scholarly journals Ultrasound PIV Uncertainty Quantification

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Rozhin Derakhshandeh ◽  
Sayantan Bhattacharya ◽  
Brett Meyers ◽  
Pavlos Vlachos
Keyword(s):  
Particle Image ◽  
Digital Signal ◽  
Working Fluid ◽  
Ultrasound Images ◽  
Complex Flows ◽  
Non Invasive ◽  
Uncertainty Sources ◽  
Image Shape ◽  
Non Gaussian ◽  
Particle Images

Ultrasound Particle image velocimetry (UPIV) is a non-invasive flow measurement technique where acousticopaque flow tracers are injected into a working fluid and ensonified to create ultrasound images. These images are processed using PIV cross-correlation based algorithms to measure the velocity field (Kim et al., 2004). UPIV is useful for opaque flows, primarily where complex flows exist, accordingly, it is used in many industrial and clinical research applications such as studying intracardiac flow (Crase et al., 2007). Furthermore, the measurement provides suitable temporal and spatial resolutions for improved diagnostic metrics. Mentioned applications and the sensitive diagnostic industrial and clinical decisions made based on these measurements intensifies the importance of characterizing the UPIV measurement accuracy and associated uncertainty. However, quantifying UPIV measurement uncertainty is non-trivial due to the complexity of possible uncertainty sources, their combination, and propagation through the measurement chain. The formation of a particle image by ultrasound significantly differs from optical imaging, introducing unique aspects to image quality that must be considered. Particle images are formed across several ultrasound scan lines, yielding an elliptical particle image shape. Furthermore, the particle’s reflected pressure wave is converted to a digital signal that undergoes signal modulation, and this process forms a non-Gaussian point spread function (PSF) along the scan line direction. Additionally, clusters of tracers produce a single, bright image intensity and speckle image pattern. Compared to conventional PIV images, UPIV incurs significantly higher image noise due to lack of filtration for the ultrasound reflection of the non-tracer obstacles.

scholarly journals Enhancement of nerve structure segmentation by a correntropy-based pre-image approach

TecnoLógicas ◽  
2017 ◽  
Vol 20 (39) ◽  
pp. 197-208
Author(s):  
Julián Gil-González ◽  
Andrés A. Álvarez-Meza ◽  
Julián D. Echeverry-Correa ◽  
Álvaro A. Orozco-Gutiérrez ◽  
Mauricio A. Álvarez-López
Keyword(s):  
Nonlinear Function ◽  
Speckle Noise ◽  
Ultrasound Images ◽  
Improvement Strategy ◽  
Anatomical Structures ◽  
Non Invasive ◽  
Nerve Structure ◽  
Non Gaussian ◽  
High Level ◽  
Suitable Approximation

Peripheral Nerve Blocking (PNB) is a commonly used technique for performing regional anesthesia and managing pain. PNB comprises the administration of anesthetics in the proximity of a nerve. In this sense, the success of PNB procedures depends on an accurate location of the target nerve. Recently, ultrasound images (UI) have been widely used to locate nerve structures for PNB, since they enable a non-invasive visualization of the target nerve and the anatomical structures around it. However, UI are affected by speckle noise, which makes it difficult to accurately locate a given nerve. Thus, it is necessary to perform a filtering step to attenuate the speckle noise without eliminating relevant anatomical details that are required for high-level tasks, such as segmentation of nerve structures. In this paper, we propose an UI improvement strategy with the use of a pre-image-based filter. In particular, we map the input images by a nonlinear function (kernel). Specifically, we employ a correntropy-based mapping as kernel functional to code higher-order statistics of the input data under both nonlinear and non-Gaussian conditions. We validate our approach against an UI dataset focused on nerve segmentation for PNB. Likewise, our Correntropy-based Pre-Image Filtering (CPIF) is applied as a pre-processing stage to segment nerve structures in a UI. The segmentation performance is measured in terms of the Dice coefficient. According to the results, we observe that CPIF finds a suitable approximation for UI by highlighting discriminative nerve patterns.

Experimental Validation of Minimax Entropy Principle in Ultrasound Images

2019 ◽  
Vol 12 (6) ◽  
pp. 487-493
Author(s):  
Neha Mehta ◽  
Svav Prasad ◽  
Leena Arya
Keyword(s):  
Region Of Interest ◽  
Ultrasound Images ◽  
Human Gallbladder ◽  
New Approach ◽  
Non Invasive ◽  
Entropy Principle ◽  
Significant Performance ◽  
Considerable Impact ◽  
Ultrasonic Devices ◽  
Measure Of Uncertainty

Ultrasound imaging is one of the non-invasive imaging, that diagnoses the disease inside a human body and there are numerous ultrasonic devices being used frequently. Entropy as a well known statistical measure of uncertainty has a considerable impact on the medical images. A procedure for minimizing the entropy with respect to the region of interest is demonstrated. This new approach has shown the experiments using Extracted Region Of Interest Based Sharpened image, called as (EROIS) image based on Minimax entropy principle and various filters. In this turn, the approach also validates the versatility of the entropy concept. Experiments have been performed practically on the real-time ultrasound images collected from ultrasound centers and have shown a significant performance. The present approach has been validated with showing results over ultrasound images of the Human Gallbladder.

A particle image velocimetry study on the pulsatile flow characteristics in straight tubes with an asymmetric bulge

2000 ◽  
Vol 214 (5) ◽  
pp. 655-671 ◽  
Author(s):  
S C M Yu ◽  
J B Zhao
Keyword(s):  
Particle Image Velocimetry ◽  
Steady Flow ◽  
Pulsatile Flow ◽  
Flow Condition ◽  
Particle Image ◽  
Flow Characteristics ◽  
Reynolds Numbers ◽  
Working Fluid ◽  
Flow Conditions ◽  
Image Velocimetry

Flow characteristics in straight tubes with an asymmetric bulge have been investigated using particle image velocimetry (PIV) over a range of Reynolds numbers from 600 to 1200 and at a Womersley number of 22. A mixture of glycerine and water (approximately 40:60 by volume) was used as the working fluid. The study was carried out because of their relevance in some aspects of physiological flows, such as arterial flow through a sidewall aneurysm. Results for both steady and pulsatile flow conditions were obtained. It was found that at a steady flow condition, a weak recirculating vortex formed inside the bulge. The recirculation became stronger at higher Reynolds numbers but weaker at larger bulge sizes. The centre of the vortex was located close to the distal neck. At pulsatile flow conditions, the vortex appeared and disappeared at different phases of the cycle, and the sequence was only punctuated by strong forward flow behaviour (near the peak flow condition). In particular, strong flow interactions between the parent tube and the bulge were observed during the deceleration phase. Stents and springs were used to dampen the flow movement inside the bulge. It was found that the recirculation vortex could be eliminated completely in steady flow conditions using both devices. However, under pulsatile flow conditions, flow velocities inside the bulge could not be suppressed completely by both devices, but could be reduced by more than 80 per cent.

PIV Measurements Within the Waves of Wavy and Wavy-Annular Horizontal Two-Phase Flow

2005 ◽  
Author(s):  
R. E. Foster ◽  
T. A. Shedd
Keyword(s):  
Particle Image ◽  
Image Processing Algorithm ◽  
Two Phase ◽  
Piv Measurements ◽  
Post Process ◽  
Image Velocimetry ◽  
Processed Form ◽  
Image Pairs ◽  
Particle Images ◽  
The Waves

A novel technique of microscopic Particle Image Velocimetry (PIV) is presented for two-phase annular, wavy-annular and stratified flow. Seeding of opaque particles in a water/dye flow allows the acquisition of instantaneous film velocity data in the film cross-section at the center of the tube in the form of digital image pairs. An image processing algorithm is also described that allows numerical velocities to be distilled from particle images by commercial PIV software. The approach yields promising results for stratified and wavy-annular flows, however highly bubbly flows remain difficult to image and post-process. Initial data images are presented in raw and processed form.

Double pulsed particle image velocimeter with directional resolution for complex flows

2004 ◽  
Vol 6 (2) ◽  
pp. 119-128 ◽  
Author(s):  
C. C. Landreth ◽  
R. J. Adrian ◽  
C. S. Yao
Keyword(s):  
Particle Image ◽  
Complex Flows ◽  
Particle Image Velocimeter

scholarly journals Ultrasonography in physiotherapy and rehabilitation

2021 ◽  
pp. 1-3
Author(s):  
Barassi Giovanni ◽  
Guerri Sergio ◽  
Tavani Roberta ◽  
Ricucci Giampiero ◽  
De Luca Giorgia ◽  
...  
Keyword(s):  
Ultrasound Image ◽  
Muscle Stiffness ◽  
Ultrasound Images ◽  
Tendon Tissue ◽  
Invasive Approach ◽  
Know How ◽  
Non Invasive ◽  
Load Transmission ◽  
Intensity Information

There is an interrelation with ultrasound / physiotherapist and the duty of the physiotherapist to know how to perform ultrasound examinations alone, not for diagnostic purposes, to follow the evolution of the therapeutic cycle of physiotherapy. For this reason, ultrasound image analysis (US) is a promising non-invasive approach that uses load-dependent changes in the intensity of the echo to characterize the rigidity of muscle and tendon tissue. The purpose of this contribution is to improve the use of ultrasound images (US) and the role of the physiotherapist, who are able to detect localized changes, in particular in stiffness of the tendon due to partial and full-thickness tendon tears. Image intensity information is less sensitive for identifying load transmission variations resulting from partial thickness cuts initiated on the joint side. Ultrasound images can be useful for quantitatively assessing the variations dependent on the tendon load and muscle stiffness in physiotherapy and that the interruption of the behavior of the acousto-elastic ultrasound images can be indicative of substantial damage to the muscle or tendon.

scholarly journals Ultrasonographic Diagnosis of Ileal Intussusception in Calf

2021 ◽  
Vol 49 ◽  
Author(s):  
Ana Clara Sarzedas Ribeiro ◽  
Rodolfo José Cavalcanti Souto ◽  
Tayrlla Polessa Rodrigues Silva ◽  
José Augusto Bastos Afonso ◽  
Carla Lopes Mendonça ◽  
...  
Keyword(s):  
Intestinal Obstruction ◽  
Low Cost ◽  
Clinical Signs ◽  
Chloride Content ◽  
Diagnostic Tools ◽  
Adjacent Segment ◽  
Ultrasound Images ◽  
Target Pattern ◽  
Non Invasive ◽  
Intestinal Obstructions

Background: Intussusception, characterized by invagination of an intestinal segment into the lumen of the adjacent segment, is one of the main causes of intestinal obstruction in cattle, and occurs more frequently in calves. The diagnosis of the disease is based on the history, clinical examination, and complementary exams, which are a challenge in this species, especially in calves, in which transrectal palpation is limited. As it is a non-invasive, effective, and low-cost test, ultrasonography could be an important tool in the diagnosis of intestinal obstructions, in which time is essential for the prognosis. Therefore, the objective was to report a case of intussusception in a calf diagnosed by ultrasound.Case: A 4-month-old calf, weaned at 3 months and raised intensively, was treated at the Clínica de Bovinos de Garanhuns, campus of the Universidade Federal Rural de Pernambuco (CBG/UFRPE), with a history of apathy, anorexia, and dyschezia for 3 days. On physical examination, fever, moderate dehydration, tachycardia, tachypnea with polypnea, bilaterally bulging abdomen, sound of fluid on ballottement, ruminal and intestinal hypomotility, and melena were observed. The hematological findings revealed leukocytosis due to neutrophilia (degenerate neutrophils), hypoproteinemia, and hyperfibrinogenemia. The analysis of the ruminal fluid showed compromised microbiota and increased chloride content. The transabdominal ultrasonography demonstrated, in the right ventral region, hypermotile and full small bowel loops and an increase in the volume of the peritoneal fluid. In addition, there was a segment of the small intestine which, in cross-section, showed multiple concentric rings (“onion rings”, “target pattern”, or “bull’s eye”) and adherence to adjacent loops, compatible with intestinal obstruction due to intussusception. Due to the seriousness of the clinical condition and the ultrasound findings, the animal was euthanized and the necropsy revealed focal fibrinous peritonitis and intestinal obstruction due to intussusception in ileum intestinal segments.Discussion: Intussusception has previously been reported in calves, however this is the first report of ultrasound diagnosis of the disease in Brazil. Although the etiology is rarely confirmed, the age group and recent changes in diet (weaning) were predisposing factors. The history, clinical signs, and laboratory tests were similar to those described in cattle with intussusception, however they may be present in other gastrointestinal illnesses. Other authors have also reported that the nonspecificity of the signs and the impossibility of performing transrectal palpation made it difficult to diagnose intestinal obstruction in calves without the use of other diagnostic tools. As it is a non-invasive and accurate technique, ultrasound has been used in ruminants for diagnostic purposes, including intestinal obstructions. In the present case, the main findings are described as the presence of a lesion with the appearance of multiple concentric rings, hypermotile, dilated, and full intestinal loops. The pathological findings were compatible with the ultrasound images and similar to those described by other authors, confirming the diagnosis. The use of ultrasonography as a diagnostic tool in cattle should be expanded, aiming at the early determination of diagnosis and prognosis, to reduce producer costs and animal discomfort. In cases of intussusception, late diagnosis makes treatment unfeasible.

scholarly journals Enhancing ultrasound texture differences for developing an in vivo 'virtual histology' approach to bovine ovarian imaging

2007 ◽  
Vol 19 (8) ◽  
pp. 910 ◽  
Author(s):  
Mark G. Eramian ◽  
Gregg P. Adams ◽  
Roger A. Pierson
Keyword(s):  
Image Processing ◽  
Ultrasound Image ◽  
Ultrasound Images ◽  
Virtual Histology ◽  
Form And Function ◽  
Non Invasive ◽  
Candidate Image ◽  
And Function ◽  
Processing Techniques

A ‘virtual histology’ can be thought of as the ‘staining’ of a digital ultrasound image via image processing techniques in order to enhance the visualisation of differences in the echotexture of different types of tissues. Several candidate image-processing algorithms for virtual histology using ultrasound images of the bovine ovary were studied. The candidate algorithms were evaluated qualitatively for the ability to enhance the visual differences in intra-ovarian structures and quantitatively, using standard texture description features, for the ability to increase statistical differences in the echotexture of different ovarian tissues. Certain algorithms were found to create textures that were representative of ovarian micro-anatomical structures that one would observe in actual histology. Quantitative analysis using standard texture description features showed that our algorithms increased the statistical differences in the echotexture of stroma regions and corpus luteum regions. This work represents a first step toward both a general algorithm for the virtual histology of ultrasound images and understanding dynamic changes in form and function of the ovary at the microscopic level in a safe, repeatable and non-invasive way.

Development of Ultrasound Imaging CAD Tool for Assessment of Pathologies in Supraspinatus Tendon

2017 ◽  
pp. 614-654
Author(s):  
Rishu Gupta ◽  
Irraivan Elamvazuthi ◽  
John George
Keyword(s):  
Supraspinatus Tendon ◽  
Ultrasound Images ◽  
Medical Work ◽  
Non Invasive ◽  
Computer Aided ◽  
Cad Tool ◽  
Intuitive User Interface ◽  
Aided Diagnosis ◽  
Shape And Size

Non-invasive diagnostic imaging methods for diagnosis of pathological conditions is increasingly gaining popularity resulting from speedy and effective recovery during follow up in several clinical trials. The accuracy of the diagnosis depends on the experience and knowledge of physicians conducting the trial. In such scenario, the need for quantitative measures for details such as shape and size of tissue can assist physicians for better intuitive understanding of tissue and its pathologies. Computer aided diagnosis (CAD) tool incorporating methods for segmentation, texture analysis and area computation can increase the accuracy of diagnosis by providing quantitative analysis of the image. This chapter briefly describes issues and challenges for building the CAD tool followed by brief description about the methods involved. The methods are validation are also discussed briefly. To summarize the work, brief discussion about a new software or CAD tool for diagnosis of pathologies supraspinatus tendon with the help of ultrasound images is provided. The new software has an intuitive user interface which is easy, quick and suitable for medical work.

Development and Application of LED Illumination Color PIV

2006 ◽  
Author(s):  
Shenq-Yuh Jaw ◽  
Robert R. Hwang ◽  
K. L. Shyu
Keyword(s):  
Turbulent Flows ◽  
Channel Flow ◽  
Particle Image ◽  
Time Derivative ◽  
Digital Camera ◽  
Soap Film ◽  
Velocity Fields ◽  
Flow Measurements ◽  
Full Field ◽  
Particle Images

In this study, red, green, and blue light-emitting diodes (LED) are adopted as the light source to illuminate sequentially a two-dimensional soap film channel flow. Triple-exposure particle image is recorded on the same image frame by a 3-ccd color camera. Since the particles illuminated by the R, G, B LED will only be recorded on the R, G, B ccd-chip of the digital camera, three sequential exposure, R, G, B particle images can be obtained from separating the triple-exposure particle image. Two sequential velocity fields can be determined from the correlation analysis of the R-G and G-B sequential particle images. Time derivative of the velocity fields, and hence the evolution of the unsteady flow or the characteristics of turbulent flows can be analyzed from the two velocity fields determined. The color PIV method incorporated with the LED light has proven to be a cheap, safe, and powerful tool for the full-field flow measurements. Results of the flow past circular cylinder in the confined soap film channel flow are presented.

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