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Sayasneh, Ahmad. "Ultrasound scan characterisation of ovarian masses." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/34343.
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Background: Different ultrasound based models, rules and descriptors are used to characterise ovarian masses. LR2 is a logistic regression model with six variables to assess the preoperative risk of ovarian malignancy. Simple rules (SR) are ten features of an adnexal mass that may be identified using ultrasonography. Simple descriptors (SD) are five ultrasound characteristics and one based on age and serum CA 125 that enable an intuitive classification of adnexal masses. Objectives: The main aim was to assess the performance of the conventional (Risk of Malignancy Index RMI) and the IOTA (International Ovarian Tumour Analysis Group) models (LR2, SR and SD) and subjective assessment (SA) by examiners of varied ultrasound training and experience (level II). Methods: We carried out a prospective single-blinded randomised controlled trial (IOTA 4a) to investigate the referral pattern following the use of RMI and LR2. In IOTA 4b, diagnostic performance measures for LR2, RMI, SR, SD and SA were compared in a three-year multicentre prospective observational study. A prospective comparison was also carried out between LR2 and ROMA (Risk of Ovarian Malignancy Algorithm). Results: In the IOTA 4a RCT, LR2 correctly classified 100% of benign masses as low risk compared to 70% for RMI (difference of 30%. p < 0.0001). In IOTA 4b study, a higher AUC for LR2 compared to RMI was observed in premenopausal women (0.93 and 0.83 respectively. p=0.05). Overall the combination of SD and SR were able to characterise 89% of masses (DOR of 348). Subjective assessment by level II ultrasound examiners had a DOR of 85.56. In relation to ROMA, the AUC of LR2 for discriminating between benign and malignant adnexal masses (0.952) was higher than that of ROMA (0.893) (p=0.0004). Conclusion: The overall test performance of IOTA LR2, SR and SD was maintained in the hands of examiners with varying levels of training and experience. This performance was generally better than the RMI. LR2 showed a better diagnostic performance than ROMA.
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Liu, Li. "An Affordable Portable Obstetric Ultrasound Simulator for Synchronous and Asynchronous Scan Training." Digital WPI, 2016. https://digitalcommons.wpi.edu/etd-dissertations/444.
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The increasing use of Point of Care (POC) ultrasound presents a challenge in providing efficient training to new POC ultrasound users. In response to this need, we have developed an affordable, compact, laptop-based obstetric ultrasound training simulator. It offers freehand ultrasound scan on an abdomen-sized scan surface with a 5 degrees of freedom sham transducer and utilizes 3D ultrasound image volumes as training material. On the simulator user interface is rendered a virtual torso, whose body surface models the abdomen of a particular pregnant scan subject. A virtual transducer scans the virtual torso, by following the sham transducer movements on the scan surface. The obstetric ultrasound training is self-paced and guided by the simulator using a set of tasks, which are focused on three broad areas, referred to as modules: 1) medical ultrasound basics, 2) orientation to obstetric space, and 3) fetal biometry. A learner completes the scan training through the following three steps: (i) watching demonstration videos, (ii) practicing scan skills by sequentially completing the tasks in Modules 2 and 3, with scan evaluation feedback and help functions available, and (iii) a final scan exercise on new image volumes for assessing the acquired competency. After each training task has been completed, the simulator evaluates whether the task has been carried out correctly or not, by comparing anatomical landmarks identified and/or measured by the learner to reference landmark bounds created by algorithms, or pre-inserted by experienced sonographers. Based on the simulator, an ultrasound E-training system has been developed for the medical practitioners for whom ultrasound training is not accessible at local level. The system, composed of a dedicated server and multiple networked simulators, provides synchronous and asynchronous training modes, and is able to operate with a very low bit rate. The synchronous (or group-learning) mode allows all training participants to observe the same 2D image in real-time, such as a demonstration by an instructor or scan ability of a chosen learner. The synchronization of 2D images on the different simulators is achieved by directly transmitting the position and orientation of the sham transducer, rather than the ultrasound image, and results in a system performance independent of network bandwidth. The asynchronous (or self-learning) mode is described in the previous paragraph. However, the E-training system allows all training participants to stay networked to communicate with each other via text channel. To verify the simulator performance and training efficacy, we conducted several performance experiments and clinical evaluations. The performance experiment results indicated that the simulator was able to generate greater than 30 2D ultrasound images per second with acceptable image quality on medium-priced computers. In our initial experiment investigating the simulator training capability and feasibility, three experienced sonographers individually scanned two image volumes on the simulator. They agreed that the simulated images and the scan experience were adequately realistic for ultrasound training; the training procedure followed standard obstetric ultrasound protocol. They further noted that the simulator had the potential for becoming a good supplemental training tool for medical students and resident doctors. A clinic study investigating the simulator training efficacy was integrated into the clerkship program of the Department of Obstetrics and Gynecology, University of Massachusetts Memorial Medical Center. A total of 24 3rd year medical students were recruited and each of them was directed to scan six image volumes on the simulator in two 2.5-hour sessions. The study results showed that the successful scan times for the training tasks significantly decreased as the training progressed. A post-training survey answered by the students found that they considered the simulator-based training useful and suitable for medical students and resident doctors. The experiment to validate the performance of the E-training system showed that the average transmission bit rate was approximately 3-4 kB/s; the data loss was less than 1% and no loss of 2D images was visually detected. The results also showed that the 2D images on all networked simulators could be considered to be synchronous even though inter-continental communication existed.
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Adeniyi, Olanrewaju Ari. "FUSION OF ULTRASONIC C-SCAN DATA WITH FINITE ELEMENT ANALYSIS." OpenSIUC, 2012. https://opensiuc.lib.siu.edu/theses/909.
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AN ABSTRACT OF THE THESIS OF Olanrewaju Ari Adeniyi for the Master of Science degree in Mechanical Engineering and Energy Processes presented June 2012, at Southern Illinois University Carbondale Title: FUSION OF ULTRASONIC C-SCAN DATA WITH FINITE ELEMENT ANALYSIS Major Professor: Dr. Tsuchin Philip Chu Ultrasonic testing is a highly valued method in the field of Non-destructive testing (NDT). It is an engineering tool that allows for non-invasive testing and evaluation. It is used widely in the aerospace industry to determine the integrity of complex materials without the use of destructive measures. This method of testing can be utilized to provide multitude of parameters such as material properties and thicknesses. It can also be used to test for discrepancies in test specimen such as voids, impurities, delamination and other defects that could degrade the integrity of a structure. The problem is that this method is limited in the area of evaluation of end results. Results are generated in the form of data images and are evaluated for quality or quantitative image assessment. Simulation models are created from an image, which causes low accuracy of analysis. The integration of Ultrasonic C-scan data with Finite Element Analysis (FEA) addresses these issues. It allows for models to be generated from Ultrasonic C-scan data, which provides the means to conduct accurate FEA simulations. The fusion of Ultrasonic C-scan data with computational methods, such as FEA, allows tested materials to be subjected to loading conditions that may be experienced in actual use. The results from FEA analysis can provide localized stress and strain fields generated from the loading conditions. The success of this analysis relies on the ability to generate high quality C-scan data to create accurate CAD data models. The generation of high quality scans will produce vital analysis information such as material properties, thickness, voids, surface inclusions and other critical deformities, all which will be used to generate a CAD analysis. With the ultrasonic data generated, finite element analysis can be utilized to further evaluate tested specimen. This technique has been applied to an isotropic aluminum block standard and an anisotropic Carbon Fiber Reinforced Polymer sample, both with known defects.
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Perrey, Christian. "Signal processing concepts for the assessment of coronary plaques with intravascular ultrasound." Berlin Logos-Verl, 2005. http://deposit.ddb.de/cgi-bin/dokserv?id=2800326&prov=M&dok_var=1&dok_ext=htm.
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Postma, Ignatius. "The HI-MAP scan : the use of emergency ultrasound to evaluate haemodynamically unstable patients." Master's thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/2870.
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Furlan, John Michael. "Particle Concentration Measurements in a Centrifugal Slurry Pump Using an A-Scan Ultrasound Technique." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1301325325.
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Lynn, F. A. "The value of a third trimester ultrasound scan in low-risk pregnancy; a discrete choice approach." Thesis, Queen's University Belfast, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.517102.
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Bevan, Peter D. "Feasibility of B-scan ultrasound attenuation mapping to monitor tissue coagulation due to high-temperature thermal therapy." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ58833.pdf.
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Lin, Win-Li. "Scan parameter optimization and a temperature controller for scanned focussed ultrasound hyperthermia: A theoretical and experimental study." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185181.
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Maintenance of the treatment temperatures at their target levels in the face of disturbances, a uniform temperature distribution within the treatment region, an acceptable temperature rise outside that volume, a fast temperature rise, and stability are desirable characteristics of an optimal hyperthermia treatment control system. Since scanned, focussed ultrasound systems (SFUS) have a great deal of flexibility it is necessary to use such a feedback system in shaping the power field during hyperthermia treatments. For best use of such a system many complicated, interacting decisions must be made to obtain an optimal hyperthermia treatment. This dissertation studies this optimization problem using a simulation program which searches for the optimal scan parameters, and presents a PID plus bang-bang feedback control system which gives a suitable power distribution to meet the above requirements for this hyperthermia system. Several objective functions were studied and compared based on temperature criteria. An extensive objective function study has been done in order to determine; the best formulation for that objection function, the characteristics of that objective function near the optimal operating point, the effects of the scan parameters on that objective function, and the domain of acceptable initial guess points for obtaining a globally optimal solution. A further comprehensive study of the optimal temperature distributions attainable with single and multiple circular scans of a tumor was done. The results show that the optimal scan parameter configuration will allow this SFUS to produce a close to ideal treatment temperature distribution for a wide variety of clinically relevant conditions. To further study the variation of the temporal and spatial blood perfusion, a controller was used to obtain a more suitable power to meet the treatment needs. Both the simulation results and experimental animal results show that the controlled region can be rapidly heated to the target temperature with a small overshoot and maintained at that level in the face of disturbances. In vitro dog kidney model and in vivo dog thigh experiments show that the controller works well in practice, and verify that it can compensate for spatial and temporal blood perfusion variations. As shown in both these experiments and in simulations, the controller can be used for controlling a single temperature or multiple temperature points simultaneously, thus allowing relatively uniform temperature fields to be created.
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Hillman, Sarah Christine. "The use of prenatal chromosomal microarrays when performed for a fetus with structural abnormalities on ultrasound scan." Thesis, University of Birmingham, 2014. http://etheses.bham.ac.uk//id/eprint/4762/.
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Fetal chromosomes are examined conventionally by G-band karyotyping. More recently Prenatal Chromosomal Microarray (CMA) has been used to look for fetal chromosomal abnormalities. Advantages of CMA include its higher detection rate. Disadvantages include its detection of Variants of Unknown Significance (VOUS). I recruited a prospective cohort of 243 women with structural abnormalities on fetal ultrasound scan. A 1Mb targeted BAC array was performed in addition to G-band karyotyping. In 62 cases from this cohort an additional higher resolution 60K oligonucleotide array was used. A health economic analysis, by use of a decision tree, was performed. Finally qualitative work determined women’s feelings about testing. The 1Mb BAC cohort found a 4.1% increase in fetal chromosomal abnormalities over karyotyping, with a low detection rate of VOUS (0.4%). The 60K sub-cohort noted an extra 4.8% pathogenic chromosomal anomalies but, in addition, a 13% increase in VOUS. The health economic analysis indicated that when CMA is £360 (per test) and the Willingness To Pay (WTP) for a “positive diagnosis” is £9768; then CMA is cost effective over karyotyping. Qualitative analysis showed that couples were keen for as much information as possible. They struggled to recall and retain information conveyed at the time of the testing.
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Navarrete, Hurtado Hugo Ariel. "Electromagnetic models for ultrasound image processing." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/398235.
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Speckle noise appears when coherent illumination is employed, as for example Laser, Synthetic Aperture Radar (SAR), Sonar, Magnetic Resonance, X-ray and Ultrasound imagery. Backscattered echoes from the randomly distributed scatterers in the microscopic structure of the medium are the origin of speckle phenomenon, which characterizes coherent imaging with a granular appearance. It can be shown that speckle noise is of multiplicative nature, strongly correlated and more importantly, with non-Gaussian statistics. These characteristics differ greatly from the traditional assumption of white additive Gaussian noise, often taken in image segmentation, filtering, and in general, image processing; which leads to reduction of the methods effectiveness for final image information extraction; therefore, this kind of noise severely impairs human and machine ability to image interpretation.
Statistical modeling is of particular relevance when dealing with speckled data in order to obtain efficient image processing algorithms; but, additionally, clinical ultrasound imaging systems employ nonlinear signal processing to reduce the dynamic range of the input echo signal to match the smaller dynamic range of the display device and to emphasize objects with weak backscatter. This reduction in dynamic range is normally achieved through a logarithmic amplifier i.e. logarithmic compression, which selectively compresses large input signals. This kind of nonlinear compression totally changes the statistics of the input envelope signal; and, a closed form expression for the density function of the logarithmic transformed data is usually hard to derive.
This thesis is concerned with the statistical distributions of the Log-compressed amplitude signal in coherent imagery, and its main objective is to develop a general statistical model for log-compressed ultrasound B-scan images. The developed model is adapted, making the pertinent physical analogies, from the multiplicative model in Synthetic Aperture Radar (SAR) context. It is shown that the proposed model can successfully describe log-compressed data generated from different models proposed in the specialized ultrasound image processing literature. Also, the model is successfully applied to model in-vivo echo-cardiographic (ultrasound) B-scan images. Necessary theorems are established to account for a rigorous mathematical proof of the validity and generality of the model. Additionally, a physical interpretation of the parameters is given, and the connections between the generalized central limit theorems, the multiplicative model and the compound representations approaches for the different models proposed up-to-date, are established. It is shown that the log-amplifier parameters are included as model parameters and all the model parameters are estimated using moments and maximum likelihood methods. Finally, three applications are developed: speckle noise identification and filtering; segmentation of in vivo echo-cardiographic (ultrasound) B-scan images and a novel approach for heart ejection fraction evaluationEl ruido Speckle aparece cuando se utilizan sistemas de iluminación coherente, como por ejemplo Láser, Radar de Apertura Sintética (SAR), Sonar, Resonancia Magnética, rayos X y ultrasonidos. Los ecos dispersados por los centros dispersores distribuidos al azar en la estructura microscópica del medio son el origen de este fenómeno, que caracteriza las imágenes coherentes con un aspecto granular. Se puede demostrar que el ruido Speckle es de carácter multiplicativo, fuertemente correlacionados y lo más importante, con estadística no Gaussiana. Estas características son muy diferentes de la suposición tradicional de ruido aditivo gaussiano blanco, a menudo asumida en la segmentación de imágenes, filtrado, y en general, en el procesamiento de imágenes; lo cual se traduce en la reducción de la eficacia de los métodos para la extracción de información de la imagen final. La modelización estadística es de particular relevancia cuando se trata con datos Speckle, a fin de obtener algoritmos de procesamiento de imágenes eficientes. Además, el procesamiento no lineal de señales empleado en sistemas clínicos de imágenes por ultrasonido para reducir el rango dinámico de la señal de eco de entrada de manera que coincida con el rango dinámico más pequeño del dispositivo de visualización y resaltar así los objetos con dispersión más débil, modifica radicalmente la estadística de los datos. Esta reducción en el rango dinámico se logra normalmente a través de un amplificador logarítmico es decir, la compresión logarítmica, que comprime selectivamente las señales de entrada y una forma analítica para la expresión de la función de densidad de los datos transformados logarítmicamente es por lo general difícil de derivar. Esta tesis se centra en las distribuciones estadísticas de la amplitud de la señal comprimida logarítmicamente en las imágenes coherentes, y su principal objetivo es el desarrollo de un modelo estadístico general para las imágenes por ultrasonido comprimidas logarítmicamente en modo-B. El modelo desarrollado se adaptó, realizando las analogías físicas relevantes, del modelo multiplicativo en radares de apertura sintética (SAR). El Modelo propuesto puede describir correctamente los datos comprimidos logarítmicamente a partir datos generados con los diferentes modelos propuestos en la literatura especializada en procesamiento de imágenes por ultrasonido. Además, el modelo se aplica con éxito para modelar ecocardiografías en vivo. Se enuncian y demuestran los teoremas necesarios para dar cuenta de una demostración matemática rigurosa de la validez y generalidad del modelo. Además, se da una interpretación física de los parámetros y se establecen las conexiones entre el teorema central del límite generalizado, el modelo multiplicativo y la composición de distribuciones para los diferentes modelos propuestos hasta a la fecha. Se demuestra además que los parámetros del amplificador logarítmico se incluyen dentro de los parámetros del modelo y se estiman usando los métodos estándar de momentos y máxima verosimilitud. Por último, tres aplicaciones se desarrollan: filtrado de ruido Speckle, segmentación de ecocardiografías y un nuevo enfoque para la evaluación de la fracción de eyección cardiaca.
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Guipieri, Séraphin. "Caractérisation ultrasonore de la qualité osseuse : application à la chirurgie orthopédique." Thesis, Paris Est, 2015. http://www.theses.fr/2015PESC0026/document.
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La qualité osseuse est un paramètre important à prendre en compte lors des différents types de chirurgie mis en œuvre pour les interventions sur le rachis. Cependant, ce paramètre reste difficile à estimer in vivo du fait notamment de la difficulté à accéder à ce site anatomique. Ce travail porte sur le développement d'une technique ultrasonore permettant d'estimer la qualité osseuse en utilisant la réponse échographique d'une tige métallique insérée dans l'os et utilisée dans le cadre de la chirurgie du rachis. Des travaux expérimentaux montrent la faisabilité de notre approche in vitro. Une tige métallique similaire à celle utilisée en clinique est insérée dans des échantillons d'os trabéculaire perpendiculairement à l'axe du traducteur. Les réponses échographiques de la tige immergée dans l'eau et insérée dans l'os sont comparées, ce qui permet de déterminer la vitesse de propagation dans l'os (SOS, Speed of Sound), ainsi que la pente du coefficient d'atténuation en fonction de la fréquence (BUA, Broadband Ultrasonic Attenuation). Les résultats obtenus pour les 21 échantillons montrent i) une corrélation significative entre SOS et la fraction volumique d'os (BV/TV, R² = 0.6 et p < 0.001); et ii) une non-linéarité de la variation du BUA et BV/TV (R² = 0.22 et p<0.001). Des simulations numériques utilisant des éléments finis spectraux en 2D permettent de mieux comprendre la propagation ultrasonore et d'estimer la sensibilité des mesures à des erreurs de positionnement de la tige et du capteur. De plus, des simulations numériques par différences finies dans le domaine temporel en 3D permettent de mieux comprendre l'interaction entre une onde ultrasonore et le tissu osseux en comparant les résultats expérimentaux et numériques. Ce travail prouve la faisabilité de cette approche de caractérisation ultrasonore pour estimer la qualité osseuse, ce qui ouvre la voie à de possibles études cliniques dans le futurBone quality is an important parameter which should be taken into account during the different types of surgical procedures used in spine surgery. However, this parameter remains difficult to be determined in vivo, mostly due to difficulties of positioning different sensors around this anatomical site. The aim of this work is to develop an ultrasonic technique allowing to assess bone quality using the echographic response of a metallic rod inserted in bone tissue and used in spine surgery. Experimental works show the feasibility of the technique in vitro. A metallic rod similar to the one used in the operating room is inserted in trabecular bone samples perpendicularly to the transducer axis. The echographic responses of the rod immersed in water and in bone tissue are compared, which allows to determine the wave velocity in bone tissue, as well as the slope of the attenuation coefficient as a function of frequency (BUA, broadband ultrasonic attenuation). The results obtained for the 21 samples show i) a significant correlation between SOS and bone volume fraction (BV/TV, R² = 0.6, p < 0.001); and ii) a non linear variation of BUA as a function of BV/TV (R² = 0.22, p<0.001).Numerical simulation using 2D spectral finite element simulation allows to better understand wave propagation and to estimate the sensitivity of the measurements to positioning errors of the rod and of the sensor. Moreover, 3-D finite difference time domain simulation allows to better understand the interaction between an ultrasonic wave and bone tissue by comparing the experimental and numerical results. This work proves the feasibility of this ultrasonic characterization approach to estimate bone quality, which opens the way to future clinical studies
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Fabík, Vojtěch. "Fantomy pro oftalmologický ultrazvukový systém." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220047.
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In our work we have studied the ultrasonic imaging systems and their use in ophthalmology, especially with the device Nidek 4000. We described ophthalmological examination methods. In addition, we are using the simulation program Field II. It simulated eye phantom and created his B-scan and biometry, where we compared the effects of different central frequency ultrasonic probes and different speeds of sound in the resulting values. We also created phantoms using agarose gel and materials of different properties. On phantoms, we studied the effect of the velocity of ultrasound in measurement results, effect of the concentration of the agarose gel to the velocity of sound. And we created phantoms simulating the human eye. Measurement protocol was created for use in teaching.
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Kamal, Dhafer M. "The value of duplex ultrasound versus contrast enhanced CT scan in the follow-up of endoluminally repaired abdominal aortic aneurysm : a blinded study." Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=19428.
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I-To compare aneurysm diameter measurements, and the detection of endoleaks in patients post endoluminal aortic aneurysm repair by colour duplex ultrasonography as compared to contrast enhanced CT scan as the gold standard. 2-To evaluate whether contrast enhanced ultrasound (levovist) improves the accuracy of colour duplex ultrasound for the detection of endoleaks as compared to CT.
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Müller, Franziska. "Hochauflösende Ultraschallverfahren und Doppler-Sonographie zur Mammadiagnostik bei der Hündin." Doctoral thesis, Universitätsbibliothek Leipzig, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-38087.
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An 53 Hündinnen aus dem Patientengut der Klinik für Kleintiere der Universität Leipzig, die mit Umfangsvermehrungen der Mamma vorgestellt und anschließend in der Klinik für Kleintiere operiert wurden, wurde präoperativ eine sonographische Untersuchung der Mamma durchgeführt. Darüber hinaus wurden die Mammarkomplexe von acht tragenden und einer laktierenden Hündin mit dieser Technik untersucht. Ziel war es, Kriterien zur Einschätzung der Dignität der Tumoren mit Hilfe dieser nichtinvasiven Methode zu erarbeiten. Es sollten die Fragen geklärt werden, ob mit Hilfe der hochauflösenden Sonographie eine Aussage über Gut- oder Bösartigkeit eines Herdes möglich ist und ob dabei dieselben Kriterien entscheidend sind, die in der Humanmedizin eine zuverlässige Differenzierung erlauben. Außerdem sollte überprüft werden, welchen Beitrag die farbkodierte Duplexsonographie oder Resistance- und Pulsatilitätsindex zur Charakterisierung von Mammatumoren der Hündin leisten. Die Gesamtzahl der in die Studie eingehenden Komplexe beträgt 114. Die sonographischen Untersuchungen erfolgten mit einem 14 MHz Matrix-Linearschallkopf. Bei 70 der 114 untersuchten Lokalisationen erfolgte zusätzlich zur B-Mode-Untersuchung eine Untersuchung mit der farbkodierten Duplexsonographie. Konnten mit Hilfe dieser Methode Gefäße in der Umfangsvermehrung nachgewiesen werden, wurde in 47 von 70 Fäl-len zusätzlich der PW-Doppler eingesetzt, um Flussspektren aus den dargestellten Gefäßen abzuleiten. Aus diesen wurden Resistance-Index und Pulsatilitätsindex bestimmt. Bei der retrospektiven Auswertung der Grauwertbilder aus der B-Mode-Untersuchung wurde für jeden Komplex die Ausprägung von 12 Parametern beurteilt. Die Bilder aus der farbkodierten Duplexsonographie lieferten zusätzlich Informationen zu Gefäßzahl, Gefäßdurchmesser und Gefäßverteilung innerhalb eines Tumors. Die Exstirpate wurden pathohistologisch untersucht. Die aus der Gewebetypisierung entsprechend der WHO-Klassifikation resultierenden Gruppen sind so klein, dass nur eine deskriptive statistische Auswertung möglich war. Es erfolgte die Zusammenfassung unterschiedlicher Gewebetypen zu den Gruppen der „malignen“ bzw. „benignen“ Tumoren. Für Malignität sprechen eine unregelmäßige Randkontur (32 von 61 malignen, 4 von 48 benignen Lokalisationen), eine Schallverstärkung (36/61 malignen, 9/48 benignen Lokalisationen) oder –auslöschung (8/61 malignen, 0 /48 benignen Lokalisationen) hinter dem Tumor, Verkalkungen (20/61 malignen, 6/48 benignen Lokalisationen) sowie ein unregelmäßiger Durchmesser der Tumorgefäße (25/61 malignen, 12/48 benignen Lokalisationen). Meist gutartig sind Umfangsvermehrungen der Mamma, denen sonographisch eine klare Abgrenzung zum umgebenden Gewebe fehlt (15/61 malignen, 36/48 benignen Lokalisationen). Außerdem solche mit indifferentem retroläsionalem Schallverhalten (17/61 malignen, 39/48 benignen Lokalisationen). Kombiniert man mehrere der Parameter miteinander, ist die resultierende Teilmenge der betreffenden Läsionen kleiner, die Aussagekraft höher. Für Bösartigkeit spricht beispielsweise eine Kombination von Verkalkung und unregelmäßiger Randkontur (13 von 61 malignen, 1 von 48 benignen Lokalisationen), Verkalkung und echodichtem Randsaum („deutlich“ oder „fraglich“; 9/61 malignen, 0/48 benignen Lokalisationen) sowie mittlerer Echodichte und retroläsionaler Schallverstärkung (21/61 malignen, 6/48 benignen Lokalisationen). Für Gutartigkeit sprechen mittlere Echodichte des Tumorzentrums in Kombination mit indifferentem Schallverhalten (13/61 malignen, 33/48 benignen Lokalisationen) sowie regelmäßiger Gefäßdurchmesser bei diffuser Gefäßverteilung (3/36 malignen, 14/29 benignen Lokalisationen). Es konnte dargestellt werden, dass sich mit Hilfe der hochauflösenden B-Mode-Sonographie Kriterien aufzeigen lassen, die tendenziell für Gut- oder Bösartigkeit eines Mammatumors sprechen. Dabei ist es zweckmäßig, mehrere Parameter in die Beurteilung einfließen zu lassen. Auch die farbkodierte Duplexsonographie kann dabei einen Beitrag leisten. Die Ermittlung von Resistance- und Pulsatilitätsindex hingegen erweist sich als nicht sinnvoll. Ein Parameter, welcher in der Humanmedizin eine entscheidende Rolle zur Unterscheidung bösartiger von gutartigen Tumoren der Mamma spielt ist die Randkontur eines Tumors. Dies ist das einzige Kriterium, das auch bei Mammatumoren der Hündin einen diagnostischen Nutzen aufweist. Anhand einzelner sonographischer Parameter ist es nicht möglich, die Dignität eines Tumors vorherzusagen. Die sonographische Untersuchung kann jedoch in einigen Fällen beim Abschätzen der Prognose helfenIn 53 bitches that underwent surgery because of tumors of the mammary gland at the Department of small animal medicine of the University of Leipzig we carried out a preoperative ultrasonographic examination of the mammary gland. Furthermore eight pregnant and one lactating bitch were examined the same way. We aimed to find out, whether high-resolution ultrasound helps differentiate benign from malignant tumors. Also we wanted to evaluate criteria established for that purpose in human medicine. Use of colour-coded duplex sonography, resistance index and pulsatility index for this question are reassessed too. The total number of mammary complexes examined for this study is 114. A GE Logiq™ 9 with a 14 MHz linear array transducer was used for all examinations. Seventy of the 114 sites of mammary tissue underwent a colour-coded duplex sonography after the B scan. Blood vessels were detectet in 70 of the tumors. In 47 of these sites the PW-Doppler was used to gain flow patterns to achieve resistance- and pulsatility-index. The images were analysed retrospectively. In B scan images lesions were judged by 12 parameters. Additional information about number, diameter and distribution of vessels within a tumor was taken from the images of colour-coded duplex sonography. The excised complexes were evaluated pathohistologically. Only descriptive statistical analysis was possible because the resulting groups were very small after being sorted according to WHO-classification. Therefore the complexes of mammary glands were subsumpted into two groups – „malignant“ and „benign“ tumours. An irregular contour of the tumor (32 of 61 malignant, 4 of 48 benign tumors), signal enhancement (36/61 malignant, 9/48 benign tumors) or total shadowing (8/61 malignant, 0/48 benign tumors) behind the tumor, calcification (20/61 malignant, 6/48 benign tumors) and irregular vessel diameters (25/61 malignant, 12/48 benign tumors) are signs of malignancy. Tumors that miss a clearly detactable borderline (15/61 malignant, 36/48 benign tumors) and tumors with no signal alteration behind the tumor (17/61 malignant, 39/48 benign tumors) are benign more often. The combination of parameters reduces the number of adequate tumors and rises significance. A tumor showing an irregular contour and calcification (13/61 malignant, 1/48 benign tumors) is more likely to be malignant as well as a tumor of medium echodensity showing signal enhancement (21/61 malignant, 6/48 benign tumors). Tumors of medium echodensity without signal alteration behind the lesion (13/61 malignant, 33/48 benign tumors) and tumors with diffusely distributed vessels of regular diameter (3/36 malignant, 14/29 benign tumors) are more likely to be benign. It could be shown that high-resolution B scan parameters can help differentiate between malignant and benign tumors of the mammary gland, especially if they are used in combination with each other. Parameters from colour-coded duplex sonography can increase predicting value of B scan examinations too but there is no use of analysing resistance index or pulsatility index. One of the criteria established in human medicine ist the contour of a tumor. This parameter is of diagnostic use in mammary tumours of the bitch too. It is not possible to clearly predict the character of a tumor of the mammary gland of a bitch by only a few parameters based on a sonogram but sonographic examination can be helpful for assessing prognosis sometimes
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Hellmark, Lindgren Birgitta. "Pregnoscape : Den gravida kroppen som arena för motstridiga perspektiv på risk, kön och medicinsk teknik." Doctoral thesis, Uppsala universitet, Institutionen för kulturantropologi och etnologi, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6749.
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Pregnancy and birth are not only physiological processes but also socially and culturally organized events. Pregnancy is an individual experience as well as the focus of collective concerns and values. In this dissertation the pregnant body is understood as an arena of social truths and contesting perspectives: a public stage where different perspectives on medical technology, risk and gender are acted out. Swedish maternity care dominates the arena, and women have to adjust to the authority of medical knowledge. This, however, does not mean that women comply without questions. As the study shows they struggle for voice and agency which is reflected in pregnant women’s differing views and uses of biomedical knowledge and technology. Although the discourse on pregnancy and birth is highly ideological and marked by strong opinions, pregnant women in practice tend to be motivated by pragmatics rather than ideology. In order to understand the complexities and nuances of reproductive culture in Sweden, we need to move beyond distinctions such as the one between technology and the body, and instead focus on the experiential world of pregnant women in which technology is an integral part in everyday life and therefore taken for granted rather than problematised. The thesis is based on fieldwork at a maternity care center and interviews with pregnant women. Furthermore, discussion groups on the Internet and debates in mass media have been valuable sources of information.Avhandlingen finns att köpa som tryckt bok för 120 SEK exkl. frakt. Maila birgitta.hellmark@comhem.se
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Naji, Osama. "Ultrasound studies of caesarean section scar in pregnancy." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/19445.
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Incomplete healing of CS scars has become a recognised sequel to this operation, and is associated with complications in later pregnancies. These can include caesarean scar pregnancy (CSP), a morbidly adherent placenta, scar dehiscence or rupture. To date there is uncertainty relating to the recognition of poor scar healing and the factors that lead to it. In recent years, there has been an increase in studies using ultrasound imaging to describe scars as deficient, or incompletely healed. However, these studies were carried out in the non-pregnant state, with a paucity of data to associate the described morphology of these scars to the functional integrity of the lower uterine segment (LUS) in subsequent pregnancy, or the actual performance in labour. We hypothesised that unenhanced transvaginal sonography (TVS) is a valid and reproducible method of assessing CS scars in pregnant women, and it can provide relevant clinical information on the effects these scars might have in pregnancy. To investigate the validity of TVS as the imaging modality of choice, we proposed a standardised approach for obtaining scar measurements. Furthermore we established a consensus agreement for nomenclature and methodology in imaging and reporting CS scars. We tested the reproducibility of the agreed methods throughout the course of pregnancy and our data showed that TVS could reliably delineate CS scar with good interobserver and intraobserver variability (IOV). We also investigated the influence of different scar dimensions on pregnant women from early pregnancy, during placental development, throughout the antenatal course and at delivery in terms of implantation sites, vaginal bleeding, and placental location, as well as the effects of scar changes on the final scar appearance at repeat CS, or during trials of vaginal birth after caesarean section (VBAC). Our data demonstrated that women who attended the early pregnancy assessment unit (EPAU) with a previous history of CS had more vaginal bleeding but similar spontaneous miscarriage rates in comparison to women without a history of CS. However, the implantation sites in the scarred uterus were significantly different from the non-scarred uterus. In the second trimester there were also significant differences in placental location. In the CS group there were more posterior and fewer fundal placentas than in the control group. We found that CS scars underwent significant changes to their shape and dimensions from the second trimester onwards. These scars were affected by the physical expansion of the gravid uterus and expanded accordingly in a cephalo- caudal pattern. Finally, we have demonstrated that certain scar measurements in the second trimester were associated with particular scar appearance at repeat caesarean delivery, and potentially predicted the likelihood of uterine scar rupture. We integrated this information and developed a prediction model on the likelihood of achieving successful VBAC from the earlier stages of pregnancy. In conclusion our data confirms that CS scar can be reliably assessed by ultrasound scan, and certain scar features are associated with complications that can be anticipated from as early as 6 weeks gestation. The results of our study provide important new information, which if validated externally may have significant bearing on our understanding of the impact of CS on the uterus, and the management of women planning to attempt a vaginal delivery after a previous CS.
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Benjamin, Alex(Alex Robert). "3D organ property mapping using freehand ultrasound scans." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/128989.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2020Cataloged from student-submitted PDF of thesis.
Includes bibliographical references (pages 141-151).
3D organ property mapping has gained a considerable amount of interest in the recent years because of its diagnostic and clinical significance. Existing methods for 3D property mapping include computed tomography (CT), magnetic resonance imaging (MRI), and 3D ultrasound (3DUS). These methods, while capable of producing 3D maps, suffer from one or more of the following drawbacks: high cost, long scan times, computational complexity, use of ionizing radiation, lack of portability, and the need for bulky equipment. We propose the development of a framework that allows for the creation of 3D property maps at point of care (specifically structure and speed of sound). A fusion of multiple low-cost sensors in a Bayesian framework localizes a conventional 1D-ultrasound probe with respect to the room or the patient's body; localizing the probe relative to the body is achieved by using the patient's superficial vasculature as a natural encoding system. Segmented 2D ultrasound images and quantitative 2D speed of sound maps obtained using numeric inversion are stitched together to create 3D property maps. A further advantage of this framework is that it provides clinicians with dynamic feedback during freehand scans; specifically, it dynamically updates the underlying structural or property map to reflect high and low uncertainty regions. This allows clinicians to repopulate regions within additional scans. Lastly, the method also allows for the registration and comparison of longitudinally acquired 3D property/structural maps.
by Alex Benjamin.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Mechanical Engineering
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Saldanha, Fatima Aparecida Targino. "Acompanhamento pré e pós-natal dos casos com translucência nucal fetal aumentada." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/5/5139/tde-09102014-111046/.
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Objetivo: analisar o resultado das gestações e pós-natal dos fetos com translucência nucal (TN) aumentada. Método: Duzentos e setenta e cinco fetos com TN aumentada foram avaliados no setor de Medicina Fetal da Clínica Obstétrica do HC-FMUSP, com análise do cariótipo, ultra-sonografia seriada, ecocardiografias fetal e pós-natal e avaliação clinica genética pós-natal. Resultados: 14,2% apresentaram cariótipos alterados e 85,8% normais. A ultra-sonografia morfológica esteve alterada em 73,1% dos casos com cariótipo anormal e em 24,7% dos normais, destes, um terço apresentou malformações estruturais maiores, sendo 35,7% cardíacas. Resultados gestacionais adversos, como abortamento, óbitos intra-útero e neonatal ocorreram em 76,5% dos fetos com anomalias cromossômicas e em 10,2% com cariótipos normais. A avaliação pós-natal foi realizada em 72,7% das crianças, mostrando-se alterada em 14,8% dos casos. A freqüência de criança viva e saudável diminuiu com a medida da TN, que variou de 37,5%, nos casos com cariótipos normais, a 18,8% com cariótipos desconhecidos, quando a TN foi igual ou maior que 4,5 mm. Conclusão: Quanto maior a TN maior o risco de anomalias cromossômicas e, nos casos com cariótipos normais, maior a freqüência de malformações estruturais, em especial defeitos cardíacos, resultados gestacionais adversos e alterações à avaliação pós-natalThe aim of this study was to evaluate pregnancy and postnatal outcomes in fetuses with increased nuchal translucency thickness (NT). Two hundred seventy five fetuses with increased NT were examined with karyotyping analysys, serial ultrasound scans, ecocardiography and postnatal clinical and genetic evaluation at the Fetal Medicine Unit - Departament of Obstetrics - São Paulo University. The karyotype was abnormal in 14.2% of the cases and normal in 85.8%. At the anomaly scan, 73.1% of the abnormal karyotype and 24.7% of the normal fetuses presented structural abnormalities, one third of these were major malformations with 35.7% of cardiac defects. Adverse pregnancy outcome as miscarriages, intrauterine and neonatal deaths occurred in 76.5% of the abnormal karyotype group and in 10.2% of the normal. 72.7% of the infants with normal karyotype had postnatal examination with 14,8% presenting abnormalities. The chances of having a live and healthy child decreased with increased NT thickness. For NT above 4.5mm this varied from 18.8%, for an unknown karyotype result, to 37.5% for a normal karyotype. The chances of abnormal karyotype increased with NT thickness. In addition, when the karyotype was normal, the frequency of fetal malformations, specially heart defects, adverse pregnancy outcome and postnatal abnormalities increased with NT thickness
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Schöne, Martin. "Possibilities of Articular Cartilage Quantification Based on High-Frequency Ultrasound Scans and Ultrasound Palpation." Doctoral thesis, Humboldt-Universität zu Berlin, 2020. http://dx.doi.org/10.18452/21781.
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In der Diagnostik und Reparatur von hyalinem Gelenkknorpel sind neue Methoden zur Quantifizierung von Struktur und mechanischer Belastbarkeit gefragt, um die Behandlung von Knorpelschäden an Millionen von Patienten weltweit zu verbessern.
Mittels hochfrequentem, fokussierten Ultraschall werden Oberflächenparameter für Reflektivität und Rauheit an Gelenkknorpel bestimmt. Es wird gezeigt wie die Oberflächenneigung kontrolliert werden kann. Die Ergebnisse vermitteln ein besseres Verständnis über die Zusammensetzung der Ultraschallsignale aus reflektierten und gestreuten Komponenten.
3D Ultraschallscans von Knorpelregeneraten erlauben die Defektstellen volumetrisch zu Quantifizieren. Die Proben wurden zusätzlich nach etablierten Bewertungssystemen benotet, welche auf makroskopischer Beurteilungen, MRT-Scans und Histologie basieren. Die ultraschallbasierten Volumendaten zeigten dabei gute Korrelationen mit den Punktwertungen.
Die im Labor verwendeten Messaufbauten zur biomechanischen Charakterisierung von Gelenkknorpel können am Patienten nicht angewandt werden. Daher können Ärzte die Festigkeit von Knorpel bisher nur mittels manueller Palpation abschätzen. Diese Arbeit entwickelt eine Methode der Ultraschall-Palpation (USP), die es erlaubt, die während der manuellen Palpation erzeugte Kraft und Deformation, basierend auf Ultraschallechos, aufzunehmen. Es wurde einen Prototyp entwickelt womit gezeigt werden konnte, dass USP eine ausreichende Genauigkeit und Reproduzierbarkeit aufweist. Wiederholte Messungen können zusätzlich zeitabhängige biomechanische Parameter von Knorpel ableiten.
Zusammenfassend zeigt diese Arbeit verbesserte und neue Möglichkeiten zur strukturellen und biomechanischen Charakterisierung von hyalinem Gelenkknorpel bzw. den Ergebnissen von Knorpelreparatur basierend auf Ultraschalldaten. Diese Methoden haben das Potenzial die Diagnostik von Gelenkknorpel und die Quantifizierung von Knorpelreparatur zu verbessern.In the diagnostics and repair of hyaline articular cartilage, new methods to quantify structure and mechanical capacity are required to improve the treatment of cartilage defects for millions of patients worldwide. This thesis uses high frequency focused ultrasound to derive surface parameters for reflectivity and roughness from articular cartilage. It is shown how to control the inclination dependency to gain more reliable results. Furthermore, the results provided a better understanding of the composition of ultrasonic signals from reflected and scattered components. 3D ultrasound scans of cartilage repair tissue were performed to quantify defect sites after cartilage repair volumetrically. The samples were also graded according to established scoring systems based on macroscopic evaluation, MRI scans and histology. The ultrasound-based volumetric parameters showed good correlation with these scores. Complex biomechanical measurement setups used in laboratories cannot be applied to the patient. Therefore, currently physicians have to estimate the stiffness of cartilage by means of manual palpation. In the last part of this thesis, a method denoted as ultrasound palpation is developed, which allows for measuring the applied force and strain during manual palpation in real time, solely based on the evaluation of the time of flight of ultrasound pulses. A prototype was developed and its measurement accuracy and reproducibility were characterized. It could be shown that ultrasound palpation has sufficient accuracy and reproducibility. Additionally, by repeated measurements it was possible to derive time-dependent biomechanical parameters of cartilage. In summary, this work shows improved and new possibilities for structural and biomechanical characterization of hyaline articular cartilage and the outcomes of cartilage repair based on ultrasound data. The methods have the potential to improve the diagnostics of articular cartilage and quantification of its repair.
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Schöne, Martin [Verfasser]. "Possibilities of Articular Cartilage Quantification Based on High-Frequency Ultrasound Scans and Ultrasound Palpation / Martin Schöne." Berlin : Humboldt-Universität zu Berlin, 2020. http://d-nb.info/1216877203/34.
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Smith, Bryan Ronain. "Nanoparticulate platforms for molecular imaging of atherosclerosis and breast cancer." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1150309580.
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Tegos, Thomas Ioannis. "The identification of the unstable carotid plaque on ultrasound." Thesis, Imperial College London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367735.
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Zardan, Jean-Philippe. "Etude d’un contrôle ultrasonore pour la détection et l’identification de l’ondulation de plis dans les CFRP aéronautiques." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4357.
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L'ondulation pli est un défaut majeur qui peut apparaître dans certains matériaux composites tels que le CFRP. Des mesures de vitesse et atténuation ultrasonore permettent la détection, mais pas l'identification, de l'ondulation pli. Dans la présente étude, il est démontré que pour identifier cette ondulation pli, il est important de prendre en compte la déviation du faisceau ultrasonore. Deux méthodes différentes, A²Scan et C²Scan, permettent de détecter et mesurer cette déviation. D'une part, de l'écart produit un comportement asymétrique dans les réponses obtenues à des angles d'incidence oblique. Ce phénomène se manifeste à travers l'étude des domaines d'angles d'incidence, qui peuvent normalement être superposés. D'autre part, la technique de C²Scan permet la mesure de la déviation du champ acoustique transmis. Dans les deux cas, l'étude de la déviation induite révèle sa sensibilité à la présence d'ondulation plis. Ces méthodes ont été validées expérimentalement et leur utilisation potentielle, en fonction de l'épaisseur de la pièce, ainsi que sont industrialisation par ultrasons laser sont discutéesPly waviness is a major defect, which can appear in certain composite materials such as CFRP. Attenuation and ultrasound velocity measurements allow the detection, but not the identification, of ply waviness. In the present study it is shown that in order to identify this ply waviness, it is important to take the deviation of the ultrasonic beam into account. Two different methods,A²Scan et C²Scan , allowing such deviations to be detected are proposed. On the one hand, the deviation produces an asymmetrical behaviour in the responses obtained at oblique incidence angles. This phenomenon is revealed through the study of incidence angle ranges, which can normally be superimposed. On the other hand, the double scanning technique allows the deviation of the energy maxima of the transmitted acoustic field to be determined. In both cases, the study of induced deviation reveals that it is sensitive to the presence of ply waviness. These methods have been experimentally validated and their potential use, depending on the thickness of the workpiece and industrialization by laser ultrasonic means are discussed
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Zhang, Hai. "Comparative study of infrared thermography, ultrasonic C-scan, X-ray computed tomography and terahertz imaging on composite materials." Doctoral thesis, Université Laval, 2017. http://hdl.handle.net/20.500.11794/36573.
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L’évaluation non destructive (NDT) des matériaux composites est compliquée en raison de la vaste gamme de défauts rencontrés (y compris délaminage, microfissuration, fracture de la fibre, retrait des fibres, fissuration matricielle, inclusions, vides et dommages aux chocs). La capacité de caractériser quantitativement le type, la géométrie et l’orientation des défauts est essentielle. La thermographie infrarouge (IRT), en tant que technique de diagnostic d’image, peut satisfaire le besoin industriel croissant de NDT&E. Dans la thèse, la thermographie par excitation optique et mécanique a été utilisée pour étudier différents matériaux composites, dont 1) des préformes sèches en fibres de carbone, 2) des composites de fibres naturelles, 3) des composites hybrides de basalte-fibres de carbone soumis à une charge d’impact (séquence de type sandwich et séquence d’empilement intercalé), 4) des défauts micro-dimensionnés dans un composite polymère renforcé de fibre de carbone (CFRP) en 3D avec une couture de type « joint en T », et 5) des peintures sur toile qui peuvent être considérées comme des matériaux composites. Une nouvelle technique IRT de thermographie de ligne par micro-laser (micro-LLT) a été proposée pour l’évaluation des porosités submillimétriques dans le CFRP. La microscopie de points par micro-laser (micro-LST) et la micro-vibrothermographie (micro-VT) ont également été présentées avec l’utilisation de microlentilles. La thermographie pulsée (PT) et la thermographie modulée « à verrouillage » (LT) ont été comparées à la tomographie par rayons X (TC) pour validation. Le C-scan ultrasonore (UT) et l’imagerie par ondes tera-hertziennes en onde continue (CW THz) ont également été réalisés à des fins comparatives. L’inspection par techniques thermographiques est une question ouverte à discuter pour le public scientifique. En fait, la thermographie par impulsions (PPT) basée sur la transformation de phase a été utilisée pour estimer la profondeur des dommages. Pour traiter les données thermographiques, on a également utilisé la reconstruction de signal thermographique de base (B-TSR), la thermographie des composants principaux (PCT) et la thermographie des moindres carrés partiels (PLST). Enfin, une analyse complète et comparative basée sur le diagnostic d’images thermographiques a été menée en vue d’applications industrielles potentielles.Non-destructive testing (NDT) of composite materials is complicated due to the wide range off laws encountered (including delamination, micro-cracking, fiber fracture, fiber pullout, matrix cracking, inclusions, voids, and impact damage). The ability to quantitatively characterize the type, geometry, and orientation of flaws is essential. Infrared thermography (IRT), as an image diagnostic technique, can satisfy the increasing industrial need for NDT&E. In the thesis, optical and mechanical excitation thermography were used to investigate different composite materials, including 1) carbon fiber dry preforms, 2) natural fiber composites, 3) basalt-carbon fiber hybrid composites subjected to impact loading (sandwich-like and intercalated stacking sequence), 4) micro-sized flaws in a stitched T-joint 3D carbon fiber reinforced polymer composite (CFRP), and 5) paintings on canvas which can be considered as composite materials. Of particular interest, a new IRT technique micro-laser line thermography (micro-LLT) was proposed for the evaluation of submillimeter porosities in CFRP. Micro-laser spot thermography (micro-LST) and micro-vibrothermography (micro-VT) were also presented with the usage of a micro-lens. Pulsed thermography (PT) and lock-in thermography (LT) were compared with x-ray computed tomography (CT) for validation. Ultrasonic C-scan (UT) and continuous wave terahertz imaging (CW THz) were also conducted for the comparative purpose. The inspection by thermographic techniques is an open matter to be discussed for the scientific audience. In fact, pulse phase thermography (PPT) based on phase transform was used to estimate the damage depth. Basic thermographic signal reconstruction (B-TSR), principal component thermography (PCT) and partial least squares thermography (PLST) (another more recent advanced image processing technique) were also used to pro-cess the thermographic data. Finally, a comprehensive and comparative analysis based on thermographic image diagnostics was conducted in view of potential industrial applications.
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Binte, Mokhtar Hanan. "Contribution to the study of impact damage on composite laminates : the effect of hygrothermal ageing and preloading." Thesis, Dijon, 2012. http://www.theses.fr/2012DIJOS045.
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Ce travail a pour but d'étudier la tolérance à l'impact de 3 stratifiés carbone/époxy soumis simultanément à différents types de chargements hygrothermiques et mécaniques. Ces stratifications présentant des caractéristiques mécaniques globales particulières d'isotropie, il s'agit ici de déterminer l'influence de la séquence d'empilement sur le développement de l'endommagement lors d'un impact. Dans un premier temps, la cinétique de vieillissement hygrothermique des trois stratifications est étudiée et analysée. Ensuite, leur tolérance à un unique impact ainsi qu'à des impacts répétés est évaluée. L'endommagement résultant de ces impacts est analysé par contrôle ultrasonore. La morphologie générale et l'amplitude de l'endommagement dans la profondeur des matériaux sont mises en relation avec les propriétés mécaniques et la séquence d'empilement spécifique à chaque stratifié. Dans un deuxième temps, l'influence combinée de plusieurs sollicitations est étudiée. Différents scénarii associant un vieillissement hygrothermique ainsi qu'un ou deux impacts sont mis en oeuvre. L'endommagement résultant est mis en rapport avec les temps relatifs de vieillissement et la position des impact durant le cycle de vieillissement. Ensuite, l'influence d'une précharge de traction sur la tolérance à l'impact est mise en évidence. Un montage spécifique a été conçu et fabriqué pour réaliser ces tests. Enfin, l'association d'un vieilllissement hygrothermique et d'une précharge de traction est abordée afin d'identifier la sollicitation la plus pénalisant en terme de tolérance et d'impactThis study examines impact damage processes in three types of CFRP composite materials simultaneously subjected to different hygrothermal and mechanical loading conditions. The composite structures tested are chosen for having particular global isotropic responses when loaded, the aim being to ascertain the exact influence of lay-up sequence on impact damage propagation. The work is presented in four main sections. Firstly by establishing hygrothermal ageing dynamics for the three composite structure types and their behaviour when impacted once or several times ; impact damage is measured and analysed using ultrasonic method. The extent and general morphology of the damage through the material thickness is correlated with mechanical properties and lay-up sequence specific to each material. Secondly the influence of simultaneous load combinations is examined. These include different durations of hygrothermal ageing associated with single or double impacts.The resulting damage incurred is analysed with respect to overall ageing time and time during the ageing cycle when the impact was applied. Thirdly the effect of tensile loading during impact on damage within the material was studied. This was achieved using a specially designed test apparatus that allows loading and impacting conditions to be independently modified. By associating a high-speed digital camera to film specimen impacts it is possible to evaluate a relationship between overall composite specimen stiffness and the impact damage. Finally, in order to identify the most unfavourable situation with regard to impact damage resistance an association between hygrothermal ageing and an applied tensile load is examined
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Aboissière, Jacky. "Propagation de dommages d'impact dans un matériau composite stratifié à fibres de carbone et résine époxyde." Toulouse 3, 2003. http://www.theses.fr/2003TOU30027.
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Loïc, Martinez. "NOUVELLES MÉTHODES D'IDENTIFICATION D'ONDES DE SURFACE - ÉTUDE DE L'ONDE A SUR UNE CIBLE COURBE." Phd thesis, Université du Havre, 1998. http://tel.archives-ouvertes.fr/tel-00583081.
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Le problème de la propagation d'ondes sur une plaque plane élastique en contact avec deux liquides différents est traité. Une étude numérique détaillée montre les propriétés de l'onde A et l'existence d'une nouvelle onde (onde A*) quand deux fluides différents sont en contact avec la lame. Une étude expérimentale des ondes A et A* est ensuite menée en utilisant des techniques expérimentales particulières à la caractérisation de l'onde A: génération d'une onde non atténuée par une impulsion et caractérisation par analyse temps-fréquence. La propagation d'une onde dans un milieu monodimensionnel infini est ensuite étudiée en utilisant les espaces de Fourier bidimensionnels. Un soin particulier est accordé à l'étude d'une onde atténuée et dispersive générée à partir d'une impulsion brève. Un nouveau lien est alors mis en évidence entre le vecteur d'onde complexe et la pulsation complexe. Ce lien autorise ainsi, et pour la première fois, une caractérisation complète des représentations toutfréquence et vecteur d'onde-temps. Sur la base de ces résultats, deux aspects sont développés: d'une part la modélisation de la propagation d'une onde autour d'un tube immergé (milieu monodimentionnel limité) et d'autre part de nouvelles méthodes de traitement du signal. L'aspect résonant dû à la propagation sur un tube d'une onde générée par une impulsion est ainsi montré et modélisé. De nouvelles méthodes de caractérisation d'ondes de surface sont mises en place, permettant de mesurer vecteur d'onde et pulsation complexes, sur des distances très courtes de l'ordre de quelques longueurs d'ondes. En utilisant ces nouveaux outils, la propagation de l'onde A est étudiée expérimentalement sur un tube immergé dans l'eau. L'influence des paramètres géométriques du tube ainsi que de son remplissage est étudiée. De nouveaux phénomènes sont mis en évidence lorsque le liquide intérieur possède une vitesse de propagation du son inférieure à celle du liquide externe, l'onde A* est observée périodiquement spatialement. On montre que la représentation tout fréquence correspondant à la somme de tous ces échos est le produit de convolution de la représentation tout fréquence de l'onde A* seule avec un résonateur de Fabry-Perot. Ce modèle expérimental est en bon accord avec les résultats théoriques.
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Porras, Pérez Antonio Reyes. "Multi-cue image integration for cardiac tissue characterization." Doctoral thesis, Universitat Pompeu Fabra, 2015. http://hdl.handle.net/10803/296796.
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Una caracterización precisa y completa del tejido cardíaco es esencial para el diagnóstico y tratamiento de problemas cardíacos. Para caracterizar la función cardíaca desde diferentes perspectivas, en la práctica clínica, se adquieren grandes cantidades de datos de distinta naturaleza sobre un mismo paciente, proporcionando información útil para la evaluación del corazón. Aunque los distintos datos obtenidos de cada paciente se suelen analizar por separado para evaluar la función cardíaca desde diferentes perspectivas, la combinación efectiva de esta información heterogénea podría ser útil para tener una mejor visión de la anatomía y la función cardíaca. El objetivo principal de esta tesis es el desarrollo de métodos para integrar imágenes e información de distinta naturaleza para una caracterización del tejido cardíaco más completa y precisa.An accurate and complete cardiac tissue characterization is essential to diagnose and treat heart problems. To characterize cardiac function from different perspectives, large amounts of data of different nature from the same patient are acquired in clinical practice, providing information that is useful for heart assessment. Although the different data obtained from each patient are often analyzed separately to assess cardiac function from different perspectives, the effective combination of this heterogeneous information may be useful for a better insight into heart anatomy and function. The main objective of this thesis is to develop methods to integrate images and information of different nature for a more complete and accurate cardiac tissue characterization.
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Hu, Pei-Chi, and 胡旆綺. "Side-Scan Technology Used in High-Frequency Ultrasound Needle Transducer." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/r6t2rt.
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碩士國立陽明大學
生物醫學工程學系
103
Epidural Anesthesia (EA) is one of the most common anesthesia methods. The anesthesiologist will insert the epidural needle, place catheter and inject anesthetic into the narrow epidural space. Too deep needle insertion would cause Dural Puncture which result in Cerebral Spinal Fluid (CSF) leakage with headache and vomit complications etc. We develop a 30 MHz high-frequency ultrasound needle transducer technology, place the needle transducer into the epidural needle and is able to provide guiding and locating in EA insertion. In this research, the 40% increase of transducer active area improves the sensitivity of ultrasound needle. We design a new and efficient process. And the time of needle fabrication is shortened from original 7 days to 3 days. The change from front sight to side scanning extends more range of vision. With real-time B-mode showing the brightness of different part of tissue in insertion path way, anesthetists can distinguish the location of the needle tip and prevent Dural Punctured.
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Lai, Chao-Wei, and 賴昭維. "Quantifying the Visual Features of Ultrasound Image Texture with Back-Scan Conversion." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/80093487983155981037.
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博士國立臺灣大學
電機工程學研究所
96
The visual features are important in clinically diagnosing liver diseases with ultrasound image texture. However, there is no consistent definition of these features. In this study, several textural features proposed by Amadasun are adopted for quantifying the visual features of ultrasound image texture. To cope with the distortion caused by the digital scan conversion (DSC) in ultrasound imaging, a back-scan conversion (BSC) algorithm is applied to homogenize the sampling format and sampling rate of ultrasound image texture before measuring these features. The effectiveness of this measure is investigated using 300 ROI’s of sponge and liver images. It is confirmed that BSC is an important preprocessing step in quantifying these features of ultrasound image texture. By this measure, the visual features may be quantified. The results show that the use of the features is dependent on what is looking for; that is, the distinction between tissue echotexture and fully developed speckles should emphasize on the “coarseness” of the echotexture, while the one between normal liver and cirrhosis should emphasize on the spatial intensity variation (busyness). This study shows a correlation between the tissue and the ultrasound echotexture.
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Lai, Chao-Wei. "Quantifying the Visual Features of Ultrasound Image Texture with Back-Scan Conversion." 2008. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2907200821261200.
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Fuller, Michael I. "Integrated circuit design for low-cost, pocket-sized, C-scan medical ultrasound imaging /." 2007. http://wwwlib.umi.com/dissertations/fullcit/3187858.
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Yen, YU-JEN, and 顏郁人. "Correlation Study of Image Features between Ultrasound and PET on Breast Cancer Scan." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/12084505898935265017.
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碩士義守大學
資訊工程學系碩士在職專班
101
In the past decade, the incidence and death rate of female with breast cancer is increasing year after year, and the mean age of patience is becoming younger. According to the study of American Joint Committee on Cancer (AJCC), early detection and treatment of breast cancer can greatly improve the survival rate of patients. The aim of this study was to retrieve the image features and to do the correlation analysis between Positron Emission Tomography (PET) and Breast Ultrasound ianges of breast cancer patients. This study collected 14 cases (mean age: 55) with breast cancer by biopsy and have received both Positron Emission Tomography (PET) and Breast Ultrasound scanning in three months. In the Ultrasound image, both of B-Mode and Elastography would be undergoing for all patients. Mean, SD and Entropy were retrieved in B-Mode Ultrasound, and the elastography factors were be assess in Elastography. Meanwhile, the maximum standardized uptake value (SUVmax) of breast lesion can be retrieved from PET images. According to the biopsy report, the patients based on their breast cancer stage can be divided into two groups. The collected data will be analyzed by the statistics analysis with Mann-Whitney U test, ROC-AUC Analysis and Kappa agreement analysis. The p-value of SUVmax and SD collected by Mann-Whitney U test are 0.0.6 and 0.036 respectively (less thanα=0.05). The result indicates that SUVmax and SD can effectively distinguish whether the lesion belongs to the first group or the second group. The cut-off point of SUVmax and SD collected by ROC-AUC Analysis are 3.050 and 35.182 respectively. The result indicates that SUVmax and SD can effectively distinguish whether the lesion belongs to the first group or the second group. The results from Kappa agreement analyses are SUVmax(Cut-off point: 3.05), Kappa=0.696 of biopsy and SD(Cut-off point: 35.182), Kappa=0.650, and Kappa=0.696 of SUVmax(Cut-off point: 3.05) and SD(Cut-off point: 35.182). The cut-off point from SUVmax and SD were highly consistency to distinguish whether the lesion belongs to the first group or the second group. Ultrasound is one of an economical, convenient and non-ionizing radiation inspection instrument. It not only can be used to identify the stage of breast cancer but also can be used to track whether there is recurrence. In the future, more data would be collected and more information can be gained for diagnosing the lesion in early stage. That will be achieving early detection and treatment of breast cancer and improving the survival rate of patients.
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Nalaila, Sungael. "Whole genome scan of QTL for ultrasound and carcass merit traits in beef cattle." Master's thesis, 2010. http://hdl.handle.net/10048/1595.
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A whole genome scan was conducted to identify and fine map QTL regions for ultrasound and carcass merit traits in beef cattle. A total of 465 steers and bulls, genotyped for 4592 SNPs, were analysed for 16 ultrasound and carcass merit traits using interval mapping, single marker regression and Bayesian shrinkage approaches. Thirty QTL and 22 SNPs associated with traits were identified by interval mapping and single marker regression respectively. In Bayesian shrinkage estimation, 218 QTL were identified, wherein 11 of the 30 QTL identified by interval mapping were confirmed. The proportions of QTL variance on the trait variations estimated by Bayesian shrinkage analysis were relatively small. They ranged from 0.1 to 4.8% compared to 6.1 to 11.7% in interval mapping because the QTL in Bayesian approach were adjusted to remove effects of other QTL in the genome. These results are useful for detection of underlying causative QTN variants.Animal Science
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Stegman, Kelly J. "Development of 2D Ultrasound Tracking Software and Hardware to Monitor Multiple Flexor Tendon Displacement for Applications Toward Hand Prostheses." Thesis, 2013. http://hdl.handle.net/1828/5129.
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This thesis work provides a new way to detect and track the displacement of flexor tendons within the human arm, using a non-invasive, ultrasound-based, speckle tracking technique. By tracking the tendons in the arm, it provides a way to monitor a person’s intention to move their hands and fingers. This has application to hand prosthetic control, as well as tendon injury assessment, which has significant contributions to the medical and rehabilitation community. The system works by capturing and processing a sequence of B-scan ultrasound images, to detect and track the flexor tendon motion (excursion) in the wrist, as the user flexes their muscles. Given the biomechanics of the hand, tendon displacement is correlated to the user’s intention to move their finger. Several speckle tracking techniques using B-scan ultrasound image sequences are developed in this work, including: auto-location of the tendon, a stationary ROI (region of interest), and novel use of similarity measures such as FT (Fisher Tippett), and hybrid methods. As well, work is done to investigate various speckle tracking parameters, and their effects on tracking accuracy. The different speckle tracking techniques are developed using data obtained from cadaver hands, and human volunteers undergoing regular surgery. The tracking techniques are compared in terms of successfully detecting the tendon, accurately tracking tendon displacement, successfully tracking multiple tendons, successfully detecting and tracking the onset of low tendon displacement, and computational efficiency of the algorithms. Another major aspect of this work is the design of a novel quad-array transducer that can collect image sequences from up to four tendons simultaneously. This transducer is instrumental to the motivation for controlling an advanced prosthesis. As well, specialized hardware is designed for the cadaver-based studies. Overall, this thesis successfully demonstrated the proposed tracking algorithms and newly designed hardware, for tracking the displacement of single and multiple flexor tendons. It has provided several important contributions to the field.Graduate
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Ferreira, Marco Andre Florindo. "Sistema de Visualização para Oftalmologia usando Dispositivos Android." Master's thesis, 2015. http://hdl.handle.net/10316/40409.
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Paulino, Diogo Gilberto Coelho. "Protocolos de fluidoterapia e sua avaliação através da Veterinary Point-Of-Care Ultrasound." Master's thesis, 2020. http://hdl.handle.net/10437/11867.
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Orientação: Rute Teixeira; co-orientação: Ângela MartinsA VPOCUS (Veterinary Point-of-Care Ultrasound) representa um conjunto de técnicas especificamente desenvolvidas para detetar não só lesões a nível abdominal, como também a nível torácico. É um exame repetível, objetivo e rápido, sendo desta forma de extrema importância na avaliação diária em doentes traumáticos e instáveis, até na avaliação geral de todos os doentes. Pretendeu-se com o presente estudo verificar a diferenciação da presença de linhas B, como sinal clínico em cães, independentemente dos sinais de SRIS (síndrome de resposta inflamatória sistémica), de modo a referenciar a VPOCUS como uma medida de avaliação dos protocolos de fluidoterapia, no momento da triagem. Para tal, recorreu-se a uma amostra de 20 cães (n=20) com sinais gastrointestinais, submetidos a avaliação para determinação dos parâmetros de SRIS e ao procedimento de VPOCUS a nível torácico, seguida da introdução de protocolo de fluidoterapia. Estes foram sujeitos a quatro momentos de monitorização, onde foram avaliados os parâmetros de SRIS e realizadas VPOCUS. Os resultados obtidos revelaram que doentes com frequências respiratórias normais tendiam apresentar uma ausência de linhas B mais do que esperado estatisticamente (X2=3,750; gl=1; p=0,053). No grupo de controlo em M1 e em M2, evidenciou que doentes com frequência respiratória elevada apresentavam tendencialmente ausência de linhas B (X2=5,000; gl=1; p=0,025). Foi possível observar ainda uma relação estatística significativa entre a temperatura normal e a ausência de linhas B (X2=4,444; gl=1; p=0,035), no grupo de controlo. Revelou-se também uma relação estatística significativa entre a presença superior a 3 linhas B e a presença de SRIS (X2=8,439; gl=2; p=0,015). No presente estudo não se verificou evidência de que a instituição de protocolos de fluidoterapia (segundo as regras da AAHA), aumentam a existência de linhas B na VPOCUS na triagem, tanto em doentes de SRIS positivo como em doentes de SRIS negativo. Apesar de ainda requerer confirmaçao numa maior amostra populacional, este estudo demonstrou que a implementaçao de fluidoterapia, respeitando protocolos estabelecidos, não provoca desta forma sinais de dispneia respiratória.
VPOCUS (Veterinary Point-of-Care Ultrasound) represents a set of techniques specifically developed to detect not only abdominal but also thoracic injuries. It is a repeatable, objective and rapid exam and is therefore extremely important in the daily assessment of traumatic and unstable patients, as well as in the general assessment of all patients. The aim of this study was to verify the capacity of differentiation of B-lines presence, as a clinical sign in dogs, independently of the signs of SRIS (systemic inflammatory response syndrome), in order to use VPOCUS as a measure of evaluation of fluid therapy protocols at the time of screening. A population of 20 dogs (n = 20) with gastrointestinal signs, submitted for evaluation of SRIS parameters and the VPOCUS at the thoracic level, followed by the introduction of established fluidtherapy protocols, was included in the current study. Participants were subjected to four monitoring moments, where the SRIS parameters were evaluated and VPOCUS performed. The results showed that patients with normal respiratory rates tended to have more than statistically expected lack of B-lines (X2=3.750; gl=1; p=0.053). In the control group, M1 and M2, it was shown that patients with an elevated respiratory rate tended to have na absense of B-lines (X2=5,000; gl=1; p=0,025). It was also possible to observe a statistically significant relationship between normal temperature and the absence of B lines (X2 = 4.444; gl = 1; p = 0.035) in the control group. There was also a statistically significant relationship between the presence of more than 3 B-lines and the presence of SRIS (X2=8.439; gl=2; p=0.015). In the present study there was no evidence that the use of fluidtherapy protocols (according to AAHA rules) increases the existence of B-lines when screening with VPOCUS in both positive and negative SRIS patients. Although still requiring confirmation in a larger population sample, this study demonstrated that the implementation of fluid therapy, following established protocols, is not responsible for signs of respiratory dyspnea.
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Müller, Franziska. "Hochauflösende Ultraschallverfahren und Doppler-Sonographie zur Mammadiagnostik bei der Hündin: High-resolution and Doppler methods in sonography of the mammary gland of the bitch." Doctoral thesis, 2009. https://ul.qucosa.de/id/qucosa%3A11014.
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An 53 Hündinnen aus dem Patientengut der Klinik für Kleintiere der Universität Leipzig, die mit Umfangsvermehrungen der Mamma vorgestellt und anschließend in der Klinik für Kleintiere operiert wurden, wurde präoperativ eine sonographische Untersuchung der Mamma durchgeführt. Darüber hinaus wurden die Mammarkomplexe von acht tragenden und einer laktierenden Hündin mit dieser Technik untersucht. Ziel war es, Kriterien zur Einschätzung der Dignität der Tumoren mit Hilfe dieser nichtinvasiven Methode zu erarbeiten. Es sollten die Fragen geklärt werden, ob mit Hilfe der hochauflösenden Sonographie eine Aussage über Gut- oder Bösartigkeit eines Herdes möglich ist und ob dabei dieselben Kriterien entscheidend sind, die in der Humanmedizin eine zuverlässige Differenzierung erlauben. Außerdem sollte überprüft werden, welchen Beitrag die farbkodierte Duplexsonographie oder Resistance- und Pulsatilitätsindex zur Charakterisierung von Mammatumoren der Hündin leisten. Die Gesamtzahl der in die Studie eingehenden Komplexe beträgt 114.
Die sonographischen Untersuchungen erfolgten mit einem 14 MHz Matrix-Linearschallkopf. Bei 70 der 114 untersuchten Lokalisationen erfolgte zusätzlich zur B-Mode-Untersuchung eine Untersuchung mit der farbkodierten Duplexsonographie. Konnten mit Hilfe dieser Methode Gefäße in der Umfangsvermehrung nachgewiesen werden, wurde in 47 von 70 Fäl-len zusätzlich der PW-Doppler eingesetzt, um Flussspektren aus den dargestellten Gefäßen abzuleiten. Aus diesen wurden Resistance-Index und Pulsatilitätsindex bestimmt.
Bei der retrospektiven Auswertung der Grauwertbilder aus der B-Mode-Untersuchung wurde für jeden Komplex die Ausprägung von 12 Parametern beurteilt. Die Bilder aus der farbkodierten Duplexsonographie lieferten zusätzlich Informationen zu Gefäßzahl, Gefäßdurchmesser und Gefäßverteilung innerhalb eines Tumors.
Die Exstirpate wurden pathohistologisch untersucht. Die aus der Gewebetypisierung entsprechend der WHO-Klassifikation resultierenden Gruppen sind so klein, dass nur eine deskriptive statistische Auswertung möglich war. Es erfolgte die Zusammenfassung unterschiedlicher Gewebetypen zu den Gruppen der „malignen“ bzw. „benignen“ Tumoren.
Für Malignität sprechen eine unregelmäßige Randkontur (32 von 61 malignen, 4 von 48 benignen Lokalisationen), eine Schallverstärkung (36/61 malignen, 9/48 benignen Lokalisationen) oder –auslöschung (8/61 malignen, 0 /48 benignen Lokalisationen) hinter dem Tumor, Verkalkungen (20/61 malignen, 6/48 benignen Lokalisationen) sowie ein unregelmäßiger Durchmesser der Tumorgefäße (25/61 malignen, 12/48 benignen Lokalisationen).
Meist gutartig sind Umfangsvermehrungen der Mamma, denen sonographisch eine klare Abgrenzung zum umgebenden Gewebe fehlt (15/61 malignen, 36/48 benignen Lokalisationen). Außerdem solche mit indifferentem retroläsionalem Schallverhalten (17/61 malignen, 39/48 benignen Lokalisationen).
Kombiniert man mehrere der Parameter miteinander, ist die resultierende Teilmenge der betreffenden Läsionen kleiner, die Aussagekraft höher. Für Bösartigkeit spricht beispielsweise eine Kombination von Verkalkung und unregelmäßiger Randkontur (13 von 61 malignen, 1 von 48 benignen Lokalisationen), Verkalkung und echodichtem Randsaum („deutlich“ oder „fraglich“; 9/61 malignen, 0/48 benignen Lokalisationen) sowie mittlerer Echodichte und retroläsionaler Schallverstärkung (21/61 malignen, 6/48 benignen Lokalisationen).
Für Gutartigkeit sprechen mittlere Echodichte des Tumorzentrums in Kombination mit indifferentem Schallverhalten (13/61 malignen, 33/48 benignen Lokalisationen) sowie regelmäßiger Gefäßdurchmesser bei diffuser Gefäßverteilung (3/36 malignen, 14/29 benignen Lokalisationen).
Es konnte dargestellt werden, dass sich mit Hilfe der hochauflösenden B-Mode-Sonographie Kriterien aufzeigen lassen, die tendenziell für Gut- oder Bösartigkeit eines Mammatumors sprechen. Dabei ist es zweckmäßig, mehrere Parameter in die Beurteilung einfließen zu lassen. Auch die farbkodierte Duplexsonographie kann dabei einen Beitrag leisten. Die Ermittlung von Resistance- und Pulsatilitätsindex hingegen erweist sich als nicht sinnvoll.
Ein Parameter, welcher in der Humanmedizin eine entscheidende Rolle zur Unterscheidung bösartiger von gutartigen Tumoren der Mamma spielt ist die Randkontur eines Tumors. Dies ist das einzige Kriterium, das auch bei Mammatumoren der Hündin einen diagnostischen Nutzen aufweist.
Anhand einzelner sonographischer Parameter ist es nicht möglich, die Dignität eines Tumors vorherzusagen. Die sonographische Untersuchung kann jedoch in einigen Fällen beim Abschätzen der Prognose helfen.In 53 bitches that underwent surgery because of tumors of the mammary gland at the Department of small animal medicine of the University of Leipzig we carried out a preoperative ultrasonographic examination of the mammary gland. Furthermore eight pregnant and one lactating bitch were examined the same way. We aimed to find out, whether high-resolution ultrasound helps differentiate benign from malignant tumors. Also we wanted to evaluate criteria established for that purpose in human medicine. Use of colour-coded duplex sonography, resistance index and pulsatility index for this question are reassessed too. The total number of mammary complexes examined for this study is 114. A GE Logiq™ 9 with a 14 MHz linear array transducer was used for all examinations. Seventy of the 114 sites of mammary tissue underwent a colour-coded duplex sonography after the B scan. Blood vessels were detectet in 70 of the tumors. In 47 of these sites the PW-Doppler was used to gain flow patterns to achieve resistance- and pulsatility-index. The images were analysed retrospectively. In B scan images lesions were judged by 12 parameters. Additional information about number, diameter and distribution of vessels within a tumor was taken from the images of colour-coded duplex sonography. The excised complexes were evaluated pathohistologically. Only descriptive statistical analysis was possible because the resulting groups were very small after being sorted according to WHO-classification. Therefore the complexes of mammary glands were subsumpted into two groups – „malignant“ and „benign“ tumours. An irregular contour of the tumor (32 of 61 malignant, 4 of 48 benign tumors), signal enhancement (36/61 malignant, 9/48 benign tumors) or total shadowing (8/61 malignant, 0/48 benign tumors) behind the tumor, calcification (20/61 malignant, 6/48 benign tumors) and irregular vessel diameters (25/61 malignant, 12/48 benign tumors) are signs of malignancy. Tumors that miss a clearly detactable borderline (15/61 malignant, 36/48 benign tumors) and tumors with no signal alteration behind the tumor (17/61 malignant, 39/48 benign tumors) are benign more often. The combination of parameters reduces the number of adequate tumors and rises significance. A tumor showing an irregular contour and calcification (13/61 malignant, 1/48 benign tumors) is more likely to be malignant as well as a tumor of medium echodensity showing signal enhancement (21/61 malignant, 6/48 benign tumors). Tumors of medium echodensity without signal alteration behind the lesion (13/61 malignant, 33/48 benign tumors) and tumors with diffusely distributed vessels of regular diameter (3/36 malignant, 14/29 benign tumors) are more likely to be benign. It could be shown that high-resolution B scan parameters can help differentiate between malignant and benign tumors of the mammary gland, especially if they are used in combination with each other. Parameters from colour-coded duplex sonography can increase predicting value of B scan examinations too but there is no use of analysing resistance index or pulsatility index. One of the criteria established in human medicine ist the contour of a tumor. This parameter is of diagnostic use in mammary tumours of the bitch too. It is not possible to clearly predict the character of a tumor of the mammary gland of a bitch by only a few parameters based on a sonogram but sonographic examination can be helpful for assessing prognosis sometimes.
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Silva, Ana Margarida Bernardo da. "Caracterização da aparência ecográfica de lesões esplénicas em relação ao seu diagnóstico histopatológico em cães." Master's thesis, 2022. http://hdl.handle.net/10437/12788.
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Orientação: Nazaré Cunha ; coorientação: Inês OliveiraAs patologias esplénicas são doenças comummente diagnosticadas em canídeos e apresentam manifestações clínicas inespecíficas, sendo necessário recorrer a exames complementares de diagnóstico, como a ecografia abdominal e a citologia. O objetivo do presente trabalho foi caracterizar uma população de canídeos esplenectomizados e a aparência ecográfica das suas lesões esplénicas de modo a determinar a capacidade de diferenciar lesões benignas de malignas. Para tal, avaliou-se a imagem ecográfica de 19 canídeos em comparação com o seu diagnóstico histopatológico, descrevendo-se também o resultado citológico em 8 animais, A maioria das lesões encontradas foram benignas (12/19), sendo a hiperplasia nodular o diagnóstico histopatológico mais frequente, seguido do hematoma e hemangiossarcoma esplénico. A ecografia obteve uma sensibilidade de 85,71%, especificidade de 41,67%, valor preditivo positivo de 54,55%, valor preditivo negativo de 83,88% e uma acuidade de 57,89%. Estes resultados permitem inferir que a ecografia é um exame útil para detetar patologias esplénicas malignas, no entanto pode apresentar um elevado número de resultados falsos positivos. Não foi possível avaliar a performance diagnóstica da citologia devido ao reduzido número de casos, mas foi possível observar uma concordância total entre os resultados obtidos na citologia e na histopatologia em 62,5% dos casos (5/8). Em suma, a aparência ecográfica das lesões esplénicas foi variável e não permitiu estabelecer um padrão para diferenciar as alterações malignas de benignas. A ecografia e a citologia, quando utilizadas em conjunto, permitem obter informações importantes para definir o plano de tratamento.
Splenic pathologies in dogs are commonly observed in the casuist of veterinary clinics. These pathologies have nonspecific clinical manifestations, making it necessary to resort to complementary diagnostic tests, such as abdominal ultrasound and cytology, for their evaluation. The aim of the present study was to characterize the population of 19 splenectomised dogs and the ultrasonography appearance of the splenic lesions to determine the ability of this test to differentiate benign from malignant splenic lesions in comparison with its histopathological diagnosis. Most of the lesions found were benign (12/19), with nodular hyperplasia being the most frequent histopathological diagnosis, followed by hematoma and splenic hemangiosarcoma. Ultrasound had a sensitivity of 100%, specificity of 42%, a positive predictive value of 50%, a negative predictive value of 100% and an accuracy of 63%. These results allow us to infer that ultrasound is a useful exam to detect malignant splenic pathologies, however it will present a high number of false positive results, that is, animals with benign splenic pathologies that present an ultrasound image suggestive of being malignant. It was not possible to determine the sensitivity of cytology due to the small number of cases, but it was possible to observe complete agreement between the results obtained in cytology and histopathology in 62.5% of cases (5/8). The ultrasonography appearance of the splenic lesions was variable and did not allow to stabilish a pattern to differentiate malignant from benign alterations. Ultrasound and cytology, when used together, provide important information to define the treatment plan.
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Chen, Hung-Ju, and 陳泓儒. "Implementation of a burn scar assessment system by ultrasound techniques." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/54039867414465029489.
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碩士國立成功大學
醫學工程研究所碩博士班
93
Tissue injury and the ensuing healing process cause scar formation. In addition to physical disability, the subsequent disfigurements from burns often bring negative psychological impacts on the survivors. Scar hypertrophy and contracture limited joints motion and body functions. With the current technologies available, therapies no longer focus sorely on the process of wound healing, but also emphasize on the cosmetic and functional outcomes. Therefore, proper evaluation and assessment of the steps to nil scar status is expected. However, the frequently employed tools remained subjective. For example, Vancouver General Hospital (VGH) scar index uses color, pigmentation, vascularity, pliability, and depth of the scar as dependent variables. These parameters of VGH scar index just estimate the superficial surface, but can not evaluate the deeper contain within dermis. Ultrasound is a safe, inexpensive, and multifunctional probe. Its resolution is not inferior to other measurement methods. Although 3D ultrasound is available clinically. It’s not popular to use in scar estimation. The intra-organs or structure deep fascia usually are the targets. Only to it’s high penetration device and high cost. In this study, we proposed a new scar assessment system using ultrasound. By utilizing reconstruction methods to search the border of the scar, many parameters of the scar become evident: depth, area and volume. This objective measurement tool permits the clinician to better understand the effects of treatments and plan further therapies. In the present study, we used our quantitative assessment system on the arm of a seriously burned patient. In order to verify the systematic reconstruction method reliably, we constructed a model to imitate the scar. The final results showed that the accuracy rate could reach above 90%. That is a paramount issue to assess the total amount of scar. Therefore, another one objective facility is to assess these problems.
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Azinhais, Marta Coutinho Candeias Viegas. "Laserterapia de alta intensidade no tratamento de tendões e ligamentos da extremidade distal do membro em equinos: aplicação a quatro casos clínicos." Master's thesis, 2022. http://hdl.handle.net/10437/12821.
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Orientação: Joana Simões ; coorientação: Mafalda Vaz PintoEnquanto atleta, o cavalo está altamente predisposto a lesões de estruturas ligamentosas e tendinosas localizadas na porção distal dos membros. O aumento do conhecimento científico sobre lesões locomotoras apela, cada vez mais, a tratamentos que preservem e otimizem o futuro da carreira desportiva do cavalo. É nesta perspetiva que se verifica uma crescente preferência por soluções pouco invasivas – onde se integra a laserterapia de alta intensidade. O presente trabalho teve por objetivo desenvolver o tema da laserterapia no tratamento de lesões de tendões e ligamentos em equinos. Assim, segue-se uma revisão bibliográfica sobre o tema e a apresentação e discussão de quatro casos clínicos, onde foi utilizado um LASER de classe IV para o tratamento de duas lesões do tendão flexor digital superficial e cinco lesões do ligamento suspensor do boleto. De forma geral, todos os casos demonstraram uma resposta positiva ao tratamento implementado, no qual se incluiu a laserterapia, sendo a resposta ao mesmo avaliada através de três parâmetros principais: dor, claudicação e imagem ecográfica. Durante os vários períodos de avaliação (T1, T2, T3 e T4), verificou-se um decréscimo da dor e da claudicação em todos os casos clínicos. Contudo, ecograficamente não se observaram alterações consideráveis em três lesões de um total de sete incluídas neste trabalho.
As an athlete, the horse is highly predisposed to injuries of ligamentous and tendon structures located in the distal portion of the limbs. The increase in scientific knowledge about locomotor injuries calls for treatments that preserve and optimize the future of the sport horse’s career. It is in this perspective that there’s an increasingly preference for low invasive solutions – where high-intensity laser therapy is included. The present work aimed to develop the theme of laser therapy in the treatment of tendon and ligament injuries in horses. Thus, it follows a bibliographical review on the theme and the presentation and discussion of four clinical cases, where a class IV laser was used for the treatment of two superficial digital flexor tendon and five suspensory ligament injuries. In general, all cases showed a positive response to the implemented treatment, including laser therapy, which was evaluated by three main parameters: pain, lameness and ultrasound. During the four evaluation periods (T1, T2, T3 and T4), there was a decrease in pain and lameness in all clinical cases, while ultrasound showed no changes in three cases out of seven included in this report.
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Taylor, Jason Richard Benjamin. "Wavelet-based blind deconvolution and denoising of ultrasound scans for non-destructive test applications." 2012. http://hdl.handle.net/1993/14161.
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A novel technique for blind deconvolution of ultrasound is introduced. Existing deconvolution techniques for ultrasound such as cepstrum-based methods and the work of Adam and Michailovich – based on Discrete Wavelet Transform (DWT) shrinkage of the log-spectrum – exploit the smoothness of the pulse log-spectrum relative to the reflectivity function to estimate the pulse. To reduce the effects of non-stationarity in the ultrasound signal on both the pulse estimation and deconvolution, the log-spectrum is time-localized and represented as the Continuous Wavelet Transform (CWT) log-scalogram in the proposed technique. The pulse CWT coefficients are estimated via DWT shrinkage of the log-scalogram and are then deconvolved by wavelet-domain Wiener filtering. Parameters of the technique are found by heuristic optimization on a training set with various quality metrics: entropy, autocorrelation 6-dB width and fractal dimension. The technique is further enhanced by using different CWT wavelets for estimation and deconvolution, similar to the WienerChop method.
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Dosedla, Erik. "Ultrazvuková charakteristika dutiny břišní v průběhu 6 tydnů po císařském řezu." Doctoral thesis, 2017. http://www.nusl.cz/ntk/nusl-372356.
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Caesarean section is one of the most frequently performed surgery in medicine. The Cesarean section scar in the uterus can lead to a number of pathological conditions which affect the women reproductive health. In industrialized countries, this issue relates to at least 30% of women, which means that it is a major medical problem. Ultrasound examination of the uterus after Cesarean section includes some specific features, resulting from the rapidly changing dimensions of the uterus, as well as from patient compliance in early puerperium. When dealing with postpartum complications, it is necessary to know the normal ultrasound findings and the dynamic changes of the uterus during puerperium, so that we can better distinguish between the pathological course and the normal course of puerperium. The clinical significance of ultrasound assessment of uterine size and area of the scar after Caesarean section during the postpartum is not yet adequately described. The knowledge of normal ultrasound findings in the uterus after Caesarean section could be helpful in choosing the right treatment in severe cases. We were watching the clinical outcomes of treatment of abnormal Cesarean section scars after their laparoscopic reconstruction. In our study, we have shown that the examination of uterus in early...
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Santos, António Manuel Barroso Rodrigues dos. "Utilização da ecografia no aumento de rentabilidade em explorações de ovinos." Master's thesis, 2013. http://hdl.handle.net/10437/4802.
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Orientação : João António Martins Cannas da Silva ; co-orientação : Maria do Carmo FelicianoNeste estudo avaliou-se a eficácia reprodutiva da aplicação de dois sistemas de maneio, na época de cobrição, em ovinos. Avaliou-se também a variação sazonal de parâmetros reprodutivos. Na exploração A houve primeiro a pré-exposição a carneiros férteis (45 dias), onde se efectuaram cobrições naturais. O diagnóstico de gestação foi feito aos 90 dias, com nova introdução de machos. Posteriormente foram retirados os carneiros, realizando-se novo diagnóstico aos 180 dias. Efetuaram-se ainda dois grupos de sincronização, sendo aplicado tratamento com progestagéneos (FGA) através de esponjas e injecção de PMSG/eCG no dia da retirada, com posterior cobrição. Na exploração B, os carneiros estiveram presentes durante toda a época reprodutiva, que decorreu entre Fevereiro e Agosto, existindo apenas cobrição natural. Nesta exploração ocorreu um parto por ovelha/ano, ao contrário da A, que teve como objectivo três partos em dois anos. A fertilidade global na exploração A foi de 92,4% e não foi afectada significativamente pelo sistema de maneio aplicado, ao contrário da B que foi de 64%. Os resultados indicaram que o sucesso da exploração A deveu-se à aplicação de tratamentos hormonais ou a técnicas como o efeito macho. Estes induzem a sincronização dos cios permitindo a obtenção de taxas de fertilidade elevadas.
In this study we evaluated the reproductive efficiency of the implementation of two systems of management at the time of mating in ovines. We also assessed the seasonal variations of reproductive parameters. In the farm A there was first the pre - exposure to fertile rams (45 days), which made natural mating. Pregnancy diagnosis was made at 90 days, with new introduction of males. Subsequently the males were removed and new pregnancy diagnosis was performed at 180 days. We carried out two further synchronization groups treated with with progestagens (FGA). It was applied using sponges and injection of PMSG / eCG on the day of withdrawal, with subsequent mating. In farm B, the sheep were present throughout the breeding season, which took place between February and August, with only natural mating. On this farm there was a birth per sheep / year, unlike A, which aimed three deliveries in two years. The overall fertility in the farm A was 92.4 % and was not significantly affected by the management system applied, unlike B that was 64 %. The results indicated that the success of the farm A was due to the application of hormonal treatments or techniques as the male effect. These induce synchronization of estrous cycle capable of producing high fertility rates.
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Bacelar, Joana Filipa Correia Soares. "Estudo da relação entre a doença renal e as alterações ecográficas observadas no rim do gato." Master's thesis, 2016. http://hdl.handle.net/10437/7523.
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Orientação : João
Requicha ; co-orientação : Ana SantanaA doença renal é uma doença diagnosticada frequentemente em gatos seniores e geriátricos, apesar de afetar gatos de todas as idades. O exame ecográfico do rim, apesar de não fornecer informações sobre o funcionamento renal, é uma ferramenta vital no diagnóstico de alterações morfológicas no sistema urinário. O presente estudo, observacional transversal, teve como objetivo avaliar as alterações ecográficas mais frequentes no rim do gato, assim como identificar relações entre a idade dos indivíduos e a presença de doença renal. Este trabalho compreendeu uma amostra de 158 gatos com idades entre os 6 meses e os 20 anos, de ambos os sexos e maioritariamente de raça Doméstico de Pelo Curto, assistidos no Hospital Vivemos o Gato (Lisboa, Portugal). A amostra foi dividida nos seguintes grupos: (i) 61 gatos com doença renal com azotemia, (ii) 48 gatos sem doença renal, não azotémicos, mas com diagnóstico de comorbilidades não renais e (iii) 49 gatos saudáveis, não azotémicos e sem qualquer patologia diagnosticada. Os parâmetros ecográficos, como o tamanho renal (p=0,023), a definição corticomedular (p<0,001), a pélvis renal (p=0,008), a arquitetura interna (p <0,001) e outras alterações incluindo a presença de rim sign, camada cortical espessada, líquido subcapsular, dilatação do ureter e mesentério adjacente aos rins reativo (p=0,046) tinham uma relação estatisticamente significativa com a doença renal. Outros parâmetros ecográficos, tais como os contornos e forma renal, a ecogenicidade e a presença de litíase ou calcificações tecidulares, não foram considerados estatisticamente significativos. Com a realização deste estudo, verificou-se que a doença renal em gatos poderá estar a ser subdiagnosticada, visto que o número de animais que apresentaram alterações renais no exame ecográfico, consequentemente sendo considerados doentes renais, ser relativamente superior ao número de animais azotémicos.
Kidney disease is a progressive disease, very common, mainly diagnosed in senior and geriatric cats, although it affects cats of all ages. The ultrasound examination, while it does not provide any information on renal function, is a vital tool in the diagnosis of morphological changes in the urinary tract. The present observational transversal study, o aimed to evaluate the ultra-sonographic changes more frequent in the feline kidney, as well as identify relations between the age of the cats and the presence of kidney disease. This study comprised a sample of 158 cats between the ages of 6 months and 20 years, of both sexes and mainly of Domestic Shorthair breed, assisted in Hospital Vivemos o Gato (Lisbon, Portugal). The sample was divided into the following groups: (i) 61 cats with kidney disease and azotemic; (ii) 48 cats without kidney disease, non-azotemic but with a diagnosed non-renal comorbidity; and (iii) 49 healthy, non-azotemic cats without any diagnosed disease. The ultrasonographic parameters, such as size (p=0,023), corticomedullary definition (p<0,001), renal pelvis (p=0,008), internal architecture (p <0,001) and other alterations (p=0,046), including the presence of rim sign, thickened renal cortex, subcapsular liquid, ureteral dilation and reactive mesenteric adjacent to the kidneys, had a statistically significant relation with kidney disease. Other ultrasonographic parameters, such as renal contours and shape, echogenicity and presence of renal lithiasis or tissue calcifications, were not considered statistically significant. With this study it was found that the kidney disease in cats might be being underdiagnosed, seeing as the number of animals with kidney abnormalities on the ultrasound examination, thus being considered renal patients is considerably higher than the number of azotemic animals.
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Leonardo, Joana Figueiredo. "Estudo ecográfico em glândulas adrenais aumentadas." Master's thesis, 2013. http://hdl.handle.net/10437/4841.
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Orientação : Margarida Alves ; co-orientação : Pedro Morais de Almeida ; responsabilidade externa : Luís CruzA ecografia abdominal tem inúmeras vantagens na observação das glândulas adrenais, especialmente em animais geriátricos. Em muitos animais, as adrenais são ecograficamente detetadas apenas quando aumentadas. Alguns tipos de aumento têm significado patológico, podendo estar ou não associado a distúrbios endócrinos, o que reforça a importância da sua observação aquando do exame ecográfico. O presente trabalho teve como objetivos, descrever os achados ecográficos de glândulas adrenais aumentadas, relacionar as suas características com os factores epidemiológicos da amostra e compreender se achados ecográficos adrenais têm, ou não,relevância clínica. O estudo desenvolvido compreendeu a análise retrospetiva 25 casos clínicos de dois Hospitais Veterinários da região de Lisboa – Hospital Veterinário das Laranjeiras e Hospital Veterinário de Lisboa – diagnosticados entre 2007 e 2012. Foram selecionados animais nos quais, pelo menos, uma das glândulas adrenais se apresentava aumentada, ou seja, com diâmetro transversal máximo acima de 7,4mm. Constatou-se que a generalidade dos cães deste estudo eram geriátricos, sem raça determinada e do sexo feminino. A maioria das adrenais estudadas não apresentou sinais de calcificação, nem metastização. O hiperadrenocorticismo foi diagnosticado em sete dos cães em estudo nos quais, quatro eram de origem hipofisária, com hiperplasia adrenal bilateral e três tumores adrenais. A maioria das alterações foram achados ecográficos ou “incidentalomas”, compatíveis com alterações benignas não funcionais, sem relevância clínica.
The abdominal sonography has several advantages in the observation of the adrenal glands, especially in geriatric animals. In most animals, the adrenal glands are only detected in the ultrasound exam when they are swollen or grown. A few kinds of growths have a pathological meaning, being or not associated with endocrinal disorders; such fact reinforces the relevance of their observation during the exam. This paper aims to describe the sonographic findings of increased adrenal glands, relate their characteristics with epidemiological factors within the sample, and understand whether such findings have or do not have clinical relevance. The study consists of the retrospective analysis of 25 clinical cases diagnosed from 2007 until 2012 in two veterinarian hospitals in Lisbon – Hospital Veterinário das Laranjeiras and Hospital Veterinário de Lisboa. The animals in this study had at least one of the adrenal glands in a grown state, whose maximum transversal diameter was over 7,4mm. Most of the dogs in this study were geriatric female mongrels. Most of the adrenal glands investigated did not show any evidence of calcification or metastasization. Hypoadrenocorticism was diagnosed in seven dogs, from which four had a hypothysial origin with bilateral adrenal hyperplasia, and three had adrenal tumors. Most of the alterations were incidental findings or “incidentalomas”, which are compatible with non-functional benign alterations without any clinical relevance.
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Serralheiro, Maria Margarida Marques. "Análise retrospetiva da utilização de ecografia convencional e ultrassonografia biomicroscópica em oftalmologia de canídeos e felídeos." Master's thesis, 2018. http://hdl.handle.net/10437/9409.
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Orientação: Daniel Murta ; orientação externa: Ana Paula ResendeA oftalmologia humana tem sofrido constantes avanços tecnológicos com a evolução da medicina ao longo dos anos, começando a haver cada vez mais formas de diagnóstico capazes de aprofundar alterações oculares, no entanto em medicina veterinária este ainda é um ramo pouco explorado, mas que se encontra em crescimento. A ultrassonografia ocular entende-se pela utilização da ondas de som, em frequências superiores às detetadas pelo ouvido humano, emitidas por um transdutor posicionado sobre o globo ocular que permite a avaliação das estruturas intra e extra oculares. Pode ser dividida em convencional, na qual as frequências de ultrassom variam de 7,5 a 20 MHz, e na ultrassonografia biomicroscópica que utiliza altas frequências acima de 25 MHz. É um método de exame não invasivo, relativamente rápido, visto que não necessita de sedação, na maioria dos casos, e o equipamento é portátil podendo ser transportado para o local onde o animal está a ser observado. Requer alguma prática de utilização e de interpretação das imagens obtidas, contudo, é o método de diagnóstico de eleição em casos de alterações oculares com opacidade dos meios e que necessitem de rápida informação sobre o estado de integridade do olho. A ultrassonografia biomicroscópica é pouco utilizada na prática clínica de medicina veterinária em Portugal, devido ao elevado custo do equipamento e especificidade sobre este exame. A presente análise retrospetiva teve lugar na Vet Visão Centro Veterinário de Benfica, entre 2013 e início de 2018, onde foram avaliados 117 animais com alterações oculares com indicação para realização de ultrassonografia ocular. No decorrer deste trabalho foi possível observar que bastantes alterações foram detetadas apenas com a utilização da ecografia convencional e da ultrassonografia biomicroscópica, devido à presença de opacidade de estruturas intraoculares. Os achados ultrassonográficos oculares permitiram chegar a um correto diagnóstico, consequente prognóstico e instituição de tratamento adequado a cada situação.
Human ophthalmology has had constant technological advances with the evolution of medicine over the years, which helped to improve diagnostic procedures capable of identifying ocular pathological alterations. However veterinary medicine still has a lot to explore and improve. Ocular ultrasonography is an exam that uses sound waves, with frequencies that human ear can’t identify, emitted by a probe positioned above the eyeball that allows an assessment of the intra and extra-ocular structures. It can be divided in conventional ultrasound, which uses frequency between 7,5 to 20 MHz, and biomicroscópica ultrasound, that uses higher frequencies, above 25 MHz. It’s a non-invasive procedure, with relatively rapid examination, since sedation is not necessary in most of the cases, and the equipment is portable which can be transported to the local where the animal is being observed. It may require practice of the operator and sometimes images can be difficult to interpret, however it is the election method for cases that requires rapid information on the eye condition in the presence of intraocular opacities. Ultrasound biomicroscopy has not a common use in the clinical practice of veterinary medicine in Portugal, due to the high cost of the equipment and specificity on this exam. The present retrospective study was carried out at the Vet Visão Veterinary Center of Benfica between 2013 and 2017, in which 117 animals with pathological ocular alterations with indication for ocular ultrasound. With this study was possible to understand that a lot of the ocular pathologies were only diagnosed by conventional ultrasound, and with ultrasound biomicroscopy, due to the presence of intraocular opacities. Ultrasonography ocular findings allowed arriving at a correct diagnosis, consequent prognosis and appropriate treatment institution for each situation.
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Rijt, Maaike Petronella Van De. "Alterações radiográficas e ecográficas de osteoartrite da articulação metacarpofalângica em cavalos de desporto." Master's thesis, 2011. http://hdl.handle.net/10437/2720.
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Orientação: Ana Teresa Silva ; co-orientação: Ana GodinhoNos equinos a articulação metacarpofalângica é submetida a vários graus de stress físico. Com o exercício intenso, o aumento da carga imposta aos seus tecidos pode provocar sinovite mecanicamente induzida, com produção e libertação de citoquinas, e consequentemente estimulação de metaloproteinases e outros componentes inflamatórios. Esta situação pode causar um desequilíbrio entre os processos de síntese e degradação de proteoglicanos e glicosaminoglicanos da matriz cartilaginosa, levando a osteoartrite. A osteoartrite é considerada uma das causas mais comuns da diminuição da performance e abandono precoce das actividades desportivas dos equinos. A utilização do Rx e da ecografia articular em conjunto tem vindo a aumentar cada vez mais na prática clínica equina, pois são dois meios relativamente baratos e de fácil acesso em comparação com outros métodos de diagnóstico imagiológicos. A utilização conjunta permite uma avaliação tanto estática como dinâmica da articulação, permitindo uma avaliação mais precisa da articulação, beneficiando o diagnóstico e avaliação de patologias ósseas. Neste trabalho, para além de falar da anatomia e fisiologia da articulação normal, faço uma breve descrição da fisiopatologia da osteoartrite, do seu diagnóstico e tratamento. No entanto dá-se ênfase as alterações radiológicas e ecográficas da osteoartite a nível da articulação metacarpofalângica e benefício destes dois métodos combinados.
In horses the metacarpophalangeal joint is submitted to various degrees of physical stress. With intense exercise, the increasing weight on the tissues can cause mechanically induced synovitis, with production and release of cytokines, and consequently stimulation of metalloproteinases and other inflammatory components. This may lead to an imbalance between the processes of synthesis and degradation of proteoglycans and glycosaminoglycans in cartilage matrix, leading to osteoarthritis. Osteoarthritis is considered one of the most common causes of decreased performance and early dropout from the equine sport. The use of ultrasound and x-ray together in joint evaluation has been increasing in equine clinical practice, because both methods are relatively cheap and easy compared to other diagnostic imaging methods. Using the two methods combined allows a dynamic and static evaluation of the joint, allowing more accurate evaluation of the joint, benefiting the diagnosis and evaluation of bone pathologies. In this work describes the anatomy and physiology of the normal joint, as well as a brief description of the pathophysiology, diagnosis and treatment of osteoarthritis. However I will emphasize the radiological and ultrasound changes of osteoarthritis in the metacarpophalangeal joint, and the combined benefit of these two methods together.
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Monteiro, Carolina Adriana Pernadas de Brito. "Caracterização ecográficas de corpos estranhos e impactações alimentares no trato gastrointestinal em animais de companhia." Master's thesis, 2013. http://hdl.handle.net/10437/6578.
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Orientação : Margarida Alves ; co-orientação : Luís ResendeA ecografia tem vindo a ser amplamente utilizada na avaliação do trato gastrintestinal (GI) em animais de companhia, sendo a técnica de eleição na pesquisa de corpos estranhos (CE). Para a sua interpretação é importante conhecer em detalhe a anatomia do trato GI e os sinais ecográficos de doença GI, em particular os associados à presença de CE. Neste trabalho pretendeu-se caracterizar ecograficamente os vários tipos de CE no trato GI, na tentativa de os identificar, bem como apresentar os principais tipos de padrões alimentares no trato GI, de modo a diferenciá-los de potenciais CE. Foram compilados, num estudo retrospetivo, vários exemplos de CE encontrados no trato GI. Os seus padrões acústicos foram revistos e analisados por um médico veterinário experiente em ecografia e classificados de acordo com o seu tipo de interface, ecogenicidade e a sua origem (alimentar, não alimentar e mista). Foram, também, compilados e analisados os padrões acústicos de vários alimentos no trato GI. Por último, foram realizados estudos ecográficos em gelatina dos principais CE’s e alimentos observados no lúmen gástrico, tendo os seus padrões ecográficos sido registados. A análise dos dados recolhidos permitiu realçar a importância não só das características ecográficas de um CE no trato GI para a delimitação da lista de possibilidades da sua origem, como do reconhecimento dos padrões ecográficos da comida no estômago e sua diferenciação de potenciais CE’s de modo a recomendar o correto procedimento clínico.
Ultrasound has been widely used in the evaluation of small animal gastrointestinal tract (GI), and is becoming the elective technique in the search of foreign bodies (FB). For its interpretation, is important to know in detail the anatomy of the GI tract and sonographic signs of GI disease, particularly those associated with the presence of a FB. This work aims to ultrasonographic characterize the various types of FB in the GI tract, in an attempt to identify them, as well as presenting the main types of food patterns in the GI tract, in order to differentiate them from potential FB. Several examples of FBs in the GI tract, were compiled in a retrospective study. Their acoustic patterns were reviewed and analyzed by a veterinarian experienced in ultrasound and classified accordingly to their type of interface, echogenicity and its origin (food, non-food and mixed). The acoustic patterns of various foods in the GI tract were also reported and analyzed. Ultrasound studies in gelatin were also performed with FB and food frequently observed in the gastric lumen; their sonographic patterns were analyzed and registered. The analysis of the collected data highlighted the importance of the sonographic characteristics of an GI foreign body, in delimiting the list of possibilities for its origin. Also, it showed the importance to recognize the sonographic patterns of food in the stomach, in order to differentiate it from potential FB, and recommend the correct clinical approach.