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https://www.readbyqxmd.com/read/28742921/quantitative-model-of-diffuse-speckle-contrast-analysis-for-flow-measurement
#1
Jialin Liu, Hongchao Zhang, Jian Lu, Xiaowu Ni, Zhonghua Shen
No abstract text is available yet for this article.
July 1, 2017: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/28742142/effects-of-water-drinking-test-on-ocular-blood-flow-waveform-parameters-a-laser-speckle-flowgraphy-study
#2
Mehwish Saba Bhatti, Tong Boon Tang, Augustinus Laude
The water-drinking test (WDT) is a provocative test used in glaucoma research to assess the effects of elevated intraocular pressure (IOP). Defective autoregulation due to changes in perfusion pressure may play a role in the pathophysiology of several ocular diseases. This study aims to examine the effects of WDT on ocular blood flow (in the form of pulse waveform parameters obtained using laser speckle flowgraphy) to gain insight into the physiology of ocular blood flow and its autoregulation in healthy individuals...
2017: PloS One
https://www.readbyqxmd.com/read/28739084/the-repeatability-and-characteristics-of-right-ventricular-longitudinal-strain-imaging-by-speckle-tracking-echocardiography-in-healthy-dogs
#3
T Morita, K Nakamura, T Osuga, N Yokoyama, N Khoirun, K Morishita, N Sasaki, H Ohta, M Takiguchi
INTRODUCTION: To assess the repeatability and characteristics of echocardiographic indices of the right ventricular (RV) function derived from speckle-tracking echocardiography. ANIMALS: Fourteen laboratory Beagles and 103 privately owned dogs without cardiac disease were involved in this study. MATERIALS AND METHODS: Right ventricular longitudinal strain, strain rate, and a strain-related index for assessing RV dyssynchrony derived from speckle-tracking echocardiography were obtained by two different observers using five Beagles...
July 21, 2017: Journal of Veterinary Cardiology: the Official Journal of the European Society of Veterinary Cardiology
https://www.readbyqxmd.com/read/28736707/abnormal-atrial-strain-with-speckle-tracking-echocardiography-predicts-the-arrhythmic-substrate-of-atypical-right-atrial-flutter
#4
Hiroshi Kawakami, Takayuki Nagai, Katsuji Inoue, Jitsuo Higaki, Shuntaro Ikeda
No abstract text is available yet for this article.
May 2017: HeartRhythm Case Reports
https://www.readbyqxmd.com/read/28736682/standardized-approach-to-quantitatively-measure-residual-limb-skin-health-in-individuals-with-lower-limb-amputation
#5
Cameron L Rink, Matthew M Wernke, Heather M Powell, Mark Tornero, Surya C Gnyawali, Ryan M Schroeder, Jayne Y Kim, Jeffrey A Denune, Alexander W Albury, Gayle M Gordillo, James M Colvin, Chandan K Sen
Objective: (1) Develop a standardized approach to quantitatively measure residual limb skin health. (2) Report reference residual limb skin health values in people with transtibial and transfemoral amputation. Approach: Residual limb health outcomes in individuals with transtibial (n = 5) and transfemoral (n = 5) amputation were compared to able-limb controls (n = 4) using noninvasive imaging (hyperspectral imaging and laser speckle flowmetry) and probe-based approaches (laser doppler flowmetry, transcutaneous oxygen, transepidermal water loss, surface electrical capacitance)...
July 1, 2017: Advances in Wound Care
https://www.readbyqxmd.com/read/28736652/statistical-properties-of-dynamic-speckles-from-flowing-brownian-scatterers-in-the-vicinity-of-the-image-plane-in-optical-coherence-tomography
#6
Ivan Popov, Andrew Weatherbee, I Alex Vitkin
A closed-form analytical expression is obtained for the spatio-temporal correlation function of the scattered radiation detected in fiber-based optical coherence tomography (OCT), assuming a clean optical system arrangement in the OCT sample arm. It is shown that the transverse flow component causes purely translational speckle motion with the predicted speckle velocity 2x higher than the velocity of the flowing particles as would be observed in the image plane under incoherent illumination. It is also shown that both speckle velocity and speckle radius do not depend on the position of the scattering volume relative to the focal plane, hence the derived correlation function is independent of the position of the scattering volume relative to the focal plane...
April 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28735735/random-forest-based-bone-segmentation-in-ultrasound
#7
Nora Baka, Sieger Leenstra, Theo van Walsum
Ultrasound (US) imaging is a safe alternative to radiography for guidance during minimally invasive orthopedic procedures. However, ultrasound is challenging to interpret because of the relatively low signal-to-noise ratio and its inherent speckle pattern that decreases image quality. Here we describe a method for automatic bone segmentation in 2-D ultrasound images using a patch-based random forest classifier and several ultrasound specific features, such as shadowing. We illustrate that existing shadow features are not robust to changes in US acquisition parameters, and propose a novel robust shadow feature...
July 20, 2017: Ultrasound in Medicine & Biology
https://www.readbyqxmd.com/read/28733311/regional-septal-hinge-point-injury-contributes-to-adverse-biventricular-interactions-in-pulmonary-hypertension
#8
Eva Amalie Nielsen, Kenichi Okumura, Mei Sun, Vibeke E Hjortdal, Andrew N Redington, Mark K Friedberg
Death and morbidity in pulmonary arterial hypertension (PAH) are often due to right ventricular (RV) failure and associated left ventricular (LV) dysfunction. We investigated regional myocardial remodeling and function as the basis for adverse ventricular-ventricular interactions in experimental chronic RV pressure overload. Two distinct animal models were studied: A rabbit model of increased RV pressure-load through progressive pulmonary artery banding A rat model of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH)...
July 2017: Physiological Reports
https://www.readbyqxmd.com/read/28729551/change-in-choroidal-blood-flow-and-choroidal-morphology-due-to-segmental-scleral-buckling-in-eyes-with-rhegmatogenous-retinal-detachment
#9
Takeshi Iwase, Misato Kobayashi, Kentaro Yamamoto, Kosei Yanagida, Eimei Ra, Hiroko Terasaki
Although scleral buckling is a well-established surgical treatment for rhegmatogenous retinal detachment (RRD), the procedure can reportedly cause problems in the ocular circulation. Segmental scleral bucking without a concomitant encircling procedure was performed on 46 eyes with successfully reattached macula-on RRD. Choroidal blood flow was assessed using laser speckle flowgraphy. Spectral-domain optical coherence tomography was used to image macular regions, to measure the subfoveal choroidal thickness (SFCT), and to calculate the luminal and the stromal areas by the binarization method preoperatively and 1, 4, 8 and 12 weeks postoperatively...
July 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28728485/factors-associated-with-global-longitudinal-strain-decline-in-hypertensive-patients-with-normal-left-ventricular-ejection-fraction
#10
Nabila Soufi Taleb Bendiab, Abderrahim Meziane-Tani, Souhila Ouabdesselam, Nadera Methia, Samia Latreche, Latefa Henaoui, Jean-Jacques Monsuez, Salim Benkhedda
Background Early detection of risk factors for left ventricular (LV) dysfunction may be useful in patients with high blood pressure (HBP). Methods Patient from an outpatient HBP clinic underwent a two-dimensional Doppler-coupled echocardiography with determination of LV global longitudinal strain (GLS) by speckle-tracking. Results Among 200 patients (mean age 61.7 ± 9.7 years), 155 were overweight, 93 had diabetes, 83 had dyslipidemia, and 109 had uncontrolled HBP. LV hypertrophy (LVH) was found in 136 patients (68%), including concentric ( n = 106) and eccentric ( n = 30) LVH...
January 1, 2017: European Journal of Preventive Cardiology
https://www.readbyqxmd.com/read/28728481/feasibility-of-two-dimensional-speckle-tracking-in-evaluation-of-arterial-stiffness-comparison-with-pulse-wave-velocity-and-conventional-sonographic-markers-of-atherosclerosis
#11
Michał Podgórski, Piotr Grzelak, Magdalena Kaczmarska, Michał Polguj, Maciej Łukaszewski, Ludomir Stefańczyk
Objective Arterial stiffening is an early marker of atherosclerosis that has a prognostic value for cardiovascular morbidity and mortality. Although many markers of arterial hardening have been proposed, the search is on for newer, more user-friendly and reliable surrogates. One such potential candidate has emerged from cardiology, the speckle-tracking technique. The aim of this study was to evaluate the feasibility of the two-dimensional speckle tracking for the evaluation of arterial wall stiffness in comparison with standard stiffness parameters...
January 1, 2017: Vascular
https://www.readbyqxmd.com/read/28727745/evaluation-of-tissue-displacement-and-regional-strain-in-the-achilles-tendon-using-quantitative-high-frequency-ultrasound
#12
Stijn Bogaerts, Catarina De Brito Carvalho, Lennart Scheys, Kaat Desloovere, Jan D'hooge, Frederik Maes, Paul Suetens, Koen Peers
The Achilles tendon has a unique structure-function relationship thanks to its innate hierarchical architecture in combination with the rotational anatomy of the sub-tendons from the triceps surae muscles. Previous research has provided valuable insight in global Achilles tendon mechanics, but limitations with the technique used remain. Furthermore, given the global approach evaluating muscle-tendon junction to insertion, regional differences in tendon mechanical properties might be overlooked. However, recent advancements in the field of ultrasound imaging in combination with speckle tracking have made an intratendinous evaluation possible...
2017: PloS One
https://www.readbyqxmd.com/read/28724961/coherence-properties-of-different-light-sources-and-their-effect-on-the-image-sharpness-and-speckle-of-holographic-displays
#13
Yuanbo Deng, Daping Chu
Coherence properties of different light sources and how they affect the image quality of holographic display are investigated. Temporal coherence is related to the intrinsic spectrum bandwidth of the light source, while spatial coherence can be affected by the size of the light source and propagation distance in use. These two coherence properties are measured for various light sources of diode-pumped solid-state (DPSS) laser, laser diode (LD), light emitting diode (LED), super luminescent light emitting diode (sLED) and micro light emitting diode (mLED) in different settings, together with the quality of the holographic reconstructed images...
July 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28721692/left-ventricular-mechanics-are-affected-in-children-with-celiac-disease-a-study-based-on-two-dimensional-speckle-tracking-echocardiography
#14
Murat Deveci, Ayşen Uncuoğlu Aydoğan, Gürkan Altun, Özlem Kayabey, Okan Tuğral, Kadir Babaoğlu
BACKGROUND: An association between cardiomyopathy and celiac disease has been reported, but not frequently. We examined the effects on cardiac mechanics in children with celiac disease (CD) by two-dimensional speckle tracking echocardiography (2DSTE). METHODS: Eighty-one children with CD were compared with a control group comprising 51 healthy children by echocardiographic examination. Children with CD who had been on gluten-free diet for more than 6 months were divided into two different groups: group 1 was positive for serum antitissue transglutaminase antibody (n=48), and group 2 was negative for serum antitissue transglutaminase antibody (n=33)...
July 18, 2017: Echocardiography
https://www.readbyqxmd.com/read/28721356/targeted-ischemic-stroke-induction-and-mesoscopic-imaging-assessment-of-blood-flow-and-ischemic-depolarization-in-awake-mice
#15
Matilde Balbi, Matthieu P Vanni, Gergely Silasi, Yuki Sekino, Luis Bolanos, Jeffrey M LeDue, Timothy H Murphy
Despite advances in experimental stroke models, confounding factors such as anesthetics used during stroke induction remain. Furthermore, imaging of blood flow during stroke is not routinely done. We take advantage of in vivo bihemispheric transcranial windows for longitudinal mesoscopic imaging of cortical function to establish a protocol for focal ischemic stroke induction in target brain regions using photothrombosis in awake head-fixed mice. Our protocol does not require any surgical steps at the time of stroke induction or anesthetics during either head fixation or photoactivation...
July 2017: Neurophotonics
https://www.readbyqxmd.com/read/28717586/evaluating-platelet-aggregation-dynamics-from-laser-speckle-fluctuations
#16
Zeinab Hajjarian, Diane M Tshikudi, Seemantini K Nadkarni
Platelets are key to maintaining hemostasis and impaired platelet aggregation could lead to hemorrhage or thrombosis. We report a new approach that exploits laser speckle intensity fluctuations, emanated from a drop of platelet-rich-plasma (PRP), to profile aggregation. Speckle fluctuation rate is quantified by the speckle intensity autocorrelation, g2(t), from which the aggregate size is deduced. We first apply this approach to evaluate polystyrene bead aggregation, triggered by salt. Next, we assess dose-dependent platelet aggregation and inhibition in human PRP spiked with adenosine diphosphate and clopidogrel...
July 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28714523/echocardiographic-parameters-versus-cha2ds2-vasc-score-in-prediction-of-overall-cardiac-events-heart-failure-and-stroke-in-non-valvular-atrial-fibrillation
#17
Li-Tan Yang, Wei-Chuan Tsai, Ho-Ming Su
BACKGROUND: Apart from stroke, atrial fibrillation (AF) is associated with higher mortality and heart failure (HF), in which risk stratification scheme is lacking. Therefore this investigation examined the prognostic value of echocardiographic predictors against CHA₂DS₂-VASc score in permanent non-valvular AF (NVAF). METHOD: In 252 asymptomatic or mildly symptomatic consecutive patients with NVAF, comprehensive echocardiography was performed. Left atrial deformation parameters were also obtained by two-dimensional speckle tracking echocardiography...
July 17, 2017: Cardiology Journal
https://www.readbyqxmd.com/read/28712069/left-atrial-dysfunction-as-a-determinant-of-pulmonary-hypertension-in-patients-with-severe-aortic-stenosis-and-preserved-left-ventricular-ejection-fraction
#18
Andreea Calin, Anca D Mateescu, Monica Rosca, Carmen C Beladan, Roxana Enache, Simona Botezatu, Iulian Cosei, Cosmin Calin, Marian Simion, Carmen Ginghina, Andreea C Popescu, Bogdan A Popescu
In patients with severe aortic stenosis (AS), the presence of pulmonary hypertension (PH) has been linked to a poor prognosis. We aimed to assess the main determinants of PH in patients with severe AS and preserved left ventricular ejection fraction (LVEF). We prospectively enrolled 108 consecutive patients with isolated severe AS (indexed aortic valve area <0.6 cm(2)/m(2)) and LVEF >50%, in sinus rhythm. Left atrial (LA) function was assessed using longitudinal deformation parameters (by speckle tracking echocardiography)...
July 15, 2017: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/28701530/the-good-the-bad-and-the-ugly-of-using-left-ventricular-longitudinal-myocardial-deformation-by-speckle-tracking-echocardiography-to-assess-patients-after-an-acute-myocardial-infarction
#19
EDITORIAL
Luigi P Badano, Denisa Muraru
No abstract text is available yet for this article.
July 2017: Circulation. Cardiovascular Imaging
https://www.readbyqxmd.com/read/28701527/relationship-between-myocardial-function-body-mass-index-and-outcome-after-st-segment-elevation-myocardial-infarction
#20
Emer Joyce, Georgette E Hoogslag, Vasileios Kamperidis, Philippe Debonnaire, Spyridon Katsanos, Bart Mertens, Nina Ajmone Marsan, Jeroen J Bax, Victoria Delgado
BACKGROUND: Better survival for overweight and obese patients after ST-segment-elevation myocardial infarction (STEMI) has been demonstrated. The association between body mass index (BMI), outcome, and left ventricular (LV) structure and function after STEMI, including LV longitudinal strain (global longitudinal strain), was evaluated. METHODS AND RESULTS: First patients with STEMI undergoing primary percutaneous coronary intervention (n=1604; mean age, 61±12 years; 75% men) had BMI measured on admission, and 2-dimensional transthoracic echocardiography performed within 48 hours...
July 2017: Circulation. Cardiovascular Imaging
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