using echocardiography and may be reversed by L-thyroxine therapy.

Refrigeration and freezing of porcine tissue does not affect the retardation of fragment simulating projectiles.

PubMed

Breeze, J; Carr, D J; Mabbott, A; Beckett, S; Clasper, J C

2015-05-01

Explosively propelled fragments are the most common cause of injury to UK service personnel in modern conflicts. Numerical injury models to simulate such injuries utilise algorithms based upon gelatin and animal tissue testing but data is limited on many fragment simulating projectiles and these simulants cannot represent human anatomy. Testing with post mortem specimens may overcome this limitation but no information exists about how post mortem tissue changes and storage conditions in humans or animals may affect projectile penetration. Two chisel nosed cylinders (0.49 g and 1.10 g) and a 0.51 g (5 mm) sphere were fired into three groups of porcine tissue (fresh, refrigerated and frozen then refrigerated) and compared to 20% gelatin. Depth of projectile penetration was ascertained with the assistance of computed tomography and kinetic energy absorption by tissues measured using Doppler radar and high speed photography. No difference in depth of penetration was found between porcine tissue stored in the different manners compared with 20% gelatin by impact velocities less than 100 m/s. Insufficient numbers of projectiles were retained in tissue at higher velocities for statistical analysis to be undertaken. Energy absorbed per millimetre of tissue ranged between 0.42 and 0.98 J/mm for different porcine tissue despite differing storage. This pilot study would suggest that the effect of refrigerating or freezing porcine tissue followed by thawing has no effect on its ability to retard these projectiles. Further research is required to ascertain if these results occur at greater velocities and for other types of projectile. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Variation of safety indices during in the learning curve for color Doppler assessment of the fetal heart at 11+0 to 13+6 weeks' gestation.

PubMed

Nemescu, Dragos; Berescu, Anca; Rotariu, Cristian

2015-12-01

The aim of our study was to analyze the variation of acoustic output, as expressed by the thermal (TI) and mechanical index (MI), during the learning curve for a fetal heart scan at 11-13 gestational weeks, with the introduction of a new ultrasound system. This was a prospective, observational study on 303 normal fetuses. The fetal heart was examined transabdominally using B-Mode and high definition (HD) color Doppler to obtain standard parameters: four-chamber, outflow tracts and three-vessel-trachea views. Data were analyzed in groups of 20 consecutive examinations and the percentage of successful examinations was calculated. TI and MI were retrieved from HD color Doppler examinations of the fetal heart and from pulsed-wave Doppler assessment of the tricuspid flow and ductus venosus. MI values from the color Doppler examination of the fetal heart showed a continuous decrease (0.81 to 0.75, p<0.001), along the learning phase. TI and MI indices from pulsed-wave Doppler evaluation of the tricuspid flow increased at the beginning of the learning phase and stabilized afterwards (0.34 to 0.36, p<0.05 and 0.37 to 0.4, p<0.001, respectively). TI from color Doppler exam of the heart and indices from ductus venosus assessment were very constant and did not change along the studied periods. The length of Doppler examination of the heart increased after about 80 cases by 25%, to a mean of 4 minutes (p<0.05). Safety indices from Doppler evaluation of the fetal heart and tricuspid flow vary during the learning curve for fetal heart assessment. Also, the occurrence of constant values suggests the potential for their supplementary active reduction. For a better adaptation to a new ultrasound technology, the sonographer should scan the fetal heart longer in the first trimester and follow displayed safety indices along the first 80 cases.

The "Swiss-cheese Doppler-guided laser tonsillectomy": a new safe cribriform approach to intracapsular tonsillectomy.

PubMed

Palmieri, B; Iannitti, T; Fistetto, G; Rottigni, V

2013-05-01

Outpatient laser ablation of palatine tonsils is a very interesting procedure that has been recently introduced as a routine in head and neck surgery departments. The aim of this study was to describe a new strategy using a Doppler-guided fibre optic neodymium-yttrium-aluminium-garnet (YAG) laser to remove up to 80 % of tonsillar tissue, as assessed in the long-term postoperative clinical evaluation of the volume of the tonsils at the follow-up, and leaving the capsule in place, thus avoiding any haemorrhagic complication and minimize pain. A total of 20 patients (men, n=13; women, n=7), aged between 6 and 63, were recruited for the procedure. They were affected by chronic hypertrophic tonsillitis with a recurrent fever and other symptoms that were related to oral inflammation. Among the 20 patients, no serious adverse events, including haemorrhage-related complications, were observed. Treatment was well tolerated, even in patients displaying an overall low pain threshold. No dropout or uncompleted procedure occurred in the present study. Minor complications included sore throat, moderate oedema, mild acute pharynx inflammation, slight peritonsillar exudate and local burning. The postoperative pain, measured by Scott-Huskisson visual analogue scale, was between 5 and 40 mm and was easily counteracted by means of external ice packages and nonsteroidal anti-inflammatory drugs, according to the individual patient's need. During the 12-36-month follow-up patients showed improved symptoms (n=7) and complete recovery (n=13). A relapse episode was observed in two patients. This study supports fibre optic laser neodymium-YAG tonsil surgery, named "cribriform intracapsular tonsillectomy" or "Swiss-cheese laser tonsillectomy", as an effective alternative to the traditional cold knife approach or electrosurgery. This approach could become the gold standard for tonsil surgery in the third millennium for safety reasons, acceptable cost-benefit ratio, the precise targeting of the beam across the affected tissues and the short- and long-term recovery.

The effect of nonlinear propagation on heating of tissue: A numerical model of diagnostic ultrasound beams

NASA Astrophysics Data System (ADS)

Cahill, Mark D.; Humphrey, Victor F.; Doody, Claire

2000-07-01

Thermal safety indices for diagnostic ultrasound beams are calculated under the assumption that the sound propagates under linear conditions. A non-axisymmetric finite difference model is used to solve the KZK equation, and so to model the beam of a diagnostic scanner in pulsed Doppler mode. Beams from both a uniform focused rectangular source and a linear array are considered. Calculations are performed in water, and in attenuating media with tissue-like characteristics. Attenuating media are found to exhibit significant nonlinear effects for finite-amplitude beams. The resulting loss of intensity by the beam is then used as the source term in a model of tissue heating to estimate the maximum temperature rises. These are compared with the thermal indices, derived from the properties of the water-propagated beams.

Needle tip localization using stylet vibration.

PubMed

Harmat, Adam; Rohling, Robert N; Salcudean, Septimiu E

2006-09-01

Power Doppler ultrasound is used to localize the tip of a needle by detecting physical vibrations. Two types of vibrations are investigated, lateral and axial. The lateral vibrations are created by rotating a stylet, whose tip is slightly bent, inside a stationary cannula while the stylet is completely within the cannula. The minute deflection at the needle tip when rotated causes tissue motion. The axial vibration is induced by extending and retracting a straight stylet inside a stationary cannula. The stylet's tip makes contact with the tissue and causes it to move. The lateral vibration method was found to perform approximately the same under a variety of configurations (e.g., different insertion angles and depths) and better than the axial vibration method. Tissue stiffness affects the performance of the lateral vibration method, but good images can be obtained through proper tuning of the ultrasound machine.

Cell-free fetal DNA concentration in plasma of patients with abnormal uterine artery Doppler waveform and intrauterine growth restriction--a pilot study.

PubMed

Caramelli, Elisabetta; Rizzo, Nicola; Concu, Manuela; Simonazzi, Giuliana; Carinci, Paolo; Bondavalli, Corrado; Bovicelli, Luciano; Farina, Antonio

2003-05-01

To evaluate if an increased amount of fetal DNA concentration can be found in women screened positive for intrauterine growth restriction because of abnormal uterine artery Doppler waveforms. We enrolled eight pregnant women (each bearing a male fetus), with the evidence of abnormal uterine artery Doppler waveforms, and 16 control patients for a case-control study matched for gestational age (1 : 2). Uterine artery Doppler was carried out at 20 to 35 weeks' gestation (median 29). The mean uterine artery resistance index (RI) was subsequently calculated, and a value >0.6 was considered positive for the clinical features of pre-eclampsia. The SRY locus was used to determine the amount of male fetal DNA in the maternal plasma at the time of Doppler analysis. Two controls (normal Doppler) were excluded from the final analysis because they had a pre-term delivery. One case (abnormal Doppler) had evidence of intrauterine growth restriction at the time of enrolment. In four out of eight cases (abnormal Doppler), intrauterine growth restriction was subsequently observed. Multiples of median (MoM) conversion of the fetal DNA values showed an increase of 1.81 times in the cases when compared to the controls. An increase of 2.16 times was instead observed for the cases with a growth-restricted fetus (5 cases out of 8) in comparison with the controls (14 cases). In subjects positive to uterine artery Doppler velocimetry analysis (Doppler analysis for pre-eclampsia screening), the fetal DNA concentration is higher than expected, in the absence of any other clinical feature. Since the increase in fetal DNA seems to be related to the presence or to the future development of intrauterine growth restriction, this paper suggests a possible integration between ultrasound and molecular markers for predicting the disease in some cases. Copyright 2003 John Wiley & Sons, Ltd.

Statistics of biospeckles with application to diagnostics of periodontitis

NASA Astrophysics Data System (ADS)

Starukhin, Pavel Y.; Kharish, Natalia A.; Sedykh, Alexey V.; Ulyanov, Sergey S.; Lepilin, Alexander V.; Tuchin, Valery V.

1999-04-01

Results of Monte-Carlo simulations Doppler shift are presented for the model of random medium that contain moving particles. The single-layered and two-layered configurations of the medium are considered. Doppler shift of the frequency of laser light is investigated as a function of such parameters as absorption coefficient, scattering coefficient, and thickness of the medium. Possibility of application of speckle interferometry for diagnostics in dentistry has been analyzed. Problem of standardization of the measuring procedure has been studied. Deviation of output characteristics of Doppler system for blood microcirculation measurements has been investigated. Dependence of form of Doppler spectrum on the number of speckles, integration by aperture, has been studied in experiments in vivo.

Three-dimensional vascular imaging of proliferative diabetic retinopathy by Doppler optical coherence tomography.

PubMed

Miura, Masahiro; Hong, Young-Joo; Yasuno, Yoshiaki; Muramatsu, Daisuke; Iwasaki, Takuya; Goto, Hiroshi

2015-03-01

To evaluate the 3-dimensional architecture of neovascularization in proliferative diabetic retinopathy using Doppler optical coherence tomography (OCT). Prospective, nonrandomized clinical trial. Seventeen eyes of 14 patients with proliferative diabetic retinopathy were prospectively studied. Prototype Doppler OCT was used to evaluate the 3-dimensional vascular architecture at vitreoretinal adhesions. Proliferative membranes were detected in all eyes with proliferative diabetic retinopathy by standard OCT images. Doppler OCT images detected blood flow by neovascularization of the disc in 12 eyes and neovascularization elsewhere in 11 eyes. Doppler OCT images showed the 3-dimensional extent of new vessels at various stages of neovascularization, and the extent of new vessels could be clearly confirmed at vitreoretinal adhesions. Doppler OCT is useful for the detection and evaluation of the 3-dimensional vascular structure of neovascularization, and can assist in the noninvasive assessment of proliferative diabetic retinopathy. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Increased tissue oxygenation explains the attenuation of hyperemia upon repetitive pneumatic compression of the lower leg.

PubMed

Messere, Alessandro; Ceravolo, Gianluca; Franco, Walter; Maffiodo, Daniela; Ferraresi, Carlo; Roatta, Silvestro

2017-12-01

The rapid hyperemia evoked by muscle compression is short lived and was recently shown to undergo a rapid decrease even in spite of continuing mechanical stimulation. The present study aims at investigating the mechanisms underlying this attenuation, which include local metabolic mechanisms, desensitization of mechanosensitive pathways, and reduced efficacy of the muscle pump. In 10 healthy subjects, short sequences of mechanical compressions ( n = 3-6; 150 mmHg) of the lower leg were delivered at different interstimulus intervals (ranging from 20 to 160 s) through a customized pneumatic device. Hemodynamic monitoring included near-infrared spectroscopy, detecting tissue oxygenation and blood volume in calf muscles, and simultaneous echo-Doppler measurement of arterial (superficial femoral artery) and venous (femoral vein) blood flow. The results indicate that 1 ) a long-lasting (>100 s) increase in local tissue oxygenation follows compression-induced hyperemia, 2 ) compression-induced hyperemia exhibits different patterns of attenuation depending on the interstimulus interval, 3 ) the amplitude of the hyperemia is not correlated with the amount of blood volume displaced by the compression, and 4 ) the extent of attenuation negatively correlates with tissue oxygenation ( r  = -0,78, P < 0.05). Increased tissue oxygenation appears to be the key factor for the attenuation of hyperemia upon repetitive compressive stimulation. Tissue oxygenation monitoring is suggested as a useful integration in medical treatments aimed at improving local circulation by repetitive tissue compression. NEW & NOTEWORTHY This study shows that 1 ) the hyperemia induced by muscle compression produces a long-lasting increase in tissue oxygenation, 2 ) the hyperemia produced by subsequent muscle compressions exhibits different patterns of attenuation at different interstimulus intervals, and 3 ) the extent of attenuation of the compression-induced hyperemia is proportional to the level of oxygenation achieved in the tissue. The results support the concept that tissue oxygenation is a key variable in blood flow regulation. Copyright © 2017 the American Physiological Society.

Transcranial Doppler Ultrasound in Peninsular Arab Patients With Sickle Cell Disease.

PubMed

Adekile, Adekunle; Hassan, Meaad; Asbeutah, Akram; Al-Hinai, Mohamed; Trad, Omar; Farhan, Nayef

2018-05-06

Transcranial Doppler ultrasound is used to identify patients with sickle cell disease (SCD) at risk for stroke. We performed transcranial Doppler studies in patients from 4 countries in the Arabian Peninsula (Kuwait, Oman, Iraq, and United Arab Emirates) to document the prevalence of abnormal transcranial Doppler findings. The patients were recruited from outpatient clinics and studied in a steady state. Transcranial Doppler examinations were performed with standard equipment by experienced operators. The time-averaged maximum mean velocity (TAMMV) was documented in the arteries of the circle of Willis. The hemoglobin (Hb) genotype was confirmed, and the fetal Hb level and complete blood counts were determined. There were 415 patients in the study, aged 2 to 18 years (mean ± SD, 8.6 ± 3.5 years). None of the patients had an abnormal TAMMV (ie, > 200 cm/s), whereas only 13 (3.1%), all from Iraq, had conditional values (170-200 cm/s) in the right middle cerebral artery and 7 (1.7%) in the left middle cerebral artery. There were no consistent TAMMV differences among male and female patients or in patients with different Hb genotypes (sickle cell anemia, sickle cell β 0- thalassemia, and sickle D). The use of hydroxyurea was associated with a lower TAMMV, whereas a blood transfusion history had no influence. Total hemoglobin, reticulocyte count, serum bilirubin, and fetal Hb values showed varying degrees of association with the TAMMV in the different vessels. This study has demonstrated the rarity of abnormal transcranial Doppler findings among Peninsular Arab patients with SCD. The guidelines for transcranial Doppler screening in this population need further studies and recommendations. © 2018 by the American Institute of Ultrasound in Medicine.

Gastric distention exacerbates ischemia in a rodent model of partial gastric devascularization.

PubMed

Urschel, J D; Antkowiak, J G; Takita, H

1997-11-01

Occult ischemia of the mobilized gastric fundus is an important etiologic factor for esophagogastric anastomotic leaks after esophagectomy. Postoperative gastric distention is another possible predisposing factor for anastomotic leakage. We hypothesized that gastric distention could worsen gastric ischemia. To test this hypothesis, gastric tissue perfusion was studied in 20 Sprague-Dawley rats. Baseline serosal gastric tissue perfusion was measured by laser-Doppler flowmetry at a point 10 mm distal to the gastroesophageal junction. Perfusion was measured after left gastric artery occlusion, gastric distention to 20 cm water pressure, and combined left gastric artery occlusion and gastric distention. Gastric tissue perfusion (in tissue perfusion units, TPU) was 64.2 +/- 9.1 TPU at baseline measurement, 18.6 +/- 4.3 TPU after left gastric artery occlusion, 22.0 +/- 4.1 TPU after gastric distention, and 7.8 +/- 1.8 TPU after combined left gastric artery occlusion and gastric distention. Distention (P < 0.0001) and arterial occlusion (P < 0.0001) both reduced gastric tissue perfusion; of the two, arterial occlusion produced the greatest reduction in perfusion (P < 0.021). The combination of distention and arterial occlusion caused greater reduction in gastric perfusion than either factor alone (P < 0.0001). In this model, gastric distention exacerbated the ischemia produced by partial gastric devascularization. In clinical esophageal surgery, postoperative gastric distention may similarly potentiate the ischemic effects of gastric transposition for esophageal reconstruction.

Automated assessment of noninvasive filling pressure using color Doppler M-mode echocardiography

NASA Technical Reports Server (NTRS)

Greenberg, N. L.; Firstenberg, M. S.; Cardon, L. A.; Zuckerman, J.; Levine, B. D.; Garcia, M. J.; Thomas, J. D.

2001-01-01

Assessment of left ventricular filling pressure usually requires invasive hemodynamic monitoring to follow the progression of disease or the response to therapy. Previous investigations have shown accurate estimation of wedge pressure using noninvasive Doppler information obtained from the ratio of the wave propagation slope from color M-mode (CMM) images and the peak early diastolic filling velocity from transmitral Doppler images. This study reports an automated algorithm that derives an estimate of wedge pressure based on the spatiotemporal velocity distribution available from digital CMM Doppler images of LV filling.

[Prenatal management of isolated IUGR].

PubMed

Senat, M-V; Tsatsaris, V

2013-12-01

To evaluate the performance of different antenatal tools for the monitoring of fetuses with isolated intrauterine growth restriction (IUGR). To define the prenatal management of IUGR and indications for delivery before and after 32 weeks of gestation. PubMed, Embase and the Cochrane databases were searched using the keywords "IUGR", "fetal growth restriction", "cardiotocography", "amniotic fluid", "ultrasound assessment", "biophysical profile", "Doppler ultrasonography", "randomized trial", "meta-analysis". These terms were also combined together. Fetal monitoring of isolated IUGR should be based on the combined use of fetal heart rate (FHR) and ultrasound Doppler. The use of computerized FHR, with short-term variability (STV) measurement allows longitudinal monitoring and provides objective values upon which to decide very premature delivery (LE3). The use of umbilical Doppler is associated with a decrease in perinatal morbidity, especially in IUGR (LE1). It should be the first-line mean for the monitoring of SGA and IUGR fetuses (LE1). The additional use of cerebral Doppler is associated with a better predictive value for a poor perinatal outcome than the umbilical Doppler alone (LE3). Therefore, cerebral Doppler should be used in fetuses with IUGR, whether the umbilical Doppler is normal or not. As morbidity and mortality is increased in IUGR with pathological ductus venosus, the use of this Doppler should be considered in the monitoring of IUGR at before 32 weeks (professional consensus). Routine hospitalization is not mandatory for the monitoring of fetuses with IUGR/SGA. However, tertiary referral is advisable in cases of severe IUGR at between 26 to 32 weeks (professional consensus). The decision for delivery cannot be standardized and should be based on the combined analysis of gestational age, fetal heart rate analysis and Doppler study (professional consensus). Monitoring of fetuses with IUGR and decision for delivery should be based on the combined analysis of gestational age, fetal heart rate analysis and Doppler study before 32 weeks, this should ideally be performed by the association of computerized FHR and arterial and venous Doppler. Copyright © 2013. Published by Elsevier Masson SAS.

Fundamental study on micro calcification detection using twinkling sign (TS): the effect of stiffness of surrounding tissue on the appearance of TS.

PubMed

Liu, Lei; Funamoto, Kenichi; Tanabe, Masayuki; Hayase, Toshiyuki

2013-01-01

The twinkling sign (TS) observed in ultrasound imaging (e.g., color flow mode and pulse Doppler mode) has been reported in previous researches as a potential phenomenon to detect micro calcification in soft tissue. However, the mechanism of the twinkling sign has not been clearly understood yet. The authors investigated the effect of stiffness of surrounding tissue on the appearance of TS using the soft tissue-mimicking phantoms and a medical ultrasound device. The author used Poly (vinyl alcohol) hydro (PVA-H) gel as the material of phantom and developed three phantoms with different PVA concentration; 8 %wt, 10 %wt and 15 %wt those correspond to Young's modulus (E) as 50 kPa, 100 kPa and 230 kPa, respectively. Micro glass and CaCO3 particles were embedded in the phantoms as pseudo micro calcification. The authors observed TS in each phantom and analyzed the temporal average of TS. The temporal average of TS was largest in the 8 %wt (E = 50 kPa) PVA-H gel phantom, and decreased with increasing the phantom stiffness. The result indicated that the micro oscillation of the particles had a close relationship with the occurrence of TS.

Effect of obstructive sleep apnea on mitral valve tenting.

PubMed

Pressman, Gregg S; Figueredo, Vincent M; Romero-Corral, Abel; Murali, Ganesan; Kotler, Morris N

2012-04-01

Obstructive apneas produce high negative intrathoracic pressure that imposes an afterload burden on the left ventricle. Such episodes might produce structural changes in the left ventricle over time. Doppler echocardiograms were obtained within 2 months of attended polysomnography. Patients were grouped according to apnea-hypopnea index (AHI): mild/no obstructive sleep apnea (OSA; AHI <15) and moderate/severe OSA (AHI ≥15). Mitral valve tenting height and area, left ventricular (LV) long and short axes, and LV end-diastolic volume were measured in addition to tissue Doppler parameters. Comparisons of measurements at baseline and follow-up between and within groups were obtained; correlations between absolute changes (Δ) in echocardiographic parameters were also performed. After a mean follow-up of 240 days mitral valve tenting height increased significantly (1.17 ± 0.12 to 1.28 ± 0.17 cm, p = 0.001) in moderate/severe OSA as did tenting area (2.30 ± 0.41 to 2.66 ± 0.60 cm(2), p = 0.0002); Δtenting height correlated with ΔLV end-diastolic volume (rho 0.43, p = 0.01) and Δtenting area (rho 0.35, p = 0.04). In patients with mild/no OSA there was no significant change in tenting height; there was a borderline significant increase in tenting area (2.20 ± 0.44 to 2.31 ± 0.43 cm(2), p = 0.05). Septal tissue Doppler early diastolic wave decreased (8.04 ± 2.49 to 7.10 ± 1.83 cm/s, p = 0.005) in subjects with moderate/severe OSA but not in in those with mild/no OSA. In conclusion, in patients with moderate/severe OSA, mitral valve tenting height and tenting area increase significantly over time. This appears to be related, at least in part, to changes in LV geometry. Copyright © 2012 Elsevier Inc. All rights reserved.

Delayed right atrial lateral electromechanical coupling relative to the septal one can be associated with paroxysmal atrial fibrillation.

PubMed

Karapinar, H; Acar, G; Kirma, C; Kaya, Z; Karavelioglu, Y; Kucukdurmaz, Z; Esen, O; Alizade, E; Dasli, T; Sirma, D; Esen, A M

2013-08-01

Non-invasive prediction of paroxysmal atrial fibrillation (PAF) is one of the most recent interests of cardiology. The current study investigates the relationship between the atrial electromechanical coupling time (EMCT) and PAF. A group of 35 patients with PAF was compared with a group of 37 subjects without PAF. Pulsed wave tissue Doppler evaluations of atrial walls were performed from apical four chambers view under ECG monitoring. The time intervals from the onset of P wave to the onset of late diastolic wave (A') at right atrial wall (P-RA), interatrial septum (P-IAS), and left atrial wall (P-LA, maximum EMCT) were measured. The right atrial EMCT (P-RA minus P-IAS), left atrial EMCT (P-LA minus P-IAS) and interatrial EMCT (P-LA minus P-RA) were computed. A' wave velocities were measured from each atrial wall. RA (16.0±13.1 vs. -8.7±18.6 ms, p < 0.001) and maximum (91.5±32.6 vs. 72.0±23.1 ms, p = 0.001) EMCT were longer, RA A' velocity was higher in the patient group. There were no differences between the groups in LA and interatrial EMCT, and septal and LA A' velocities. Regression analysis revealed that only RA [OR: 1.148 (1.041-1.267), p = 0.006] and maximum [OR: 1.099 (1.009-1.197), p = 0.031] EMCT were independent variables for PAF. In order to predict patients with PAF, we have chosen +7.5 msn for the RA EMCT which yielded 69% sensitivity and 71.4% specificity to predict patients. Delayed RA lateral EMCT relative to septal one and delayed maximum EMCT detected by tissue Doppler could be a valuable method for identifying patients with PAF.

[Nailfold capillaroscopy and blood flow laser-doppler analysis of the microvascular damage in systemic sclerosis: preliminary results].

PubMed

Secchi, M E; Sulli, A; Pizzorni, C; Cutolo, M

2009-01-01

Systemic sclerosis (SSc) is characterized by altered microvascular structure and function. Nailfold videocapillaroscopy (NVC) is the tool to evaluate capillary morphological structure and laser-Doppler Blood flowmetry (LDF) can be used to estimate cutaneous blood flow of microvessels. The aim of this study was to investigate possible relationships between capillary morphology and blood flow in SSc. Twenty-seven SSc patients and 12 healthy subjects were enrolled. SSc microvascular involvement, as evaluated by NVC, was classified in three different patterns ("Early", "Active", "Late"). LDF analysis was performed at the II, III, IV, V hand fingers in both hands and both at cutaneous temperature and at 36 degrees C. Statistical evaluation was carried out by non-parametric procedures. Blood flow was found significantly lower in SSc patients when compared with healthy subjects (p<0.05). The heating of the probe to 36 degrees C induced a significant increase in peripheral blood flow in all subjects compared to baseline (p <0.05), however, the amount of variation was significantly lower in patients with SSc, compared with healthy controls (p <0.05). The SSc patients with NVC "Late" pattern, showed lower values of peripheral blood flow than patients with NVC "Active" or "Early" patterns (p<0.05). Moreover, a negative correlation between the tissue perfusion score and the progression of the SSc microangiopathy was observed, as well as between the tissue perfusion and the duration of the Raynaud's phenomenon (p <0.03). LDF can be employed to evaluate blood perfusion in the microvascular circulation in SSc patients. The blood flow changes observed with the LDF seem to correlate with the severity of microvascular damage in SSc as detected by NVC.

Detection of Early Right Ventricular Dysfunction in Young Patients With Thalassemia Major Using Tissue Doppler Imaging

PubMed Central

Bornaun, Helen; Dedeoglu, Reyhan; Oztarhan, Kazim; Dedeoglu, Savas; Erfidan, Erkan; Gundogdu, Muge; Aydogan, Gonul; Cengiz, Dicle

2016-01-01

Background Myocardial iron overload is the most common cause of mortality in patients with thalassemia major (TM), also known as beta-thalassemia. T2* cardiovascular magnetic resonance imaging (MRI) is the best way of monitoring cardiac iron, and new echocardiographic techniques can be used to assess cardiac function. Objectives The aim of this study was to assess the systolic and diastolic right ventricular (RV) function of patients with TM using tissue Doppler imaging (TDI) and to determine whether this echocardiographic technique is an adequate diagnostic tool for the screening and detection of subclinical cardiac dysfunction. Patients and Methods Eighty-four patients with TM were evaluated by conventional echocardiography and pulse-wave TDI. The data of the TM group (Group 1) were compared with that of 85 age- and sex-matched healthy controls (Group 2). Cardiovascular T2* MRI examinations were performed in 49 of the 85 patients. Results The patients with TM had significantly lower values for weight, height, body mass index, systolic arterial pressure, deceleration time, E’/A’, and ejection time (ET) than the controls. Group 1 also had significantly higher values for peak early diastolic velocity (E) over peak late diastolic velocity (A), peak early diastolic velocity of TDI (E’), peak late diastolic velocity of TDI (A’), E/E’, isovolumetric relaxation time, isovolumetric contraction time, and RV magnetic perfusion imaging (MPI) than Group 2. Conclusions RV diastolic dysfunction occurs before systolic deterioration in patients with TM and cannot be screened with conventional echocardiographic techniques. In routine practice, TDI measurements, MPI (for global function) and the E/E’ parameter (for diastolic function) can be used to screen and detect early RV dysfunction. PMID:27617076

Doppler spectra of airborne ultrasound forward scattered by the rough surface of open channel turbulent water flows.

PubMed

Dolcetti, Giulio; Krynkin, Anton

2017-11-01

Experimental data are presented on the Doppler spectra of airborne ultrasound forward scattered by the rough dynamic surface of an open channel turbulent flow. The data are numerically interpreted based on a Kirchhoff approximation for a stationary random water surface roughness. The results show a clear link between the Doppler spectra and the characteristic spatial and temporal scales of the water surface. The decay of the Doppler spectra is proportional to the velocity of the flow near the surface. At higher Doppler frequencies the measurements show a less steep decrease of the Doppler spectra with the frequency compared to the numerical simulations. A semi-empirical equation for the spectrum of the surface elevation in open channel turbulent flows over a rough bed is provided. The results of this study suggest that the dynamic surface of open channel turbulent flows can be characterized remotely based on the Doppler spectra of forward scattered airborne ultrasound. The method does not require any equipment to be submerged in the flow and works remotely with a very high signal to noise ratio.

Doppler term in the galaxy two-point correlation function: Wide-angle, velocity, Doppler lensing and cosmic acceleration effects

NASA Astrophysics Data System (ADS)

Raccanelli, Alvise; Bertacca, Daniele; Jeong, Donghui; Neyrinck, Mark C.; Szalay, Alexander S.

2018-03-01

We study the parity-odd part (that we shall call Doppler term) of the linear galaxy two-point correlation function that arises from wide-angle, velocity, Doppler lensing and cosmic acceleration effects. As it is important at low redshift and at large angular separations, the Doppler term is usually neglected in the current generation of galaxy surveys. For future wide-angle galaxy surveys, however, we show that the Doppler term must be included. The effect of these terms is dominated by the magnification due to relativistic aberration effects and the slope of the galaxy redshift distribution and it generally mimics the effect of the local type primordial non-Gaussianity with the effective nonlinearity parameter fNLeff of a few; we show that this would affect forecasts on measurements of fNL at low-redshift. Our results show that a survey at low redshift with large number density over a wide area of the sky could detect the Doppler term with a signal-to-noise ratio of ∼ 1 - 20, depending on survey specifications.

Wayside Bearing Fault Diagnosis Based on a Data-Driven Doppler Effect Eliminator and Transient Model Analysis

PubMed Central

Liu, Fang; Shen, Changqing; He, Qingbo; Zhang, Ao; Liu, Yongbin; Kong, Fanrang

2014-01-01

A fault diagnosis strategy based on the wayside acoustic monitoring technique is investigated for locomotive bearing fault diagnosis. Inspired by the transient modeling analysis method based on correlation filtering analysis, a so-called Parametric-Mother-Doppler-Wavelet (PMDW) is constructed with six parameters, including a center characteristic frequency and five kinematic model parameters. A Doppler effect eliminator containing a PMDW generator, a correlation filtering analysis module, and a signal resampler is invented to eliminate the Doppler effect embedded in the acoustic signal of the recorded bearing. Through the Doppler effect eliminator, the five kinematic model parameters can be identified based on the signal itself. Then, the signal resampler is applied to eliminate the Doppler effect using the identified parameters. With the ability to detect early bearing faults, the transient model analysis method is employed to detect localized bearing faults after the embedded Doppler effect is eliminated. The effectiveness of the proposed fault diagnosis strategy is verified via simulation studies and applications to diagnose locomotive roller bearing defects. PMID:24803197

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

PubMed Central

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 (100 μm, 1 ms). 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 (500 Hz compounded sequence with three tilted plane waves, PRF = 1500Hz with a 128 element 15 MHz 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 9 dB 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. PMID:26416649

Independent and incremental prognostic value of Doppler-derived left ventricular total isovolumic time in patients with systolic heart failure.

PubMed

Bajraktari, Gani; Dini, Frank Lloyd; Fontanive, Paolo; Elezi, Shpend; Berisha, Venera; Napoli, Anna Maria; Ciuti, Manrico; Henein, Michael

2011-05-05

A prolonged total isovolumic time (T-IVT) has been shown to be associated with worsening survival in patients submitted to coronary artery surgery. However, it is not known whether it has prognostic significance in patients with chronic systolic heart failure (HF). To determine the prognostic value of T-IVT in comparison with other clinical, biochemical and echocardiographic variables in patients with chronic systolic HF. Patients (n=107; age 68±12 years, 25% women) with chronic systolic HF, left ventricular ejection fraction (EF)<45%, and sinus rhythm, underwent a complete Doppler echocardiographic study, that included tissue Doppler long axis velocities and total isovolumic time (T-IVT), determined as [60-(total ejection time+total filling time)]. Plasma N-terminal pro-B natriuretic peptide (NT-pro-BNP) was also measured. The associations of dichotomous variables selected according to the Receiver Operator Characteristic analysis were assessed using the Cox proportional hazard model. Follow-up period was 37±18 months. Multivariate predictors of events were T-IVT≥12.3% s/min, mean E/Em ratio≥10, log NT-pro-BNP levels≥2.47 pg/ml and LV EF≤32.5%. On Kaplan-Meier analysis, patients with prolonged T-IVT, high mean E/Em ratio, increased NT-pro-BNP levels and decreased LV EF had a worse outcome compared with those without. The addition of T-IVT and NT-pro-BNP to conventional clinical and echocardiographic variables significantly improved the chi-square for the prediction of the outcome from 33.1 to 38.0, (P<0.001). Prolonged T-IVT added to the prognostic stratification of patients with systolic HF. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Hepatic vein transit time of second-generation ultrasound contrast agent: new tool in the assessment of portal hypertension.

PubMed

Luisa, Siciliani; Vitale, Giovanna; Sorbo, Anna Rita; Maurizio, Pompili; Lodovico, Rapaccini Gian

2017-03-01

It has been demonstrated that Doppler waveform of the hepatic vein (normally triphasic) is transformed into a biphasic or monophasic waveform in cirrhotic patients. The compressive mechanism of liver tissue has been considered up till now the cause of this change. Moreover, cirrhotics show, after USCA injection, a much earlier HVTT due to intrahepatic shunts. Our aim was to prospectively evaluate the correlation between Doppler pattern of hepatic vein and HVTT of a second-generation USCA; we also correlated HVTT with the most common indexes of portal hypertension. We enrolled 38 participants: 33 cirrhotics and 5 healthy controls. Doppler shift signals were obtained from the right hepatic vein. To characterize the hepatic vein pattern, we used the hepatic vein waveform index (HVWI). This index becomes >1 with the appearance of the triphasic waveform. We recorded a clip from 20 s before to 2 min after a peripheral intravenous bolus injection of 2.4 ml of USCA (sulfur hexafluoride).The time employed by USCA to cross the liver from the hepatic artery and portal vein to the hepatic vein was defined as HA-HVTT and PV-HVTT, respectively. Cirrhotics with low HVWI showed an earlier transit time; participants with higher HVWI had a longer transit time ( p  < 0.001). HVTT was earlier as MELD, Child-Pugh score and spleen diameter increased. Patients with ascites and varices of large size had significantly shorter transit times. Abnormal hepatic vein Doppler waveform in cirrhotic patients could be due to intrahepatic shunts. HVTT could be useful in the non-invasive evaluation of portal hypertension.

Doppler Feature Based Classification of Wind Profiler Data

NASA Astrophysics Data System (ADS)

Sinha, Swati; Chandrasekhar Sarma, T. V.; Lourde. R, Mary

2017-01-01

Wind Profilers (WP) are coherent pulsed Doppler radars in UHF and VHF bands. They are used for vertical profiling of wind velocity and direction. This information is very useful for weather modeling, study of climatic patterns and weather prediction. Observations at different height and different wind velocities are possible by changing the operating parameters of WP. A set of Doppler power spectra is the standard form of WP data. Wind velocity, direction and wind velocity turbulence at different heights can be derived from it. Modern wind profilers operate for long duration and generate approximately 4 megabytes of data per hour. The radar data stream contains Doppler power spectra from different radar configurations with echoes from different atmospheric targets. In order to facilitate systematic study, this data needs to be segregated according the type of target. A reliable automated target classification technique is required to do this job. Classical techniques of radar target identification use pattern matching and minimization of mean squared error, Euclidean distance etc. These techniques are not effective for the classification of WP echoes, as these targets do not have well-defined signature in Doppler power spectra. This paper presents an effective target classification technique based on range-Doppler features.

Use of cloud radar Doppler spectra to evaluate stratocumulus drizzle size distributions in large-eddy simulations with size-resolved microphysics

DOE PAGES

Remillard, J.; Fridlind, Ann M.; Ackerman, A. S.; ...

2017-09-20

Here, a case study of persistent stratocumulus over the Azores is simulated using two independent large-eddy simulation (LES) models with bin microphysics, and forward-simulated cloud radar Doppler moments and spectra are compared with observations. Neither model is able to reproduce the monotonic increase of downward mean Doppler velocity with increasing reflectivity that is observed under a variety of conditions, but for differing reasons. To a varying degree, both models also exhibit a tendency to produce too many of the largest droplets, leading to excessive skewness in Doppler velocity distributions, especially below cloud base. Excessive skewness appears to be associated withmore » an insufficiently sharp reduction in droplet number concentration at diameters larger than ~200 μm, where a pronounced shoulder is found for in situ observations and a sharp reduction in reflectivity size distribution is associated with relatively narrow observed Doppler spectra. Effectively using LES with bin microphysics to study drizzle formation and evolution in cloud Doppler radar data evidently requires reducing numerical diffusivity in the treatment of the stochastic collection equation; if that is accomplished sufficiently to reproduce typical spectra, progress toward understanding drizzle processes is likely.« less

Use of cloud radar Doppler spectra to evaluate stratocumulus drizzle size distributions in large-eddy simulations with size-resolved microphysics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Remillard, J.; Fridlind, Ann M.; Ackerman, A. S.

Here, a case study of persistent stratocumulus over the Azores is simulated using two independent large-eddy simulation (LES) models with bin microphysics, and forward-simulated cloud radar Doppler moments and spectra are compared with observations. Neither model is able to reproduce the monotonic increase of downward mean Doppler velocity with increasing reflectivity that is observed under a variety of conditions, but for differing reasons. To a varying degree, both models also exhibit a tendency to produce too many of the largest droplets, leading to excessive skewness in Doppler velocity distributions, especially below cloud base. Excessive skewness appears to be associated withmore » an insufficiently sharp reduction in droplet number concentration at diameters larger than ~200 μm, where a pronounced shoulder is found for in situ observations and a sharp reduction in reflectivity size distribution is associated with relatively narrow observed Doppler spectra. Effectively using LES with bin microphysics to study drizzle formation and evolution in cloud Doppler radar data evidently requires reducing numerical diffusivity in the treatment of the stochastic collection equation; if that is accomplished sufficiently to reproduce typical spectra, progress toward understanding drizzle processes is likely.« less

High-intensity focused ultrasound ablation assisted using color Doppler imaging for the treatment of hepatocellular carcinomas.

PubMed

Fukuda, Hiroyuki; Numata, Kazushi; Nozaki, Akito; Kondo, Masaaki; Morimoto, Manabu; Maeda, Shin; Tanaka, Katsuaki; Ohto, Masao; Ito, Ryu; Ishibashi, Yoshiharu; Oshima, Noriyoshi; Ito, Ayao; Zhu, Hui; Wang, Zhi-Biao

2013-12-01

We evaluated the usefulness of color Doppler flow imaging to compensate for the inadequate resolution of the ultrasound (US) monitoring during high-intensity focused ultrasound (HIFU) for the treatment of hepatocellular carcinoma (HCC). US-guided HIFU ablation assisted using color Doppler flow imaging was performed in 11 patients with small HCC (<3 lesions, <3 cm in diameter). The HIFU system (Chongqing Haifu Tech) was used under US guidance. Color Doppler sonographic studies were performed using an HIFU 6150S US imaging unit system and a 2.7-MHz electronic convex probe. The color Doppler images were used because of the influence of multi-reflections and the emergence of hyperecho. In 1 of the 11 patients, multi-reflections were responsible for the poor visualization of the tumor. In 10 cases, the tumor was poorly visualized because of the emergence of a hyperecho. In these cases, the ability to identify the original tumor location on the monitor by referencing the color Doppler images of the portal vein and the hepatic vein was very useful. HIFU treatments were successfully performed in all 11 patients with the assistance of color Doppler imaging. Color Doppler imaging is useful for the treatment of HCC using HIFU, compensating for the occasionally poor visualization provided by B-mode conventional US imaging.

Analysis of placenta vascularization in patients with uterine altered artery Doppler flow velocity exams.

PubMed

Gilio, Daniel Bruno; Miranda Corrêa, Rosana Rosa; Souza de Oliveira Guimarães, Camila; Peres, Luiz Cesar; Marques Salge, Ana Karina; Cavellani, Camila Lourencini; de Paula Antunes Teixeira, Vicente; Costa da Cunha Castro, Eumenia

2009-08-01

One of the frequent questions in obstetric practice is to determine placental vascular changes that may account for abnormal Doppler flow velocity alterations in maternal uterine vessels from women and fetuses without pregnancy pathology. A retrospective morphometric study was realized using 27 placentas from patients submitted for Doppler flow velocity exam during pregnancy. The placentas were morphologically examined using hematoxylin-eosin staining. Measurements of villi were made with the use of a video camera coupled to a common light microscope and a computer with automatic image analyzing software. Of the 27 placentas, 13 (48%) were of patients showing unaltered Doppler and 14 (52%) showing altered Doppler. The number of stem villi vessels was significantly larger in the placentas of patients with Doppler exam alterations (P = 0.003). This group also presented greater stem villi vessel thickness, although without significant difference. The number of intermediary and terminal villi vessels was greater in the placentas of patients with altered Doppler exams (P < 0.001), and a greater terminal villi area was observed in these cases (P < 0.001). The morphological proof that uterine artery Doppler flow velocity exam alterations are associated with placental vascular alterations demonstrates the importance of this exam during prenatal care, even in the absence of maternal-fetal alterations.

In vivo endoscopic Doppler optical coherence tomography imaging of the colon

PubMed Central

Welge, Weston A.; Barton, Jennifer K.

2017-01-01

Background and Objective Colorectal cancer remains the second deadliest cancer in the United States. Several screening methods exist, however detection of small polyps remains a challenge. Optical coherence tomography has been demonstrated to be capable of detecting lesions as small as 1 mm in the mouse colon, but detection is based on measuring a doubling of the mucosa thickness. The colon microvasculature may be an attractive biomarker of early tumor development because tumor vessels are characterized by irregular structure and dysfunction. Our goal was to develop an endoscopic method of detecting and segmenting colon vessels using Doppler optical coherence tomography to enable future studies for improving early detection and development of novel chemopreventive agents. Method We conducted in vivo colon imaging in an azoxymethane (AOM)-treated mouse model of colorectal cancer using a miniature endoscope and a swept-source OCT system at 1040 nm with a 16 kHz sweep rate. We applied the Kasai autocorrelation algorithm to laterally oversampled OCT B-scans to resolve vascular flow in the mucosa and submucosa. Vessels were segmented by applying a series of image processing steps: (1) intensity thresholding, (2) two-dimensional matched filtering, and (3) histogram segmentation. Results We observed differences in the vessels sizes and spatial distribution in a mature adenoma compared to surrounding undiseased tissue and compared the results with histology. We also imaged flow in four young mice (2 AOM-treated and 2 control) showing no significant differences, which is expected so early after carcinogen exposure. We also present flow images of adenoma in a living mouse and a euthanized mouse to demonstrate that no flow is detected after euthanasia. Conclusion We present, to the best of our knowledge, the first Doppler OCT images of in vivo mouse colon collected with a fiber-based endoscope. We also describe a fast and robust image processing method for segmenting vessels in the colon. These results suggest that Doppler OCT is a promising imaging modality for vascular imaging in the colon that requires no exogenous contrast agents. PMID:27546786

Comments on Doppler radar applications

NASA Technical Reports Server (NTRS)

Kessler, E.

1969-01-01

The application of Doppler methods to theoretical or meteorological problems is discussed. Research for using radar to study and monitor severe thunderstorms, turbulence, and tornadoes is recommended.

Changes in blood velocity following microvascular free tissue transfer.

PubMed

Hanasono, Matthew M; Ogunleye, Olubunmi; Yang, Justin S; Hartley, Craig J; Miller, Michael J

2009-09-01

Understanding how pedicle blood velocities change after free tissue transfer may enable microvascular surgeons to predict when thrombosis is most likely to occur. A 20-MHz Doppler probe was used to measure arterial and venous blood velocities prior to pedicle division and 20 minutes after anastomosis in 32 microvascular free flaps. An implantable Doppler probe was then used to measure arterial and venous blood velocities daily for 5 days. Peak arterial blood velocity averaged 30.6 cm/s prior to pedicle division and increased to 36.5 cm/s 20 minutes after anastomosis ( P < 0.05). Peak venous blood velocity averaged 7.6 cm/s prior to pedicle division and increased to 12.4 cm/s 20 minutes after anastomosis ( P < 0.05). Peak arterial blood velocities averaged 34.0, 37.7, 43.8, 37.9, 37.6 cm/s on postoperative days (PODs) 1 through 5, respectively. Peak venous blood velocities averaged 11.9, 14.5, 18.2, 16.8, 17.7 cm/s on PODs 1 through 5, respectively. The peak arterial blood velocity on POD 3, and peak venous blood velocities on PODs 2, 3, and 5 were significantly higher than 20 minutes after anastomosis ( P < 0.05). Arterial and venous blood velocities increase for the first 3 postoperative days, potentially contributing to the declining risk for pedicle thrombosis during this time period.

The development of a combined b-mode, ARFI, and spectral Doppler ultrasound imaging system for investigating cardiovascular stiffness and hemodynamics

NASA Astrophysics Data System (ADS)

Doherty, Joshua R.; Dumont, Douglas M.; Trahey, Gregg E.

2011-03-01

The progression of atherosclerotic disease, caused by the formation of plaques within arteries, is a complex process believed to be a function of the localized mechanical properties and hemodynamic loading associated with the arterial wall. It is hypothesized that measurements of vascular stiffness and wall-shear rate (WSR) may provide important information regarding vascular remodeling, endothelial function, and the growth of soft-lipid filled plaques that could help a clinician better diagnose a patient's risk of clinical events such as stroke. To that end, the approach taken in this work was to combine conventional B-mode, Acoustic Radiation Force Impulse (ARFI), Shear Wave Elasticity Imaging (SWEI), and spectral Doppler techniques into a single imaging system capable of simultaneously measuring the tissue displacements and WSR throughout the cardiac cycle and over several heartbeats. Implemented on a conventional scanner, the carotid arteries of human subjects were scanned to demonstrate the initial in vivo feasibility of the method. Two non-invasive ultrasound based imaging methods, SAD-SWEI and SAD-Gated Imaging, were developed that measure ARF-induced on-axis tissue displacements, off-axis transverse wave velocities, and WSR throughout the cardiac cycle. Human carotid artery scans were performed in vivo on 5 healthy subjects. Statistical differences were observed in both on-axis proximal wall displacements and transverse wave velocities during diastole compared to systole.

Doppler lidar power, aperture diameter, and FFT size trade-off study

NASA Astrophysics Data System (ADS)

Chester, David B.; Budge, Scott E.

2017-05-01

In the design or selection of a Doppler lidar instrument for a spacecraft landing system, it is important to evaluate the balance between performance requirements and cost, weight, and power consumption. Leveraging the capability of LadarSIM, a trade-off study was performed to evaluate the interaction between the laser transmission power, aperture diameter, and FFT size in a Doppler lidar system. For this study the probabilities of detection and false alarm were calculated using LadarSIM to simulate FMCW lidar systems with varying power, aperture diameter, and FFT size. This paper reports the results of this trade-off study.

A Case-study on Turbulence in a Stratocumulus Topped Marine Boundary Layer Observed during VOCALS-Rex

NASA Astrophysics Data System (ADS)

Ghate, V. P.; Albrecht, B. A.; Fairall, C. W.; Miller, M. A.; Brewer, A.

2010-12-01

Turbulence in the stratocumulus topped marine boundary layer (BL) is an important factor that is closely connected to both the cloud macro- and micro-physical characteristics, which can substantially affect their radiaitve properties. Data collected by ship borne instruments on the R/V Ronald H. Brown on November 27, 2008 as a part of the VAMOS Ocean-Cloud-Atmosphere-Land-Study Regional Experiment (VOCALS-Rex) are analyzed to study the turbulence structure of a stratocumulus topped marine BL. The first half of the analyzed 24 hour period was characterized by a coupled BL topped by a precipitating stratocumulus cloud; the second half had clear sky conditions with a decoupled BL. The motion stabilized vertically pointing W-band Doppler cloud radar reported the full Doppler spectrum at a temporal and spatial resolution of 3 Hz and 25 m respectively. The collocated motion stabilized Doppler lidar was operating at 2 micron wavelength and reported the Signal to Noise Ratio (SNR) and Doppler velocity at temporal and spatial resolution of 2 Hz and 30 m respectively. Data from the cloud Doppler radar and Doppler lidar were combined to yield the turbulence structure of entire BL in both cloudy and clear sky conditions. Retrievals were performed to remove the contribution of precipitating drizzle drops to the mean Doppler velocity measured by the radar. Hourly profiles of vertical velocity variance suggested high BL variance during coupled BL conditions and low variance during decoupled BL conditions. Some of the terms in second and third moment budget of vertical velocity are calculated and their diurnal evolution is explored.

Applications of Doppler-free saturation spectroscopy for edge physics studies (invited)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, E. H., E-mail: martineh@ornl.gov; Caughman, J. B. O.; Isler, R. C.

Doppler-free saturation spectroscopy provides a very powerful method to obtain detailed information about the electronic structure of the atom through measurement of the spectral line profile. This is achieved through a significant decrease in the Doppler broadening and essentially an elimination of the instrument broadening inherent to passive spectroscopic techniques. In this paper we present the technique and associated physics of Doppler-free saturation spectroscopy in addition to how one selects the appropriate transition. Simulations of H{sub δ} spectra are presented to illustrate the increased sensitivity to both electric field and electron density measurements.

Effect of Doppler flow meter position on discharge measurement in surcharged manholes.

PubMed

Yang, Haoming; Zhu, David Z; Liu, Yanchen

2018-02-01

Determining the proper installation location of flow meters is important for accurate measurement of discharge in sewer systems. In this study, flow field and flow regimes in two types of manholes under surcharged flow were investigated using a commercial computational fluid dynamics (CFD) code. The error in measuring the flow discharge using a Doppler flow meter (based on the velocity in a Doppler beam) was then estimated. The values of the corrective coefficient were obtained for the Doppler flow meter at different locations under various conditions. Suggestions for selecting installation positions are provided.

Applications of Doppler-free saturation spectroscopy for edge physics studies (invited).

PubMed

Martin, E H; Zafar, A; Caughman, J B O; Isler, R C; Bell, G L

2016-11-01

Doppler-free saturation spectroscopy provides a very powerful method to obtain detailed information about the electronic structure of the atom through measurement of the spectral line profile. This is achieved through a significant decrease in the Doppler broadening and essentially an elimination of the instrument broadening inherent to passive spectroscopic techniques. In this paper we present the technique and associated physics of Doppler-free saturation spectroscopy in addition to how one selects the appropriate transition. Simulations of H δ spectra are presented to illustrate the increased sensitivity to both electric field and electron density measurements.

An audit of a hospital-based Doppler ultrasound quality control protocol using a commercial string Doppler phantom.

PubMed

Cournane, S; Fagan, A J; Browne, J E

2014-05-01

Results from a four-year audit of a Doppler quality assurance (QA) program using a commercially available Doppler string phantom are presented. The suitability of the phantom was firstly determined and modifications were made to improve the reliability and quality of the measurements. QA of Doppler ultrasound equipment is very important as data obtained from these systems is used in patient management. It was found that if the braided-silk filament of the Doppler phantom was exchanged with an O-ring rubber filament and the velocity range below 50 cm/s was avoided for Doppler quality control (QC) measurements, then the maximum velocity accuracy (MVA) error and intrinsic spectral broadening (ISB) results obtained using this device had a repeatability of 18 ± 3.3% and 19 ± 3.5%, respectively. A consistent overestimation of the MVA of between 12% and 56% was found for each of the tested ultrasound systems. Of more concern was the variation of the overestimation within each respective transducer category: MVA errors of the linear, curvilinear and phased array probes were in the range 12.3-20.8%, 32.3-53.8% and 27-40.7%, respectively. There is a dearth of QA data for Doppler ultrasound; it would be beneficial if a multicentre longitudinal study was carried out using the same Doppler ultrasound test object to evaluate sensitivity to deterioration in performance measurements. Copyright © 2013 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Steady-state phase error for a phase-locked loop subjected to periodic Doppler inputs

NASA Technical Reports Server (NTRS)

Chen, C.-C.; Win, M. Z.

1991-01-01

The performance of a carrier phase locked loop (PLL) driven by a periodic Doppler input is studied. By expanding the Doppler input into a Fourier series and applying the linearized PLL approximations, it is easy to show that, for periodic frequency disturbances, the resulting steady state phase error is also periodic. Compared to the method of expanding frequency excursion into a power series, the Fourier expansion method can be used to predict the maximum phase error excursion for a periodic Doppler input. For systems with a large Doppler rate fluctuation, such as an optical transponder aboard an Earth orbiting spacecraft, the method can be applied to test whether a lower order tracking loop can provide satisfactory tracking and thereby save the effect of a higher order loop design.

Observation of acoustic-gravity waves in the upper atmosphere during severe storm activity

NASA Technical Reports Server (NTRS)

Hung, R. J.

1975-01-01

A nine-element continuum wave spectrum, high-frequency, Doppler sounder array has been used to detect upper atmospheric wave-like disturbances during periods with severe weather activity, particularly severe thunderstorms and tornadoes. Five events of severe weather activity, including extreme tornado outbreak of April 3, 1974, were chosen for the present study. The analysis of Doppler records shows that both infrasonic waves and gravity waves were excited when severe storms appeared in the north Alabama area. Primarily, in the case of tornado activity, S-shaped Doppler fluctuations or Doppler fold-backs are observed, while quasi-sinusoidal fluctuations are more common in the case of thunderstorm activity. A criterion for the production of Doppler fold-backs is derived and compared with possible tornado conditions.

Doppler characteristics of sea clutter.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raynal, Ann Marie; Doerry, Armin Walter

2010-06-01

Doppler radars can distinguish targets from clutter if the target's velocity along the radar line of sight is beyond that of the clutter. Some targets of interest may have a Doppler shift similar to that of clutter. The nature of sea clutter is different in the clutter and exo-clutter regions. This behavior requires special consideration regarding where a radar can expect to find sea-clutter returns in Doppler space and what detection algorithms are most appropriate to help mitigate false alarms and increase probability of detection of a target. This paper studies the existing state-of-the-art in the understanding of Doppler characteristicsmore » of sea clutter and scattering from the ocean to better understand the design and performance choices of a radar in differentiating targets from clutter under prevailing sea conditions.« less

Estimation of physiological sub-millimeter displacement with CW Doppler radar.

PubMed

Jia Xu; Xiaomeng Gao; Padasdao, Bryson E; Boric-Lubecke, Olga

2015-01-01

Doppler radar physiological sensing has been studied for non-contact detection of vital signs including respiratory and heartbeat rates. This paper presents the first micrometer resolution Wi-Fi band Doppler radar for sub-millimeter physiological displacement measurement. A continuous-wave Doppler radar working at 2.4GHz is used for the measurement. It is intended for estimating small displacements on the body surface resulting from physiological activity. A mechanical mover was used as target, and programmed to conduct sinusoidal motions to simulate pulse motions. Measured displacements were compared with a reference system, which indicates a superior performance in accuracy for having absolute errors less than 10μm, and relative errors below 4%. It indicates the feasibility of highly accurate non-contact monitoring of physiological movements using Doppler radar.

Dual-Doppler Feasibility Study

NASA Technical Reports Server (NTRS)

Huddleston, Lisa L.

2012-01-01

When two or more Doppler weather radar systems are monitoring the same region, the Doppler velocities can be combined to form a three-dimensional (3-D) wind vector field thus providing for a more intuitive analysis of the wind field. A real-time display of the 3-D winds can assist forecasters in predicting the onset of convection and severe weather. The data can also be used to initialize local numerical weather prediction models. Two operational Doppler Radar systems are in the vicinity of Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS); these systems are operated by the 45th Space Wing (45 SW) and the National Weather Service Melbourne, Fla. (NWS MLB). Dual-Doppler applications were considered by the 45 SW in choosing the site for the new radar. Accordingly, the 45th Weather Squadron (45 WS), NWS MLB and the National Aeronautics and Space Administration tasked the Applied Meteorology Unit (AMU) to investigate the feasibility of establishing dual-Doppler capability using the two existing systems. This study investigated technical, hardware, and software requirements necessary to enable the establishment of a dual-Doppler capability. Review of the available literature pertaining to the dual-Doppler technique and consultation with experts revealed that the physical locations and resulting beam crossing angles of the 45 SW and NWS MLB radars make them ideally suited for a dual-Doppler capability. The dual-Doppler equations were derived to facilitate complete understanding of dual-Doppler synthesis; to determine the technical information requirements; and to determine the components of wind velocity from the equation of continuity and radial velocity data collected by the two Doppler radars. Analysis confirmed the suitability of the existing systems to provide the desired capability. In addition, it is possible that both 45 SW radar data and Terminal Doppler Weather Radar data from Orlando International Airport could be used to alleviate any radar geometry issues at the NWS MLB radar, such as the "cone of silence" or beam blockage. In the event of a radar outage at one of the sites, the multi-radar algorithms would provide continuing coverage of the area through use of the data from the remaining operational radar sites. There are several options to collect, edit, synthesize and display dual-Doppler data sets. These options include commercial packages available for purchase and a variety of freeware packages available from the National Center for Atmospheric Research (NCAR) for processing raw radar data. However, evaluation of the freeware packages revealed that they do not have sufficient documentation and configuration control to be certified for 45 SW use. Additionally, a TI data line must be installed/leased from the NWS MLB office and CCAFS to enable the receipt of NWS MLB raw radar data to use in the dual-Doppler synthesis. Integration of the TI data line into the Eastern Range infrastructure that will meet the security requirements necessary for 45 SW use is time-consuming and costly. Overall evaluation indicates that establishment of the dual-Doppler capability using the existing operational radar systems is desirable and feasible with no technical concerns. Installation of such a system represents a significant enhancement to forecasting capabilities at the 45 WS and at NWS MLB. However, data security and cost considerations must be evaluated in light of current budgetary constraints. In any case, gaining the dual-Doppler capability will provide opportunities for better visualization of the wind field and better forecasting of the onset of convection and severe weather events to support space launch operations at KSC and CCAFS.

Positron Spectroscopy Investigation of Normal Brain Section and Brain Section with Glioma Derived from a Rat Glioma Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, SH.; Ballmann, C.; Quarles, C. A.

2009-03-10

The application of positron annihilation lifetime spectroscopy (PALS) and Doppler broadening spectroscopy (DBS) to the study of animal or human tissue has only recently been reported [G. Liu, et al. phys. stat. sol. (C) 4, Nos. 10, 3912-3915 (2007)]. We have initiated a study of normal brain section and brain section with glioma derived from a rat glioma model. For the rat glioma model, 200,000 C6 cells were implanted in the basal ganglion of adult Sprague Dawley rats. The rats were sacrificed at 21 days after implantation. The brains were harvested, sliced into 2 mm thick coronal sections, and fixedmore » in 4% formalin. PALS lifetime runs were made with the samples soaked in formalin, and there was not significant evaporation of formalin during the runs. The lifetime spectra were analyzed into two lifetime components. While early results suggested a small decrease in ortho-Positronium (o-Ps) pickoff lifetime between the normal brain section and brain section with glioma, further runs with additional samples have showed no statistically significant difference between the normal and tumor tissue for this type of tumor. The o-Ps lifetime in formalin alone was lower than either the normal tissue or glioma sample. So annihilation in the formalin absorbed in the samples would lower the o-Ps lifetime and this may have masked any difference due to the glioma itself. DBS was also used to investigate the difference in positronium formation between tumor and normal tissue. Tissue samples are heterogeneous and this needs to be carefully considered if PALS and DBS are to become useful tools in distinguishing tissue samples.« less

Contrast-enhanced power Doppler endosonography and pathological assessment of vascularization in advanced gastric carcinomas--a feasibility study.

PubMed

Iordache, Sevastiţa; Filip, Maria-Monalisa; Georgescu, Claudia-Valentina; Angelescu, Cristina; Ciurea, Tudorel; Săftoiu, Adrian

2012-06-01

Besides representing angiogenesis markers, microvascular density (MVD) and vascular endothelial growth factor (VEGF) are two important tools for the assessment of prognosis in patients with gastric cancer. The aim of our study was to assess the Doppler parameters (resistivity and pulsatility indexes) and vascularity index (VI) calculated by contrast-enhanced power Doppler endoscopic ultrasound (CEPD-EUS) in correlation with the expression of intra-tumoral MVD and VEGF in patients with gastric cancer. The study included 20 consecutive patients with advanced gastric carcinoma, but without distant metastasis at initial assessment. All the patients were assessed by contrast-enhanced power Doppler endoscopic ultrasound (EUS) combined with pulsed Doppler examinations in the late venous phase. The vascularity index (VI) was calculated before and after injection of second generation microbubble contrast specific agent (SonoVue 2.4 mL), used as a Doppler signal enhancer. Moreover, pulsed Doppler parameters (resistivity and pulsatility indexes) were further calculated. The correlation between power Doppler parameters and pathological/molecular parameters (MVD assessed through immunohistochemistry with CD31 and CD34, as well as VEGF assessed through real-time PCR) was assessed. Kaplan-Meier survival analysis was used for the assessment of prognosis. Significantly statistical correlations were found between post-contrast VI and CD34 (p=0.0226), VEGF (p=0.0231), VEGF-A (p=0.0464) and VEGF-B (p=0.0022) while pre-contrast VI was correlated only with CD34 expression. Pulsatility index and resistivity index were not correlated with MVD or VEGF expression. Survival analysis demonstrated that VEGF-A is an accurate parameter for survival rate (p=0.045), as compared to VEGF (p=0.085) and VEGF-B (p=0.230). We did not find any correlation between the survival rate and ultrasound parameters (RI, PI, pre-contrast VI or post-contrast VI). Assessment of tumor vascularity using contrast-enhanced EUS, including analysis of spectral Doppler parameters is possible and feasible in gastric cancer patients. A correlation between measured EUS vascularity and pathological parameters of angiogenesis (MVD and VEGF expression) was found.

THD Doppler procedure for hemorrhoids: the surgical technique.

PubMed

Ratto, C

2014-03-01

Transanal hemorrhoidal dearterialization (THD) is an effective treatment for hemorrhoidal disease. The ligation of hemorrhoidal arteries (called "dearterialization") can provide a significant reduction of the arterial overflow to the hemorrhoidal piles. Plication of the redundant rectal mucosa/submucosa (called "mucopexy") can provide a repositioning of prolapsing tissue to the anatomical site. In this paper, the surgical technique and perioperative patient management are illustrated. Following adequate clinical assessment, patients undergo THD under general or spinal anesthesia, in either the lithotomy or the prone position. In all patients, distal Doppler-guided dearterialization is performed, providing the selective ligation of hemorrhoidal arteries identified by Doppler. In patients with hemorrhoidal/muco-hemorrhoidal prolapse, the mucopexy is performed with a continuous suture including the redundant and prolapsing mucosa and submucosa. The description of the surgical procedure is complemented by an accompanying video (see supplementary material). In long-term follow-up, there is resolution of symptoms in the vast majority of patients. The most common complication is transient tenesmus, which sometimes can result in rectal discomfort or pain. Rectal bleeding occurs in a very limited number of patients. Neither fecal incontinence nor chronic pain should occur. Anorectal physiology parameters should be unaltered, and anal sphincters should not be injured by following this procedure. When accurately performed and for the correct indications, THD is a safe procedure and one of the most effective treatments for hemorrhoidal disease.

A Microfluidics-based Pulpal Arteriole Blood Flow Phantom for Validation of Doppler Ultrasound Devices in Pulpal Blood Flow Velocity Measurement.

PubMed

Kim, Dohyun; Park, Sung-Ho

2016-11-01

Recently, Doppler ultrasound has been used for the measurement of pulpal blood flow in human teeth. However, the reliability of this method has not been verified. In this study, we developed a model to simulate arteriole blood flow within the dental pulp by using microfluidics. This arteriole simulator, or flow phantom, was used to determine the reliability of measurements obtained by using a Doppler ultrasound device. A microfluidic chip was fabricated by using the soft lithography technique, and blood-mimicking fluid was pumped through the channel by a microfluidic system. A Doppler ultrasound device was used for the measurement of flow velocity. The peak, mean, and minimal flow velocities obtained from the phantom and the Doppler ultrasound device were compared by using linear regression analysis and Pearson correlation coefficient. Bland-Altman analyses were performed to evaluate the velocity differences between the flow generated by the phantom and the flow measurements made with the Doppler ultrasound device. The microfluidic system was able to generate the flow profiles as intended, and the fluid flow could be monitored and controlled by the software program. There were excellent linear correlations between the peak, mean, and minimal flow velocities of the phantom and those of the Doppler ultrasound device (r = 0.94-0.996, P < .001). However, the velocities were overestimated by the Doppler ultrasound device. This phantom provides opportunities for research and education involving the Doppler ultrasound technique in dentistry. Although Doppler ultrasound can be an effective tool for the measurement of pulpal blood flow velocity, it is essential to validate and calibrate the device before clinical use. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Reappraisal of quantitative evaluation of pulmonary regurgitation and estimation of pulmonary artery pressure by continuous wave Doppler echocardiography.

PubMed

Lei, M H; Chen, J J; Ko, Y L; Cheng, J J; Kuan, P; Lien, W P

1995-01-01

This study assessed the usefulness of continuous wave Doppler echocardiography and color flow mapping in evaluating pulmonary regurgitation (PR) and estimating pulmonary artery (PA) pressure. Forty-three patients were examined, and high quality Doppler spectral recordings of PR were obtained in 32. All patients underwent cardiac catheterization, and simultaneous PA and right ventricular (RV) pressures were recorded in 17. Four Doppler regurgitant flow velocity patterns were observed: pandiastolic plateau, biphasic, peak and plateau, and early diastolic triangular types. The peak diastolic and end-diastolic PA-to-RV pressure gradients derived from the Doppler flow profiles correlated well with the catheter measurements (r = 0.95 and r = 0.95, respectively). As PA pressure increased, the PR flow velocity became higher; a linear relationship between either systolic or mean PA pressure and Doppler-derived peak diastolic pressure gradient was noted (r = 0.90 and 0.94, respectively). Based on peak diastolic gradients of < 15, 15-30 or > 30 mm Hg, patients could be separated as those with mild, moderate or severe pulmonary hypertension, respectively (p < 0.05). A correlation was also observed between PA diastolic pressure and Doppler-derived end-diastolic pressure gradient (r = 0.91). Moreover, the Doppler velocity decay slope of PR closely correlated with that derived from the catheter method (r = 0.98). The decay slope tended to be steeper with the increment in regurgitant jet area and length obtained from color flow mapping. In conclusion, continuous wave Doppler evaluation of PR is a useful means for noninvasive estimation of PA pressure, and the Doppler velocity decay slope seems to reflect the severity of PR.

Importance of the concept of inner organs-dental relations in dentistry.

PubMed

Abasova, I; Rustamova, P; Seidbekov, O

2009-12-01

The current article is presenting an effective treatment scheme, providing reliable positive result of therapy and prophylaxis of dental diseases and its complications on the patients through the study of pathology of meridian - inner organs - dental system, bound by system of traces - meridians, using Doppler ultrasonography, rheovasography, photoplethysmography, Electroacupuncture, ultrasound investigations of the inner organs, X-Ray, laboratory investigations, electrocardiography methods. We had studied the efficiency of the odontic Microsystem, developed by R. Voll and R. Dale in dental practice by oral examination of 100 patients, average aged 25,5+/-0,74, which were divided into three groups. The necessity of complex treatment of the patients with pathology of inner organs and related with that demineralization process of the hard tissues of the teeth and the periodontitis had been demonstrated.

Temporal variability of vena contracta and jet areas with color Doppler in aortic regurgitation: a chronic animal model study.

PubMed

Ishii, M; Jones, M; Shiota, T; Yamada, I; Sinclair, B; Heinrich, R S; Yoganathan, A P; Sahn, D J

1998-11-01

The purpose of our study was to determine the temporal variability of regurgitant color Doppler jet areas and the width of the color Doppler imaged vena contracta for evaluating the severity of aortic regurgitation. Twenty-nine hemodynamically different states were obtained pharmacologically in 8 sheep 20 weeks after surgery to produce aortic regurgitation. Aortic regurgitation was quantified by peak and mean regurgitant flow rates, regurgitant stroke volumes, and regurgitant fractions determined using pulmonary and aortic electromagnetic flow probes and meters balanced against each other. The regurgitant jet areas and the widths of color Doppler imaged vena contracta were measured at 4 different times during diastole to determine the temporal variability of this parameter. When measured at 4 different temporal points in diastole, a significant change was observed in the size of the color Doppler imaged regurgitant jet (percent of difference: from 31.1% to 904%; 233% +/- 245%). Simple linear regression analysis between each color jet area at 4 different periods in diastole and flow meter-based severity of the aortic regurgitation showed only weak correlation (0.23 < r < 0.49). In contrast, for most conditions only a slight change was observed in the width of the color Doppler imaged vena contracta during the diastolic regurgitant period (percent of difference, vena contracta: from 2.4% to 12.9%, 5.8% +/- 3.2%). In addition, for each period the width of the color Doppler imaged vena contracta at the 4 different time periods in diastole correlated quite strongly with volumetric measures of the severity of aortic regurgitation (0.81 < r < 0.90) and with the instantaneous flow rate for the corresponding period (0.85 < r < 0.87). Color Doppler imaged vena contracta may provide a simple, practical, and accurate method for quantifying aortic regurgitation, even when using a single frame color Doppler flow mapping image.

Early Changes in Atrial Electromechanical Coupling in Patients with Hypertension: Assessment by Tissue Doppler Imaging.

PubMed

Avci, Burcak Kilickiran; Gulmez, Oyku; Donmez, Guclu; Pehlivanoglu, Seckin

2016-06-05

Hypertension (HT) is associated with atrial electrophysiological abnormalities. Echocardiographic pulsed wave tissue Doppler imaging (TDI) is one of the noninvasive methods for evaluation of atrial electromechanical properties. The aims of our study were to investigate the early changes in atrial electromechanical conduction in patients with HT and to assess the parameters that affect atrial electromechanical conduction. Seventy-six patients with HT (41 males, mean age 52.6 ± 9.0 years) and 41 controls (22 males, mean age 49.8 ± 7.9 years) were included in the study. Atrial electromechanical coupling at the right (PRA), left (PLA), interatrial septum (PIS) were measured with TDI. Intra- (right: PIS-PRA, left: PLA-PIS) and inter-atrial (PLA-PRA) electromechanical delays were calculated. Maximum P-wave duration (Pmax) was calculated from 12-lead electrocardiogram. Atrial electromechanical coupling at PLA (76.6 ± 14.1 ms vs. 82.9 ± 15.8 ms, P = 0.036), left intra-atrial (10.9 ± 5.0 ms vs. 14.0 ± 9.7 ms, P = 0.023), right intra-atrial (10.6 ± 7.8 ms vs. 14.5 ± 10.1 ms, P = 0.035), and interatrial electromechanical (21.4 ± 9.8 ms vs. 28.3 ± 12.7 ms, P = 0.003) delays were significantly longer in patients with HT. The linear regression analysis showed that left ventricular (LV) mass index and Pmax were significantly associated with PLA (P = 0.001 and P = 0.002, respectively), and the LV mass index was the only related factor for interatrial delay (P = 0.001). Intra- and interatrial electromechanical delay, PLA were significantly prolonged in hypertensive patients. LV mass index and Pmax were significantly associated with PLA, and the LV mass index was the only related factor for interatrial delay. The atrial TDI can be a valuable method to assess the early changes of atrial electromechanical conduction properties in those patients.

Early Changes in Atrial Electromechanical Coupling in Patients with Hypertension: Assessment by Tissue Doppler Imaging

PubMed Central

Avci, Burcak Kilickiran; Gulmez, Oyku; Donmez, Guclu; Pehlivanoglu, Seckin

2016-01-01

Background: Hypertension (HT) is associated with atrial electrophysiological abnormalities. Echocardiographic pulsed wave tissue Doppler imaging (TDI) is one of the noninvasive methods for evaluation of atrial electromechanical properties. The aims of our study were to investigate the early changes in atrial electromechanical conduction in patients with HT and to assess the parameters that affect atrial electromechanical conduction. Methods: Seventy-six patients with HT (41 males, mean age 52.6 ± 9.0 years) and 41 controls (22 males, mean age 49.8 ± 7.9 years) were included in the study. Atrial electromechanical coupling at the right (PRA), left (PLA), interatrial septum (PIS) were measured with TDI. Intra- (right: PIS-PRA, left: PLA-PIS) and inter-atrial (PLA-PRA) electromechanical delays were calculated. Maximum P-wave duration (Pmax) was calculated from 12-lead electrocardiogram. Results: Atrial electromechanical coupling at PLA (76.6 ± 14.1 ms vs. 82.9 ± 15.8 ms, P = 0.036), left intra-atrial (10.9 ± 5.0 ms vs. 14.0 ± 9.7 ms, P = 0.023), right intra-atrial (10.6 ± 7.8 ms vs. 14.5 ± 10.1 ms, P = 0.035), and interatrial electromechanical (21.4 ± 9.8 ms vs. 28.3 ± 12.7 ms, P = 0.003) delays were significantly longer in patients with HT. The linear regression analysis showed that left ventricular (LV) mass index and Pmax were significantly associated with PLA (P = 0.001 and P = 0.002, respectively), and the LV mass index was the only related factor for interatrial delay (P = 0.001). Conclusions: Intra- and interatrial electromechanical delay, PLA were significantly prolonged in hypertensive patients. LV mass index and Pmax were significantly associated with PLA, and the LV mass index was the only related factor for interatrial delay. The atrial TDI can be a valuable method to assess the early changes of atrial electromechanical conduction properties in those patients. PMID:27231168

Assessment of atrial electromechanical delay by tissue Doppler echocardiography in obese subjects.

PubMed

Yagmur, Julide; Cansel, Mehmet; Acikgoz, Nusret; Ermis, Necip; Yagmur, Murat; Atas, Halil; Tasolar, Hakan; Karakus, Yasin; Pekdemir, Hasan; Ozdemir, Ramazan

2011-04-01

Our aim was to evaluate whether atrial electromechanical delay measured by tissue Doppler imaging (TDI), which is an early predictor of atrial fibrillation (AF) development, is prolonged in obese subjects. A total of 40 obese and 40 normal-weight subjects with normal coronary angiograms were included in this study. P-wave dispersion (PWD) was calculated on the 12-lead electrocardiogram (ECG). Systolic and diastolic left ventricular (LV) functions, inter- and intra-atrial electromechanical delay were measured by TDI and conventional echocardiography. Inter- and intra-atrial electromechanical delay were significantly longer in the obese subjects compared with the controls (44.08 ± 10.06 vs. 19.35 ± 5.94 ms and 23.63 ± 6.41 vs. 5.13 ± 2.67 ms, P < 0.0001 for both, respectively). PWD was higher in obese subjects (53.40 ± 5.49 vs. 35.95 ± 5.93 ms, P < 0.0001). Left atrial (LA) diameter, LA volume index and LV diastolic parameters were significantly different between the groups. Interatrial electromechanical delay was correlated with PWD (r = 0.409, P = 0.009), high-sensitivity C-reactive protein (hsCRP) levels (r = 0.588, P < 0.0001). Interatrial electromechanical delay was positively correlated with LA diameter, LA volume index, and LV diastolic function parameters consisting of mitral early wave (E) deceleration time (DT) and isovolumetric relaxation time (IVRT; r = 0.323, P = 0.042; r = 0.387, P = 0.014; r = 0.339, P = 0.033; r = 0.325, P = 0.041; respectively) and, negatively correlated with mitral early (E) to late (A) wave ratio (E/A) (r = -0.380, P = 0.016) and myocardial early-to-late diastolic wave ratio (E(m)/A(m)) (r = -0.326, P = 0.040). This study showed that atrial electromechanical delay is prolonged in obese subjects. Prolonged atrial electromechanical delay is due to provoked low-grade inflammation as well as LA enlargement and early LV diastolic dysfunction in obese subjects.

Right heart function in impaired left ventricular diastolic function: 2D speckle tracking echocardiography-based and Doppler tissue imaging-based analysis of right atrial and ventricular function.

PubMed

Brand, Anna; Bathe, Marny; Oertelt-Prigione, Sabine; Seeland, Ute; Rücke, Mirjam; Regitz-Zagrosek, Vera; Stangl, Karl; Knebel, Fabian; Stangl, Verena; Dreger, Henryk

2018-01-01

The aim of our study was to describe right atrial (RA) and right ventricular (RV) function, assessed by Doppler tissue imaging and 2D speckle tracking echocardiography (2DSTE), in women with signs of early impaired left ventricular diastolic function (DD). In a cross-sectional trial, standard parameters of diastolic and right heart function were investigated in 438 women of the Berlin Female Risk Evaluation (BEFRI) study. In a subset of women, average peak systolic RA strain (RAS), as well as the average peak systolic RV strain of the free wall (RVS free wall) and of all RV segments (average RV strain; RVS Avg), was analyzed using 2DSTE. Compared to women with normal diastolic function (DD0), RAS, RVS free wall and RVS Avg were significantly reduced in DD (43.1% ± 11.9%, -26.7% ± 5.6%, and -23.3% ± 3.5% in DD0; vs 35.1% ± 10.4%, -23.9% ± 5.5%, and -20.6% ± 3.8% in DD; P < .01). Peak RV myocardial velocity (RV-IVV) and acceleration during isovolumetric contraction (RV-IVA) were markedly higher in DD (15.0 ± 3.9 cm/s and 3.1 ± 1.0 m/s² in DD vs 11.9 ± 3.2 cm/s and 2.8 ± 0.8 m/s² in DD0; P < .05). RAS and RV-IVV were significantly associated with DD after adjustment to age, BMI, and left atrial strain in multivariate regression analysis. Systolic right heart function is significantly altered in DD. DTI as well as 2DSTE constitute sensitive echocardiographic tools that enable the diagnosis of impaired right heart mechanics in early-staged DD. © 2017 Wiley Periodicals, Inc.

Doppler-guided retrograde catheterization system

NASA Astrophysics Data System (ADS)

Frazin, Leon J.; Vonesh, Michael J.; Chandran, Krishnan B.; Khasho, Fouad; Lanza, George M.; Talano, James V.; McPherson, David D.

1991-05-01

The purpose of this study was to investigate a Doppler guided catheterization system as an adjunctive or alternative methodology to overcome the disadvantages of left heart catheterization and angiography. These disadvantages include the biological effects of radiation and the toxic and volume effects of iodine contrast. Doppler retrograde guidance uses a 20 MHz circular pulsed Doppler crystal incorporated into the tip of a triple lumen multipurpose catheter and is advanced retrogradely using the directional flow information provided by the Doppler waveform. The velocity detection limits are either 1 m/second or 4 m/second depending upon the instrumentation. In a physiologic flow model of the human aortic arch, multiple data points revealed a positive wave form when flow was traveling toward the catheter tip indicating proper alignment for retrograde advancement. There was a negative wave form when flow was traveling away from the catheter tip if the catheter was in a branch or bent upon itself indicating improper catheter tip position for retrograde advancement. In a series of six dogs, the catheter was able to be accurately advanced from the femoral artery to the left ventricular chamber under Doppler signal guidance without the use of x-ray. The potential applications of a Doppler guided retrograde catheterization system include decreasing time requirements and allowing safer catheter guidance in patients with atherosclerotic vascular disease and suspected aortic dissection. The Doppler system may allow left ventricular pressure monitoring in the intensive care unit without the need for x-ray and it may allow left sided contrast echocardiography. With pulse velocity detection limits of 4 m/second, this system may allow catheter direction and passage into the aortic root and left ventricle in patients with aortic stenosis. A modification of the Doppler catheter may include transponder technology which would allow precise catheter tip localization once the catheter tip is placed in the aortic root. Such technology may conceivably assist in allowing selective coronary catheterization. These studies have demonstrated that Doppler guided retrograde catheterization provides an accurate method to catheterization the aortic root and left ventricular chamber without x-ray. In humans, it may prove useful in a variety of settings including the development of invasive ultrasonic diagnostic and therapeutic technology.

Correlation between uteroplacental three-dimensional power Doppler indices and true uterine blood flow: evaluation in a pregnant sheep model.

PubMed

Morel, O; Pachy, F; Chavatte-Palmer, P; Bonneau, M; Gayat, E; Laigre, P; Evain-Brion, D; Tsatsaris, V

2010-11-01

Three-dimensional (3D) Doppler quantification within the uteroplacental unit could be of great help in understanding and screening for pre-eclampsia and intrauterine growth restriction. Yet the correlation between 3D Doppler indices and true blood flow has not been confirmed in vivo. The aim of this study was to evaluate this correlation in a pregnant sheep model. A blood flow quantitative sensor and a controllable vascular occlusion system were placed around the common uterine artery in seven sheep in late pregnancy, while all the other arterial supplies were ligated. Several occlusion levels were applied, from 0 to 100%, simultaneously with 3D Doppler acquisitions of several placentomes, using standardized settings. Each placentome was analyzed using VOCAL™ (Virtual Organ Computer-aided AnaLysis) software. The correlation between true blood flow and Doppler indices (vascularization index (VI), flow index (FI) and vascularization flow index (VFI)) was evaluated, together with measurement reproducibility. Forty-eight acquisitions were analyzed. All 3D Doppler indices were significantly correlated with true blood flow. Higher correlations were observed for VI and VFI (r = 0.81 (0.74-0.87), P < 0.0001 and r = 0.75 (0.67-0.82), P < 0.0001) compared with FI (r = 0.53 (0.38-0.64) P < 0.0001). Both intra- and interobserver reproducibility were high, with intraclass correlation coefficients of at least 0.799. This is the first in-vivo experimental study confirming a significant correlation between true blood perfusion and quantitative 3D Doppler indices measured within the uteroplacental unit. These results confirm the potential usefulness of 3D Doppler ultrasound for the assessment of placental vascular insufficiency both in clinical cases and in a research setting. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.

Clinical Tests Combined with Color Doppler Versus Color Doppler Alone in Identifying Incompetent Perforator Veins of the Lower Limb: A Prospective Analytical Study.

PubMed

Sureshkumar, Sathasivam; Vignesh, Narayan; Venkatachalam, J; Vijayakumar, Chellappa; Sudharsanan, Sundaramurthi

2018-01-05

Background The color Doppler, a better investigation to identify the perforators objectively has replaced the clinical examination for the same. However, this has led to a significant number of negative explorations and cosmetic disfigurement. Objective To compare the efficacy of the clinical tests combined with the color Doppler versus color Doppler alone to identify the perforator incompetence during the surgery for primary varicose veins of the lower limb. Methods This was a prospective analytical study, including 61 lower limb varicose vein patients who belonged to the Clinical-Etiology-Anatomy-Pathophysiology (CEAP) class four-six, planned for the surgical treatment for perforator incompetence, excluding those requiring additional vascular or nonvascular procedure, recurrent varicose veins and those who had injection sclerotherapy prior to the surgery. The clinical tests, including Trendelenburg's test, multiple tourniquet tests and, the Fegan's tests were performed and incompetent perforators were marked on a template as 'C' to indicate the clinically positive perforator incompetence. The patients were then examined with the color Doppler ultrasound and the pathological incompetent perforators were marked as 'D'. The surgical management of the perforator incompetence was done by stab ligation. The incision was made in the color Doppler 'D' marked sites as it has been the standard protocol. The number of incompetent perforators identified during the surgical exploration were categorized as 'D' positive or 'C' and 'D' positive and were recorded in the specified proforma. Results It was found that the mean number of the perforator incompetence identified by the color Doppler alone was 8.2 whereas during the surgery, only a mean of six perforators was identified, leading to 20 unnecessary explorations per 10 patients (8.2 vs. 6; mean difference 2.229; P <0.001). The mean number of the perforator incompetence identified by the color Doppler combined with the clinical tests was 4.5 and during the surgery, a mean of four perforators was identified (4.5 vs. 4; mean difference 0.377; P <0.001). The color Doppler combined with the clinical examination lead to only four unnecessary explorations per 10 patients. Conclusion A combination of both the clinical tests and the color Doppler ultrasound has a higher accuracy in detecting perforator incompetence and can reduce the number of negative explorations by the rate of 16 unnecessary explorations per 10 patients.

Three-dimensional imaging of absolute blood flow velocity and blood vessel position under low blood flow velocity based on Doppler signal information included in scattered light from red blood cells

NASA Astrophysics Data System (ADS)

Kyoden, Tomoaki; Akiguchi, Shunsuke; Tajiri, Tomoki; Andoh, Tsugunobu; Hachiga, Tadashi

2017-11-01

The development of a system for in vivo visualization of occluded distal blood vessels for diabetic patients is the main target of our research. We herein describe two-beam multipoint laser Doppler velocimetry (MLDV), which measures the instantaneous multipoint flow velocity and can be used to observe the blood flow velocity in peripheral blood vessels. By including a motorized stage to shift the measurement points horizontally and in the depth direction while measuring the velocity, the path of the blood vessel in the skin could be observed using blood flow velocity in three-dimensional space. The relationship of the signal power density between the blood vessel and the surrounding tissues was shown and helped us identify the position of the blood vessel. Two-beam MLDV can be used to simultaneously determine the absolute blood flow velocity distribution and identify the blood vessel position in skin.

Early Ambulation After Microsurgical Reconstruction of the Lower Extremity.

PubMed

Orseck, Michael J; Smith, Christopher Robert; Kirby, Sean; Trujillo, Manuel

2018-06-01

Successful outcomes after microsurgical reconstruction of the lower extremity include timely return to ambulation. Some combination of physical examination, ViOptix tissue oxygen saturation monitoring, and the implantable venous Doppler have shown promise in increasing sensitivity of current flap monitoring. We have incorporated this system into our postoperative monitoring protocol in an effort to initiate earlier dependency protocols. A prospective analysis of 36 anterolateral thigh free flap and radial forearm flaps for lower extremity reconstruction was performed. Indications for reconstruction were acute and chronic wounds, as well as oncologic resection. Twenty-three patients were able to ambulate and 3 were able to dangle their leg on the first postoperative day. One flap showed early mottling that improved immediately after elevation. After reelevation and return to baseline, the dependency protocol was successfully implemented on postoperative day 3. All flaps went on to successful healing. Physical examination, implantable venous Doppler, and ViOptix can be used reliably as an adjunct to increase the sensitivity of detecting poorly performing flaps during the postoperative progression of dependency.

Dynamic spatio-temporal imaging of early reflow in a neonatal rat stroke model.

PubMed

Leger, Pierre-Louis; Bonnin, Philippe; Lacombe, Pierre; Couture-Lepetit, Elisabeth; Fau, Sebastien; Renolleau, Sylvain; Gharib, Abdallah; Baud, Olivier; Charriaut-Marlangue, Christiane

2013-01-01

The aim of the study was to better understand blood-flow changes in large arteries and microvessels during the first 15 minutes of reflow in a P7 rat model of arterial occlusion. Blood-flow changes were monitored by using ultrasound imaging with sequential Doppler recordings in internal carotid arteries (ICAs) and basilar trunk. Relative cerebral blood flow (rCBF) changes were obtained by using laser speckle Doppler monitoring. Tissue perfusion was measured with [(14)C]-iodoantipyrine autoradiography. Cerebral energy metabolism was evaluated by mitochondrial oxygen consumption. Gradual increase in mean blood-flow velocities illustrated a gradual perfusion during early reflow in both ICAs. On ischemia, the middle cerebral artery (MCA) territory presented a residual perfusion, whereas the caudal territory remained normally perfused. On reflow, speckle images showed a caudorostral propagation of reperfusion through anastomotic connections, and a reduced perfusion in the MCA territory. Autoradiography highlighted the caudorostral gradient, and persistent perfusion in ventral and medial regions. These blood-flow changes were accompanied by mitochondrial respiration impairment in the ipsilateral cortex. Collectively, these data indicate the presence of a primary collateral pathway through the circle of Willis, providing an immediate diversion of blood flow toward ischemic regions, and secondary efficient cortical anastomoses in the immature rat brain.

3-D ultrafast Doppler imaging applied to the noninvasive mapping of blood vessels in vivo.

PubMed

Provost, Jean; Papadacci, Clement; Demene, Charlie; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu

2015-08-01

Ultrafast Doppler imaging was introduced as a technique to quantify blood flow in an entire 2-D field of view, expanding the field of application of ultrasound imaging to the highly sensitive anatomical and functional mapping of blood vessels. We have recently developed 3-D ultrafast ultrasound imaging, a technique that can produce thousands of ultrasound volumes per second, based on a 3-D plane and diverging wave emissions, and demonstrated its clinical feasibility in human subjects in vivo. In this study, we show that noninvasive 3-D ultrafast power Doppler, pulsed Doppler, and color Doppler imaging can be used to perform imaging of blood vessels in humans when using coherent compounding of 3-D tilted plane waves. A customized, programmable, 1024-channel ultrasound system was designed to perform 3-D ultrafast imaging. Using a 32 × 32, 3-MHz matrix phased array (Vermon, Tours, France), volumes were beamformed by coherently compounding successive tilted plane wave emissions. Doppler processing was then applied in a voxel-wise fashion. The proof of principle of 3-D ultrafast power Doppler imaging was first performed by imaging Tygon tubes of various diameters, and in vivo feasibility was demonstrated by imaging small vessels in the human thyroid. Simultaneous 3-D color and pulsed Doppler imaging using compounded emissions were also applied in the carotid artery and the jugular vein in one healthy volunteer.

3-D Ultrafast Doppler Imaging Applied to the Noninvasive and Quantitative Imaging of Blood Vessels in Vivo

PubMed Central

Provost, J.; Papadacci, C.; Demene, C.; Gennisson, J-L.; Tanter, M.; Pernot, M.

2016-01-01

Ultrafast Doppler Imaging was introduced as a technique to quantify blood flow in an entire 2-D field of view, expanding the field of application of ultrasound imaging to the highly sensitive anatomical and functional mapping of blood vessels. We have recently developed 3-D Ultrafast Ultrasound Imaging, a technique that can produce thousands of ultrasound volumes per second, based on three-dimensional plane and diverging wave emissions, and demonstrated its clinical feasibility in human subjects in vivo. In this study, we show that non-invasive 3-D Ultrafast Power Doppler, Pulsed Doppler, and Color Doppler Imaging can be used to perform quantitative imaging of blood vessels in humans when using coherent compounding of three-dimensional tilted plane waves. A customized, programmable, 1024-channel ultrasound system was designed to perform 3-D Ultrafast Imaging. Using a 32X32, 3-MHz matrix phased array (Vermon, France), volumes were beamformed by coherently compounding successive tilted plane wave emissions. Doppler processing was then applied in a voxel-wise fashion. 3-D Ultrafast Power Doppler Imaging was first validated by imaging Tygon tubes of varying diameter and its in vivo feasibility was demonstrated by imaging small vessels in the human thyroid. Simultaneous 3-D Color and Pulsed Doppler Imaging using compounded emissions were also applied in the carotid artery and the jugular vein in one healthy volunteer. PMID:26276956

Proceedings of Workshop on Laser Diagnostics in Fluid Mechanics and Combustion

NASA Astrophysics Data System (ADS)

1993-10-01

Proceedings of the Workshop on Laser Diagnostics in Fluid Mechanics and Combustion are presented. Topics included are: Accuracy of Laser Doppler Anemometry; Applications of Raman-Rayleigh-LIF Diagnostics in Combustion Research; Phase Doppler Anemometer Technique Concepts and Applications; CARS; Particle Image Velocimetry; Practical Consideration in the Use and Design of Laser Velocimetry Systems in Turbomachinery Applications; Phase Doppler Measurements of Gas-Particle Flow Through a Tube Bank; Degenerate Four Wave Mixing for Shock Tunnel Studies of Supersonic Combustion; Laser Induced Photodissociation and Fluorescence (LIPF) of Sodium Species Present in Coal Combustion; 3D Holographic Measurements Inside a Spark Ignition Engine; Laser Doppler Velocimeter Measurements in Compressible Flow; Bursting in a Tornado Vortex; Quantitative Imaging of OH and Temperature Using a Single Laser Source and Single Intensified Camera; and Laser Doppler Measurements Inside an Artificial Heart Valve.

Carotid Doppler ultrasound findings in patients with left ventricular assist devices.

PubMed

Cervini, Patrick; Park, Soon J; Shah, Dipesh K; Penev, Irina E; Lewis, Bradley D

2010-12-01

Left ventricular assist devices (LVADs) have been used to treat advanced heart failure refractory to medical management, as bridge therapy to myocardial recovery, as bridge therapy to cardiac transplantation, or as destination therapy for patients with unfavorable transplant candidacy. Neurologic complications are some of the most common and devastating complications in these patients. Preoperative carotid ultrasound is, therefore, a standard evaluation in patients at risk for cerebrovascular disease. Postoperative carotid artery Doppler sonography is performed in those patients with neurologic symptoms. It is likely, therefore, that sonographers, radiologists, and other physicians working in a center where LVADs are implanted will likely encounter a carotid artery Doppler study in this patient group. To our knowledge, the carotid Doppler findings in these patients have never been published. We review the Doppler ultrasound findings in 6 patients after LVAD insertion.

Validation of high temporal resolution spiral phase velocity mapping of temporal patterns of left and right coronary artery blood flow against Doppler guidewire.

PubMed

Keegan, Jennifer; Raphael, Claire E; Parker, Kim; Simpson, Robin M; Strain, Stephen; de Silva, Ranil; Di Mario, Carlo; Collinson, Julian; Stables, Rod H; Wage, Ricardo; Drivas, Peter; Sugathapala, Malindie; Prasad, Sanjay K; Firmin, David N

2015-10-02

Temporal patterns of coronary blood flow velocity can provide important information on disease state and are currently assessed invasively using a Doppler guidewire. A non-invasive alternative would be beneficial as it would allow study of a wider patient population and serial scanning. A retrospectively-gated breath-hold spiral phase velocity mapping sequence (TR 19 ms) was developed at 3 Tesla. Velocity maps were acquired in 8 proximal right and 15 proximal left coronary arteries of 18 subjects who had previously had a Doppler guidewire study at the time of coronary angiography. Cardiovascular magnetic resonance (CMR) velocity-time curves were processed semi-automatically and compared with corresponding invasive Doppler data. When corrected for differences in heart rate between the two studies, CMR mean velocity through the cardiac cycle, peak systolic velocity (PSV) and peak diastolic velocity (PDV) were approximately 40 % of the peak Doppler values with a moderate - good linear relationship between the two techniques (R(2): 0.57, 0.64 and 0.79 respectively). CMR values of PDV/PSV showed a strong linear relationship with Doppler values with a slope close to unity (0.89 and 0.90 for right and left arteries respectively). In individual vessels, plots of CMR velocities at all cardiac phases against corresponding Doppler velocities showed a consistent linear relationship between the two with high R(2) values (mean +/-SD: 0.79 +/-.13). High temporal resolution breath-hold spiral phase velocity mapping underestimates absolute values of coronary flow velocity but allows accurate assessment of the temporal patterns of blood flow.

Analyzing the value of monitoring duodenal mucosal perfusion using photoplethysmography.

PubMed

Fink, Mitchell P

2014-10-13

Photoplethysmography (PPG) is a technique that permits noninvasive measurement of changes in the volume of tissues. A novel device uses PPG to assess changes in duodenal mucosal perfusion. When tested in septic piglets, data obtained using this device correlate with the blood lactate concentration and duodenal serosal microvascular blood flow as measured with a laser Doppler flowmeter. This new PPG-based approach for continuously monitoring gut mucosal perfusion warrants further development, leading to prospective clinical trials in patients.

Ultrasonic Doppler measurement of renal artery blood flow

NASA Technical Reports Server (NTRS)

Freund, W. R.; Beaver, W. L.; Meindl, J. D.

1976-01-01

Studies were made of (1) blood flow redistribution during lower body negative pressure (LBNP), (2) the profile of blood flow across the mitral annulus of the heart (both perpendicular and parallel to the commissures), (3) testing and evaluation of a number of pulsed Doppler systems, (4) acute calibration of perivascular Doppler transducers, (5) redesign of the mitral flow transducers to improve reliability and ease of construction, and (6) a frequency offset generator designed for use in distinguishing forward and reverse components of blood flow by producing frequencies above and below the offset frequency. Finally methodology was developed and initial results were obtained from a computer analysis of time-varying Doppler spectra.

Medical application of artificial immune recognition system (AIRS): diagnosis of atherosclerosis from carotid artery Doppler signals.

PubMed

Latifoğlu, Fatma; Kodaz, Halife; Kara, Sadik; Güneş, Salih

2007-08-01

This study was conducted to distinguish between atherosclerosis and healthy subjects. Hence, we have employed the maximum envelope of the carotid artery Doppler sonograms derived from Fast Fourier Transformation-Welch method and Artificial Immune Recognition System (AIRS). The fuzzy appearance of the carotid artery Doppler signals makes physicians suspicious about the existence of diseases and sometimes causes false diagnosis. Our technique gets around this problem using AIRS to decide and assist the physician to make the final judgment in confidence. AIRS has reached 99.29% classification accuracy using 10-fold cross validation. Results show that the proposed method classified Doppler signals successfully.

Doppler ultrasonography of the anterior knee tendons in elite badminton players: colour fraction before and after match.

PubMed

Koenig, M J; Torp-Pedersen, S; Boesen, M I; Holm, C C; Bliddal, H

2010-02-01

Anterior knee tendon problems are seldom reported in badminton players although the game is obviously stressful to the lower extremities. Painful anterior knee tendons are common among elite badminton players. The anterior knee tendons exhibit colour Doppler activity. This activity increases after a match. Painful tendons have more Doppler activity than tendons without pain. Cohort study. 72 elite badminton players were interviewed about training, pain and injuries. The participants were scanned with high-end ultrasound equipment. Colour Doppler was used to examine the tendons of 64 players before a match and 46 players after a match. Intratendinous colour Doppler flow was measured as colour fraction (CF). The tendon complex was divided into three loci: the quadriceps tendon, the proximal patellar tendon and the insertion on the tibial tuberosity. Interview: Of the 72 players, 62 players had problems with 86 tendons in the lower extremity. Of these 86 tendons, 48 were the anterior knee tendons. Ultrasound: At baseline, the majority of players (87%) had colour Doppler flow in at least one scanning position. After a match, the percentage of the knee complexes involved did not change. CF increased significantly in the dominant leg at the tibial tuberosity; single players had a significantly higher CF after a match at the tibial tuberosity and in the patellar tendon both before and after a match. Painful tendons had the highest colour Doppler activity. Most elite badminton players had pain in the anterior knee tendons and intratendinous Doppler activity both before and after match. High levels of Doppler activity were associated with self-reported ongoing pain.

The subxiphoid view cannot replace the apical view for transthoracic echocardiographic assessment of hemodynamic status

PubMed Central

2013-01-01

Introduction This prospective study aimed to assess whether use of the subxiphoid acoustic window in transthoracic echocardiography (TTE) can be an accurate alternative in the absence of an apical view to assess hemodynamic parameters. Methods This prospective study took place in a teaching hospital medical ICU. Over a 4-month period, TTE was performed in patients admitted for more than 24 hours. Two operators rated the quality of parasternal, apical, and subxiphoid acoustic windows as Excellent, Good, Acceptable, Poor, or No image. In the subpopulation presenting adequate (rated as acceptable or higher) apical and subxiphoid views, we compared the left ventricular ejection fraction (LVEF), the ratio between right and left ventricular end-diastolic areas (RVEDA/LVEDA), the ratio between early and late mitral inflow on pulsed Doppler (E/A ratio), the aortic velocity time integral (Ao VTI), and the ratio between early mitral inflow and displacement of the mitral annulus on tissue Doppler imaging (E/Ea ratio). Results An adequate apical view was obtained in 80%, and an adequate subxiphoid view was obtained in 63% of the 107 patients included. Only 5% of patients presented an adequate subxiphoid view without an adequate apical view. In the subpopulation of patients with adequate apical and subxiphoid windows (n = 65), LVEF, E/A, and RVEDA/LVEDA were comparable on both views, and were strongly correlated (r > 0.80) with acceptable biases and precision. However, the Ao VTI and the E/Ea ratio were lower on the subxiphoid view than on the apical view (18 ± 5 versus 16 ± 5 cm and 9.6 ± 4.6 versus 7.6 ± 4 cm, respectively, P = 0.001 for both). Conclusions An adequate TTE subxiphoid window was obtained in fewer than two thirds of ICU patients. In addition to the classic indication for the subxiphoid window to study the vena cava and pericardium, this view can be used to study right and left ventricular morphology and function, but does not provide accurate hemodynamic Doppler information. ICU echocardiographers should therefore record both apical and subxiphoid views to assess comprehensively the cardiac function and hemodynamic status. PMID:24004960

Multimodal optical measurement for study of lower limb tissue viability in patients with diabetes mellitus

NASA Astrophysics Data System (ADS)

Dremin, Viktor V.; Zherebtsov, Evgeny A.; Sidorov, Victor V.; Krupatkin, Alexander I.; Makovik, Irina N.; Zherebtsova, Angelina I.; Zharkikh, Elena V.; Potapova, Elena V.; Dunaev, Andrey V.; Doronin, Alexander A.; Bykov, Alexander V.; Rafailov, Ilya E.; Litvinova, Karina S.; Sokolovski, Sergei G.; Rafailov, Edik U.

2017-08-01

According to the International Diabetes Federation, the challenge of early stage diagnosis and treatment effectiveness monitoring in diabetes is currently one of the highest priorities in modern healthcare. The potential of combined measurements of skin fluorescence and blood perfusion by the laser Doppler flowmetry method in diagnostics of low limb diabetes complications was evaluated. Using Monte Carlo probabilistic modeling, the diagnostic volume and depth of the diagnosis were evaluated. The experimental study involved 76 patients with type 2 diabetes mellitus. These patients were divided into two groups depending on the degree of complications. The control group consisted of 48 healthy volunteers. The local thermal stimulation was selected as a stimulus on the blood microcirculation system. The experimental studies have shown that diabetic patients have elevated values of normalized fluorescence amplitudes, as well as a lower perfusion response to local heating. In the group of people with diabetes with trophic ulcers, these parameters also significantly differ from the control and diabetes only groups. Thus, the intensity of skin fluorescence and level of tissue blood perfusion can act as markers for various degrees of complications from the beginning of diabetes to the formation of trophic ulcers.

Coronary CT Angiography Incorporating Doppler-Guided Prospective ECG Gating in Patients with High Heart Rate: Comparison with Results of Traditional Prospective ECG Gating

PubMed Central

Li, Min; Yu, Bing-bing; Wu, Jian-hua; Xu, Lin; Sun, Gang

2013-01-01

Purpose As Doppler ultrasound has been proven to be an effective tool to predict and compress the optimal pulsing windows, we evaluated the effective dose and diagnostic accuracy of coronary CT angiography (CTA) incorporating Doppler-guided prospective electrocardiograph (ECG) gating, which presets pulsing windows according to Doppler analysis, in patients with a heart rate >65 bpm. Materials and Methods 119 patients with a heart rate >65 bpm who were scheduled for invasive coronary angiography were prospectively studied, and patients were randomly divided into traditional prospective (n = 61) and Doppler-guided prospective (n = 58) ECG gating groups. The exposure window of traditional prospective ECG gating was set at 30%–80% of the cardiac cycle. For the Doppler group, the length of diastasis was analyzed by Doppler. For lengths greater than 90 ms, the pulsing window was preset during diastole (during 60%–80%); otherwise, the optimal pulsing intervals were moved from diastole to systole (during 30%–50%). Results The mean heart rates of the traditional ECG and the Doppler-guided group during CT scanning were 75.0±7.7 bpm (range, 66–96 bpm) and 76.5±5.4 bpm (range: 66–105 bpm), respectively. The results indicated that whereas the image quality showed no significant difference between the traditional and Doppler groups (P = 0.42), the radiation dose of the Doppler group was significantly lower than that of the traditional group (5.2±3.4mSv vs. 9.3±4.5mSv, P<0.001). The sensitivities of CTA applying traditional and Doppler-guided prospective ECG gating to diagnose stenosis on a segment level were 95.5% and 94.3%, respectively; specificities 98.0% and 97.1%, respectively; positive predictive values 90.7% and 88.2%, respectively; negative predictive values 99.0% and 98.7%, respectively. There was no statistical difference in concordance between the traditional and Doppler groups (P = 0.22). Conclusion Doppler-guided prospective ECG gating represents an improved method in patients with a high heart rate to reduce effective radiation doses, while maintaining high diagnostic accuracy. PMID:23696793

The effects of probe placement on measured flow velocity in transcranial Doppler ultrasound imaging in-vitro and in-vivo experiments

NASA Astrophysics Data System (ADS)

de Jong, Daan L. K.; Meel-van den Abeelen, Aisha S. S.; Lagro, Joep; Claassen, Jurgen A. H. R.; Slump, Cornelis H.

2014-03-01

The measurement of the blood flow in the middle cerebral artery (MCA) using transcranial Doppler ultrasound (US) imaging is clinically relevant for the study of cerebral autoregulation. Especially in the aging population, impairement of the autoregulation may coincide or relate to loss of perfusion and consequently loss of brain function. The cerebral autoregulation can be assessed by relating the blood pressure to the blood flow in the brain. Doppler US is a widely used, non-invasive method to measure the blood flow in the MCA. However, Doppler flow imaging is known to produce results that are dependent of the operator. The angle of the probe insonation with respect to the centerline of the blood vessel is a well known factor for output variability. In patients also the skull must be traversed and the MCA must be detected, influencing the US signal intensity. In this contribution we report two studies. We describe first an in-vitro setup to study the Doppler flow in a situation where the ground truth is known. Secondly, we report on a study with healthy volunteers where the effects of small probe displacements on the flow velocity signals are investigated. For the latter purpose, a special probe holder was designed to control the experiment.

Use of near-infrared systems for investigations of hemodynamics in human in vivo bone tissue: A systematic review.

PubMed

Meertens, Robert; Casanova, Francesco; Knapp, Karen M; Thorn, Clare; Strain, William David

2018-05-04

A range of technologies using near infrared (NIR) light have shown promise at providing real time measurements of hemodynamic markers in bone tissue in vivo, an exciting prospect given existing difficulties in measuring hemodynamics in bone tissue. This systematic review aimed to evaluate the evidence for this potential use of NIR systems, establishing their potential as a research tool in this field. Major electronic databases including MEDLINE and EMBASE were searched using pre-planned search strategies with broad scope for any in vivo use of NIR technologies in human bone tissue. Following identification of studies by title and abstract screening, full text inclusion was determined by double blind assessment using predefined criteria. Full text studies for inclusion were data extracted using a predesigned proforma and quality assessed. Narrative synthesis was appropriate given the wide heterogeneity of included studies. Eighty-eight full text studies fulfilled the inclusion criteria, 57 addressing laser Doppler flowmetry (56 intra-operatively), 21 near infrared spectroscopy, and 10 photoplethysmography. The heterogeneity of the methodologies included differing hemodynamic markers, measurement protocols, anatomical locations, and research applications, making meaningful direct comparisons impossible. Further, studies were often limited by small sample sizes with potential selection biases, detection biases, and wide variability in results between participants. Despite promising potential in the use of NIR light to interrogate bone circulation, the application of NIR systems in bone requires rigorous assessment of the reproducibility of potential hemodynamic markers and further validation of these markers against alternative physiologically relevant reference standards. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 9999:1-9, 2018. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Optical assessment of intravascular and intracellular parameters related to tissue viability

NASA Astrophysics Data System (ADS)

Mayevsky, Avraham; Sherman, Efrat; Cohen-Kashi, Meir; Dekel, Nava; Pewzner, Eliyahu

2007-02-01

Tissue viability represents the balance between O II supply and demand. In our previous paper (Mayevsky et al; Proc.SPIE 6083 : z1-z10, 2006) the HbO II was added to the multiparametric tissue spectroscope (Mayevsky et al J.Biomedical Optics 9:1028-1045,2004). This parameter provides relative values of microcirculatory blood oxygenation (MC-HbO II) evaluated by the 2 wavelength reflectometry principle. The advantage of this approach as compared to pulse oximetry is that the measurement is not dependent of the existence of the pulse of the heart. Also in the MC-HbO II the information is collected from small vessels providing O II to the mitochondria as compared to the pulse oximeter indicating blood oxygenation by the respiratory and cardiovascular systems. In the present study we compared the level of blood oxygenation measured by the pulse oximeter to that measured by the CritiView in the brain exposed to various systemic and localized perturbations of O II supply or demand. We exposed gerbils to anoxia, hypoxia, ischemia and terminal anoxia. In addition we measured mitochondrial NADH (surface fluorometry), tissue reflectance, tissue blood flow (laser Doppler flowmetry) from the same site of MC-HbO II measurement. A clear connection was found between the two blood oxygenation parameters only when systemic perturbations were used (anoxia, hypoxia and terminal anoxia). Under local events (ischemia) the MC-HbO II was responsive while the systemic oxygenation was unchanged. We concluded that MC-HbO II has a significant value in interpretation of tissue energy metabolism under pathophysiological conditions.

Noninvasive diagnosis of right-sided extracardiac conduit obstruction by combined magnetic resonance imaging and continuous-wave Doppler echocardiography.

PubMed

Canter, C E; Gutierrez, F R; Molina, P; Hartmann, A F; Spray, T L

1991-04-01

Right-sided extracardiac conduits are frequently complicated by obstruction over time. We compared the utility of two-dimensional and Doppler echocardiography and magnetic resonance imaging in the diagnosis of postoperative right-sided obstruction with cardiac catheterization and angiography in 10 patients with xenograft or homograft conduits. Correlation (r = 0.95) between continuous-wave Doppler estimates and catheter pullback pressure gradients across the conduits was excellent. Echocardiography could only visualize five of 10 conduits in their entirety. Magnetic resonance imaging visualized all conduits and showed statistically significant (kappa = 0.58) agreement with angiography in the localization and estimation of severity of a variety of right-sided obstructions in these patients. However, flow voids created by the metallic ring around xenograft valves led to a false negative diagnosis of valvular stenosis in four patients when magnetic resonance imaging was used alone. Doppler studies correctly indicated obstruction in these patients. The combination of magnetic resonance imaging studies and continuous-wave Doppler echocardiography can be useful to noninvasively evaluate right-sided obstruction in postoperative patients with right-sided extracardiac conduits.

Doppler synthetic aperture radar interferometry: a novel SAR interferometry for height mapping using ultra-narrowband waveforms

NASA Astrophysics Data System (ADS)

Yazıcı, Birsen; Son, Il-Young; Cagri Yanik, H.

2018-05-01

This paper introduces a new and novel radar interferometry based on Doppler synthetic aperture radar (Doppler-SAR) paradigm. Conventional SAR interferometry relies on wideband transmitted waveforms to obtain high range resolution. Topography of a surface is directly related to the range difference between two antennas configured at different positions. Doppler-SAR is a novel imaging modality that uses ultra-narrowband continuous waves (UNCW). It takes advantage of high resolution Doppler information provided by UNCWs to form high resolution SAR images. We introduce the theory of Doppler-SAR interferometry. We derive an interferometric phase model and develop the equations of height mapping. Unlike conventional SAR interferometry, we show that the topography of a scene is related to the difference in Doppler frequency between two antennas configured at different velocities. While the conventional SAR interferometry uses range, Doppler and Doppler due to interferometric phase in height mapping; Doppler-SAR interferometry uses Doppler, Doppler-rate and Doppler-rate due to interferometric phase in height mapping. We demonstrate our theory in numerical simulations. Doppler-SAR interferometry offers the advantages of long-range, robust, environmentally friendly operations; low-power, low-cost, lightweight systems suitable for low-payload platforms, such as micro-satellites; and passive applications using sources of opportunity transmitting UNCW.

Microcirculation and structural reorganization of the bladder mucosa in chronic cystitis under conditions of ozone therapy.

PubMed

Neimark, A I; Nepomnyashchikh, L M; Lushnikova, E L; Bakarev, M A; Abdullaev, N A; Sizov, K A

2014-01-01

Structural reorganization of the bladder mucosa in chronic cystitis and its correction by ozone therapy were studied. A relationship between the epithelial layer restructuring of different kinds (dystrophy, metaplasia, and degeneration), level of cell proliferation, and ultrastructural organization of urotheliocytes was detected. This complex of structural reactions was combined with dysregulation of tissue bloodflow in the bladder mucosa, shown by laser Doppler flowmetry. Positive structural changes were most marked in intravesical and less so in parenteral ozone therapy added to the therapeutic complex and manifested in reduction of inflammation and alteration in parallel with more intense reparative reactions. A special feature of parenteral ozone therapy was a significant improvement of microcirculation in the bladder mucosa.

Assessment of ureterovesical jet dynamics in obstructed ureter by urinary stone with color Doppler and duplex Doppler examinations.

PubMed

Jandaghi, Ali Babaei; Falahatkar, Siavash; Alizadeh, Ahmad; Kanafi, Alireza Rajabzadeh; Pourghorban, Ramin; Shekarchi, Babak; Zirak, Amin Keshavarz; Esmaeili, Samaneh

2013-04-01

This study was designed to evaluate ureterovesical jet dynamics in obstructed ureter and to compare it with those of contralateral unobstructed side. Forty-six patients with diagnosis of ureteral stone, based on imaging findings in computed tomography were enrolled in this study. The gray-scale ultrasound exam from both kidneys and urinary bladder was performed. Then, ureterovesical jet characteristics including ureteral jet frequency, duration and peak velocity were assessed by color Doppler and duplex Doppler studies in both obstructed and unobstructed ureters by a radiologist, 15-30 min after oral hydration with 750-1,000 mL of water. When compared with contralateral normal side, the ureterovesical jet in obstructed ureter showed less frequency (0.59 vs. 3.04 jets/min; P < 0.05), shorter duration (1.24 vs. 5.26 s; P < 0.05) and lower peak velocity (5.41 vs. 32.09 cm/s; P < 0.05). The cut-off points of 1.5 jets/min, 2.5 s and 19.5 cm/s for difference of ureteral jet frequency, duration and peak velocity between obstructed and contralateral normal ureters yielded sensitivities of 97.8, 95.6 and 100 % and specificities of 87, 87.9 and 97.8 %, respectively for diagnosis of ureteral obstruction. Given the safety of Doppler study and significant differences in flow dynamics of obstructed versus unobstructed ureters, our findings demonstrated the utility of Doppler ultrasound examination as a useful adjunct to gray-scale ultrasound by improving the accuracy of ultrasound exam in diagnosis of ureteral obstruction.

Validation of On-Orbit Methodology for the Assessment of Cardiac Function and Changes in the Circulating Volume Using Ultrasound and Braslet-M Occlusion Cuffs

NASA Technical Reports Server (NTRS)

Hamilton, Douglas; Sargsyan, Ashot E.; Ebert, Douglas; Duncan, Michael; Bogomolov, Valery V.; Alferova, Irina V.; Matveev, Vladimir P.; Dulchavsky, Scott A.

2010-01-01

The objective of this joint U.S. - Russian project was the development and validation of an in-flight methodology to assess a number of cardiac and vascular parameters associated with circulating volume and its manipulation in long-duration space flight. Responses to modified Valsalva and Mueller maneuvers were measured by cardiac and vascular ultrasound (US) before, during, and after temporary volume reduction by means of Braslet-M thigh occlusion cuffs (Russia). Materials and Methods: The study protocol was conducted in 14 sessions on 9 ISS crewmembers, with an average exposure to microgravity of 122 days. Baseline cardiovascular measurements were taken by echocardiography in multiple modes (including tissue Doppler of both ventricles) and femoral and jugular vein imaging on the International Space Station (ISS). The Braslet devices were then applied and measurements were repeated after >10 minutes. The cuffs were then released and the hemodynamic recovery process was monitored. Modified Valsalva and Mueller maneuvers were used throughout the protocol. All US data were acquired by the HDI-5000 ultrasound system aboard the ISS (ATL/Philips, USA) during remotely guided sessions. The study protocol, including the use of Braslet-M for this purpose, was approved by the ISS Human Research Multilateral Review Board (HRMRB). Results: The effects of fluid sequestration on a number of echocardiographic and vascular parameters were readily detectable by in-flight US, as were responses to respiratory maneuvers. The overall volume status assessment methodology appears to be valid and practical, with a decrease in left heart lateral E (tissue Doppler) as one of the most reliable measures. Increase in the femoral vein cross-sectional areas was consistently observed with Braslet application. Other significant differences and trends within the extensive cardiovascular data were also observed. (Decreased - RV and LV preload indices, Cardiac Output, LV E all maneuvers, LV Stroke Volume). Conclusions: This Study: 1) Addressed specific aspects of operational space medicine and space physiology, including assessment of circulating volume disturbances 2) Expanded the applications of diagnostic ultrasound imaging and Doppler techniques in microgravity. 3) Used respiratory maneuvers against the background of acute circulating volume manipulations which appear to enhance our ability to noninvasively detect volume-dependency in a number of cardiac and vascular parameters. 4) Determined that Tei index is not clinically changed therefore contractility not altered in the face of reduced preload. 5) Determined that increased Femoral Vein Area indicating blood being sequestered in lower extremities correlates with reduced preload and cardiac output. 6) That Braslet may be the only feasible means of acutely treating high pressure pulmonary edema in reduced gravity environments.

The Effect of Sea Surface Slicks on the Doppler Spectrum Width of a Backscattered Microwave Signal.

PubMed

Karaev, Vladimir; Kanevsky, Mikhail; Meshkov, Eugeny

2008-06-06

The influence of a surface-active substance (SAS) film on the Doppler spectrum width at small incidence angles is theoretically investigated for the first time for microwave radars with narrow-beam and knife-beam antenna patterns. It is shown that the requirements specified for the antenna system depend on the radar motion velocity. A narrow-beam antenna pattern should be used to detect slicks by an immobile radar, whereas radar with a knife-beam antenna pattern is needed for diagnostics from a moving platform. The study has revealed that the slick contrast in the Doppler spectrum width increases as the radar wavelength diminishes, thus it is preferable to utilize wavelengths not larger than 2 cm for solving diagnostic problems. The contrast in the Doppler spectrum width is generally weaker than that in the radar backscattering cross section; however, spatial and temporal fluctuations of the Doppler spectrum width are much weaker than those of the reflected signal power. This enables one to consider the Doppler spectrum as a promising indicator of slicks on water surface.

Investigation of Osteoinductive Effects of Different Compositions of Bioactive Glass Nanoparticles for Bone Tissue Engineering.

PubMed

Tavakolizadeh, AmirHossein; Ahmadian, Mehdi; Fathi, Mohammad Hossein; Doostmohammadi, Ali; Seyedjafari, Ehsan; Ardeshirylajimi, Abdolreza

Bioactive glasses (BG) is one of the well-known materials that used as dental and bone implants, for this reason it is always interesting for researchers has been to increase BG efficiency in the bone tissue engineering. The aim of this study was to evaluate the osteoinductivity of BG different composition nanoparticles with SiO2-CaO-P2O5. The 45S, 58S, and 63S compositions were prepared via the sol-gel technique. Characterization techniques such as x-ray diffraction, field emission scanning electron microscopy (FE-SEM), and laser Doppler electrophoresis (LDE) were used. The osteoinductive capacity of prepared nanoparticles was investigated using unrestricted somatic stem cells (USSC). The particle size of the samples with an amorphous structure mainly ranged less than 40 nm. The zeta potential was negative for all compositions in distilled water at pH 7.4. Bioactive glass nanoparticles were shown to support proliferation of USSC, as shown by microculture tetrazolium (MTT) assay. During osteogenic differentiation, significantly highest values of alkaline phosphatase (ALP) activity and biomineralization were observed on 45S BG. Subsequently, these markers were measured in higher amounts in USSC on 58S and 63S BG compared with tissue culture polystyrene. The nanometric particle size, osteoinductivity, and negative zeta potential make this material a possible candidate for bone tissue engineering applications.

Potential of Higher Moments of the Radar Doppler Spectrum for Studying Ice Clouds

NASA Astrophysics Data System (ADS)

Loehnert, U.; Maahn, M.

2015-12-01

More observations of ice clouds are required to fill gaps in understanding of microphysical properties and processes. However, in situ observations by aircraft are costly and cannot provide long term observations which are required for a deeper understanding of the processes. Ground based remote sensing observations have the potential to fill this gap, but their observations do not contain sufficient information to unambiguously constrain ice cloud properties which leads to high uncertainties. For vertically pointing cloud radars, usually only reflectivity and mean Doppler velocity are used for retrievals; some studies proposed also the use of Doppler spectrum width.In this study, it is investigated whether additional information can be obtained by exploiting also higher moments of the Doppler spectrum such as skewness and kurtosis together with the slope of the Doppler peak. For this, observations of pure ice clouds from the Indirect and Semi-Direct Aerosol Campaign (ISDAC) in Alaska 2008 are analyzed. Using the ISDAC data set, an Optimal Estimation based retrieval is set up based on synthetic and real radar observations. The passive and active microwave radiative transfer model (PAMTRA) is used as a forward model together with the Self-Similar Rayleigh-Gans approximation for estimation of the scattering properties. The state vector of the retrieval consists of the parameters required to simulate the radar Doppler spectrum and describes particle mass, cross section area, particle size distribution, and kinematic conditions such as turbulence and vertical air motion. Using the retrieval, the information content (degrees of freedom for signal) is quantified that higher moments and slopes can contribute to an ice cloud retrieval. The impact of multiple frequencies, radar sensitivity and radar calibration is studied. For example, it is found that a single-frequency measurement using all moments and slopes contains already more information content than a dual-frequency measurement using only reflectivity and mean Doppler velocity. Eventually, the errors and uncertainties of the retrieved ice cloud parameters are investigated for the various retrieval configurations.

Potential of Higher Moments of the Radar Doppler Spectrum for Studying Ice Clouds

NASA Astrophysics Data System (ADS)

Lunt, M. F.; Rigby, M. L.; Ganesan, A.; Manning, A.; O'Doherty, S.; Prinn, R. G.; Saito, T.; Harth, C. M.; Muhle, J.; Weiss, R. F.; Salameh, P.; Arnold, T.; Yokouchi, Y.; Krummel, P. B.; Steele, P.; Fraser, P. J.; Li, S.; Park, S.; Kim, J.; Reimann, S.; Vollmer, M. K.; Lunder, C. R.; Hermansen, O.; Schmidbauer, N.; Young, D.; Simmonds, P. G.

2014-12-01

More observations of ice clouds are required to fill gaps in understanding of microphysical properties and processes. However, in situ observations by aircraft are costly and cannot provide long term observations which are required for a deeper understanding of the processes. Ground based remote sensing observations have the potential to fill this gap, but their observations do not contain sufficient information to unambiguously constrain ice cloud properties which leads to high uncertainties. For vertically pointing cloud radars, usually only reflectivity and mean Doppler velocity are used for retrievals; some studies proposed also the use of Doppler spectrum width.In this study, it is investigated whether additional information can be obtained by exploiting also higher moments of the Doppler spectrum such as skewness and kurtosis together with the slope of the Doppler peak. For this, observations of pure ice clouds from the Indirect and Semi-Direct Aerosol Campaign (ISDAC) in Alaska 2008 are analyzed. Using the ISDAC data set, an Optimal Estimation based retrieval is set up based on synthetic and real radar observations. The passive and active microwave radiative transfer model (PAMTRA) is used as a forward model together with the Self-Similar Rayleigh-Gans approximation for estimation of the scattering properties. The state vector of the retrieval consists of the parameters required to simulate the radar Doppler spectrum and describes particle mass, cross section area, particle size distribution, and kinematic conditions such as turbulence and vertical air motion. Using the retrieval, the information content (degrees of freedom for signal) is quantified that higher moments and slopes can contribute to an ice cloud retrieval. The impact of multiple frequencies, radar sensitivity and radar calibration is studied. For example, it is found that a single-frequency measurement using all moments and slopes contains already more information content than a dual-frequency measurement using only reflectivity and mean Doppler velocity. Eventually, the errors and uncertainties of the retrieved ice cloud parameters are investigated for the various retrieval configurations.

Color Doppler Sonographic and Cadaveric Study of the Arterial Vascularity of the Lateral Upper Arm Flap.

PubMed

Sun, Ruimei; Ding, Yu; Sun, Chuanzheng; Li, Xiaojiang; Wang, Jinde; Li, Lei; Yang, Jie; Ren, Yanxin; Zhong, Zhaoming

2016-04-01

To determine the importance of adequate preoperative assessment with color Doppler sonography to assist in the successful transfer of lateral upper arm flaps by studying the lateral upper arm flap with color Doppler sonography and analyzing the anatomic features of the radial collateral artery. A clinical case-control study was performed. The radial collateral artery was studied with color Doppler sonography in 15 healthy volunteers. The origins, courses, variations, and locations of the perforators of the radial collateral artery were recorded. The results and data from the color Doppler sonographic investigation were compared with an anatomic study that was performed on 22 adult cadaveric upper limb specimens. The volunteer group (14 of 15 volunteers) and the cadaveric group (19 of 22 upper arm specimens) clearly showed that the branch pattern of the arterial supply was as follows: brachial artery → deep brachial artery → radial collateral artery → posterior radial collateral artery → myocutaneous perforator. Variations in the origin of the radial collateral artery were identified in 1 volunteer bilaterally and in 3 upper arm specimens. The diameters of the artery and vein measured at the distal insertion of the deltoid and the origin of the deep brachial artery were not significantly different between the volunteer and cadaver groups (P > .05). Due to the difference in measuring methods, the length of the vascular pedicles was significantly different between the groups (P < .05). Color Doppler sonography can facilitate the preoperative assessment of the origin, course, variations, and locations of the radial collateral artery and therefore may increase the success rate of lateral upper arm flap transfer. © 2016 by the American Institute of Ultrasound in Medicine.

Tissue velocity imaging of coronary artery by rotating-type intravascular ultrasound.

PubMed

Saijo, Yoshifumi; Tanaka, Akira; Owada, Naoki; Akino, Yoshihisa; Nitta, Shinichi

2004-04-01

Intravascular ultrasound (IVUS) provides not only the dimensions of coronary artery but the information of tissue components. In catheterization laboratory, soft and hard plaques are classified by visual inspection of echo intensity. So-called soft plaque contains lipid core or thrombus and it is believed to be more vulnerable than a hard plaque. However, it is not simple to analyze the echo signals quantitatively. When we look at a reflection signal, the intensity is affected by the distance of the object, the medium between transducer and objects and the fluctuation caused by rotation of IVUS probe. The time of flight is also affected by the sound speed of the medium and Doppler shift caused by tissue motion but usually those can be neglected. Thus, the analysis of RF signal in time domain can be more quantitative than intensity of RF signal. In the present study, a novel imaging technique called "intravascular tissue velocity imaging" was developed for searching a vulnerable plaque. Radio-frequency (RF) signal from a clinically used IVUS apparatus was digitized at 500 MSa/s and stored in a workstation. First, non-uniform rotation was corrected by maximizing the correlation coefficient of circumferential RF signal distribution in two consecutive frames. Then, the correlation and displacement were calculated by analyzing the radial difference of RF signal. Tissue velocity was determined by the displacement and the frame rate. The correlation image of normal and atherosclerotic coronary arteries clearly showed the internal and external borders of arterial wall. Soft plaque with low echo area in the intima showed high velocity while the calcified lesion showed the very low tissue velocity. This technique provides important information on tissue character of coronary artery.

In-vivo imaging of the morphology and blood perfusion of brain tumours in rats with UHR-OCT (Conference Presentation)

NASA Astrophysics Data System (ADS)

Bizheva, Kostadinka; Tan, Bingyao; Fisher, Carl J.; Mason, Erik; Lilge, Lothar D.

2017-02-01

Brain tumors are characterized with morphological changes at cellular level such as enlarged, non-spherical nuclei, microcalcifications, cysts, etc., and are highly vascularized. In this study, two research-grade optical coherence tomography (OCT) systems operating at 800 nm and 1060 nm with axial resolution of 0.95 µm and 3.5 µm in biological tissue respectively, were used to image in vivo and ex vivo the structure of brain tumours in rats. Female Fischer 344 rats were used for this study, which has received ethics clearance by the Animal Research Ethics Committees of the University of Waterloo and the University Health Network, Toronto. Brain tumours were induced by injection of rat brain cancer cell line (RG2 glioma) through a small craniotomy. Presence of brain tumours was verified by MRI imaging on day 7 post tumour cells injection. The in vivo OCT imaging session was conducted on day 14 of the study with the 1060 nm OCT system and both morphological OCT, Doppler OCT and OMAG images were acquired from the brain tumour and the surrounding healthy brain tissue. After completion of the imaging procedure, the brains were harvested, fixed in formalin and reimaged after 2 weeks with the 800 nm OCT system. The in vivo and ex vivo OCT morphological images were correlated with H and E histology. Results from this study demonstrate that UHR-OCT can distinguish between healthy and cancerous brain tissue based on differences in structural and vascular pattern.

[Doppler study of gluteal arteries. A useful tool for excluding gluteal arterial pathology snd an important adjunct to lower limb Doppler studies].

PubMed

Bruninx, G; Salame, H; Wery, D; Delcour, C

2002-02-01

1) To determine the negative predictive value (VPN) of duplex scan in patients complaining of buttock or hip pain and thereby to distinguish vascular claudication from other musculoskeletal or neurological diseases. 2) To show its complementarity in doppler investigation of lower limb arteries. Prospective study by duplex scan and arteriography of 60 gluteal arteries in 30 consecutive patients referred to check up for lower limb arteriopathy or sexual impotence. Duplex scan was performed by posterior approach. Correlation between doppler ultrasound and arteriography was studied. The study of normal arteries was possible in all cases and only one normal gluteal artery could not be detected in a diabetic overweight patient. On 60 arteries, sensitivity of duplex was 100 percent, specificity 96 percent and VPN 100 percent. Significant obstructive lesions were always associated with pathological velocimetric waveform or were not detected. Buttock claudication can appear like a typical vascular claudication or mimic neurological or musculoskeletal diseases. It is very useful to rule out a vascular causality responsible for buttock or hip pain by simple, non-invasive and cheap exploration. A normal doppler ultrasound of gluteal arteries can rule out vascular disease responsible for buttock or hip pain thereby avoiding arteriography. The strategy of diagnostic or therapy can be modified by such additional information as shown in two case reports.

In arthritis the Doppler based degree of hypervascularisation shows a positive correlation with synovial leukocyte count and distinguishes joints with leukocytes greater and less than 5/nL.

PubMed

Löffler, Christian; Sattler, Horst; Peters, Lena; Tuleweit, Anika; Löffler, Uta; Wadsack, Daniel; Uppenkamp, Michael; Bergner, Raoul

2016-10-01

Power Doppler ultrasound is used to assess joint vascularity in acute arthritis. PDUS signals have been correlated with synovial histology and bone deterioration. Little is known about the correlation between power Doppler signals and synovial white blood count. In our study, we analyzed power Doppler signals in inflammatory joint diseases including gout, calcium pyrophosphate deposition disease, rheumatoid arthritis, spondyloarthritis and others and correlated power Doppler signals with synovial white blood count and with serologic markers of inflammation. We retrospectively evaluated 194 patients with arthritis. All patients underwent joint sonography, power Doppler ultrasound, synovial fluid analysis and blood examination of C-reactive protein and erythrocyte sedimentation rate. Correlation analyses (Spearman and Pearson), Chi(2) test, t-tests, a unifactorial ANOVA and regression analyses were applied. Hypervascularisation in power Doppler was most prominent in gout and calcium pyrophosphate deposition disease. Spondyloarthritis and non-inflammatory joint diseases presented with low degrees of hypervascularisation. Mean synovial white blood count did not differ significantly between crystal-related arthritides, rheumatoid arthritis, spondyloarthritis or other inflammatory joint diseases. There was a positive but weak correlation between power Doppler signals and synovial white blood count (P<0.001, rs=0.283), erythrocyte sedimentation rate (P<0.001, rs=0.387) and C-reactive protein (P<0.001, rs=0.373) over all diagnoses. This was especially relevant in rheumatoid arthritis (P<0.01, rs=0.479). Power Doppler degrees 0 and 1 were able to predict synovial leukocytes<5/nL, degrees 2 and 3 predict leukocytes≥5/nL (P<0.001). Copyright © 2016 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

Phase-sensitive optical coherence tomography characterization of pulse-induced trabecular meshwork displacement in ex vivo non-human primate eyes

NASA Astrophysics Data System (ADS)

Li, Peng; Reif, Roberto; Zhi, Zhongwei; An, Lin; Martin, Elizabeth; Shen, Tueng T.; Johnstone, Murray; Wang, Ruikang K.

2013-03-01

Purpose. It is suspected that the abnormalities of aqueous outflow pump composed of trabecular meshwork (TM) and Schlemm's canal (SC) results in the increased outflow resistance and then elevated intraocular pressure (IOP) in initial glaucoma. In order to explore the casual mechanism and the early diagnosis of glaucoma, the dynamic characterizations of aqueous outflow pump were explored. Methods. As a functional extension of optical coherence tomography (OCT), tissue Doppler OCT (tissue-DOCT) method capable of measuring the slow tissue movement was developed. The tissue-DOCT imaging was conducted on the corneo-scleral limbus of 4 monkey eyes. The eye was mounted in an anterior segment holder, together with a perfusion system to control the mean IOP and to induce the cyclic IOP transients with amplitude 3 mm Hg at frequency 1 pulse/second. IOP was monitored on-line by a pressure transducer. Tissue-DOCT data and pressure data were recorded simultaneously. The IOP-transient induced Doppler velocity, displacement and strain rate of TM and the normalized area of SC were quantified at 7 different mean IOPs (5, 8, 10, 20, 30, 40, 50 mm Hg). Results. The outflow system, including TM, SC and CCs, was visualized in the micro-structural imaging. The IOP-transient induced pulsatile TM movement and SC deformation were detected and quantified by tissue-DOCT. The TM movement was depth-dependent and the largest movement was located in the area closest to SC endothelium (SCE). Both the pulsations of TM and SC were found to be synchronous with the IOP pulse wave. At 8 mm Hg IOP, the global TM movement was around 0.65μm during one IOP transient. As IOP elevated, a gradual attenuation of TM movement and SC deformation was observed. Conclusions. The observed pulsation of TM and SC induced by the pulsatile IOP transients was in good agreement with the predicated role of TM and SC acting as a biomechanical pump (pumping aqueous from anterior chamber into SC and from SC into CCs) in the aqueous outflow system. As the IOP elevated, the attenuated pulsation amplitude of the aqueous outflow pump indicated the failure of the mechanical pump and the increase of aqueous outflow resistance. The promising results revealed the potential of using the proposed tissue-DOCT for diagnosis and associated therapeutic guidance of the initial and progressive glaucoma process by monitoring the pulsation of the outflow pump.

Physical And Medical Attributes Of Six Contemporary Noninvasive Imaging Techniques

NASA Astrophysics Data System (ADS)

Budinger, Thomas F.

1981-11-01

Digital subtraction angiography(DSA)is compared to five other noninvasive imaging methods with respect to physical attributes and medical applications. 1) Digital subtraction angiography measures flow channel (vessel) anatomy and vascular leaks in regions where signals from under and overlying vascular pools do not conflict in strength with the vessel or tissue of interest. 2) X-ray computed tomography, in principle, can separate the under and overlying signals, yet presently it is limited in speed, axial coverage, and computational burden for tasks DSA can efficiently perform. Possible exceptions are the dynamic spatial reconstructor (DSR) of Mayo Clinic and the system under construction at the University of California, San Francisco. 3) Heavy ion imaging measures electron density and is less sensitive to injected contrast than x-ray imaging which has the advantage of the photoelectric effect. A unique attribute of heavy ion imaging is its potential for treatment planning and the fact that beam hardening is not a physical problem. 4) Ultrasound detects surfaces, bulk tissue characteristics, and blood velocity. Doppler ultrasound competes with DSA in some regions of the body and generally involves less equipment and patient procedures. Ultrasound vessel imaging and range-gated Doppler have limitations due to sound absorption by atheromatous tissue and available imaging windows. 5) Emission tomography measures receptor site distribution, metabolism, permeability, and tissue perfusion. Resolution is limited to 7mm full width half maximum (FWHM) in the near future, and extraction of metabolic and perfusion information usually requires kinetic analyses with statistically poor data. The ability of positron tomography to measure metabolism (sugar, fatty acid, and oxygen utilization) and the ability to measure tissue perfusion with single photon tomography (17 mm FWHM) or PET (7 mm FWHM) using non-cyclotron produced radionuclides are the major unique features of emission tomography. 6) Nuclear magnetic resonance procedures measure the concentration of some nuclei (e.g., 1H, 23Na, 32P) as well as their chemical state and the local physical-chemical environment of the resolution volume. Velocity and diffusion are also potential measurements. Two unique capabilities of contemporary interest are the ability to image the spatial distribu-tion of relaxation parameters which give information about the local tissue characteristics, and the ability of NMR spectroscopy to sample (not image) the energy state of phosphorous in selected regions of the body. A third attribute of importance is that possible tissue heating seems to be the only hazard and this can be controlled.

Laser Doppler anemometer signal processing for blood flow velocity measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borozdova, M A; Fedosov, I V; Tuchin, V V

A new method for analysing the signal in a laser Doppler anemometer based on the differential scheme is proposed, which provides the flow velocity measurement in strongly scattering liquids, particularly, blood. A laser Doppler anemometer intended for measuring the absolute blood flow velocity in animal and human near-surface arterioles and venules is developed. The laser Doppler anemometer signal structure is experimentally studied for measuring the flow velocity in optically inhomogeneous media, such as blood and suspensions of scattering particles. The results of measuring the whole and diluted blood flow velocity in channels with a rectangular cross section are presented. (lasermore » applications and other topics in quantum electronics)« less

Doppler Ultrasound: What Is It Used for?

MedlinePlus

... During a Doppler ultrasound, a technician trained in ultrasound imaging (sonographer) presses a small hand-held device (transducer), ... neurologic-disorders/neurologic-tests-and-procedures/other-neurologic-imaging-studies. Accessed Oct. 18, 2016. ... . Mayo Clinic Footer Legal ...

Clinical Tests Combined with Color Doppler Versus Color Doppler Alone in Identifying Incompetent Perforator Veins of the Lower Limb: A Prospective Analytical Study

PubMed Central

Vignesh, Narayan; Venkatachalam, J; Vijayakumar, Chellappa; Sudharsanan, Sundaramurthi

2018-01-01

Background The color Doppler, a better investigation to identify the perforators objectively has replaced the clinical examination for the same. However, this has led to a significant number of negative explorations and cosmetic disfigurement. Objective To compare the efficacy of the clinical tests combined with the color Doppler versus color Doppler alone to identify the perforator incompetence during the surgery for primary varicose veins of the lower limb. Methods This was a prospective analytical study, including 61 lower limb varicose vein patients who belonged to the Clinical-Etiology-Anatomy-Pathophysiology (CEAP) class four-six, planned for the surgical treatment for perforator incompetence, excluding those requiring additional vascular or nonvascular procedure, recurrent varicose veins and those who had injection sclerotherapy prior to the surgery. The clinical tests, including Trendelenburg’s test, multiple tourniquet tests and, the Fegan’s tests were performed and incompetent perforators were marked on a template as ‘C’ to indicate the clinically positive perforator incompetence. The patients were then examined with the color Doppler ultrasound and the pathological incompetent perforators were marked as ‘D’. The surgical management of the perforator incompetence was done by stab ligation. The incision was made in the color Doppler ‘D’ marked sites as it has been the standard protocol. The number of incompetent perforators identified during the surgical exploration were categorized as ‘D’ positive or ’C’ and ‘D’ positive and were recorded in the specified proforma. Results It was found that the mean number of the perforator incompetence identified by the color Doppler alone was 8.2 whereas during the surgery, only a mean of six perforators was identified, leading to 20 unnecessary explorations per 10 patients (8.2 vs. 6; mean difference 2.229; P <0.001). The mean number of the perforator incompetence identified by the color Doppler combined with the clinical tests was 4.5 and during the surgery, a mean of four perforators was identified (4.5 vs. 4; mean difference 0.377; P <0.001). The color Doppler combined with the clinical examination lead to only four unnecessary explorations per 10 patients. Conclusion A combination of both the clinical tests and the color Doppler ultrasound has a higher accuracy in detecting perforator incompetence and can reduce the number of negative explorations by the rate of 16 unnecessary explorations per 10 patients. PMID:29531879

Scandinavia studies of recent crustal movements and the space geodetic baseline network

NASA Technical Reports Server (NTRS)

Anderson, A. J.

1980-01-01

A brief review of crustal movements within the Fenno-Scandia shield is given. Results from postglacial studies, projects for measuring active fault regions, and dynamic ocean loading experiments are presented. The 1979 Scandinavian Doppler Campaign Network is discussed. This network includes Doppler translocation baseline determination of future very long baseline interferometry baselines to be measured in Scandinavia. Intercomparison of earlier Doppler translocation measurements with a high precision terrestrial geodetic baseline in Scandinavia has yielded internal agreement of 6 cm over 887 km. This is a precision of better than 1 part in to the 7th power.

European multicentre validation study of the accuracy of E/e' ratio in estimating invasive left ventricular filling pressure: EURO-FILLING study.

PubMed

Galderisi, Maurizio; Lancellotti, Patrizio; Donal, Erwan; Cardim, Nuno; Edvardsen, Thor; Habib, Gilbert; Magne, Julien; Maurer, Gerald; Popescu, Bogdan A

2014-07-01

The non-invasive estimation of left ventricular filling pressures (LVFPs) represents a main goal in the clinical setting. Current recommendations encourage the use of pulsed-wave Tissue Doppler for calculating the ratio between the preload-dependent transmitral E velocity and the average of septal and lateral early diastolic velocities (e') of the mitral annulus. Despite its wide use, real utility of the E/e' ratio has been recently challenged in patients with either very advanced heart failure or preserved left ventricular (LV) ejection fraction. However, only few studies performed the invasive and non-invasive estimation of LVFP simultaneously. The EURO-FILLING Study will validate the E/e' ratio (and additional non-invasive estimates) against simultaneously measured LVFP obtained by left heart catheterization in a multicentre study involving reference European echo laboratories collecting a wide population sample size of cardiac patients with and without heart failure. The EURO-FILLING study is a large, prospective observational study in which simultaneous assessment of invasive and non-invasive measurements of LVFP will be acquired in eight reference European centres. Centralized reading of the collected parameters will be performed in a core laboratory. Not only standardized echo Doppler measurements but also novel echo parameters such as LV global longitudinal strain and global atrial strain (obtainable by two-dimensional speckle tracking echocardiography) will be tested for predicting invasive measurements of LVFP. The EURO-FILLING study is expected to provide important information on non-invasive assessment of LVFP and to contribute to the standardization of this assessment in clinical practice. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Doppler ultrasound of the central retinal artery in microgravity.

PubMed

Sirek, Adam S; Garcia, Kathleen; Foy, Millennia; Ebert, Doug; Sargsyan, Ashot; Wu, Jimmy H; Dulchavsky, Scott A

2014-01-01

Ocular changes have been noted during long-duration spaceflight; we studied central retinal artery (CRA) blood flow using Doppler before, during, and after long-term microgravity exposure in astronauts compared with data from a control group of nonastronauts subjected to head-down tilt (HDT). Available Doppler spectra of International Space Station (ISS) crewmembers were obtained from the NASA Lifetime Surveillance of Astronaut Health database, along with 2D ultrasound-derived measurements of the optic nerve sheath diameter (ONSD). CRA Doppler spectra and optic nerve sheath images were also obtained from healthy test subjects in an acute HDT experiment at 20 min of exposure (the ground-based analogue). HDT CRA peak systolic velocity in the ground-based analogue group increased by an average of 3 cm -s(-1) (33%) relative to seated values. ONSD at 300 of HDT increased by 0.5 mm relative to supine values. CRA Doppler spectra obtained on orbit were of excellent quality and demonstrated in-flight changes of +5 cm x s(-1) (50%) compared to preflight. ONSD increased in ISS crewmembers during flight relative to before flight, with some reversal postflight. A significant ONSD response to acute postural change and to spaceflight was demonstrated in this preliminary study. Increases in Doppler peak flow velocities correlated with increases in ONSD. Further investigations are warranted to corroborate the relationship between ONSD, intracranial pressure, and central retinal blood flow for occupational surveillance and research purposes.

Doppler ultrasonography and single-fiber laser Doppler flowmetry for measurement of hind limb blood flow in anesthetized horses.

PubMed

Raisis, A L; Young, L E; Taylor, P M; Walsh, K P; Lekeux, P

2000-03-01

To use Doppler ultrasonography and single-fiber laser Doppler flowmetry (LDF) to evaluate blood flow in the dependent and nondependent hind limbs of anesthetized horses and to evaluate changes in femoral arterial blood flow and microvascular skeletal muscle perfusion in response to administration of phenylephrine hydrochloride or dobutamine hydrochloride. 6 healthy adult horses. Horses were anesthetized and positioned in left lateral recumbency. Doppler ultrasonography was used to measure velocity and volumetric flow in the femoral vessels. Single-fiber LDF was used to measure relative microvascular perfusion at a single site in the semimembranosus muscles. Phenylephrine or dobutamine was then administered to decrease or increase femoral arterial blood flow, and changes in blood flow and microvascular perfusion were recorded. Administration of phenylephrine resulted in significant decreases in femoral arterial and venous blood flows and cardiac output and significant increases in mean aortic blood pressure, systemic vascular resistance, and PCV. Administration of dobutamine resulted in significant increases in femoral arterial blood flow, mean aortic blood pressure, and PCV. Significant changes in microvascular perfusion were not detected. Results suggest that Doppler ultrasonography and single-fiber LDF can be used to study blood flows in the hind limbs of anesthetized horses. However, further studies are required to determine why changes in femoral arterial blood flows were not associated with changes in microvascular perfusion.

Toward Exploring the Synergy Between Cloud Radar Polarimetry and Doppler Spectral Analysis in Deep Cold Precipitating Systems in the Arctic

NASA Astrophysics Data System (ADS)

Oue, Mariko; Kollias, Pavlos; Ryzhkov, Alexander; Luke, Edward P.

2018-03-01

The study of Arctic ice and mixed-phase clouds, which are characterized by a variety of ice particle types in the same cloudy volume, is challenging research. This study illustrates a new approach to qualitative and quantitative analysis of the complexity of ice and mixed-phase microphysical processes in Arctic deep precipitating systems using the combination of Ka-band zenith-pointing radar Doppler spectra and quasi-vertical profiles of polarimetric radar variables measured by a Ka/W-band scanning radar. The results illustrate the frequent occurrence of multimodal Doppler spectra in the dendritic/planar growth layer, where locally generated, slower-falling particle populations are well separated from faster-falling populations in terms of Doppler velocity. The slower-falling particle populations contribute to an increase of differential reflectivity (ZDR), while an enhanced specific differential phase (KDP) in this dendritic growth temperature range is caused by both the slower and faster-falling particle populations. Another area with frequent occurrence of multimodal Doppler spectra is in mixed-phase layers, where both populations produce ZDR and KDP values close to 0, suggesting the occurrence of a riming process. Joint analysis of the Doppler spectra and the polarimetric radar variables provides important insight into the microphysics of snow formation and allows the separation of the contributions of ice of different habits to the values of reflectivity and ZDR.

Blood transfusions increase cerebral, splanchnic, and renal oxygenation in anemic preterm infants.

PubMed

Dani, Carlo; Pratesi, Simone; Fontanelli, Giulia; Barp, Jacopo; Bertini, Giovanna

2010-06-01

Multiprobe near infrared spectroscopy (NIRS) has been used to study regional cerebral (rSO(2)C), splanchnic (rSO(2)S), and renal (rSO(2)R) tissue oxygenation in newborns. We used this method to study the effects of red blood cell (RBC) transfusions in anemic preterm infants to assess if thresholds for transfusions were appropriate for recognizing a clinical condition permitting tissue oxygenation improvement. Multiprobe NIRS (INVOS 5100, Somanetics) was applied during transfusion to 15 preterm infants with symptomatic anemia of prematurity (hematocrit level of <25%). rSO(2)C, rSO(2)S, and rSO(2)R were recorded at selected times, and then fractional oxygen cerebral extraction ratio [FOEC: (SaO(2)-rSO(2)C)/SaO(2)], fractional oxygen splanchnic extraction ratio [FOES: (SaO(2)-rSO(2)S)/SaO(2)], fractional oxygen renal extraction ratio [FOER: (SaO(2)-rSO(2)R)/SaO(2)], cerebrosplanchnic oxygenation ratio [CSOR: (rSO(2)S/rSO(2)C)], and cerebrorenal oxygenation ratio [CROR: (rSO(2)R/rSO(2)C)] were calculated. In addition, we used Doppler ultrasonography for evaluating cerebral blood flow (CBF), splanchnic blood flow (SBF), and renal blood flow (RBF) velocity. rSO(2)C, rSO(2)S, and rSO(2)R significantly increased during transfusions, while FOEC, FOES, and FOER decreased. CSOR and CROR increased during transfusions. CBF velocity decreased during the study period, while SBF and RBF velocities did not vary. RBC transfusions performed at used thresholds permitted an increase in cerebral, splanchnic, and renal oxygenation. The associated decreases in oxygen tissue extraction might suggest that transfusions were well timed for preventing tissue hypoxia or too early and theoretically prooxidant. Further studies could help to clarify this issue.

First Insights into Human Fingertip Regeneration by Echo-Doppler Imaging and Wound Microenvironment Assessment.

PubMed

Jafari, Paris; Muller, Camillo; Grognuz, Anthony; Applegate, Lee Ann; Raffoul, Wassim; di Summa, Pietro G; Durand, Sébastien

2017-05-13

Fingertip response to trauma represents a fascinating example of tissue regeneration. Regeneration derives from proliferative mesenchymal cells (blastema) that subsequently differentiate into soft and skeletal tissues. Clinically, conservative treatment of the amputated fingertip under occlusive dressing can shift the response to tissue loss from a wound repair process towards regeneration. When analyzing by Immunoassay the wound exudate from occlusive dressings, the concentrations of brain-derived neurotrophic factor (BDNF) and leukemia inhibitory factor (LIF) were higher in fingertip exudates than in burn wounds (used as controls for wound repair versus regeneration). Vascular endothelial growth factor A (VEGF-A) and platelet-derived growth factor (PDGF) were highly expressed in both samples in comparable levels. In our study, pro-inflammatory cytokines were relatively higher expressed in regenerative fingertips than in the burn wound exudates while chemokines were present in lower levels. Functional, vascular and mechanical properties of the regenerated fingertips were analyzed three months after trauma and the data were compared to the corresponding fingertip on the collateral uninjured side. While sensory recovery and morphology (pulp thickness and texture) were similar to uninjured sides, mechanical parameters (elasticity, vascularization) were increased in the regenerated fingertips. Further studies should be done to clarify the importance of inflammatory cells, immunity and growth factors in determining the outcome of the regenerative process and its influence on the clinical outcome.

First Insights into Human Fingertip Regeneration by Echo-Doppler Imaging and Wound Microenvironment Assessment

PubMed Central

Jafari, Paris; Muller, Camillo; Grognuz, Anthony; Applegate, Lee Ann; Raffoul, Wassim; di Summa, Pietro G.; Durand, Sébastien

2017-01-01

Fingertip response to trauma represents a fascinating example of tissue regeneration. Regeneration derives from proliferative mesenchymal cells (blastema) that subsequently differentiate into soft and skeletal tissues. Clinically, conservative treatment of the amputated fingertip under occlusive dressing can shift the response to tissue loss from a wound repair process towards regeneration. When analyzing by Immunoassay the wound exudate from occlusive dressings, the concentrations of brain-derived neurotrophic factor (BDNF) and leukemia inhibitory factor (LIF) were higher in fingertip exudates than in burn wounds (used as controls for wound repair versus regeneration). Vascular endothelial growth factor A (VEGF-A) and platelet-derived growth factor (PDGF) were highly expressed in both samples in comparable levels. In our study, pro-inflammatory cytokines were relatively higher expressed in regenerative fingertips than in the burn wound exudates while chemokines were present in lower levels. Functional, vascular and mechanical properties of the regenerated fingertips were analyzed three months after trauma and the data were compared to the corresponding fingertip on the collateral uninjured side. While sensory recovery and morphology (pulp thickness and texture) were similar to uninjured sides, mechanical parameters (elasticity, vascularization) were increased in the regenerated fingertips. Further studies should be done to clarify the importance of inflammatory cells, immunity and growth factors in determining the outcome of the regenerative process and its influence on the clinical outcome. PMID:28505080

Normal Values of Tissue-Muscle Perfusion Indexes of Lower Limbs Obtained with a Scintigraphic Method.

PubMed

Manevska, Nevena; Stojanoski, Sinisa; Pop Gjorceva, Daniela; Todorovska, Lidija; Miladinova, Daniela; Zafirova, Beti

2017-09-01

Introduction Muscle perfusion is a physiologic process that can undergo quantitative assessment and thus define the range of normal values of perfusion indexes and perfusion reserve. The investigation of the microcirculation has a crucial role in determining the muscle perfusion. Materials and method The study included 30 examinees, 24-74 years of age, without a history of confirmed peripheral artery disease and all had normal findings on Doppler ultrasonography and pedo-brachial index of lower extremity (PBI). 99mTc-MIBI tissue muscle perfusion scintigraphy of lower limbs evaluates tissue perfusion in resting condition "rest study" and after workload "stress study", through quantitative parameters: Inter-extremity index (for both studies), left thigh/right thigh (LT/RT) left calf/right calf (LC/RC) and perfusion reserve (PR) for both thighs and calves. Results In our investigated group we assessed the normal values of quantitative parameters of perfusion indexes. Indexes ranged for LT/RT in rest study 0.91-1.05, in stress study 0.92-1.04. LC/RC in rest 0.93-1.07 and in stress study 0.93-1.09. The examinees older than 50 years had insignificantly lower perfusion reserve of these parameters compared with those younger than 50, LC (p=0.98), and RC (p=0.6). Conclusion This non-invasive scintigraphic method allows in individuals without peripheral artery disease to determine the range of normal values of muscle perfusion at rest and stress condition and to clinically implement them in evaluation of patients with peripheral artery disease for differentiating patients with normal from those with impaired lower limbs circulation.

Visible hyperspectral imaging evaluating the cutaneous response to ultraviolet radiation

NASA Astrophysics Data System (ADS)

Ilias, Michail A.; Häggblad, Erik; Anderson, Chris; Salerud, E. Göran

2007-02-01

In vivo diagnostics of skin diseases as well as understanding of the skin biology constitute a field demanding characterization of physiological and anatomical parameters. Biomedical optics has been successfully used, to qualitatively and quantitatively estimate the microcirculatory conditions of superficial skin. Capillaroscopy, laser Doppler techniques and spectroscopy, all elucidate different aspects of microcirculation, e.g. capillary anatomy and distribution, tissue perfusion and hemoglobin oxygenation. We demonstrate the use of a diffuse reflectance hyperspectral imaging system for spatial and temporal characterization of tissue oxygenation, important to skin viability. The system comprises: light source, liquid crystal tunable filter, camera objective, CCD camera, and the decomposition of the spectral signature into relative amounts of oxy- and deoxygenized hemoglobin as well as melanin in every pixel resulting in tissue chromophore images. To validate the system, we used a phototesting model, creating a graded inflammatory response of a known geometry, in order to evaluate the ability to register spatially resolved reflectance spectra. The obtained results demonstrate the possibility to describe the UV inflammatory response by calculating the change in tissue oxygen level, intimately connected to a tissue's metabolism. Preliminary results on the estimation of melanin content are also presented.

Detection and three-dimensional visualization of lesion models using sonoelastography

NASA Astrophysics Data System (ADS)

Taylor, Lawrence S.; Gaborski, Thomas R.; Strang, John G.; Rubens, Deborah; Parker, Kevin J.

2002-04-01

Sonoelastography is a vibration Doppler technique for imaging the relative elasticity of tissues. Detectability of hard lesions of various sizes has previously been demonstrated in tissue phantoms by our group. Because real tissue differs from phantom material, the injection of formaldehyde in fresh liver tissue is being used as an in-vitro lesion model. Pieces of fresh calf liver were embedded in an agar gel then injected with a bolus of 37% formaldehyde to create a stiff lesion. Two and three-dimensional sonoelastography and b-mode images were acquired. The lesions were visible in each sonoelastography image as a region of reduced vibration. After imaging, lesions were dissected and measured for size and volume. One 0.4 cc bolus injection of formaldehyde created a lesion with a volume of 10.3 cc in the sonoelastography image compared to 9.3 cc using fluid displacement of the dissected lesion. A 0.33 cc injection of formaldehyde lesion created a volume of 5 cc in the sonoelastography image compared to 4.4 cc using fluid displacement. Sonoelastography imaging techniques for imaging hard lesions in phantoms can be successfully extended to imaging formaldehyde induced lesions in real tissue.

The biomechanics of leg ulceration.

PubMed Central

Chant, A.

1999-01-01

Research performed in the late 1960s, using 24Na, suggested that the perfusion of skin and subcutaneous tissues is critically dependent on the relationship between capillary (Pc) and tissue pressures (Pt). Perfusion changes differed significantly between controls and patients with venous disease and the differences could be interpreted as evidence that Pt remained high in venous diseased patients. From this starting point, a biomechanical theory for the aetiology of venous ulceration was developed and tested by measuring skin elasticity, limb cross-sectional area and laser Doppler flux. The results confirm that, modelled as a two-compartment system (vascular and interstitial fluid), forces can be demonstrated sufficient to cause intermittent capillary closure and subsequent reperfusion injury. These forces are maximal in the gaiter area, the site of most leg ulcers. Images Figure 2 Figure 4 PMID:10364960

LASER BIOLOGY AND MEDICINE: Arterial pulse shape measurement using self-mixing effect in a diode laser

NASA Astrophysics Data System (ADS)

Hast, J.; Myllylä, Risto; Sorvoja, H.; Miettinen, J.

2002-11-01

The self-mixing effect in a diode laser and the Doppler technique are used for quantitative measurements of the cardiovascular pulses from radial arteries of human individuals. 738 cardiovascular pulses from 10 healthy volunteers were studied. The Doppler spectrograms reconstructed from the Doppler signal, which is measured from the radial displacement of the radial artery, are compared to the first derivative of the blood pressure signals measured from the middle finger by the Penaz technique. The mean correlation coefficient between the Doppler spectrograms and the first derivative of the blood pressure signals was 0.84, with a standard deviation of 0.05. Pulses with the correlation coefficient less than 0.7 were neglected in the study. Percentage of successfully detected pulses was 95.7%. It is shown that cardiovascular pulse shape from the radial artery can be measured noninvasively by using the self-mixing interferometry.

Application of vector analysis on study of illuminated area and Doppler characteristics of airborne pulse radar

NASA Astrophysics Data System (ADS)

Wang, Haijiang; Yang, Ling

2014-12-01

In this paper, the application of vector analysis tool in the illuminated area and the Doppler frequency distribution research for the airborne pulse radar is studied. An important feature of vector analysis is that it can closely combine the geometric ideas with algebraic calculations. Through coordinate transform, the relationship between the frame of radar antenna and the ground, under aircraft motion attitude, is derived. Under the time-space analysis, the overlap area between the footprint of radar beam and the pulse-illuminated zone is obtained. Furthermore, the Doppler frequency expression is successfully deduced. In addition, the Doppler frequency distribution is plotted finally. Using the time-space analysis results, some important parameters of a specified airborne radar system are obtained. Simultaneously, the results are applied to correct the phase error brought by attitude change in airborne synthetic aperture radar (SAR) imaging.

Echocardiography Practice: Insights into Appropriate Clinical Use, Technical Competence and Quality Improvement Program

PubMed Central

Kossaify, Antoine; Grollier, Gilles

2014-01-01

Echocardiography accounts for nearly half of all cardiac imaging techniques. It is a widely available and adaptable tool, as well as being a cost-effective and mainly a non-invasive test. In addition, echocardiography provides extensive clinical data, which is related to the presence or advent of different modalities (tissue Doppler imaging, speckle tracking imaging, three-dimensional mode, contrast echo, etc.), different approaches (transesophageal, intravascular, etc.), and different applications (ie, heart failure/resynchronization studies, ischemia/stress echo, etc.). In view of this, it is essential to conform to criteria of appropriate use and to keep standards of competence. In this study, we sought to review and discuss clinical practice of echocardiography in light of the criteria of appropriate clinical use, also we present an insight into echocardiographic technical competence and quality improvement project. PMID:24516342

A novel modality for intrapartum fetal heart rate monitoring.

PubMed

Ashwal, Eran; Shinar, Shiri; Aviram, Amir; Orbach, Sharon; Yogev, Yariv; Hiersch, Liran

2017-11-02

Intrapartum fetal heart rate (FHR) monitoring is well recommended during labor to assess fetal wellbeing. Though commonly used, the external Doppler and fetal scalp electrode monitor have significant shortcomings. Lately, non-invasive technologies were developed as possible alternatives. The objective of this study is to compare the accuracy of FHR trace using novel Electronic Uterine Monitoring (EUM) to that of external Doppler and fetal scalp electrode monitor. A comparative study conducted in a single tertiary medical center. Intrapartum FHR trace was recorded simultaneously using three different methods: internal fetal scalp electrode, external Doppler, and EUM. The latter, a multichannel electromyogram (EMG) device acquires a uterine signal and maternal and fetal electrocardiograms. FHR traces obtained from all devices during the first and second stages of labor were analyzed. Positive percent of agreement (PPA) and accuracy (by measuring root means square error between observed and predicted values) of EUM and external Doppler were both compared to internal scalp electrode monitoring. A Bland-Altman agreement plot was used to compare the differences in FHR trace between all modalities. For momentary recordings of fetal heart rate <110 bpm or >160 bpm level of agreement, sensitivity, and specificity were also evaluated. Overall, 712,800 FHR momentary recordings were obtained from 33 parturients. Although both EUM and external Doppler highly correlated with internal scalp electrode monitoring (r 2  = 0.98, p < .001 for both methods), the accuracy of EUM was significantly higher than external Doppler (99.0% versus 96.6%, p < .001). In addition, for fetal heart rate <110 bpm or >160 bpm, the PPA, sensitivity, and specificity of EUM as compared with internal fetal scalp electrode, were significantly greater than those of external Doppler (p < .001). Intrapartum FHR using EUM is both valid and accurate, yielding higher correlations with internal scalp electrode monitoring than external Doppler. As such, it may provide a good framework for non-invasive evaluation of intrapartum FHR.

Studying cerebral hemodynamics and metabolism using simultaneous near-infrared spectroscopy and transcranial Doppler ultrasound: a hyperventilation and caffeine study

PubMed Central

Yang, Runze; Brugniaux, Julien; Dhaliwal, Harinder; Beaudin, Andrew E; Eliasziw, Misha; Poulin, Marc J; Dunn, Jeff F

2015-01-01

Caffeine is one of the most widely consumed psycho-stimulants in the world, yet little is known about its effects on brain oxygenation and metabolism. Using a double-blind, placebo-controlled, randomized cross-over study design, we combined transcranial Doppler ultrasound (TCD) and near-infrared spectroscopy (NIRS) to study caffeine's effect on middle cerebral artery peak blood flow velocity (Vp), brain tissue oxygenation (StO2), total hemoglobin (tHb), and cerebral oxygen metabolism (CMRO2) in five subjects. Hyperventilation-induced hypocapnia served as a control to verify the sensitivity of our measurements. During hypocapnia (∼16 mmHg below resting values), Vp decreased by 40.0 ± 2.4% (95% CI, P < 0.001), while StO2 and tHb decreased by 2.9 ± 0.3% and 2.6 ± 0.4%, respectively (P = 0.003 and P = 0.002, respectively). CMRO2, calculated using the Fick equation, was reduced by 29.3 ± 9% compared to the isocapnic-euoxia baseline (P < 0.001). In the pharmacological experiments, there was a significant decrease in Vp, StO2, and tHb after ingestion of 200 mg of caffeine compared with placebo. There was no significant difference in CMRO2 between caffeine and placebo. Both showed a CMRO2 decline compared to baseline showing the importance of a placebo control. In conclusion, this study showed that profound hypocapnia impairs cerebral oxidative metabolism. We provide new insight into the effects of caffeine on cerebral hemodynamics. Moreover, this study showed that multimodal NIRS/TCD is an excellent tool for studying brain hemodynamic responses to pharmacological interventions and physiological challenges. PMID:25907789

Evaluation of the effects of fasting associated dehydration on maternal NGAL levels and fetal renal artery Doppler parameters.

PubMed

Bayoglu Tekin, Yesim; Guvendag Guven, Emine Seda; Mete Ural, Ulku; Yazici, Zihni Acar; Kirbas, Aynur; Kir Sahin, Figen

2016-01-01

The aim of this study was to evaluate maternal neutrophil gelatinase-asssociated lipocalin (NGAL) levels and fetal renal artery (fRA) Doppler flow indices in pregnant women fasting in Ramadan in respect of dehydration in long hot summer days as a marker of hypoperfusion and early renal injury. A cross-sectional observational study was carried out at a University Hospital. Fasting pregnant women and non-fasting age, gravidity and gestational age-matched women were evaluated for hematologic, blood biochemistry and urine parameters in the first and fourth weeks of the Ramadan. Umbilical artery and fRA Doppler flows were studied in each evaluation. Blood urea nitrogen, potassium and hematocrit levels, blood and urine NGAL levels were significantly higher, and fRA Doppler indices increased in fasting women (p < 0.05) during the second visit in the last week of the Ramadan, while non-fasting women had no significant alterations in each evaluation (p > 0.05). Adequate maternal vascular volume is essential for the maintenance of healthy pregnancy. Fasting during the long and hot summer days leads to fluid deprivation and dehydration which was found to be related to subclinical maternal renal dysfunction and increased fRA Doppler indices.

Laser Doppler flowmetry in endodontics: a review.

PubMed

Jafarzadeh, H

2009-06-01

Vascular supply is the most accurate marker of pulp vitality. Tests for assessing vascular supply that rely on the passage of light through a tooth have been considered as possible methods for detecting pulp vitality. Laser Doppler flowmetry (LDF), which is a noninvasive, objective, painless, semi-quantitative method, has been shown to be reliable for measuring pulpal blood flow. The relevant literature on LDF in the context of endodontics up to March 2008 was reviewed using PubMed and MEDLINE database searches. This search identified papers published between June 1983 and March 2008. Laser light is transmitted to the pulp by means of a fibre optic probe. Scattered light from moving red blood cells will be frequency-shifted whilst that from the static tissue remains unshifted. The reflected light, composed of Doppler-shifted and unshifted light, is returned by afferent fibres and a signal is produced. This technique has been successfully employed for estimating pulpal vitality in adults and children, differential diagnosis of apical radiolucencies (on the basis of pulp vitality), examining the reactions to pharmacological agents or electrical and thermal stimulation, and monitoring of pulpal responses to orthodontic procedures and traumatic injuries. Assessments may be highly susceptible to environmental and technique-related factors. Nonpulpal signals, principally from periodontal blood flow, may contaminate the signal. Because this test produces no noxious stimuli, apprehensive or distressed patients accept it more readily than current methods of pulp vitality assessment. A review of the literature and a discussion of the application of this system in endodontics are presented.

Local cooling reduces skin ischemia under surface pressure in rats: an assessment by wavelet analysis of laser Doppler blood flow oscillations.

PubMed

Jan, Yih-Kuen; Lee, Bernard; Liao, Fuyuan; Foreman, Robert D

2012-10-01

The objectives of this study were to investigate the effects of local cooling on skin blood flow response to prolonged surface pressure and to identify associated physiological controls mediating these responses using the wavelet analysis of blood flow oscillations in rats. Twelve Sprague-Dawley rats were randomly assigned to three protocols, including pressure with local cooling (Δt = -10 °C), pressure with local heating (Δt = 10 °C) and pressure without temperature changes. Pressure of 700 mmHg was applied to the right trochanter area of rats for 3 h. Skin blood flow was measured using laser Doppler flowmetry. The 3 h loading period was divided into non-overlapping 30 min epochs for the analysis of the changes of skin blood flow oscillations using wavelet spectral analysis. The wavelet amplitudes and powers of three frequencies (metabolic, neurogenic and myogenic) of skin blood flow oscillations were calculated. The results showed that after an initial loading period of 30 min, skin blood flow continually decreased under the conditions of pressure with heating and of pressure without temperature changes, but maintained stable under the condition of pressure with cooling. Wavelet analysis revealed that stable skin blood flow under pressure with cooling was attributed to changes in the metabolic and myogenic frequencies. This study demonstrates that local cooling may be useful for reducing ischemia of weight-bearing soft tissues that prevents pressure ulcers.

Ultrasound in differential diagnosis of periapical radiolucencies: A radiohistopathological study

PubMed Central

Khambete, Neha; Kumar, Rahul

2015-01-01

Objectives: To evaluate the efficacy of ultrasound in differential diagnosis of periapical radiolucencies. Materials and Methods: Ten patients aged between 19 years and 40 years with periapical lesions associated with anterior maxillary or mandibular teeth were selected and consented for the study. Pre-operative periapical radiographs were obtained. Measurements and provisional diagnoses of the apical areas were made by two specialist observers on two separate occasions. Preoperative ultrasound examinations with Doppler flowmetry were then performed and the images assessed by two specialist observers for the size, contents, vascular supply and a provisional diagnosis made as to whether the lesion was a cyst or granuloma. Endodontic surgery was performed including curettage of the apical tissues to enable histopathological investigation, which provided the gold standard diagnosis. All measurements and findings were compared and statistically analyzed. Results: Total 10 lesions were identified in 10 patients. On periapical radiographs, lesions were readily identified but observers were unable to differentiate granuloma from cyst using either modality. Where sufficient buccal cortical bone had been resorbed, ultrasound imaging was simple but underestimated the size of the lesions compared with periapical radiographs. In all cases, the ultrasound diagnosis agreed with the histopathological gold standard. Conclusion: Ultrasonography (USG) can provide accurate information about the nature of intraosseous lesions of the jaws before any surgical procedure. It is proposed that USG with Doppler flowmetry can provide an additional diagnostic tool without invasive surgery, where treatment option is nonsurgical. PMID:25657525

Local cooling reduces skin ischemia under surface pressure in rats: an assessment by wavelet analysis of laser Doppler blood flow oscillations

PubMed Central

Jan, Yih-Kuen; Lee, Bernard; Liao, Fuyuan; Foreman, Robert D.

2012-01-01

The objectives of this study were to investigate the effects of local cooling on skin blood flow response to prolonged surface pressure and to identify associated physiological controls mediating these responses using wavelet analysis of blood flow oscillations in rats. Twelve Sprague Dawley rats were randomly assigned into three protocols, including pressure with local cooling (Δt= −10°C), pressure with local heating (Δt= 10°C), and pressure without temperature changes. Pressure of 700 mmHg was applied to the right trochanter area of rats for 3 hours. Skin blood flow was measured using laser Doppler flowmetry. The 3-hour loading period was divided into non-overlapping 30 min epochs for analysis of the changes of skin blood flow oscillations using wavelet spectral analysis. The wavelet amplitudes and powers of three frequencies (metabolic, neurogenic and myogenic) of skin blood flow oscillations were calculated. The results showed that after an initial loading period of 30 min, skin blood flow continually decreased in the conditions of pressure with heating and of pressure without temperature changes, but maintained stable in the condition of pressure with cooling. Wavelet analysis revealed that stable skin blood flow under pressure with cooling was attributed to changes in the metabolic and myogenic frequencies. This study demonstrates that local cooling may be useful for reducing ischemia of weight-bearing soft tissues that prevents pressure ulcers. PMID:23010955

Clinical use of ultrasonography associated with color Doppler in the diagnosis and follow-up of acute pyelonephritis.

PubMed

Dell'Atti, Lucio; Borea, Pier Andrea; Ughi, Gianni; Russo, Gian Rosario

2010-12-01

The purpose of this study is to evaluate the current role of the Ultrasound associated with the color-Doppler in the diagnosis of acute pyelonephritis (APN) and to compare ultrasound images with CT images in order to reduce the amount radiation absorbe without significant loss of diagnostic efficacy, since this disease in most cases affects young adults. We studied 38 patients (aged 17-65 years) who presented from September 2007 to March 2010 to the emergency department with suspected diagnosis of APN. All patients underwent first to an ultrasound study, then to abdominal CT. Renal, perirenal and extrarenal tomographic findings usually associated with acute pyelonephritis were analyzed, in an attempt to identify what are the differences with respect to the images obtained with an ultrasound study. All patients then performed ultrasonography and/or abdominal CT evaluation one month later, 25 patients repeated both examinations, while the other 13 repeated only ultrasound. In 38 subjects with suspected APN, CT assessed the presence in 79% and in 21% the absence of the disease. Ultrasonography in 68% of cases diagnosed APN, by an increase in kidney size related to the presence of hypoechoic areas associated to edema, blurred margins and reduction of the color-Doppler vascularity. Ultrasound associated with the use of color-Doppler revealed a sensibility of 76% and specificity of 75%. Color and power-Doppler have better diagnostic accuracy than basic gray scale ultrasound, in the diagnosis of focal pyelonephritis. Therefore the combined use of ultrasound and color-Doppler can obtain useful information about the diagnosis and follow-up of the disease, with an improvement in terms of cost, without significantly altering the diagnostic efficacy and reducing the amount of radiation absorbed.

Doppler lidar characterization of the boundary layer for aircraft mass-balance estimates of greenhouse gas emissions

NASA Astrophysics Data System (ADS)

Hardesty, R.; Brewer, A.; Banta, R. M.; Senff, C. J.; Sandberg, S. P.; Alvarez, R. J.; Weickmann, A. M.; Sweeney, C.; Karion, A.; Petron, G.; Frost, G. J.; Trainer, M.

2012-12-01

Aircraft-based mass balance approaches are often used to estimate greenhouse gas emissions from distributed sources such as urban areas and oil and gas fields. A scanning Doppler lidar, which measures range-resolved wind and aerosol backscatter information, can provide important information on mixing and transport processes in the planetary boundary layer for these studies. As part of the Uintah Basin Winter Ozone Study, we deployed a high resolution Doppler lidar to characterize winds and turbulence, atmospheric mixing, and mixing layer depth in the oil and gas fields near Vernal, Utah. The lidar observations showed evolution of the horizontal wind field, vertical mixing and aerosol structure for each day during the 5-week deployment. This information was used in conjunction with airborne in situ observations of methane and carbon dioxide to compute methane fluxes and estimate basin-wide methane emissions. A similar experiment incorporating a lidar along with a radar wind profiler and instrumented aircraft was subsequently carried out in the vicinity of the Denver-Julesburg Basin in Colorado. Using examples from these two studies we discuss the use of Doppler lidar in conjunction with other sources of wind information and boundary layer structure for mass-balance type studies. Plans for a one-year deployment of a Doppler lidar as part of the Indianapolis Flux experiment to estimate urban-scale greenhouse gas emissions near are also presented.

Investigation of the Representation of OLEs and Terrain Effects Within the Coastal Zone in the EDMF Parameterization Scheme: An Airborne Doppler Wind Lidar Perspective

DTIC Science & Technology

2013-10-07

OLEs and Terrain Effects Within the Coastal Zone in the EDMF Parameterization Scheme: An Airborne Doppler Wind Lidar Perspective Annual Report Under...UPP related investigations that will be carried out in Year 3. RELATED PROJECTS ONR contract to study the utilization of Doppler wind lidar (DWL...MATERHORN2012) Paper presented at the Coherent Laser Radar Conference, June 2013 Airborne DWL investigations of flow over complex terrain (MATERHORN

Added value of cerebro-placental ratio and uterine artery Doppler at routine third trimester screening as a predictor of SGA and FGR in non-selected pregnancies.

PubMed

Rial-Crestelo, M; Martinez-Portilla, R J; Cancemi, A; Caradeux, J; Fernandez, L; Peguero, A; Gratacos, E; Figueras, Francesc

2018-03-04

The objective of this study is to determine the added value of cerebroplacental ratio (CPR) and uterine Doppler velocimetry at third trimester scan in an unselected obstetric population to predict smallness and growth restriction. We constructed a prospective cohort study of women with singleton pregnancies attended for routine third trimester screening (32 +0 -34 +6 weeks). Fetal biometry and fetal-maternal Doppler ultrasound examinations were performed by certified sonographers. The CPR was calculated as a ratio of the middle cerebral artery to the umbilical artery pulsatility indices. Both attending professionals and patients were blinded to the results, except in cases of estimated fetal weight < p10. The association between third trimester Doppler parameters and small for gestational age (SGA) (birth weight <10th centile) and fetal growth restriction (FGR) (birth weight below the third centile) was assessed by logistic regression, where the basal comparison was a model comprising maternal characteristics and estimated fetal weight (EFW). A total of 1030 pregnancies were included. The mean gestational age at scan was 33 weeks (SD 0.6). The addition of CPR and uterine Doppler to maternal characteristics plus EFW improved the explained uncertainty of the predicting models for SGA (15 versus 10%, p < .001) and FGR (12 versus 8%, p = .03). However, the addition of CPR and uterine Doppler to maternal characteristics plus EFW only marginally improved the detection rates for SGA (38 versus 34% for a 10% of false positives) and did not change the predictive performance for FGR. The added value of CPR and uterine Doppler at 33 weeks of gestation for detecting defective growth is poor.

Assessment of internal mammary artery and saphenous vein graft patency and flow reserve using transthoracic Doppler echocardiography

NASA Technical Reports Server (NTRS)

Chirillo, F.; Bruni, A.; Balestra, G.; Cavallini, C.; Olivari, Z.; Thomas, J. D.; Stritoni, P.

2001-01-01

OBJECTIVE: To investigate transthoracic Doppler echocardiography in the identification of coronary artery bypass graft (CABG) flow for assessing graft patency. DESIGN: The initial study group comprised 45 consecutive patients with previous CABG undergoing elective cardiac catheterisation for recurrent ischaemia. The Doppler variables best correlated with angiographic graft patency were then tested prospectively in a further 84 patients (test group). SETTING: Three tertiary referral centres. INTERVENTIONS: Flow velocities in grafts were recorded at rest and during hyperaemia induced by dipyridamole (0.56 mg/kg/4 min), under the guidance of transthoracic colour Doppler flow mapping. Findings on transthoracic Doppler were compared with angiography. MAIN OUTCOME MEASURES: Feasibility of identifying open grafts by Doppler and diagnostic accuracy for Doppler detection of significant (>/= 70%) graft stenosis. RESULTS: In the test group the identification rate for mammary artery grafts was 100%, for saphenous vein grafts to left anterior descending coronary artery 91%, for vein grafts to right coronary artery 96%, and for vein grafts to circumflex artery 90%. Coronary flow reserve (the ratio between peak diastolic velocity under hyperaemia and at baseline) of < 1.9 (95% confidence interval 1.83 to 2.08) had 100% sensitivity, 98% specificity, 87.5% positive predictive value, and 100% negative predictive value for mammary artery graft stenosis. Coronary flow reserve of < 1.6 (95% CI 1.51 to 1.73) had 91% sensitivity, 87% specificity, 85.4% positive predictive value, and 92.3% negative predictive value for significant vein graft stenosis. CONCLUSIONS: Transthoracic Doppler can provide non-invasive assessment of CABG patency.

Uterine Artery Doppler in Screening for Preeclampsia and Fetal Growth Restriction.

PubMed

Pedroso, Marianna Amaral; Palmer, Kirsten Rebecca; Hodges, Ryan James; Costa, Fabricio da Silva; Rolnik, Daniel Lorber

2018-05-01

 To perform a comprehensive review of the current evidence on the role of uterine artery Doppler, isolated or in combination with other markers, in screening for preeclampsia (PE) and fetal growth restriction (FGR) in the general population. The review included recently published large cohort studies and randomized trials.  A search of the literature was conducted using Medline, PubMed, MeSH and ScienceDirect. Combinations of the search terms "preeclampsia," "screening," "prediction," "Doppler," "Doppler velocimetry," "fetal growth restriction," "small for gestational age" and "uterine artery" were used. Articles in English (excluding reviews) reporting the use of uterine artery Doppler in screening for PE and FGR were included.  Thirty articles were included. As a single predictor, uterine artery Doppler detects less than 50% of the cases of PE and no more than 40% of the pregnancies affected by FGR. Logistic regression-based models that allow calculation of individual risk based on the combination of multiple markers, in turn, is able to detect ∼ 75% of the cases of preterm PE and 55% of the pregnancies resulting in small for gestational age infants.  The use of uterine artery Doppler as a single predictive test for PE and FGR has poor accuracy. However, its combined use in predictive models is promising, being more accurate in detecting preterm PE than FGR. Thieme Revinter Publicações Ltda Rio de Janeiro, Brazil.

[Per partum acidosis: Interest and feasibility of cerebral Doppler during labor].

PubMed

Barrois, M; Chartier, M; Lecarpentier, E; Goffinet, F; Tsatsaris, V

2016-09-01

To evaluate feasibility and interest of fetal cerebral Doppler during labor and the link with fetal pH to predict perinatal fetal asphyxia. Our prospective study in a university perinatal center, included patients during labor. There were no risk factors during pregnancy and patients were included after 37 weeks of pregnancy. For each patient an ultrasound with cerebral Doppler was done concomitant to a fetal scalp blood sample. We collected maternal and fetal characteristics as well as cervix dilatation, fetal heart rate analysis and fetal presentation. Among 49 patients included over a period of 4 months, cerebral Doppler failed in 7 cases (11%). Majority of failure occurred at 10cm of dilatation (P=0.007, OR=14.1 [1.483; 709.1275]). Others factors like: maternal age, body mass index, parity, history of C-Section were not associated with higher rate of failure. We did not found either significant correlation between cerebral fetal Doppler and pH on fetal scalp blood sample (r=0.15) nor pH at cord blood sample (r=0.13). No threshold of cerebral Doppler is significant for fetal asphyxia prediction. Fetal cerebral Doppler is feasible during labor with a low rate of failure but not a good exam to predict fetal acidosis and asphyxia. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Vector Doppler: spatial sampling analysis and presentation techniques for real-time systems

NASA Astrophysics Data System (ADS)

Capineri, Lorenzo; Scabia, Marco; Masotti, Leonardo F.

2001-05-01

The aim of the vector Doppler (VD) technique is the quantitative reconstruction of a velocity field independently of the ultrasonic probe axis to flow angle. In particular vector Doppler is interesting for studying vascular pathologies related to complex blood flow conditions. Clinical applications require a real-time operating mode and the capability to perform Doppler measurements over a defined volume. The combination of these two characteristics produces a real-time vector velocity map. In previous works the authors investigated the theory of pulsed wave (PW) vector Doppler and developed an experimental system capable of producing off-line 3D vector velocity maps. Afterwards, for producing dynamic velocity vector maps, we realized a new 2D vector Doppler system based on a modified commercial echograph. The measurement and presentation of a vector velocity field requires a correct spatial sampling that must satisfy the Shannon criterion. In this work we tackled this problem, establishing a relationship between sampling steps and scanning system characteristics. Another problem posed by the vector Doppler technique is the data representation in real-time that should be easy to interpret for the physician. With this in mine we attempted a multimedia solution that uses both interpolated images and sound to represent the information of the measured vector velocity map. These presentation techniques were experimented for real-time scanning on flow phantoms and preliminary measurements in vivo on a human carotid artery.

Remote Sensing Wind and Wind Shear System.

DTIC Science & Technology

Contents: Remote sensing of wind shear and the theory and development of acoustic doppler; Wind studies; A comparison of methods for the remote detection of winds in the airport environment; Acoustic doppler system development; System calibration; Airport operational tests.

Live imaging of rat embryos with Doppler swept-source optical coherence tomography

NASA Astrophysics Data System (ADS)

Larina, Irina V.; Furushima, Kenryo; Dickinson, Mary E.; Behringer, Richard R.; Larin, Kirill V.

2009-09-01

The rat has long been considered an excellent system to study mammalian embryonic cardiovascular physiology, but has lacked the extensive genetic tools available in the mouse to be able to create single gene mutations. However, the recent establishment of rat embryonic stem cell lines facilitates the generation of new models in the rat embryo to link changes in physiology with altered gene function to define the underlying mechanisms behind congenital cardiovascular birth defects. Along with the ability to create new rat genotypes there is a strong need for tools to analyze phenotypes with high spatial and temporal resolution. Doppler OCT has been previously used for 3-D structural analysis and blood flow imaging in other model species. We use Doppler swept-source OCT for live imaging of early postimplantation rat embryos. Structural imaging is used for 3-D reconstruction of embryo morphology and dynamic imaging of the beating heart and vessels, while Doppler-mode imaging is used to visualize blood flow. We demonstrate that Doppler swept-source OCT can provide essential information about the dynamics of early rat embryos and serve as a basis for a wide range of studies on functional evaluation of rat embryo physiology.

Live imaging of rat embryos with Doppler swept-source optical coherence tomography

PubMed Central

Larina, Irina V.; Furushima, Kenryo; Dickinson, Mary E.; Behringer, Richard R.; Larin, Kirill V.

2009-01-01

The rat has long been considered an excellent system to study mammalian embryonic cardiovascular physiology, but has lacked the extensive genetic tools available in the mouse to be able to create single gene mutations. However, the recent establishment of rat embryonic stem cell lines facilitates the generation of new models in the rat embryo to link changes in physiology with altered gene function to define the underlying mechanisms behind congenital cardiovascular birth defects. Along with the ability to create new rat genotypes there is a strong need for tools to analyze phenotypes with high spatial and temporal resolution. Doppler OCT has been previously used for 3-D structural analysis and blood flow imaging in other model species. We use Doppler swept-source OCT for live imaging of early postimplantation rat embryos. Structural imaging is used for 3-D reconstruction of embryo morphology and dynamic imaging of the beating heart and vessels, while Doppler-mode imaging is used to visualize blood flow. We demonstrate that Doppler swept-source OCT can provide essential information about the dynamics of early rat embryos and serve as a basis for a wide range of studies on functional evaluation of rat embryo physiology. PMID:19895102

[The dynamics of blood circulation in marginal gingiva after crown preparation by different ledge locations].

PubMed

Shcherbakov, A S; Kuznetsova, M B; Kuznetsov, D L; Ivanova, S B

2013-01-01

The periodontal tissue level may change after gingival margin retraction and tooth preparation. The aim of the study was to assess the influence of these manipulations on the condition of free gingival margin. The study included 53 persons (29 women and 24 men) divided into 4 groups followed-up for 6 to 8 weeks. Blood circulation in marginal gingiva of 118 teeth with healthy periodontal tissues was assessed by ultrasonic Doppler evaluation to reveal the circulation impairments in cervical margin after teeth crown preparation. The first group included 39 teeth, in which the gum was retracted by Roeko stay put non impregna cords ("Langenau", Germany). The second group included 39 teeth with shoulders prepared at the gingival margin; in the third group (40 teeth) the shoulder was located subgingivally. The fourth group (40 teeth) was control. The changes in recovery indices have been analyzed. The linear values were established as most significant and demonstrative. The indices variations and recovery period length depended on the coronal edge location. Statistically significant differences were found among all the groups (p>0.05). The results may be used to improve crown preparation for fixed dentures and decrease the recession rate of free gingival margin.

Use of colour Doppler and M-mode ultrasonography to confirm the location of an epidural catheter - a retrospective case series.

PubMed

Elsharkawy, Hesham; Sonny, Abraham; Govindarajan, Srinivasa Raghavan; Chan, Vincent

2017-05-01

Epidural anesthesia and analgesia has a reported failure rate ranging from 13% to 32%. We describe a technique using colour Doppler and M-mode ultrasonography to determine the position of the epidural catheter after placement in adults. This retrospective review included 37 adult patients who received postoperative epidural analgesia and underwent technically difficult epidural catheter placement. The demographic characteristics, type of surgery, use of ultrasonography, method of insertion, intervertebral level, and success of epidural localization using colour Doppler were noted for each patient. Pain scores on postoperative day 1 and the presence of a patchy block were also reviewed. Colour Doppler study helped to indicate the catheter's path from the skin to the epidural space during saline injection in 33 patients (89%). Saline flow within the epidural space (catheter tip confirmation) was successfully detected with colour Doppler in 25 patients (67.5%) and with M-mode ultrasonography in 28 patients (75%). Appropriate dermatomal analgesia was noted in 35 patients (94.5%) during local anesthetic infusion. Our preliminary data suggest the feasibility of using colour Doppler and M-mode ultrasonography to confirm proper epidural catheter placement.

Cerebral Lateralization and General Intelligence: Gender Differences in a Transcranial Doppler Study

ERIC Educational Resources Information Center

Njemanze, P.C.

2005-01-01

The present study evaluated cerebral lateralization during Raven's progressive matrices (RPM) paradigm in female and male subjects. Bilateral simultaneous transcranial Doppler (TCD) ultrasound was used to measure mean blood flow velocities (MBFV) in the right and left middle cerebral arteries (MCAs) in 24 (15 females and 9 males) right-handed…

Airborne Doppler radar detection of low altitude windshear

NASA Technical Reports Server (NTRS)

Bracalente, Emedio M.; Jones, William R.; Britt, Charles L.

1990-01-01

As part of an integrated windshear program, the Federal Aviation Administration, jointly with NASA, is sponsoring a research effort to develop airborne sensor technology for the detection of low altitude windshear during aircraft take-off and landing. One sensor being considered is microwave Doppler radar operating at X-band or above. Using a Microburst/Clutter/Radar simulation program, a preliminary feasibility study was conducted to assess the performance of Doppler radars for this application. Preliminary results from this study are presented. Analysis show, that using bin-to-bin Automatic Gain Control (AGC), clutter filtering, limited detection range, and suitable antenna tilt management, windshear from a wet microburst can be accurately detected 10 to 65 seconds (.75 to 5 km) in front of the aircraft. Although a performance improvement can be obtained at higher frequency, the baseline X-band system that was simulated detected the presence of a windshear hazard for the dry microburst. Although this study indicates the feasibility of using an airborne Doppler radar to detect low altitude microburst windshear, further detailed studies, including future flight experiments, will be required to completely characterize the capabilities and limitations.

Micro-Doppler analysis of multiple frequency continuous wave radar signatures

NASA Astrophysics Data System (ADS)

Anderson, Michael G.; Rogers, Robert L.

2007-04-01

Micro-Doppler refers to Doppler scattering returns produced by non rigid-body motion. Micro-Doppler gives rise to many detailed radar image features in addition to those associated with bulk target motion. Targets of different classes (for example, humans, animals, and vehicles) produce micro-Doppler images that are often distinguishable even by nonexpert observers. Micro-Doppler features have great potential for use in automatic target classification algorithms. Although the potential benefit of using micro-Doppler in classification algorithms is high, relatively little experimental (non-synthetic) micro-Doppler data exists. Much of the existing experimental data comes from highly cooperative targets (human or vehicle targets directly approaching the radar). This research involved field data collection and analysis of micro-Doppler radar signatures from non-cooperative targets. The data was collected using a low cost Xband multiple frequency continuous wave (MFCW) radar with three transmit frequencies. The collected MFCW radar signatures contain data from humans, vehicles, and animals. The presented data includes micro-Doppler signatures previously unavailable in the literature such as crawling humans and various animal species. The animal micro-Doppler signatures include deer, dog, and goat datasets. This research focuses on the analysis of micro-Doppler from noncooperative targets approaching the radar at various angles, maneuvers, and postures.

Role of Doppler Diastolic Parameters in Differentiating Physiological Left Ventricular Hypertrophy from Hypertrophic Cardiomyopathy.

PubMed

Finocchiaro, Gherardo; Dhutia, Harshil; D'Silva, Andrew; Malhotra, Aneil; Sheikh, Nabeel; Narain, Rajay; Ensam, Bode; Papatheodorou, Stathis; Tome, Maite; Sharma, Rajan; Papadakis, Michael; Sharma, Sanjay

2018-05-01

The association between athletic participation and alteration in diastolic function is not well established. The aims of this study were to determine the spectrum of Doppler parameters of left ventricular (LV) diastolic function in a large cohort of healthy athletes and to quantify the overlap between physiologic LV hypertrophy and hypertrophic cardiomyopathy (HCM). A retrospective analysis of indices of LV diastolic function was performed in 1,510 healthy athletes (mean age, 22 ± 5 years; range, 13-33 years; 72% men). The results were compared with those from 58 young patients with HCM. Septal E' < 7 cm/sec and lateral E' < 10 cm/sec were found in five (0.3%) and eight (0.5%) athletes, respectively. Septal E' was >14.6 cm/sec in 170 (11%) and lateral E' was >19.9 cm/sec in 430 (28%) athletes. Athletes aged >25 years showed lower E' velocities compared with younger athletes (mean septal E', 11.8 ± 6.1 vs 12.9 ± 5.9 cm/sec [P < .001]; mean lateral E', 17.1 ± 3.6 vs 19.3 ± 4.1 cm/sec [P < .001]). Athletes with high indexed LV end-diastolic diameters (>32 mm/m 2 ) exhibited lower septal E' compared with athletes with normal indexed LV end-diastolic diameters (mean septal E', 11.9 ± 6 vs 12.7 ± 6 cm/sec; P = .002). Septal E' < 10 cm/sec and lateral E' < 12 cm/sec showed the best accuracy in differentiating between HCM and athlete's heart. Reduced septal and lateral E' are rarely observed in young elite athletes. Tissue Doppler velocities tend to decrease with increasing age and LV size, and values representative of supernormal diastolic function are found in less than one-third of young athletes. Cutoff thresholds for Doppler parameters of diastolic function should be corrected for multiple demographic and clinical variables to differentiate cardiac adaptation to exercise from HCM in young individuals. Copyright © 2017 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Photodetachment and Doppler laser cooling of anionic molecules

NASA Astrophysics Data System (ADS)

Gerber, Sebastian; Fesel, Julian; Doser, Michael; Comparat, Daniel

2018-02-01

We propose to extend laser-cooling techniques, so far only achieved for neutral molecules, to molecular anions. A detailed computational study is performed for {{{C}}}2- molecules stored in Penning traps using GPU based Monte Carlo simulations. Two cooling schemes—Doppler laser cooling and photodetachment cooling—are investigated. The sympathetic cooling of antiprotons is studied for the Doppler cooling scheme, where it is shown that cooling of antiprotons to subKelvin temperatures could becomes feasible, with impacts on the field of antimatter physics. The presented cooling schemes also have applications for the generation of cold, negatively charged particle sources and for the sympathetic cooling of other molecular anions.

Chronic mitral regurgitation and Doppler estimation of left ventricular filling pressures in patients with heart failure

NASA Technical Reports Server (NTRS)

Temporelli, P. L.; Scapellato, F.; Corra, U.; Eleuteri, E.; Firstenberg, M. S.; Thomas, J. D.; Giannuzzi, P.

2001-01-01

Previous studies relating Doppler parameters and pulmonary capillary wedge pressures (PCWP) typically exclude patients with severe mitral regurgitation (MR). We evaluated the effects of varying degrees of chronic MR on the Doppler estimation of PCWP. PCWP and mitral Doppler profiles were obtained in 88 patients (mean age 55 +/- 8 years) with severe left ventricular (LV) dysfunction (mean ejection fraction 23% +/- 5%). Patients were classified by severity of MR. Patients with severe MR had greater left atrial areas, LV end-diastolic volumes, and mean PCWPs and lower ejection fractions (each P <.01). In patients with mild MR, multiple echocardiographic parameters correlated with PCWP; however, with worsening MR, only deceleration time strongly related to PCWP. From stepwise multivariate analysis, deceleration time was the best independent predictor of PCWP overall, and it was the only predictor in patients with moderate or severe MR. Doppler-derived early mitral deceleration time reliably predicts PCWP in patients with severe LV dysfunction irrespective of degree of MR.

Doppler sonography characteristics of vertebrobasilar circulation in patients with Parkinson's disease.

PubMed

Vidović, Mirjana; Sinanović, Osman; Smajlović, Dzevdet; Burina, Adnan; Hudić, Josip

2008-08-01

The objective of the study was to analyze the doppler sonography findings of vertebrobasilar circulation (VB) in patients with Parkinson's disease. 40 patients were analyzed (25 men's and 15 women) with Parkinson's disease, average age was 61.9 years (SD=11.43), treated at the Clinic for Neurology in Tuzla. Device for doppler sonography was Multidop x 4. Doppler sonography findings of VB circulation were analyzed in order to computerized tomography (CT) findings of the brain (with or without ischemic lacunar lesions) and in order to presence of postural disturbances as one of dominant Parkinson's disease symptoms during actual hospitalization. Our results suggest that vertebrobasilar insufficiency is more frequent in patients with Parkinson's disease (no matter of type) and postural disturbances as a dominant symptom comparing to group of Parkinson's disease patients without postural disturbances. These results implicate the importance of doppler sonography findings of vertebrobasilar circulation in patients with Parkinson's disease and possibility of considering role of vertebrobasilar insufficiency in development of postural disturbances.

A low cost Doppler system for vascular dialysis access surveillance.

PubMed

Molina, P S C; Moraes, R; Baggio, J F R; Tognon, E A

2004-01-01

The National Kidney Foundation guidelines for vascular access recommend access surveillance to avoid morbidity among patients undergoing hemodialysis. Methods to detect access failure based on CW Doppler system are being proposed to implement surveillance programs at lower cost. This work describes a low cost Doppler system implemented in a PC notebook designed to carry out this task. A Doppler board samples the blood flow velocity and delivers demodulated quadrature Doppler signals. These signals are sampled by a notebook sound card. Software for Windows OS (running at the notebook) applies CFFT to consecutive 11.6 ms intervals of Doppler signals. The sonogram is presented on the screen in real time. The software also calculates the maximum and the intensity weighted mean frequency envelopes. Since similar systems employ DSP boards to process the Doppler signals, cost reduction was achieved. The Doppler board electronic circuits and routines to process the Doppler signals are presented.

Noninvasive assessment of normal carotid bifurcation hemodynamics with color-flow ultrasound imaging.

PubMed

Zierler, R E; Phillips, D J; Beach, K W; Primozich, J F; Strandness, D E

1987-08-01

The combination of a B-mode imaging system and a single range-gate pulsed Doppler flow velocity detector (duplex scanner) has become the standard noninvasive method for assessing the extracranial carotid artery. However, a significant limitation of this approach is the small area of vessel lumen that can be evaluated at any one time. This report describes a new duplex instrument that displays blood flow as colors superimposed on a real-time B-mode image. Returning echoes from a linear array of transducers are continuously processed for amplitude and phase. Changes in phase are produced by tissue motion and are used to calculate Doppler shift frequency. This results in a color assignment: red and blue indicate direction of flow with respect to the ultrasound beam, and lighter shades represent higher velocities. The carotid bifurcations of 10 normal subjects were studied. Changes in flow velocities across the arterial lumen were clearly visualized as varying shades of red or blue during the cardiac cycle. A region of flow separation was observed in all proximal internal carotids as a blue area located along the outer wall of the bulb. Thus, it is possible to detect the localized flow patterns that characterize normal carotid arteries. Other advantages of color-flow imaging include the ability to rapidly identify the carotid bifurcation branches and any associated anatomic variations.

Prospects for in vivo blood velocimetry using acoustic resolution photoacoustic Doppler

NASA Astrophysics Data System (ADS)

Brunker, J.; Beard, P.

2016-03-01

Acoustic resolution photoacoustic Doppler flowmetry (AR-PAF) is a technique that has the potential to overcome the spatial resolution and depth penetration limitations of current blood flow measuring methods. Previous work has shown the potential of the technique using blood-mimicking phantoms, but it has proved difficult to make accurate measurements in blood, and thus in vivo application has not yet been possible. One explanation for this difficulty is that whole blood is insufficiently heterogeneous. Through experimental measurements in red blood cell suspensions of different concentrations, as well as in whole blood, we provide new insight and evidence that refutes this assertion. We show that the velocity measurement accuracy is influenced by bandlimiting not only due to the detector frequency response, but also due to spatial averaging of absorbers within the detector field-of-view. In addition, there is a detrimental effect of limited light penetration, but this can be mitigated by selecting less attenuated wavelengths of light, and also by employing range-gating signal processing. By careful choice of these parameters as well as the detector centre frequency, bandwidth and field-of-view, it is possible to make AR-PAF measurements in whole blood using transducers with bandwidths in the tens of MHz range. These findings have profound implications for the prospects of making deep tissue measurements of blood flow relevant to the study of microcirculatory abnormalities associated with cancer, diabetes, atherosclerosis and other conditions.

Single hind limb burn injury to mice alters nuclear factor-κB expression and [¹⁸F] 2-fluoro-2-deoxy-D-glucose uptake.

PubMed

Carter, Edward A; Hamrahi, Victoria; Paul, Kasie; Bonab, Ali A; Jung, Walter; Tompkins, Ronald G; Fischman, Alan J

2014-01-01

Burn trauma to the extremities can produce marked systemic effects in mice. Burn injury to the dorsal surface of mice is also associated with changes in glucose metabolism ([18F] 2-fluoro-2-deoxy-D-glucose [18FDG] uptake) by brown adipose tissue (BAT) and nuclear factor (NF)-κB activity in several tissues including skeletal muscle. This study examined the effect of a single hind limb burn in mice on 18FDG uptake by NF-κB activity in vivo, and blood flow was determined by laser Doppler techniques. Male NF-κB luciferase reporter mice (28-30 g) were anesthetized, both legs were shaven, and the right leg was subjected to scald injury by immersion in 90°C water for 5 seconds. Sham-treated animals were used as controls. Each burned and sham mouse was resuscitated with saline (2 mL, i.p.). The individual animals were placed in wire bottom cages with no food and free access to water. After 24 hours, the animals were imaged with laser Doppler for measuring blood flow in the hind limb. The animals were then unanesthetized with 50 μCi of FDG or luciferin (1.0 mg, i.v.) via tail vein. Five minutes after luciferin injection, NF-κB mice were studied by bioluminescence imaging with a charge-coupled device camera. One hour after 18FDG injection, the animals were killed with carbon dioxide overdose, and 18FDG biodistribution was measured. Tissues were also analyzed for NF-κB luciferase activity. The scalding procedure used here produced a full-thickness burn injury to the leg with sharp margins. 18FDG uptake by the burned leg was lower than that in the contralateral limb. Similarly, luciferase activity and blood flow in the burned leg were lower than those in the contralateral leg. 18FDG uptake by BAT and heart increased, whereas that by brain decreased. In conclusion, the present study suggests that burn injury to a single leg decreased FDG uptake by skeletal muscle but increased 18FDG uptake by BAT. The injury to the leg reduced NF-κB expression compared with the contralateral leg and the uninjured skeletal muscle of the sham but activated NF-κB expression in a number of other organs. These findings are consistent with the hypothesis that burn trauma to the extremities can produce marked systemic effects, including activation of NF-κB expression and activation of 18FDG uptake by BAT.

Single Hind Limb Burn Injury to Mice Alters NF Kappa B (NF-κB) Expression and [18F] 2-Fluoro-2-Deoxy-d-Glucose (FDG) Uptake

PubMed Central

Carter, Edward A.; Hamrahi, Victoria; Paul, Kasie; Bonab, Ali A.; Jung, Walter; Tompkins, Ronald G.; Fischman, Alan J.

2014-01-01

Burn trauma to the extremities can produce marked systemic effects in mice1, 6, 7. Burn injury to the dorsal surface of mice is also associated with changes in glucose metabolism (18FDG uptake) by brown adipose tissue (BAT) and NF-κB activity in a number of tissues including skeletal muscle. This study examined the effect of a single hindlimb burn in mice on 18FDG uptake by in vivo, NF-κB activity in vivo, and blood flow determined by laser Doppler techniques. Male mice NF-κB luciferase reporter mice (28 grams- 30 grams, male) were anesthetized, both legs were shaven, and the right leg was subjected to scald injury by immersion in 90°C water for 5 seconds. Sham treated animals were used as controls. Each burned and sham mouse was resuscitated with saline (2 ml, IP). The individual animals were placed in wire bottom cages with no food and free access to water. 24 hrs later, the animals were imaged with Laser Doppler for measurements of blood flow in the hind limb. The animals were then injected unanesthetized with 50 µCi of FDG or luciferin (1.0 mg), I.V. via tail vein. Five minutes after luciferin injection, NF-kB mice were studied by bioluminescence imaging with a CCD camera. One hour after 18FDG injection the animals were euthanized with carbon dioxide overdose and 18FDG biodistribution was measured. Tissues were also analyzed for NF-κB luciferase activity. The scalding procedure used here produced a full thickness burn injury to the leg with sharp margins. 18FDG uptake by the burned leg was lower than in the contralateral limb. Similarly luciferase activity and blood flow in the burned leg were lower than in the contralateral leg. 18FDG uptake by BAT and heart was increased, while brain was decreased. In conclusion, the present study suggests that burn injury to a single leg reduced 18FDG uptake by skeletal muscle but increased 18FDG uptake by BAT. The injury to the leg reduced NF-κB expression as compared to the contralateral leg and the uninjured skeletal muscle of the sham, but activated NF-κB expression in a number of other organs. These findings are consistent with the hypothesis that burn trauma to the extremities can produce marked systemic effects, including activation of NF-κB expression and activation of 18FDG uptake by BAT. PMID:25100541

Percutaneous ethanol injection of hyperfunctioning thyroid nodules: long-term follow-up in 125 patients.

PubMed

Tarantino, Luciano; Francica, Giampiero; Sordelli, Ignazio; Sperlongano, Pasquale; Parmeggiani, Domenico; Ripa, Carmine; Parmeggiani, Umberto

2008-03-01

The purpose of this study was to assess the long-term efficacy of percutaneous ethanol injection (PEI) for the treatment of hyperfunctioning thyroid nodules. One hundred twenty-five patients (88 women, 37 men; age range, 17-76 years; mean age, 53 years) with 127 hyperfunctioning thyroid nodules (volume, 1.2-90 mL; mean, 10.3 mL) were treated with PEI. There were 1-11 PEI sessions per patient (average, 3.9) performed, with injection of 1-14 mL of ethanol per session (total injected ethanol per patient, 3-108 mL; mean, 14.0 mL). Efficacy of the treatment was assessed with color Doppler sonography; scintigraphy; and free triiodothyronine (FT3), free thyroxine (FT4), and thyroid-stimulating hormone (TSH) assays. Follow-up (9-144 months; median, 60 months) was performed with TSH and color Doppler sonography every 2 months for 6 months and every 6 months thereafter. Three (2.4%) of 125 patients refused completion of PEI therapy because of pain. Results are reported in 122 patients with 124 nodules. All 122 patients showed posttreatment normal levels of FT3, FT4, and TSH. A complete cure (absent uptake in the nodule and recovery of normal uptake in the thyroid parenchyma) was obtained in 113 (93%) of 122 patients-115 (92.7%) of 124 treated nodules. Residual hyperfunctioning nodular tissue along with decreased thyroid parenchyma uptake (partial cure) was present in nine patients accounting for nine (7.3%) of 124 nodules. Rates of complete cure after PEI were: overall nodules, 115 (92.7%) of 124; nodules < or = 10 mL, 63 (94.0%) of 67; nodules > 10 to < or = 30 mL, 32 (91.4%) of 35; nodules > 30 to < or = 60 mL, 17 (89.5%) of 19; nodules > 60 mL, three (100%) of three. The overall rate of major complications (transient laryngeal nerve damage, two patients; abscess and hematoma, one patient each) was four (3.2%) of 125 patients. Follow-up examinations showed marked shrinkage of 112 treated nodules ranging from 50% to 90% of the pretreatment volume (mean, 66%) and new growth of hyperfunctioning tissue in four patients at color Doppler sonography and scintigraphy at 12, 18, 18, and 48 months' follow-up, respectively. However, all patients remained euthyroid (low or normal TSH and normal FT3 and FT4) during follow-up. PEI of hyperfunctioning thyroid nodules seems to be an effective and safe alternative to traditional treatment. It also appears to be effective in patients with hyperfunctioning thyroid nodules larger than 30 mL.

Toward Exploring the Synergy Between Cloud Radar Polarimetry and Doppler Spectral Analysis in Deep Cold Precipitating Systems in the Arctic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oue, Mariko; Kollias, Pavlos; Ryzhkov, Alexander

The study of Arctic ice and mixed-phase clouds, which are characterized by a variety of ice particle types in the same cloudy volume, is challenging research. This study illustrates a new approach to qualitative and quantitative analysis of the complexity of ice and mixed-phase microphysical processes in Arctic deep precipitating systems using the combination of Ka-band zenith-pointing radar Doppler spectra and quasi-vertical profiles of polarimetric radar variables measured by a Ka/W-band scanning radar. The results illustrate the frequent occurrence of multimodal Doppler spectra in the dendritic/planar growth layer, where locally generated, slower-falling particle populations are well separated from faster-falling populationsmore » in terms of Doppler velocity. The slower-falling particle populations contribute to an increase of differential reflectivity (Z DR), while an enhanced specific differential phase (K DP) in this dendritic growth temperature range is caused by both the slower and faster-falling particle populations. Another area with frequent occurrence of multimodal Doppler spectra is in mixed-phase layers, where both populations produce Z DR and K DP values close to 0, suggesting the occurrence of a riming process. A Joint analysis of the Doppler spectra and the polarimetric radar variables provides important insight into the microphysics of snow formation and allows the separation of the contributions of ice of different habits to the values of reflectivity and Z DR.« less

Toward Exploring the Synergy Between Cloud Radar Polarimetry and Doppler Spectral Analysis in Deep Cold Precipitating Systems in the Arctic

DOE PAGES

Oue, Mariko; Kollias, Pavlos; Ryzhkov, Alexander; ...

2018-03-16

The study of Arctic ice and mixed-phase clouds, which are characterized by a variety of ice particle types in the same cloudy volume, is challenging research. This study illustrates a new approach to qualitative and quantitative analysis of the complexity of ice and mixed-phase microphysical processes in Arctic deep precipitating systems using the combination of Ka-band zenith-pointing radar Doppler spectra and quasi-vertical profiles of polarimetric radar variables measured by a Ka/W-band scanning radar. The results illustrate the frequent occurrence of multimodal Doppler spectra in the dendritic/planar growth layer, where locally generated, slower-falling particle populations are well separated from faster-falling populationsmore » in terms of Doppler velocity. The slower-falling particle populations contribute to an increase of differential reflectivity (Z DR), while an enhanced specific differential phase (K DP) in this dendritic growth temperature range is caused by both the slower and faster-falling particle populations. Another area with frequent occurrence of multimodal Doppler spectra is in mixed-phase layers, where both populations produce Z DR and K DP values close to 0, suggesting the occurrence of a riming process. A Joint analysis of the Doppler spectra and the polarimetric radar variables provides important insight into the microphysics of snow formation and allows the separation of the contributions of ice of different habits to the values of reflectivity and Z DR.« less

The study of synchronization of rhythms of microvascular blood flow and oxygen saturation during adaptive changes

NASA Astrophysics Data System (ADS)

Dunaev, Andrey V.; Sidorov, Victor V.; Krupatkin, Alexander I.; Rafailov, Ilya E.; Palmer, Scott G.; Sokolovski, Sergei G.; Stewart, Neil A.; Rafailov, Edik U.

2014-02-01

Multi-functional laser non-invasive diagnostic systems, such as "LAKK-M", allow the study of a number of microcirculatory parameters, including blood microcirculatory index (Im) (by laser Doppler flowmetry, LDF) and oxygen saturation (StO2) of skin tissue (by tissue reflectance oximetry, TRO). Such systems may provide significant information relevant to physiology and clinical medicine. The aim of this research was to use such a system to study the synchronization of microvascular blood flow and oxygen saturation rhythms under normal and adaptive change conditions. Studies were conducted with 8 healthy volunteers - 3 females and 5 males of 21-49 years. Each volunteer was subjected to basic 3 minute tests. The volunteers were observed for between 1-4 months each, totalling 422 basic tests. Measurements were performed on the palmar surface of the right middle finger and the forearm medial surface. Wavelet analysis was used to study rhythmic oscillations in LDF- and TRO-data. Tissue oxygen consumption (from arterial and venal blood oxygen saturation and nutritive flux volume) was calculated for all volunteers during "adaptive changes" as (617+/-123 AU) and (102+/-38 AU) with and without arteriovenous anastomoses (AVAs) respectively. This demonstrates increased consumption compared to normal (495+/-170 AU) and (69+/-40 AU) with and without AVAs respectively. Data analysis demonstrated the emergence of resonance and synchronization of rhythms of microvascular blood flow and oxygen saturation as an adaptive change in myogenic oscillation (vasomotion) resulting from exercise and potentially from psychoemotional stress. Synchronization of myogenic rhythms during adaptive changes suggest increased oxygen consumption resulting from increased microvascular blood flow velocity.

Blood flow changes using a 3D xenogeneic collagen matrix or a subepithelial connective tissue graft for root coverage procedures: a pilot study.

PubMed

Tatarakis, Nikolaos; Gkranias, Nikolaos; Darbar, Ulpee; Donos, Nikolaos

2018-05-01

The study investigated the early healing process following the treatment of single Miller class I and II recessions with a 3D xenogeneic collagen matrix (CMX) or connective tissue graft (CTG). This pilot investigation was designed as a single-center randomized controlled parallel trial. A total of eight subjects (four per group) were treated with either CMX or CTG in the anterior maxilla. Vascular flow changes were assessed by laser Doppler flowmetry (LDF) before and after surgery and at days 1, 2, 3, 7, 14, and 30 while clinical evaluations took place at baseline and at days 60 and 180. Pain intensity perception was evaluated by the short-form McGill pain questionnaire (SF-MPQ), at days 1 and 14. The vascular flow fluctuated similarly in both groups pre- and post-operatively, but the CTG exhibited a more homogeneous pattern as opposed to CMX that showed a second phase of increased blood flow at 14 days. Clinically, the CTG led to greater change in mean root coverage and keratinized tissue gain but CMX was associated with lower early pain intensity scores. Within the limits of the study, the vascular flow alterations during the early healing of both graft types followed a similar pattern. The CMX was associated with a second peak of increased blood flow. The vascular flow changes after the application of CMX for single tooth recession root coverage did not show major differences from those observed after the use of a CTG. A trend for better clinical performance in terms of root coverage and keratinized tissue gain was noted for the CTG, but the initial patient morbidity was less for CMX.

Cerebral venous circulatory system evaluation by ultrasonography.

PubMed

Zavoreo, Iris; Basić-Kes, Vanja; Zadro-Matovina, Lucija; Lisak, Marijana; Corić, Lejla; Cvjeticanin, Timon; Ciliga, Dubravka; Bobić, Tatjana Trost

2013-06-01

Venous system can be classified as pulmonary veins, systemic veins and venous sinuses that are present only within the skull. Cerebral venous system is divided into two main parts, the superficial and the deep system. The main assignment of veins is to carry away deoxygenated blood and other maleficient materials from the tissues towards the heart. Veins have thinner walls and larger lumina than arteries. Between 60% and 70% of the total blood volume is found in veins. The major factors that influence venous function are the respiratory cycle, venous tone, the function of the right heart, gravity, and the muscle pump. Venous system, in general, can be presented by selective venography, Doppler sonography, computed tomography (CT) venography and magnetic resonance (MR) venography, and cerebral venous system can be displayed by selective venography, cerebral CT venography, cerebral MR venography, and specialized extracranial and transcranial Doppler sonography. The aim of this paper is to show the possibilities of intracranial and extracranial ultrasound evaluation of the head and neck venous circulation and chronic cerebrospinal venous insufficiency as one of the most common pathologies evaluated as part of neurodegenerative processes in the central nervous system.

Contrast-enhanced harmonic ultrasound imaging in ablation therapy for primary hepatocellular carcinoma.

PubMed

Minami, Yasunori; Kudo, Masatoshi

2009-12-31

The success rate of percutaneous radiofrequency (RF) ablation for hepatocellular carcinoma (HCC) depends on correct targeting via an imaging technique. However, RF electrode insertion is not completely accurate for residual HCC nodules because B-mode ultrasound (US), color Doppler, and power Doppler US findings cannot adequately differentiate between treated and viable residual tumor tissue. Electrode insertion is also difficult when we must identify the true HCC nodule among many large regenerated nodules in cirrhotic liver. Two breakthroughs in the field of US technology, harmonic imaging and the development of second-generation contrast agents, have recently been described and have demonstrated the potential to dramatically broaden the scope of US diagnosis of hepatic lesions. Contrast-enhanced harmonic US imaging with an intravenous contrast agent can evaluate small hypervascular HCC even when B-mode US cannot adequately characterize tumor. Therefore, contrast-enhanced harmonic US can facilitate RF ablation electrode placement in hypervascular HCC, which is poorly depicted by B-mode US. The use of contrast-enhanced harmonic US in ablation therapy for liver cancer is an efficient approach.

Hemodynamic parameters change earlier than tissue oxygen tension in hemorrhage.

PubMed

Pestel, Gunther J; Fukui, Kimiko; Kimberger, Oliver; Hager, Helmut; Kurz, Andrea; Hiltebrand, Luzius B

2010-05-15

Untreated hypovolemia results in impaired outcome. This study tests our hypothesis whether general hemodynamic parameters detect acute blood loss earlier than monitoring parameters of regional tissue beds. Eight pigs (23-25 kg) were anesthetized and mechanically ventilated. A pulmonary artery catheter and an arterial catheter were inserted. Tissue oxygen tension was measured with Clark-type electrodes in the jejunal and colonic wall, in the liver, and subcutaneously. Jejunal microcirculation was assessed by laser Doppler flowmetry (LDF). Intravascular volume was optimized using difference in pulse pressure (dPP) to keep dPP below 13%. Sixty minutes after preparation, baseline measurements were taken. At first, 5% of total blood volume was withdrawn, followed by another 5% increment, and then in 10% increments until death. After withdrawal of 5% of estimated blood volume, dPP increased from 6.1% +/- 3.0% to 20.8% +/- 2.7% (P < 0.01). Mean arterial pressure (MAP), mean pulmonary artery pressure (PAP) and pulmonary artery occlusion pressure (PAOP) decreased with a blood loss of 10% (P < 0.01). Cardiac output (CO) changed after a blood loss of 20% (P < 0.05). Tissue oxygen tension in central organs, and blood flow in the jejunal muscularis decreased (P < 0.05) after a blood loss of 20%. Tissue oxygen tension in the skin, and jejunal mucosa blood flow decreased (P < 0.05) after a blood loss of 40% and 50%, respectively. In this hemorrhagic pig model systemic hemodynamic parameters were more sensitive to detect acute hypovolemia than tissue oxygen tension measurements or jejunal LDF measurements. Acute blood loss was detected first by dPP. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Successful human long-term application of in situ bone tissue engineering

PubMed Central

Horch, Raymund E; Beier, Justus P; Kneser, Ulrich; Arkudas, Andreas

2014-01-01

Tissue Engineering (TE) and Regenerative Medicine (RM) have gained much popularity because of the tremendous prospects for the care of patients with tissue and organ defects. To overcome the common problem of donor-site morbidity of standard autologous bone grafts, we successfully combined tissue engineering techniques for the first time with the arteriovenous loop model to generate vascularized large bone grafts. We present two cases of large bone defects after debridement of an osteomyelitis. One of the defects was localized in the radius and one in the tibia. For osseus reconstruction, arteriovenous loops were created as vascular axis, which were placed in the bony defects. In case 1, the bone generation was achieved using cancellous bone from the iliac crest and fibrin glue and in case 2 using a clinically approved β-tricalciumphosphate/hydroxyapatite (HA), fibrin glue and directly auto-transplanted bone marrow aspirate from the iliac crest. The following post-operative courses were uneventful. The final examinations took place after 36 and 72 months after the initial operations. Computer tomogrphy (CT), membrane resonance imaging (MRI) and doppler ultrasound revealed patent arterio-venous (AV) loops in the bone grafts as well as completely healed bone defects. The patients were pain-free with normal ranges of motion. This is the first study demonstrating successfully axially vascularized in situ tissue engineered bone generation in large bone defects in a clinical scenario using the arteriovenous loop model without creation of a significant donor-site defect utilizing TE and RM techniques in human patients with long-term stability. PMID:24801710