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1.
Acta sci. vet. (Impr.) ; 51(supl.1): Pub. 876, 2023. ilus
Article in English | VETINDEX | ID: biblio-1434879

ABSTRACT

Background: Caudal vena cava thrombosis (CVCT) is a serious disease that affects cattle. Due to being commonly a fatal pathology, it causes economic losses for producers and national livestock. Thus, the present study describes the epidemiological, clinical, ultrasonographic imaging and pathological findings in 4 cattle with CVCT attended at the Veterinary Hospital (HV) of the Institute of Veterinary Medicine (IMV) of the Federal University of Pará (UFPA). Cases: The animals were crossbreds of the Gir x Holstein and Jersey x Holstein breeds, aged between 4 and 8 years old, raised in semi-extensive and intensive systems. The main clinical signs were pale mucous membranes, reluctance to move, markedly positive venous pulse, engorged jugular with positive stasis test, and serous to mucopurulent nasal exudation. The auscultation of the lung fields revealed tachypnea, silent areas, wheezing, and pleural friction, in addition to coughing, expiratory dyspnea, mouth breathing, and expiratory grunts. One animal had severe hemoptysis. The ultrasound examination performed on a bovine revealed a circular and dilated caudal vena cava in cross-section. Laboratory tests in 3 cattle revealed anemia, leukocytosis with neutrophil left shift, and increased liver enzymes. At necropsy, all cattle had thrombi in the hepatic segment of the caudal vena cava. In the lung, multiple abscesses and areas of parenchymal consolidation, crateriform areas, as well as thrombi in the arteries were observed. Pleural effusion and ascites were seen in all cattle. Clotted blood was seen in the trachea, bronchi, and on rumen contents of an animal. Histopathological alterations seen in the liver were centrilobular hepatocytes with frequent intensely eosinophilic cytoplasm, and pyknotic, karyorrhexic, or absent nuclei and cell borders barely distinguishable. In the lung were nodular and random formations, with a thick wall of mature connective tissue and a central area full of cellular debris, necrotic cells, and intact and degenerated neutrophils (abscesses). Discussion: The set of diagnostic tools that include epidemiology, clinical signs and clinical examinations, ultrasound, necropsy, and histopathology were efficient in the diagnosis of CVCT. The possible causes that led the animals to develop CVCT were diffuse septic pododermatitis in the medial nail of the right pelvic limb associated with traumatic reticuloabomasitis and liver abscesses. In 1 cow, it was not possible to establish the probable cause of CVCT, but for the other cattle in the present study, the probable causes are in agreement with studies that have shown that this disease can occur as a sequel to several septic conditions such as jugular phlebitis, mastitis, hoof rot, enteritis, pneumonia, traumatic reticulopericarditis, acidosis and rumen laminitis, as well as omphalophlebitis in calves. The tachypnea, serous to purulent nasal exudation, pulmonary wheezing, pleural friction, coughing, and expiratory dyspnea, usually with open mouth breathing and expiratory grunts evidenced in the animals of this study, occurred as a result of embolic abscess pneumonia. The presence of multiple lung abscesses, areas of parenchymal consolidation, crateriform foci, and thrombi in the pulmonary arteries and chronic suppurative pneumonia, found at necropsy of the animals in the present study, are related to the development of a thrombus in the caudal vena cava that detaches and embolizes and lodges in the pulmonary arteries. The histopathological findings in 1 cow are compatible with lesions found at necropsy and draw attention to embolic pneumonia and liver lesions, which, are related to thrombi in pulmonary arteries and abscesses formed from CVCT, as well as venous stasis exerted in the return circulation.


Subject(s)
Animals , Cattle , Tail/pathology , Blood Vessels/diagnostic imaging , Venous Thrombosis/veterinary
2.
Rev. bras. reprod. anim ; 46(1): 17-27, Janeiro-Março 2022. tab
Article in Portuguese | VETINDEX | ID: biblio-1378025

ABSTRACT

O objetivo desta revisão foi descrever as principais técnicas de avaliação e achados ultrassonográficos da próstata canina. A ultrassonografia é o método de escolha para avaliação da glândula prostática, sendo imprescindível como auxílio no diagnóstico na detecção de anormalidades, principalmente quando há suspeita da presença de tumores. Com inovação dos equipamentos, surgiram técnicas complementares à ultrassonografia modo Bidimensional (B), tais como Doppler, ultrassonografia contrastada e elastografia, que aumentam a acurácia diagnóstica. O Doppler fornece informações sobre arquitetura vascular e aspectos hemodinâmicos dos vasos sanguíneos. A ultrassonografia contrastada permite determinar parâmetros relacionados à perfusão sanguínea das estruturas pelos agentes de contraste (ex.: microbolhas), definindo, portanto, padrões de alta e baixa intensidade da arquitetura vascular. A elastografia proporciona a avaliação da rigidez tecidual tanto de forma qualitativa, por meio de elastogramas, quanto quantitativa, por meio das velocidades de cisalhamento. Espera-se que esta revisão possa contribuir com informações relevantes aos leitores e veterinários da área de ultrassonografia e reprodução animal.(AU)


The purpose of this review was to describe the main assessment techniques and ultrasound findings of the canine prostate. Ultrasonography is the method of choice for assessing the prostate gland, being essential as an aid in the diagnosis in the detection of abnormalities, especially when the presence of tumors is suspected. With the innovation of the equipment, complementary techniques to B-mode ultrasonography have emerged, such as Doppler, contrasted ultrasound and elastography, which increase the diagnostic accuracy. Doppler provides information on vascular architecture and hemodynamic aspects of blood vessels. Contrast ultrasonography allows to determine parameters related to the blood perfusion of structures by contrast agents (eg, microbubbles), thus defining high and low intensity patterns of vascular architecture. ARFI elastography provides assessment of tissue stiffness both qualitatively, using elastograms, and quantitative, using shear speeds. It is hoped that this review can contribute with relevant information to readers and veterinarians in the area of asound and animal reproduction.(AU)


Subject(s)
Animals , Dogs , Prostate/diagnostic imaging , Prostatic Neoplasms/diagnostic imaging , Magnetic Resonance Imaging/methods , Ultrasonography, Doppler/methods , Diagnostic Equipment/veterinary , Elasticity Imaging Techniques/methods , Blood Vessels/diagnostic imaging , Contrast Media/adverse effects , Microbubbles/veterinary , Perfusion Imaging/veterinary , Vascular Stiffness/physiology
3.
Gac Med Mex ; 157(2): 160-166, 2021.
Article in English | MEDLINE | ID: mdl-34270531

ABSTRACT

INTRODUCTION: Different optical coherence tomography angiography (OCTA) scanning protocols evaluate the macula. OBJECTIVE: To compare the determination coefficients (R2) between vessel and perfusion densities of two OCTA scanning protocols in order to determine if their metrics could be interchanged. METHOD: Cross-sectional, prospective, comparative, observational, study between two OCTA scanning protocols (Angioplex, Zeiss) in healthy subjects. The R2 between central, inner, and full densities (3 x 3 mm protocol) and between central, inner, outer and full densities (6 x 6 mm protocol) was identified, both for vessel and perfusion densities. RESULTS: Seventy-eight eyes were evaluated; subjects' median age was 23 years. There were high R2 between inner and full densities with the 3 x 3 mm protocol (0.96), between outer and full densities with the 6 x 6 mm protocol (0.96), and between central vessel and perfusion densities (≥ 0.96); R2 between central vessel and perfusion densities of different protocols was ≤ 0.71. CONCLUSIONS: Vessel and perfusion densities have high determination coefficients within a scanning protocol, but not between protocols, given that each one preferentially measures different macular areas. Metrics from different protocols should not be interchanged for follow up.


INTRODUCCIÓN: Distintos protocolos de angiotomografía de coherencia óptica evalúan la mácula. OBJETIVO: R2 entre las densidades vascular y de perfusión de dos protocolos de angiotomografía de coherencia óptica, para determinar si sus mediciones podían intercambiarse. MÉTODO: Estudio observacional, comparativo, prospectivo, transversal entre dos protocolos de angiotomografía de coherencia óptica (AngioPlex, Zeiss) en sujetos sanos. Se identificó la R2 entre las densidades vascular y de perfusión central, interna y completa (protocolo de 3 x 3 mm), y central, interna, externa y completa (protocolo de 6 x 6 mm). RESULTADOS: 78 ojos, mediana de edad 23 años. Hubo R2 altas entre las densidades interna y completa del protocolo de 3 x 3 mm (0.96), externa y completa del de 6 x 6 mm (0.96), y centrales vasculares y de perfusión (≥ 0.96); la R2 entre las densidades centrales vascular y de perfusión de distintos protocolos fue ≤ 0.71. CONCLUSIONES: Las densidades vasculares y de perfusión tienen R2 alta dentro de un protocolo, pero no entre protocolos, porque estos miden preferentemente zonas distintas, lo cual limita intercambiar mediciones.


Subject(s)
Angiography/methods , Macula Lutea/blood supply , Tomography, Optical Coherence/methods , Adult , Blood Vessels/diagnostic imaging , Cross-Sectional Studies , Female , Healthy Volunteers , Humans , Macula Lutea/diagnostic imaging , Male , Prospective Studies , Regional Blood Flow/physiology , Statistics, Nonparametric , Visual Acuity , Young Adult
4.
Ultrasound Med Biol ; 47(6): 1506-1513, 2021 06.
Article in English | MEDLINE | ID: mdl-33812692

ABSTRACT

Ultrasound Core Laboratories (UCL) are used in multicenter trials to assess imaging biomarkers to define robust phenotypes, to reduce imaging variability and to allow blinded independent review with the purpose of optimizing endpoint measurement precision. The Household Air Pollution Intervention Network, a multicountry randomized controlled trial (Guatemala, Peru, India and Rwanda), evaluates the effects of reducing household air pollution on health outcomes. Field studies using portable ultrasound evaluate fetal, lung and vascular imaging endpoints. The objective of this report is to describe administrative methods and training of a centralized clinical research UCL. A comprehensive administrative protocol and training curriculum included standard operating procedures, didactics, practical scanning and written/practical assessments of general ultrasound principles and specific imaging protocols. After initial online training, 18 sonographers (three or four per country and five from the UCL) participated in a 2 wk on-site training program. Written and practical testing evaluated ultrasound topic knowledge and scanning skills, and surveys evaluated the overall course. The UCL developed comprehensive standard operating procedures for image acquisition with a portable ultrasound system, digital image upload to cloud-based storage, off-line analysis and quality control. Pre- and post-training tests showed significant improvements (fetal ultrasound: 71% ± 13% vs. 93% ± 7%, p < 0.0001; vascular lung ultrasound: 60% ± 8% vs. 84% ± 10%, p < 0.0001). Qualitative and quantitative feedback showed high satisfaction with training (mean, 4.9 ± 0.1; scale: 1 = worst, 5 = best). The UCL oversees all stages: training, standardization, performance monitoring, image quality control and consistency of measurements. Sonographers who failed to meet minimum allowable performance were identified for retraining. In conclusion, a UCL was established to ensure accurate and reproducible ultrasound measurements in clinical research. Standardized operating procedures and training are aimed at reducing variability and enhancing measurement precision from study sites, representing a model for use of portable digital ultrasound for multicenter field studies.


Subject(s)
Air Pollution, Indoor/prevention & control , Blood Vessels/diagnostic imaging , Computers, Handheld , Fetus/diagnostic imaging , Lung/diagnostic imaging , Female , Guatemala , Humans , India , Peru , Rwanda , Ultrasonics/education , Ultrasonography/instrumentation
5.
Gac. méd. Méx ; Gac. méd. Méx;157(2): 166-173, mar.-abr. 2021. tab, graf
Article in Spanish | LILACS | ID: biblio-1279097

ABSTRACT

Resumen Introducción: Distintos protocolos de angiotomografía de coherencia óptica evalúan la mácula. Objetivo: R2) entre las densidades vascular y de perfusión de dos protocolos de angiotomografía de coherencia óptica, para determinar si sus mediciones podían intercambiarse. Método: Estudio observacional, comparativo, prospectivo, transversal entre dos protocolos de angiotomografía de coherencia óptica (AngioPlex, Zeiss) en sujetos sanos. Se identificó la R2 entre las densidades vascular y de perfusión central, interna y completa (protocolo de 3 x 3 mm), y central, interna, externa y completa (protocolo de 6 x 6 mm). Resultados: 78 ojos, mediana de edad 23 años. Hubo R2 altas entre las densidades interna y completa del protocolo de 3 x 3 mm (0.96), externa y completa del de 6 x 6 mm (0.96), y centrales vasculares y de perfusión (≥ 0.96); la R2 entre las densidades centrales vascular y de perfusión de distintos protocolos fue ≤ 0.71. Conclusiones: Las densidades vasculares y de perfusión tienen R2 alta dentro de un protocolo, pero no entre protocolos, porque estos miden preferentemente zonas distintas, lo cual limita intercambiar mediciones.


Abstract Introduction: Different optical coherence tomography angiography (OCTA) scanning protocols evaluate the macula. Objective: To compare the determination coefficients (R2) between vessel and perfusion densities of two OCTA scanning protocols, to learn whether their metrics could be interchanged. Method: Non-experimental, comparative, prospective, observational, cross-sectional study, between two OCTA scanning protocols (Angioplex, Zeiss) in healthy subjects. We found the R2 between central, inner, and full densities (3 x 3 mm protocol), and between central, inner, outer and full densities (6 x 6 mm protocol), both for vessel and perfusion densities. Results: 78 eyes, median age 23 years. There were high R2 between inner and full densities in the 3 x 3 mm protocol (0.96), between outer and full densities in the 6 x 6 mm protocol (0.96) and between central vessel and perfusion densities (≥0.96); R2 between central vessel and perfusion densities of different protocols (≤0.71). Conclusions: Vessel and perfusion densities have high determination coefficients within a scanning protocol, but not between protocols, because each preferentially measures different macular areas. The metrics of different protocols should not be interchanged for follow-up.


Subject(s)
Humans , Male , Female , Adult , Young Adult , Angiography/methods , Tomography, Optical Coherence/methods , Macula Lutea/blood supply , Regional Blood Flow/physiology , Blood Vessels/diagnostic imaging , Visual Acuity , Cross-Sectional Studies , Prospective Studies , Statistics, Nonparametric , Healthy Volunteers , Macula Lutea/diagnostic imaging
6.
Biomed Phys Eng Express ; 6(3): 035019, 2020 04 21.
Article in English | MEDLINE | ID: mdl-33438664

ABSTRACT

Super-resolution ultrasound imaging relies on the sub-wavelength localization of microbubble contrast agents. By tracking individual microbubbles, the velocity and flow within microvessels can be estimated. It has been shown that the average flow velocity, within a microvessel ranging from tens to hundreds of microns in diameter, can be measured. However, a 2D super-resolution image can only localize bubbles with sub-wavelength resolution in the imaging plane whereas the resolution in the elevation plane is limited by conventional beamwidth physics. Since ultrasound imaging integrates echoes over the elevation dimension, velocity estimates at a single location in the imaging plane include information throughout the imaging slice thickness. This slice thickness is typically a few orders or magnitude larger than the super-resolution limit. It is shown here that in order to estimate the velocity, a spatial integration over the elevation direction must be considered. This operation yields a multiplicative correction factor that compensates for the elevation integration. A correlation-based velocity estimation technique is then presented. Calibrated microtube phantom experiments are used to validate the proposed velocity estimation method and the proposed elevation integration correction factor. It is shown that velocity measurements are in excellent agreement with theoretical predictions within the considered range of flow rates (10 to 90 µl/min) in a microtube with a diameter of 200 µm. Then, the proposed technique is applied to two in-vivo mouse tail experiments imaged with a low frequency human clinical transducer (ATL L7-4) with human clinical concentrations of microbubbles. In the first experiment, a vein was visible with a diameter of 140 µm and a peak flow velocity of 0.8 mm s-1. In the second experiment, a vein was observed in the super-resolved image with a diameter of 120 µm and with maximum local velocity of ≈4.4 mm s-1. It is shown that the parabolic flow profiles within these micro-vessels are resolvable.


Subject(s)
Blood Vessels/diagnostic imaging , Microbubbles , Microvessels/diagnostic imaging , Transducers , Ultrasonography/instrumentation , Ultrasonography/methods , Algorithms , Animals , Blood Flow Velocity , Calibration , Contrast Media , Equipment Design , Humans , Image Processing, Computer-Assisted , In Vitro Techniques , Mice , Microscopy/methods , Phantoms, Imaging , Reproducibility of Results , Signal Processing, Computer-Assisted
7.
J. vasc. bras ; 17(1): 19-25, jan.-mar. 2018. tab
Article in Portuguese | LILACS | ID: biblio-904885

ABSTRACT

Contexto: Diferenças morfológicas da artéria de Adamkiewicz (AKA) entre a população portadora e não portadora de doença aórtica têm importância clínica, influenciando as complicações neuroisquêmicas da medula espinhal em procedimentos operatórios. Ainda não é conhecida a correlação entre parâmetros clínicos e a previsibilidade da identificação dessa artéria pela angiotomografia. Objetivo: Desenvolver um modelo matemático que, através de parâmetros clínicos correlacionados com aterosclerose, possa prever a probabilidade de identificação da AKA em pacientes submetidos a angiotomografias. Método: Estudo observacional transversal utilizando banco de imagens e dados de pacientes. Foi feita análise estatística multivariada e criado modelo matemático logit de predição para identificação da AKA. Variáveis significativas foram utilizadas na montagem da fórmula para cálculo da probabilidade de identificação. O modelo foi calibrado, e a discriminação foi avaliada pela curva receiver operating characteristic (ROC). A seleção das variáveis explanatórias foi guiada pela maior área na curva ROC (p = 0,041) e pela significância combinada das variáveis. Resultados: Foram avaliados 110 casos (54,5% do sexo masculino, com idade média de 60,97 anos e etnia com coeficiente B -2,471, M -1,297, N -0,971), com AKA identificada em 60,9%. Índice de massa corporal: 27,06 ± 0,98 (coef. -0,101); fumantes: 55,5% (coef. -1,614/-1,439); diabéticos: 13,6%; hipertensos: 65,5% (coef. -1,469); dislipidêmicos: 58,2%; aneurisma aórtico: 38,2%; dissecção aórtica: 12,7%; e trombo mural: 24,5%. Constante de 6,262. Fórmula para cálculo da probabilidade de detecção: ( ) ( ) . . . . . tan 1 ( 1) Coef Etnia Coef IMC IMC Coef fumante Coef HAS Coe f dislip Cons te e − + ×+ + + + − + . O modelo de predição foi criado e disponibilizado no link https://vascular.pro/aka-model. Conclusão: Com as covariáveis etnia, índice de massa corporal, tabagismo, hipertensão arterial e dislipidemia, foi possível criar um modelo matemático de predição de identificação da AKA com significância combinada de nove coeficientes (p = 0,042)


Background: There are clinically important morphological differences in the Adamkiewicz artery (AKA) between populations that do and do not have aortic disease and they have an influence on the neuroischemic complications involving the spinal cord during surgical operations. It is not yet known whether clinical parameters correlate with the predictability of identification of the artery using angiotomography. Objective: To develop a mathematical model that by correlating clinical parameters with atherosclerosis enables prediction of the probability of identification of the AKA in patients examined with angiotomography. Method: This is a cross-sectional, observational study using a patient database and image bank. A multivariate statistical analysis was conducted and a logit mathematical model was constructed to predict AKA identification. Significant variables were used to build a formula for calculation of the probability of identification. This model was calibrated and its power of discrimination was assessed using receiver operating characteristic (ROC) curves. Selection of explanatory variables was based on largest area under the ROC curve (p = 0.041) and combined significance of variables. Results: A total of 110 cases were analyzed (54.5% were male, mean age was 60.97 years, and ethnicity coefficients were white -2.471, brown -1.297, and black -0.971) and the AKA was identified in 60.9%. Body mass index: 27.06 ± 0.98 (coef. -0.101); smokers: 55.5% (coef. -1.614/-1.439); diabetes: 13.6%; hypertension: 65.5% (coef. -1.469); dyslipidemia: 58.2%; aortic aneurysm: 38.2%; aortic dissection: 12.7%; and mural thrombus: 24.5%. The constant was 6.262. The formula for calculating the probability of detection is as follows: ( ) ( ) . . . ker . . tan 1 ( 1) Coef Etnicity Coef BMI BMI Coef smo Coef SAH Coef dyslip Cons t e − + ×+ + + + − + . The prediction model was constructed and made available at: https://vascular.pro/aka-model. Conclusions: Using the covariates ethnicity, body mass index, smoking, arterial hypertension, and dyslipidemia, it proved possible to create a mathematical model for predicting identification of the AKA with a combined significance of nine coefficients (p = 0.042)


Subject(s)
Humans , Male , Female , Middle Aged , Aorta , Aortic Diseases/therapy , Aortic Diseases/diagnostic imaging , Spinal Cord , Blood Vessels/diagnostic imaging , Cross-Sectional Studies , Aortic Aneurysm , Tobacco Use Disorder , Body Mass Index , Multivariate Analysis , Risk Factors , Metabolic Syndrome , Diabetes Mellitus , Equipment and Supplies , Dyslipidemias , Hypertension
8.
J. vasc. bras ; 17(1): f:81-l:88, jan.-mar. 2018. ilus
Article in Portuguese | LILACS | ID: biblio-905078

ABSTRACT

Nos últimos anos, balões farmacológicos surgiram como promissora alternativa terapêutica em intervenções endovasculares. Com essa tecnologia, transferem-se drogas antiproliferativas à parede arterial, sem a necessidade de implante metálico para liberação. Descreve-se o caso de um paciente com uma segunda recidiva de reestenose intra-stent renal tratada por angioplastia com balão coberto por droga, com boa evolução clínica caracterizada por adequado controle pressórico e redução de classes e dosagem dos anti-hipertensivos. Os resultados obtidos com balões farmacológicos em outros territórios e esta experiência isolada podem contribuir como sugestão para o uso desses dispositivos na reestenose intra-stent renal, com resultados iniciais satisfatórios


During recent years, drug-coated balloons (DCBs) have emerged as a promising therapeutic option. DCBs directly transfer antiproliferative drugs to the arterial wall in order to decrease myointimal hyperplasia. We describe a case of de novo renal artery in-stent restenosis (ISR) treated with drug-coated balloon angioplasty with acceptable short-term results, achieving blood pressure control using fewer antihypertensive agents. The experience and results obtained with DCBs in other territories could suggest and justify use of this technology in renal artery ISR


Subject(s)
Humans , Male , Middle Aged , Angioplasty, Balloon/methods , Renal Artery/diagnostic imaging , Stents , Angiography/methods , Aorta, Abdominal , Blood Vessels/diagnostic imaging , Catheterization/methods , Endovascular Procedures/methods
9.
Article in English | MEDLINE | ID: mdl-28884520

ABSTRACT

The relative pressure difference across stenotic blood vessels serves as an important clinical index for the diagnosis of many cardiovascular diseases. While the clinical gold standard for relative pressure difference measurements is invasive catheterization, Phase-Contrast Magnetic Resonance Imaging has emerged as a promising tool for enabling a noninvasive quantification, by linking highly spatially resolved velocity measurements with relative pressures via the incompressible Navier-Stokes equations. In this work, we provide a review and analysis of current methods for relative pressure estimation and propose 3 additional techniques. Methods are compared using synthetic data from numerical examples, and sensitivity to subsampling and noise was explored. Through our analysis, we verify that the newly proposed approaches are more robust with respect to spatial subsampling and less sensitive to noise and therefore provide improved means for estimating relative pressure differences noninvasively.


Subject(s)
Blood Flow Velocity/physiology , Blood Pressure/physiology , Models, Theoretical , Blood Vessels/diagnostic imaging , Humans , Magnetic Resonance Imaging
10.
J Ultrasound Med ; 37(1): 255-261, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28736982

ABSTRACT

OBJECTIVES: Although power Doppler imaging has been used to quantify tissue and organ vascularity, many studies showed that limitations in defining adequate ultrasound machine settings and attenuation make such measurements complex to be achieved. However, most of these studies were conducted by using the output of proprietary software, such as Virtual Organ computer-aided analysis (GE Healthcare, Kretz, Zipf, Austria); therefore, many conclusions may not be generalizable because of unknown settings and parameters used by the software. To overcome this limitation, our goal was to evaluate the impact of the flow velocity, pulse repetition frequency (PRF), and wall motion filter (WMF) on power Doppler image quantification using beam-formed ultrasonic radiofrequency data. METHODS: The setup consisted of a blood-mimicking fluid flowing through a phantom. Radiofrequency signals were collected using PRFs ranging from 0.6 to 10 kHz for 6 different flow velocities (5-40 cm/s). Wall motion filter cutoff frequencies were varied between 50 and 250 Hz. RESULTS: The power Doppler magnitude was deeply influenced by the WMF cutoff frequency. The effect of using different WMF values varied with the PRF; therefore, the power Doppler signal intensity was dependent on the PRF. Finally, we verified that power Doppler quantification can be affected by the aliasing effect, especially when using a PRF lower than 1.3 kHz. CONCLUSIONS: The WMF and PRF greatly influenced power Doppler quantification, mainly when flow velocities lower than 20 cm/s were used. Although the experiments were conducted in a nonclinical environment, the evaluated parameters are equivalent to those used in clinical practice, which makes them valuable for aiding the interpretation of related data in future research.


Subject(s)
Blood Flow Velocity , Blood Vessels/diagnostic imaging , Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Ultrasonography, Doppler/methods , Models, Biological , Motion , Phantoms, Imaging , Reproducibility of Results
11.
J Biomed Opt ; 22(6): 66004, 2017 06 01.
Article in English | MEDLINE | ID: mdl-28604934

ABSTRACT

Visualization of deep blood vessels in speckle images is an important task as it is used to analyze the dynamics of the blood flow and the health status of biological tissue. Laser speckle imaging is a wide-field optical technique to measure relative blood flow speed based on the local speckle contrast analysis. However, it has been reported that this technique is limited to certain deep blood vessels (about ? = 300 ?? ? m ) because of the high scattering of the sample; beyond this depth, the quality of the vessel's image decreases. The use of a representation based on homogeneity values, computed from the co-occurrence matrix, is proposed as it provides an improved vessel definition and its corresponding diameter. Moreover, a methodology is proposed for automatic blood vessel location based on the kurtosis analysis. Results were obtained from the different skin phantoms, showing that it is possible to identify the vessel region for different morphologies, even up to 900 ?? ? m in depth.


Subject(s)
Blood Vessels/diagnostic imaging , Optical Imaging , Skin/blood supply , Lasers , Phantoms, Imaging , Skin/diagnostic imaging
12.
Sensors (Basel) ; 16(4)2016 Apr 08.
Article in English | MEDLINE | ID: mdl-27070610

ABSTRACT

In this paper, a method of vascular structure identification in intraoperative 3D Contrast-Enhanced Ultrasound (CEUS) data is presented. Ultrasound imaging is commonly used in brain tumor surgery to investigate in real time the current status of cerebral structures. The use of an ultrasound contrast agent enables to highlight tumor tissue, but also surrounding blood vessels. However, these structures can be used as landmarks to estimate and correct the brain shift. This work proposes an alternative method for extracting small vascular segments close to the tumor as landmark. The patient image dataset involved in brain tumor operations includes preoperative contrast T1MR (cT1MR) data and 3D intraoperative contrast enhanced ultrasound data acquired before (3D-iCEUS(start) and after (3D-iCEUS(end) tumor resection. Based on rigid registration techniques, a preselected vascular segment in cT1MR is searched in 3D-iCEUS(start) and 3D-iCEUS(end) data. The method was validated by using three similarity measures (Normalized Gradient Field, Normalized Mutual Information and Normalized Cross Correlation). Tests were performed on data obtained from ten patients overcoming a brain tumor operation and it succeeded in nine cases. Despite the small size of the vascular structures, the artifacts in the ultrasound images and the brain tissue deformations, blood vessels were successfully identified.


Subject(s)
Blood Vessels/diagnostic imaging , Brain Neoplasms/diagnostic imaging , Image Processing, Computer-Assisted , Monitoring, Intraoperative , Ultrasonography/methods , Blood Vessels/physiopathology , Blood Vessels/ultrastructure , Brain/diagnostic imaging , Brain/physiopathology , Brain/surgery , Brain/ultrastructure , Brain Neoplasms/physiopathology , Brain Neoplasms/surgery , Contrast Media/administration & dosage , Humans , Imaging, Three-Dimensional/methods , Models, Theoretical , Neurosurgical Procedures
13.
Rev Col Bras Cir ; 42(3): 138-42, 2015 Jun.
Article in English, Portuguese | MEDLINE | ID: mdl-26291252

ABSTRACT

OBJECTIVE: to determine the accuracy of Doppler ultrasonography (USD) for hemodialysis arteriovenous fistula (AVF) maturity. METHODS: we included patients with no prior AVF. Each patient underwent two USD examinations. After initiation of hemodialysis, we followed the patients during the first month of the access use and verified its adequacy to hemodialysis sessions. At statistical analysis we measured specificity, sensitivity, accuracy, ROC curve (Receiver operator characteristic) curve, TG-ROC (Two graph - receiver operator characteristic) and logistic regression. RESULTS: we included 76 patients, of which 51 completed the study. They formed two groups, those who have had good adequacy for hemodialysis (45) and those who had not (6). The average flow volume (FV) and the average draining vein diameter (DVD) of each group were, respectively: 940mL/min (95% CI: 829-1052) and 325mL/min (95% CI: 140-510); and 0.48cm (95% CI: 0.45-0.52) and 0.33cm (95% CI: 0.27-0.40). The area under the ROC curve of FV and DVD were 0.926 and 0.766, respectively. CONCLUSION: the accuracy of the measured volume flow measured at the draining vein to evaluate maturation of hemodialysis arteriovenous fistula was 85%.


Subject(s)
Arteriovenous Shunt, Surgical , Renal Dialysis , Ultrasonography, Doppler , Blood Vessels/diagnostic imaging , Female , Humans , Male , Prospective Studies , Reproducibility of Results
14.
Ann Hepatol ; 10(4): 559-61, 2011.
Article in English | MEDLINE | ID: mdl-21911899

ABSTRACT

Hepatic sinusoidal dilatation (HSD) is pathological entity that is characterized by peliosis hepatis (PH) like lesions, with vascular lesions that consist of multiple cyst-like, blood-filled cavities within the liver. To the best of our knowledge, neither PH nor HSD have been associated with systemic vasculitis. We describe herein two cases of idiopathic HSD associated with Takayasu arteritis (TA), diagnosed at an early stage of vasculitis. The same endothelial target in HSD and TA, and the favorable outcome of HSD with treatment of TA, suggest a pathogenic link between the two diseases.


Subject(s)
Liver Diseases/etiology , Liver/blood supply , Takayasu Arteritis/diagnosis , Adolescent , Biopsy , Blood Vessels/diagnostic imaging , Blood Vessels/pathology , Dilatation, Pathologic , Female , Humans , Liver Diseases/drug therapy , Liver Diseases/pathology , Steroids/therapeutic use , Takayasu Arteritis/complications , Takayasu Arteritis/drug therapy , Treatment Outcome , Ultrasonography, Doppler, Color , Young Adult
15.
J Pediatr Surg ; 45(1): E9-12, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20105573

ABSTRACT

Polypoid arteriovenous malformations, which are localized in the colon, are extremely rare in adults, with only 7 cases published to date. Here we present the case of a 6-year-old girl with a jejunal polypoid tumor that a sonogram and a computed tomographic scan have shown to resemble intussusception. Histologically, numerous large ectatic veins intermixed with small-caliber arteries, venules, arterioles, and capillaries were observed in the intestinal wall. A retrospective computed tomographic scan 3-dimensional angiographic reconstruction demonstrated that this may be a diagnostic characteristic. Clinical and morphologic comparisons with previously reported cases were discussed.


Subject(s)
Arteriovenous Malformations/diagnosis , Blood Vessels/abnormalities , Intestinal Polyps/diagnosis , Intussusception/diagnosis , Jejunal Diseases/diagnosis , Jejunum/blood supply , Arteriovenous Malformations/pathology , Arteriovenous Malformations/surgery , Blood Vessels/diagnostic imaging , Child , Diagnosis, Differential , Female , Humans , Intestinal Polyps/pathology , Intestinal Polyps/surgery , Intussusception/etiology , Intussusception/surgery , Jejunal Diseases/etiology , Jejunal Diseases/surgery , Jejunum/pathology , Jejunum/surgery , Retrospective Studies , Tomography, X-Ray Computed , Ultrasonography , Vascular Surgical Procedures
16.
Rev Bras Ginecol Obstet ; 31(10): 513-26, 2009 Oct.
Article in Portuguese | MEDLINE | ID: mdl-19943000

ABSTRACT

The present context of medical practice demands from the obstetrician and gynecologist broad understanding of the scientific and technological advances of the area. The main purpose of prenatal evaluation is to identify fetuses at risk for adverse events or death, for preventive action to avoid mishappenings. The determination of fetal biophysical profile reaches its maximum efficiency when applied within the clinical context of each case. In high risk gestations, the Doppler velocimetry of the umbilical artery has shown to be useful to improve perinatal outcome. In the fetal growth deficit, due to severe placentary insufficiency, Doppler velocimetry of the venous duct has been showing to be an important tool in handling of the cases before the 34th week of gestation. Although no test itself is considered the best to evaluate the fetus's prenatal vitality, the joint analysis of all methods may lead to a better understanding of the fetal response to hypoxia.


Subject(s)
Fetal Monitoring , Blood Vessels/diagnostic imaging , Cardiotocography/methods , Female , Fetal Monitoring/methods , Humans , Pregnancy , Ultrasonography, Doppler , Ultrasonography, Prenatal/methods
17.
Eur J Obstet Gynecol Reprod Biol ; 133(2): 213-7, 2007 Aug.
Article in English | MEDLINE | ID: mdl-16895744

ABSTRACT

OBJECTIVES: The objective was to evaluate the cross-sectional area (CSA) and the Doppler velocimetric parameters of the levator ani muscle vessels in premenopausal women with and without urinary stress incontinence. STUDY DESIGN: Sixty-three premenopausal women constituted three groups: GI (nulliparous), GII (continent multiparous), and GIII (incontinent multiparous). The patients had undergone transperineal ultrasound in which the CSA was measured and Doppler velocimetry was performed. The examination was repeated by a second observer using the same procedure. RESULTS: There was a statistically significant correlation between the measurements of the observers I and II regarding all the parameters studied, except for the A/B ratio in GIII. The CSA was significantly greater in GI and GII than in GIII. As far as Doppler velocimetry is concerned there were no differences in the Doppler velocimetric indices among the three groups. Concerning the absent end diastolic shift, it was observed that there was a significantly greater incidence of such findings in GI+GII (continent women) towards GIII (incontinent women). CONCLUSIONS: The CSA evaluation and the Doppler velocimetry of the levator ani muscle vessels were highly reproducible. The CSA was higher in continent women and the frequency of the absent end diastolic shift was higher in incontinent women.


Subject(s)
Anal Canal/physiopathology , Muscle Contraction , Muscle, Skeletal/blood supply , Muscle, Skeletal/physiopathology , Urinary Incontinence, Stress/etiology , Adolescent , Adult , Anal Canal/diagnostic imaging , Blood Vessels/diagnostic imaging , Blood Vessels/physiopathology , Doppler Effect , Female , Humans , Middle Aged , Muscle, Skeletal/diagnostic imaging , Premenopause , Rheology/methods , Ultrasonography
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