Journal articles: 'Pulsed Ultrasound Velocimetry (PUV)'

1

K, Anusha, Sadasiva Rao K, Srinivas M, Sreenu M, and Aswani Kumar K. "Doppler Velocimetry of Uterine Artery in Bitches with Cystic Endometrial Hyperplasia-Pyometra Complex." Indian Journal of Veterinary Sciences & Biotechnology 18, no. 5 (November 7, 2022): 51–55. http://dx.doi.org/10.48165/ijvsbt.18.5.10.

Full text

Abstract:

Doppler ultrasound is a useful diagnostic tool to evaluate uterine blood flow in different canine reproductive states. The aim of this study was to describe and compare uterine blood flow in bitches suffering from pyometra according to the ultrasonographic appearance of uterus. Seventy-five bitches with pyometra confirmed clinically, haematologically and ultrasonographically were included in the study. Ten healthy bitches with no haematological and ultrasonographic abnormality of uterus were also included in the study as control group. The bitches with pyometra were divided into four groups based on the sonographic characterization of uterus and its luminal contents, viz., B (few small cysts, normal endometrial surface, anechoic uterine content, n=11), C (many large cysts, irregular surface and hypertrophic endometrium, n=24), DH (many large cysts, irregular surface and hypertrophic endometrium, hyperechoic content, n=31) and DA (many large cysts, irregular surface and atrophic endometrium, hyperechoic content, n=9). The uterine horn diameter and uterine wall thickness was measured with two-dimensional ultrasonography. With the use of pulsed-wave Doppler, flow velocity waveforms of uterine artery were obtained. Parameters of blood flow velocity such as peak systolic velocity (PSV), end diastolic velocity (EDV), as well as haemodynamic parameters such as resistance index (RI), pulsatility index (PI) and systolic-diastolic ratio (S/D) were calculated electronically. Peak systolic velocity and end diastolic velocity were significantly higher in pyometra group than control with highest velocities recorded in DA group (P<0.05). The RI, PI and S/D were significantly lower in pyometra group than in control (P<0.05). The RI was significantly lower in group C and DA compared to groups B and DH (P<0.05). However, no significant difference was reported in PI and S/D among the groups of pyometra (P>0.05). It was concluded that the uterine artery blood flow velocity of bitches suffering from pyometra differs, not only from normal bitches, but also varies with the type of pyometra with varying pathological nature. Furthermore, haemodynamic parameters appear as useful markers to differentiate uterine pathologic conditions and to understand the pathological type of pyometra.

APA, Harvard, Vancouver, ISO, and other styles

2

Lin, Wei-Cheng, Ruei-Wen Ou, Hsiao-Chuan Liu, and Jian-Xing Wu. "Particle image velocimetry for estimating shear wave elasticity imaging (SWEI) in the esophagus dysplasia." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A76. http://dx.doi.org/10.1121/10.0015599.

Full text

Abstract:

In this study, a 128-channel high-frequency pulse generator/receiver system was used to emit multi-angle wave propagation, and the generator plane excitation was used to generate a focused beam, which induced the phenomenon of particle displacement in the esophagus phantom recorded. Shear wave electrography is generated by using a micro-ultrasound probe (ARFI), which excites the shear waves with the output acoustic energy. In addition, we perform the method of PIV proper orthogonal decomposition to better qualify and quantify the differences between the PIV and Doppler, especially for analysis block into PIV for particle tracking, in which the external environment, with a Doppler similarity index of 82%, and PIV mainly uses the Doppler algorithm for analysis and obtains 97 frames, and fixed 0.33 ms time difference to output pictures. Each pass interrogation area is set to 128 in sequence, the distance is defined in calibration, in which the low filter contrast of image-based validation is set to 0.004, and the bright filter objects are set to 0.5. Through the analysis results of PIV, each particle's speed and movement are critical for the hospital to think. The relative position of the lesion and the effect of ARFI on the lesion are to be understood by understanding the direction of movement of the contrast agent. Overall, the shear wave and Doppler output amplitudes provided the best image quality and PIV results for esophagus dysplasia.

APA, Harvard, Vancouver, ISO, and other styles

3

Blair, William F., Thomas D. Brown, and E. R. Greene. "Pulsed ultrasound doppler velocimetry in the assessment of microvascular hemodynamics." Journal of Orthopaedic Research 6, no. 2 (March 1988): 300–309. http://dx.doi.org/10.1002/jor.1100060219.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Schovanec, Petr, Darina Jasikova, Michal Kotek, Karel Havlicek, Magda Nechanicka, Jakub Eichler, Jiri Cech, and Petra Subrtova. "Sterilization of Biofilm in Foam Using a Single Cavitation Bubble." MATEC Web of Conferences 328 (2020): 05003. http://dx.doi.org/10.1051/matecconf/202032805003.

Full text

Abstract:

This article presents the sterilization of bacteria using cavitation bubbles. Cavitation generated by ultrasound creates a cavitation cloud. Therefore is more advantageous to generate the cavitation bubbles by laser-induced breakdown, because it is possible to generate individual bubbles for the purpose of study single impact and physical mechanism of acting. The cavitation bubble is generated by a Nd: YAG 532nm laser beam, a short 10ns pulse. Here, we used optics to focus the laser beam and a high-speed camera to visualize characteristics the bubble. We used the method of long-distance microscopy and shadowgraph lightening for the visualization. We used the particle image velocimetry (PIV) method to determine the interaction of the bubble with the surrounding liquid and solid surface. The main goal of the research is to use cavitation to sterilize bacteria and biofilm in impact of single bubble collapse on living cells.

APA, Harvard, Vancouver, ISO, and other styles

5

Grayburn, Paul A., John E. Willard, Donald R. Haagen, M. Elizabeth Brickner, Luis Alvarez, and Eric J. Eichhorn. "Measurement of coronary flow using high-frequency intravascular ultrasound imaging and pulsed doppler velocimetry." Journal of the American College of Cardiology 17, no. 2 (February 1991): A234. http://dx.doi.org/10.1016/0735-1097(91)91901-p.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Eichhorn, Eric J., Luis G. Alvarez, Michael E. Jessen, Steven M. Fass, Robert Y. Chao, Donald Haagen, and Paul A. Grayburn. "Measurement of coronary and peripheral artery flow by intravascular ultrasound and pulsed Doppler velocimetry." American Journal of Cardiology 70, no. 4 (August 1992): 542–45. http://dx.doi.org/10.1016/0002-9149(92)91208-l.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Brown, T. D., L. D. Bell, D. R. Pedersen, and W. F. Blair. "A Three-Dimensional Computational Simulation of Some Sources of Measurement Artifact in Microvascular Pulsed Ultrasound Doppler Velocimetry." Journal of Biomechanical Engineering 107, no. 3 (August 1, 1985): 274–80. http://dx.doi.org/10.1115/1.3138553.

Full text

Abstract:

Recent applications of 20 MHz pulsed ultrasound Doppler velocimetry (PUDVM) in microsurgical research have necessarily employed piezoelectric crystals whose diameter is not negligible compared to the lumen size (1–2 mm) of many vessels of interest. A three-dimensional numerical model was developed to explore relationships between actual and detected flow field parameters, for (steady) Poiseuille flow, when appreciable velocity gradients exist within the PUDVM sample volume. Validation studies showed that highly accurate velocity profiles could be obtained in the limiting case of a very small sample volume (0.1 mm radius), but that for currently employed crystals ( ≈ 0.5 mm radius) there was appreciable underestimation of the centersteam velocity, and appreciable overestimation of the flow stream diameter. Errors in perceived velocity and flow rate were found to be relatively insensitive to perturbations in the sample volume thickness, in the size of the sampling range increment, or in the angle of insonation beam divergence. By contrast, these apparent flow parameters were found to be very sensitive to perturbations of sample volume diameter or of the Dopper angle. Small variations in the degree of partial sample volume overlap of the flowstream periphery were shown to be capable of causing large fluctuations in apparent flow stream diameter.

APA, Harvard, Vancouver, ISO, and other styles

8

Messer, Matthias, and Cyrus K. Aidun. "Main effects on the accuracy of Pulsed-Ultrasound-Doppler-Velocimetry in the presence of rigid impermeable walls." Flow Measurement and Instrumentation 20, no. 2 (April 2009): 85–94. http://dx.doi.org/10.1016/j.flowmeasinst.2008.11.002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Grayburn, Paul A., John E. Willard, Donald R. Haagen, M. Elizabeth Brickner, Luis G. Alvarez, and Eric J. Eichhorn. "Measurement of Coronary Flow Using High-Frequency Intravascular Ultrasound Imaging and Pulsed Doppler Velocimetry: In Vitro Feasibility Studies." Journal of the American Society of Echocardiography 5, no. 1 (January 1992): 5–12. http://dx.doi.org/10.1016/s0894-7317(14)80098-9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Kasparek, Milos, Ludmila Novakova, and Jan Malik. "Effect of Roller Pump Pulse in the Arterial Needle Area during Hemodialysis." Diagnostics 11, no. 11 (October 29, 2021): 2010. http://dx.doi.org/10.3390/diagnostics11112010.

Full text

Abstract:

Vascular access is a lifeline for hemodialysis patients. Its lifetime is affected by many hemodynamic factors such as pressure, flow regime and wall shear stress. During hemodialysis, changes in hemodynamic parameters occur due to the flow from needles inserted into the vascular system. Primarily, there is a change in shear stress that affects the vascular wall. Pathological effects of high or low WSS are known. The effect of jet from a venous needle on hemodynamics parameters was studied, but the influence of the arterial needle on hemodynamics parameters is not sufficiently studied. To understand its possible effects, we performed in vivo and in vitro studies. Methods. In vivo experiment: The existence of flow reversal around the suction needle was visualized in a group of 12 randomly selected patients using ultrasound velocity profiling (Doppler ultrasonography) during hemodialysis. In vitro experiment: The flow field was measured using the stereo particle image velocimetry method (stereo PIV). Two regimes were studied. In the first regime, the fluid in the extracorporeal circuit was pumped by a peristaltic pump. In the second regime, the continuous pump was used in the extracorporeal circuit. The conditions were set to resemble those in vascular access during a hemodialysis session. Flow volume was set to 600 mL/min for vascular access and 200 mL/min for the extracorporeal circuit. Results. The main finding of this study was that the wall in the region of the arterial needle was stressed by backflow through the arterial needle. Since this was a variable, low-shear stress loading, it was one of the risk factors for the development of stenosis. Cyclic flow reversal was apparent in all of the included hemodialysis patients. The stereo PIV in vitro experiment revealed the oscillating character of wall shear stress (WSS) inside the model. High shear stress was documented upstream of the injection point of the arterial needle. An area of very low WSS was detected right behind the injection point during a pulse of the peristaltic pump. The minimal and maximal values of the WSS during a pulse of the peristaltic pump in the observed area were −0.7 Pa and 6 Pa, respectively. The distribution of wall shear stress with the continual pump used in the extracorporeal circuit was similar to the distribution during a pulse of the peristaltic one. However, the WSS values were continual; the WSS did not oscillate. WSS ranged between 4.8 Pa and 1.0 Pa.

APA, Harvard, Vancouver, ISO, and other styles

11

Nauber, Richard, Lars Büttner, and Jürgen Czarske. "Measurement uncertainty analysis of field-programmable gate-array-based, real-time signal processing for ultrasound flow imaging." Journal of Sensors and Sensor Systems 9, no. 2 (July 31, 2020): 227–38. http://dx.doi.org/10.5194/jsss-9-227-2020.

Full text

Abstract:

Abstract. Research in magnetohydrodynamics (MHD) aims to understand the complex interactions of electrically conductive fluids and magnetic fields. A promising approach for investigating complex instationary flow phenomena are lab-scale experiments with low-melting alloys. They require a noninvasive flow instrumentation for opaque liquids with a high spatiotemporal resolution, a low velocity uncertainty and a long measurement duration. Ultrasound Doppler velocimetry can achieve multiplane, multicomponential flow imaging with multiple linear ultrasound arrays. However the average raw data output amounts to 1.2 GBs−1 at a frame rate of 33 Hz in a typical configuration for 200 transducers. This usually prevents long-duration measurements when offline signal processing is used. In this paper, we propose an online signal-processing chain for pulsed-wave Doppler velocimetry that is tailored to the specific requirements of flow imaging for lab-scale experiments. The trade-off between measurement uncertainty and computational complexity is evaluated for different algorithmic variants in relation to the Cramér–Rao bound. By utilizing selected approximations and parameter choices, a prepossessing could be efficiently implemented on a field-programmable gate array (FPGA), enabling a typical reduction of the data bandwidth of 6.5:1 and online flow visualization. We validated the performance of the signal processing on a test rig, yielding a velocity standard deviation that is a factor of 3 above the theoretical limit despite a low computational complexity. Potential applications for this signal processing include multihour flow measurements during a crystal-growth process and closed-loop velocity feedback for model experiments.

APA, Harvard, Vancouver, ISO, and other styles

12

Shamu, Tafadzwa John, Reinhardt Kotze, and Johan Wiklund. "Characterization of Acoustic Beam Propagation Through High-Grade Stainless Steel Pipes for Improved Pulsed Ultrasound Velocimetry Measurements in Complex Industrial Fluids." IEEE Sensors Journal 16, no. 14 (July 2016): 5636–47. http://dx.doi.org/10.1109/jsen.2016.2569491.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Qazi, Waqas M., Olle Ekberg, Johan Wiklund, Rashid Mansoor, and Mats Stading. "Simultaneous X-ray Video-Fluoroscopy and Pulsed Ultrasound Velocimetry Analyses of the Pharyngeal Phase of Swallowing of Boluses with Different Rheological Properties." Dysphagia 35, no. 6 (February 11, 2020): 898–906. http://dx.doi.org/10.1007/s00455-020-10092-4.

Full text

Abstract:

AbstractThe Ultrasound Velocity Profiling (UVP) technique allows real-time, non-invasive flow mapping of a fluid along a 1D-measuring line. This study explores the possibility of using the UVP technique and X-ray video-fluoroscopy (XVF) to elucidate the deglutition process with the focus on bolus rheology. By positioning the UVP probe so that the pulsed ultrasonic beam passes behind the air-filled trachea, the bolus flow in the pharynx can be measured. Healthy subjects in a clinical study swallowed fluids with different rheological properties: Newtonian (constant shear viscosity and non-elastic); Boger (constant shear viscosity and elastic); and shear thinning (shear rate-dependent shear viscosity and elastic). The results from both the UVP and XVF reveal higher velocities for the shear thinning fluid, followed by the Boger and the Newtonian fluids, demonstrating that the UVP method has equivalent sensitivities for detecting the velocities of fluids with different rheological properties. The velocity of the contraction wave that clears the pharynx was measured in the UVP and found to be independent of bolus rheology. The results show that UVP not only assesses accurately the fluid velocity in a bolus flow, but it can also monitor the structural changes that take place in response to a bolus flow, with the added advantage of being a completely non-invasive technique that does not require the introduction of contrast media.

APA, Harvard, Vancouver, ISO, and other styles

14

Gaziano, Emanuel, G. Eric Knox, Gael P. Wager, Richard P. Bendel, Deborah J. Boyce, and Jeanne Olson. "The predictability of the small-for-gestational-age infant by real-time ultrasound-derived measurements combined with pulsed Doppler umbilical artery velocimetry." American Journal of Obstetrics and Gynecology 158, no. 6 (June 1988): 1431–39. http://dx.doi.org/10.1016/0002-9378(88)90378-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Kulkarni, Nitin, Radhika Bansal, and Pankaj Pawar. "Serum Beta HCG and uterine artery Doppler studies in second trimester to predict preeclampsia and eclampsia." International Journal of Reproduction, Contraception, Obstetrics and Gynecology 7, no. 5 (April 28, 2018): 1924. http://dx.doi.org/10.18203/2320-1770.ijrcog20181930.

Full text

Abstract:

Background: Hypertensive disorders during pregnancy remain amongst the most significant and intriguing unsolved problems in obstetrics. The study aims at testing the hypothesis that women with high serum beta hCG levels and alterations in waveforms in the uterine artery doppler in early second trimester have high risk of developing pre-eclampsia.Methods: Serum Beta hCG estimation was done by Sandwich chemiluminescence immunoassay method. All uterine artery waveforms were obtained using a Toshiba nemio ultrasound machine attached to a 3.5 MHz curvilinear transducer, with colour and pulsed Doppler abilities.Results: For prediction of preeclampsia or eclampsia uterine artery Doppler velocimetry alone shows specificity of 96.30%, sensitivity of 90%, positive predictive value of 94% and negative predictive value of 80%. When it is combined with serum beta HCG sensitivity and specificity are almost same, but alone serum beta HCG levels are showing sensitivity of 96% and specificity of just 76%.Conclusions: Abnormal waveforms on uterine Doppler studies are the better predictors for preeclampsia and eclampsia when done in early second trimester.

APA, Harvard, Vancouver, ISO, and other styles

16

Ramírez-González, David, Ángel Poto, Begoña Peinado, Laura Almela, Sergio Navarro-Serna, and Salvador Ruiz. "Ultrasonography of Pregnancy in Murciano-Granadina Goat Breed: Fetal Growth Indices and Umbilical Artery Doppler Parameters." Animals 13, no. 4 (February 9, 2023): 618. http://dx.doi.org/10.3390/ani13040618.

Full text

Abstract:

The evolution of some fetal growth indices and arterial blood flow parameters in the umbilical cord of the embryos and fetuses of primiparous pregnant goats of Murciano-Granadina breed were analyzed by ultrasonography. Weekly ultrasonographic sessions took place from 18- to 125-days post-breeding. Fetal measures were carried out by ultrasound B-mode. This mode was used to take a series of measurements in the embryo/fetus throughout pregnancy: crown-rump length (CRL, from 24-days post-mating -dpm- to 61 dpm), trunk diameter (TD, 24–34 dpm), biparietal diameter (BPD, 28–125 dpm) and eye orbit diameter (EOD, 75–125 dpm). Spectral Doppler was used to study blood flow from umbilical artery. Different blood flow parameters were obtained as follows: Arterial Pulse, Peak Systolic Velocity (PSV), End Diastolic Velocity (EDV), Mean Velocity (MV), Systolic velocity/Diastolic velocity Ratio (S/D), Pulsatility Index (PI) and Resistance Index (RI). In this study, the umbilical cord was first noticed between 32- and 35-days post-breeding. However, these umbilical arterial blood flow parameters were not conclusive (positive S/D ratios and RI < 1) until 65–80 days of pregnancy. The explanation to these results could be that vascular development related to umbilical arteries elasticity and diameter is not good enough in early pregnancy. Therefore, these vessels have already acquired their appropriate characteristics in order to allow blood flow parameters and Doppler index measures from only 2.5 months of pregnancy. This is the first time that a detailed study of fetal growth indices and umbilical artery flow rates in fetuses from Murciano-Granadina goats has been performed throughout virtually the entire duration of gestation. In conclusion, the evolution of the fetal growth indices in this breed has determined that the umbilical artery velocimetric parameters (PSV, EDV, MV) increase significantly and the AP, S/D, PI and RI indices decrease significantly throughout the analyzed pregnancy period.

APA, Harvard, Vancouver, ISO, and other styles

17

Mann, K. A., S. Deutsch, J. M. Tarbell, D. B. Geselowitz, G. Rosenberg, and W. S. Pierce. "An Experimental Study of Newtonian and Non-Newtonian Flow Dynamics in a Ventricular Assist Device." Journal of Biomechanical Engineering 109, no. 2 (May 1, 1987): 139–47. http://dx.doi.org/10.1115/1.3138656.

Full text

Abstract:

The fluid dynamic behavior of a Newtonian water/glycerol solution, a non-Newtonian polymer (separan) solution, and bovine blood were compared in the Penn State Electrical Ventricular Assist Device (EVAD). Pulsed doppler ultrasound velocimetry was used to measure velocities in the near wall region (0.95–2.7 mm) along the perimeter of the pump. Mean velocity, turbulence intensity, local and convective acceleration, and shear rate were calculated from the PDU velocity measurements. Flow visualization provided qualitative information about the general flow patterns in the EVAD. Results indicate that water/glycerol does not accurately model the flow characteristics of bovine blood in the EVAD. The non-Newtonian separan solution produced results closer to those of the bovine blood than did the water/glycerol solution. Near wall velocity magnitudes for the separan were similar to those of the bovine blood, but the profile shapes differed for portions of the pump cycle. All three fluids exhibited periods of stagnation. Bovine blood results indicated the presence of a desired rotational washout pattern at mid-systole, while results with the other fluids did not show this feature.

APA, Harvard, Vancouver, ISO, and other styles

18

Falahatpisheh, Ahmad, and Arash Kheradvar. "Abstract 14952: Volumetric Echocardiographic Particle Image Velocimetry (V-Echo-PIV)." Circulation 130, suppl_2 (November 25, 2014). http://dx.doi.org/10.1161/circ.130.suppl_2.14952.

Full text

Abstract:

Introduction: The two-dimensional (2D) echocardiographic particle image velocimetry technique that was introduced in 2010 received much attention in clinical cardiology. Cardiac flow visualization based on contrast echocardiography results in images with high temporal resolution that are obtainable at relatively low cost. This makes it an ideal diagnostic and follow-up tool for routine clinical use. However, cardiac flow in a cardiac cycle is multidirectional with a tendency to spin in three dimensions rather than two-dimensional curl. Here, for the first time, we introduce a volumetric echocardiographic particle image velocimetry technique that robustly acquires the flow in three spatial dimensions and in time: Volumetric Echocardiographic Particle Image Velocimetry (V-Echo-PIV). Methods: V-Echo-PIV technique utilizes matrix array 3D ultrasound probes to capture the flow seeded with an ultrasound contrast agent (Definity). For this feasibility study, we used a pulse duplicator with a silicone ventricular sac along with bioprosthetic heart valves at the inlet and outlet. GE Vivid E9 system with an Active Matrix 4D Volume Phased Array probe at 30 Hz was used to capture the flow data (Figure 1). Results: The 3D particle field was obtained with excellent spatial resolution without significant noise (Figure 1). 3D velocity field was successfully captured for multiple cardiac cycles. Flow features are shown in Figure 2 where the velocity vectors in two selected slices and some streamlines in 3D space are depicted. Conclusions: We report successful completion of the feasibility studies for volumetric echocardiographic PIV in an LV phantom. The small-scale features of flow in the LV phantom were revealed by this technique. Validation and human studies are currently in progress.

APA, Harvard, Vancouver, ISO, and other styles

19

"A Comparative Study of Continuous- and Pulsed-Wave Doppler Velocimetry in Fetal and Uteroplacental Circulation." Journal of Diagnostic Medical Sonography 7, no. 5 (September 1991): 309. http://dx.doi.org/10.1177/875647939100700527.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Martínez-Díaz, Sandra, Francisco Alberto García-Vázquez, Chiara Luongo, and Salvador Ruiz López. "VALORACIÓN DEL FLUJO ARTERIAL DEL CORDÓN UMBILICAL EN FETOS CAPRINOS DE RAZA MURCIANO-GRANADINA MEDIANTE ECOGRAFÍA DOPPLER ESPECTRAL." Anales de Veterinaria de Murcia 36 (April 5, 2022). http://dx.doi.org/10.6018/analesvet.513941.

Full text

Abstract:

The Murciano-Granadina (M-G) breed is the most representative goat breed in Spain. Ultrasound has proven to be a very useful procedure in animal reproduction for detection and monitoring of pregnancy and Doppler ultrasound has made it possible to obtain non-invasive objective measurements of the vascular supply and the functionality of various organs and structures. The objective of this work has been the evaluation of the hemodynamic characteristics of the umbilical artery in M-G goat fetuses using Doppler parameters and indices to assess the applicability of Doppler ultrasound in the evaluation of fetal vascularization. The study was carried out in 4 pregnant goats M-G, belonging to IMIDA, located in the Veterinary Teaching Farm. Examinations and measurements of Doppler parameters in the umbilical artery were carried out once a week between days 75 and 120 of gestation, assuming a total of 5 to 7 ultrasound sessions in each female. Doppler parameters analyzed were Peak Sistolic Velocity (PSV), End Diastolic Velocity (EDV), Mean Velocity (MV), Resistive Index (RI), Pulsatility Index (PI), Systolic/Diastolic Ratio (S/D) and umbilical artery pulse (AP). PSV increased without significant differences until day 120 of gestation, when it reached its maximum value. EDV progressively increased significantly during pregnancy. MV of umbilical arterial flow remained with similar values, without significant differences between days of pregnancy, reaching its maximum value on day 120. Values of RI, PI and S/D ratio decreased continuously and significantly during the gestational period. AP values varied significantly during pregnancy, reaching the maximum on day 90 and minimum value on day 120 of pregnancy. This study has shown that Doppler ultrasound is an effective, safe and repeatable tool that offers good accuracy to successfully analyze blood flow and velocimetric parameters of the umbilical cord during physiological changes and intrauterine development of the fetus throughout pregnancy in M-G goats. The objective of this work has been the evaluation of the hemodynamic characteristics of the umbilical artery in M-G goat fetuses using Doppler parameters and indices to assess the applicability of Doppler ultrasound in the evaluation of fetal vascularization. The study was carried out in 4 pregnant goats M-G, belonging to IMIDA, located in the Veterinary Teaching Farm. Examinations and measurements of Doppler parameters in the umbilical artery were carried out once a week between days 75 and 120 of gestation, assuming a total of 5 to 7 ultrasound sessions in each female. Doppler parameters analyzed were Peak Sistolic Velocity (PSV), End Diastolic Velocity (EDV), Mean Velocity (MV), Resistive Index (RI), Pulsatility Index (PI), Systolic/Diastolic Ratio (S/D) and umbilical artery pulse (AP). PSV increased without significant differences until day 120 of gestation, when it reached its maximum value. EDV progressively increased significantly during pregnancy. MV of umbilical arterial flow remained with similar values, without significant differences between days of pregnancy, reaching its maximum value on day 120. Values of RI, PI and S/D ratio decreased continuously and significantly during the gestational period. AP values varied significantly during pregnancy, reaching the maximum on day 90 and minimum value on day 120 of pregnancy. This study has shown that Doppler ultrasound is an effective, safe and repeatable tool that offers good accuracy to successfully analyze blood flow and velocimetric parameters of the umbilical cord during physiological changes and intrauterine development of the fetus throughout pregnancy in M-G goats. La raza Murciano-Granadina (M-G) es considerada la raza caprina más representativa de España y su sistema productivo presenta una elevada trascendencia. La ecografía ha demostrado ser un procedimiento de gran utilidad en reproducción animal para la detección y seguimiento de la gestación y la ecografía Doppler ha posibilitado obtener mediciones objetivas no invasivas del aporte vascular y la funcionalidad de diversos órganos y estructuras. El objetivo de este trabajo ha sido la evaluación de las características hemodinámicas de la arteria umbilical en fetos caprinos de raza M-G empleando parámetros e índices Doppler para valorar la aplicabilidad de la ecografía Doppler en la evaluación de la vascularización fetal. El estudio se llevó a cabo en 4 cabras gestantes M-G, pertenecientes al IMIDA, ubicadas en la Granja Docente Veterinaria. Los exámenes y mediciones de los parámetros Doppler en la arteria umbilical se llevaron a cabo una vez por semana entre los días 75 y 120 de gestación, suponiendo un total de 5 a 7 sesiones ecográficas en cada hembra. Se analizaron los siguientes parámetros Doppler: velocidad sistólica máxima (PSV), velocidad diastólica final (EDV), velocidad media (VM), índice de resistividad (IR), índice de pulsatilidad (IP) y relación sístole/diástole (S/D) además, del pulso de la arteria umbilical (PA). PSV y VM se mantuvieron con valores similares, sin diferencias significativas, mientras que EDV aumentó con diferencias significativas en el periodo gestacional analizado. Los valores de IR, IP y S/D descendieron de forma continua y significativa. Los valores de PA variaron de forma significativa durante la gestación, alcanzado su máximo en el día 90 y llegando a su valor mínimo el día 120. Los índices Doppler ofrecen gran precisión y pueden utilizarse con éxito para estudiar la perfusión sanguínea y los parámetros velocimétricos del cordón umbilical en fetos durante el periodo de gestación en cabras M-G. El objetivo de este trabajo ha sido la evaluación de las características hemodinámicas de la arteria umbilical en fetos caprinos de raza M-G empleando parámetros e índices Doppler para valorar la aplicabilidad de la ecografía Doppler en la evaluación de la vascularización fetal. El estudio se llevó a cabo en 4 cabras gestantes M-G, pertenecientes al IMIDA, ubicadas en la Granja Docente Veterinaria. Los exámenes y mediciones de los parámetros Doppler en la arteria umbilical se llevaron a cabo una vez por semana entre los días 75 y 120 de gestación, suponiendo un total de 5 a 7 sesiones ecográficas en cada hembra. Se analizaron los siguientes parámetros Doppler: velocidad sistólica máxima (PSV), velocidad diastólica final (EDV), velocidad media (VM), índice de resistividad (IR), índice de pulsatilidad (IP) y relación sístole/diástole (S/D) además, del pulso de la arteria umbilical (PA). PSV y VM se mantuvieron con valores similares, sin diferencias significativas, mientras que EDV aumentó con diferencias significativas en el periodo gestacional analizado. Los valores de IR, IP y S/D descendieron de forma continua y significativa. Los valores de PA variaron de forma significativa durante la gestación, alcanzado su máximo en el día 90 y llegando a su valor mínimo el día 120. Los índices Doppler ofrecen gran precisión y pueden utilizarse con éxito para estudiar la perfusión sanguínea y los parámetros velocimétricos del cordón umbilical en fetos durante el periodo de gestación en cabras M-G.

APA, Harvard, Vancouver, ISO, and other styles

21

"Vaginosonographic Velocimetry of Both Main Uterine Arteries by Visual Vessel Recognition and Pulsed Doppler Method During Pregnancy." Journal of Diagnostic Medical Sonography 5, no. 2 (March 1989): 86–87. http://dx.doi.org/10.1177/875647938900500229.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

"Fetal Umbilical Velocimetry Using Continuous-Wave and Pulsed-Wave Doppler Ultrasound in High-Risk Pregnancies: A Comparison of Systolic to Diastolic Ratios." Journal of Diagnostic Medical Sonography 5, no. 1 (January 1989): 26–27. http://dx.doi.org/10.1177/875647938900500114.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

"A Comparative Study of Fetal Umbilical Velocimetry with Continuous and Pulsed-wave Doppler Ultrasonography in High-risk Pregnancies: Relationship to Outcome." Journal of Diagnostic Medical Sonography 5, no. 3 (May 1989): 138. http://dx.doi.org/10.1177/875647938900500313.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Strachinaru, Mihai, Jason Voorneveld, Lana B. H. Keijzer, Daniel J. Bowen, Ferit O. Mutluer, Folkert ten Cate, Nico de Jong, Hendrik J. Vos, Johan G. Bosch, and Annemien E. van den Bosch. "Left ventricular high frame rate echo-particle image velocimetry: clinical application and comparison with conventional imaging." Cardiovascular Ultrasound 20, no. 1 (April 26, 2022). http://dx.doi.org/10.1186/s12947-022-00283-4.

Full text

Abstract:

Abstract Background Echo-Particle Image Velocimetry (echoPIV) tracks speckle patterns from ultrasound contrast agent(UCA), being less angle-sensitive than colour Doppler. High frame rate (HFR) echoPIV enables tracking of high velocity flow in the left ventricle (LV). We aimed to demonstrate the potential clinical use of HFR echoPIV and investigate the feasibility and accuracy in patients. Methods Nineteen patients admitted for heart failure were included. HFR contrast images were acquired from an apical long axis view (ALAX), using a fully-programmable ultrasound system. A clinical UCA was continuously infused with a dedicated pump. Additionally, echocardiographic images were obtained using a clinical system, including LV contrast-enhanced images and pulsed-wave (PW) Doppler of the LV inflow and outflow in ALAX. 11 patients underwent CMR and 4 cardiac CT as clinically indicated. These CMR and CT images were used as reference. In 10 patients with good echoPIV tracking and reference imaging, the intracavitary flow was compared between echoPIV, conventional and UCA echocardiography. Results EchoPIV tracking quality was good in 12/19 (63%), moderate in 2/19 (10%) and poor in 5/19 (26%) subjects. EchoPIV could determine inflow velocity in 17/19 (89%), and outflow in 14/19 (74%) patients. The correlation of echoPIV and PW Doppler was good for the inflow (R2 = 0.77 to PW peak; R2 = 0.80 PW mean velocity) and moderate for the outflow (R2 = 0.54 to PW peak; R2 = 0.44 to PW mean velocity), with a tendency for echoPIV to underestimate PW velocities. In selected patients, echoPIV was able in a single acquisition to demonstrate flow patterns which required multiple interrogations with classical echocardiography. Those flow patterns could also be linked to anatomical abnormalities as seen in CMR or CT. Conclusion HFR echoPIV tracks multidirectional and complex flow patterns which are unapparent with conventional echocardiography, while having comparable feasibility. EchoPIV tends to underestimate flow velocities as compared to PW Doppler. It has the potential to provide in one acquisition all the functional information obtained by conventional imaging, overcoming the angle dependency of Doppler and low frame rate of classical contrast imaging.

APA, Harvard, Vancouver, ISO, and other styles

25

Strachinaru, Mihai, Jason Voorneveld, Lana B. H. Keijzer, Daniel J. Bowen, Ferit O. Mutluer, Folkert ten Cate, Nico de Jong, Hendrik J. Vos, Johan G. Bosch, and Annemien E. van den Bosch. "Left ventricular high frame rate echo-particle image velocimetry: clinical application and comparison with conventional imaging." Cardiovascular Ultrasound 20, no. 1 (April 26, 2022). http://dx.doi.org/10.1186/s12947-022-00283-4.

Full text

Abstract:

Abstract Background Echo-Particle Image Velocimetry (echoPIV) tracks speckle patterns from ultrasound contrast agent(UCA), being less angle-sensitive than colour Doppler. High frame rate (HFR) echoPIV enables tracking of high velocity flow in the left ventricle (LV). We aimed to demonstrate the potential clinical use of HFR echoPIV and investigate the feasibility and accuracy in patients. Methods Nineteen patients admitted for heart failure were included. HFR contrast images were acquired from an apical long axis view (ALAX), using a fully-programmable ultrasound system. A clinical UCA was continuously infused with a dedicated pump. Additionally, echocardiographic images were obtained using a clinical system, including LV contrast-enhanced images and pulsed-wave (PW) Doppler of the LV inflow and outflow in ALAX. 11 patients underwent CMR and 4 cardiac CT as clinically indicated. These CMR and CT images were used as reference. In 10 patients with good echoPIV tracking and reference imaging, the intracavitary flow was compared between echoPIV, conventional and UCA echocardiography. Results EchoPIV tracking quality was good in 12/19 (63%), moderate in 2/19 (10%) and poor in 5/19 (26%) subjects. EchoPIV could determine inflow velocity in 17/19 (89%), and outflow in 14/19 (74%) patients. The correlation of echoPIV and PW Doppler was good for the inflow (R2 = 0.77 to PW peak; R2 = 0.80 PW mean velocity) and moderate for the outflow (R2 = 0.54 to PW peak; R2 = 0.44 to PW mean velocity), with a tendency for echoPIV to underestimate PW velocities. In selected patients, echoPIV was able in a single acquisition to demonstrate flow patterns which required multiple interrogations with classical echocardiography. Those flow patterns could also be linked to anatomical abnormalities as seen in CMR or CT. Conclusion HFR echoPIV tracks multidirectional and complex flow patterns which are unapparent with conventional echocardiography, while having comparable feasibility. EchoPIV tends to underestimate flow velocities as compared to PW Doppler. It has the potential to provide in one acquisition all the functional information obtained by conventional imaging, overcoming the angle dependency of Doppler and low frame rate of classical contrast imaging.

APA, Harvard, Vancouver, ISO, and other styles

26

Strachinaru, M., J. Voorneveld, LBH Keijzer, DJ Bowen, FO Mutluer, FJ Ten Cate, N. De Jong, HJ Vos, JG Bosch, and AE Van Den Bosch. "Left ventricular high frame rate echo-particle image velocimetry: feasibility and comparison with conventional echocardiography." European Heart Journal - Cardiovascular Imaging 23, Supplement_1 (February 1, 2022). http://dx.doi.org/10.1093/ehjci/jeab289.001.

Full text

Abstract:

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Echo-Particle Image Velocimetry (echoPIV) tracks speckle patterns from ultrasound contrast agent (UCA) microbubbles injected intravenously, being less angle-sensitive than colour Doppler. One limitation of conventional echoPIV is the inability to accurately resolve high velocities, because of relatively low frame rates. In contrast, high frame rate (HFR) echoPIV enables tracking of fast flow in the left ventricle (LV). Purpose To investigate the feasibility and precision of HFR echoPIV in patients. Methods 19 heart failure patients were included. UCA was infused with a dedicated pump. HFR contrast images were acquired, in apical long axis view (ALAX, ensuring simultaneous visualization of LV inflow and outflow), using a fully-programmable research ultrasound system, with a phased array probe. In the same session, complete echocardiographic studies were obtained using a clinical ultrasound system, with a matrix array probe, including LV UCA. Non-contrast pulsed-wave (PW) Doppler were also obtained in ALAX (Figure 1) from the mitral valve tips (inflow) and the LV outflow tract (outflow). HFR echoPIV image quality and tracking were assessed offline by two independent observers. The peak velocity of the inflow and outflow were determined by the automated tracking algorithm of the HFR echoPIV, and measured by the peak modal velocity of the conventional PW. These velocities were compared using Pearson’s correlations and Bland-Altman plots. All patients gave their informed consent. The study was approved by the institutional review board. Results Conventional echo image quality was good in 12 (63%), medium in 5 (26%) and bad in 2 (11%). EchoPIV tracking was good in 12 (63%), medium in 2 (10%) and bad in 5 (26%). In the 12 patients where echoPIV tracking was good, the direction and velocity of intracavitary vortices could be visualized (Figure 1). The inflow velocity could be determined by echoPIV in 17/19 (89%), and outflow in 14/19 (74%). EchoPIV tended to underestimate the maximal velocity as determined by PW (Figure 2), with a bias of 0.19 m/s (inflow) and 0.28 m/s (outflow). This negative bias is expected as the PW is assessing maximum velocity in the interrogation kernel whereas echoPIV returns the mean velocity. The correlation of the two methods was good for the inflow (R2 = 0.77, p < 0.001) and moderate for the outflow (R2 = 0.54, p < 0.001). This may be explained by the position of the LV outflow tract deeper in the image, leading to increased attenuation, clutter and reduced lateral resolution. Conclusion HFR echoPIV has comparable feasibility to routine echocardiography, and the ability to correctly estimate intraventricular flow velocity. It can provide in one acquisition all the functional information that can be detected by routine echocardiography, PW and color Doppler, as well as contrast. It succeeds in surpassing the shortcomings of Doppler (angle dependency) and classical contrast imaging (low frame rate). Abstract Figure 1: HFR echoPIV in study patients Abstract Figure 2: study results

APA, Harvard, Vancouver, ISO, and other styles

27

"Assessment of Doppler Velocimetry of the Fetal Umbilical Artery by Multigate Spectral Doppler Scanning and Traditional Pulsed Doppler Ultrasonography Plus Color Flow Mapping." Journal of Diagnostic Medical Sonography 16, no. 2 (March 2000): 87. http://dx.doi.org/10.1177/875647930001600220.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Pulsed Ultrasound Velocimetry (PUV)'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles