published_or_final_version / abstract / Obstetrics and Gynaecology / Doctoral / Doctor of Philosophy

published_or_final_version / Obstetrics and Gynaecology / Master / Master of Philosophy

Orientador: Maria Emilia Franco Oliveira / Coorientador: Fabio Morato Monteiro / Coorientador: Vera Fernanda Martins Hossepian de Lima / Banca: Letícia Zoccolaro Oliveira / Banca: Lindsay Unno Gimenes / Resumo: O exame andrológico em bovinos reprodutores é de extrema importância para identificação da capacidade reprodutiva de touros. A ultrassonografia é uma ferramenta diagnóstica que pode fornecer importantes informações de forma não invasiva da integridade dos órgãos reprodutivos, no entanto, ainda vem sendo pouco aplicada na prática de avaliação de reprodutores. O objetivo do trabalho foi caracterizar e comparar parâmetros biométricos e atributos ultrassonográficos de testículos, epidídimos e glândulas genitais acessórias, bem como, índices vasculares das artérias testiculares e ilíacas internas de touros das raças Nelore (n=203) e Caracu (n=79), agrupados de acordo com as classes de idade (≤ 18 meses e > 18 meses). Os dados foram analisados pelo PROC MIXED do programa SAS (p<0,05). O perímetro escrotal, comprimento testicular e medida dorsoventral da cauda do epidídimo foram diferentes entre animais ≤ 18 meses e > 18 meses nas raças Nelore e Caracu. A biometria das glândulas vesiculares, porção disseminada da próstata e medida craniocaudal da glândula bulbouretral apresentaram diferença entre raças. Houve diferença entre as idades para glândulas vesiculares, medidas dorsoventral e craniocaudal do corpo da próstata e próstata disseminada. Houve correlações significativas (p<0,05) entre a biometria dos testículos, cauda dos epidídimos e glândulas genitais acessórias, exceto com o corpo da próstata. A intensidade de pixel do parênquima testicular diferiu entre raças e classes de id... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The andrological examination in breeding cattle is of extreme importance for the identification of the reproductive capacity of bulls. Ultrasonography is a diagnostic tool that can provide important noninvasive information on the integrity of reproductive organs, however, it still has been little applied in practice of reproductive evaluation. The objective of this study was to characterize and compare biometric parameters and ultrasonographic attributes of the testes, epididymis and accessory sex glands, as well as vascular indices of internal testes and iliac arteries of Nellore (n=203) and Caracu bulls (n=79), grouped according to age classes (≤18 months and >18 months). Data were analyzed by PROC MIXED of SAS program (p<0.05). The scrotal perimeter, testicular length and dorsoventral measurement of the tail of the epididymis were different between animals ≤18 months and >18 months in the Nellore and Caracu races. The biometry of vesicular glands, disseminated portion of prostate and craniocaudal measurement of bulbourethral gland showed differences between breeds. Were differences between ages for vesicular glands, dorsoventral and craniocaudal measurements of prostate body and disseminated prostate. Were significant correlations (p<0.05) between the biometry of the testes, tail of the epididymides and accessory sex glands, except with the body of the prostate. The pixel intensity of the testicular parenchyma differed between breeds and age classes. The echogenicity (mea... (Complete abstract click electronic access below) / Mestre

Three dimensional (3D) ultrasound has become an increasingly popular medical imaging tool over the last decade. It offers significant advantages over Two Dimensional (2D) ultrasound, such as improved accuracy, the ability to display image planes that are physically impossible with 2D ultrasound, and reduced dependence on the skill of the sonographer. Among 3D medical imaging techniques, ultrasound is the only one portable enough to be used by first responders, on the battlefield, and in rural areas. There are three basic methods of acquiring 3D ultrasound images. In the first method, a 2D array transducer is used to capture a 3D volume directly, using electronic beam steering. This method is mainly used for echocardiography. In the second method, a linear array transducer is mechanically actuated, giving a slower and less expensive alternative to the 2D array. The third method uses a linear array transducer that is moved by hand. This method is known as freehand 3D ultrasound. Whether using a 2D array or a mechanically actuated linear array transducer, the position and orientation of each image is known ahead of time. This is not the case for freehand scanning. To reconstruct a 3D volume from a series of 2D ultrasound images, assumptions must be made about the position and orientation of each image, or a mechanism for detecting the position and orientation of each image must be employed. The most widely used method for freehand 3D imaging relies on the assumption that the probe moves along a straight path with constant orientation and speed. This method requires considerable skill on the part of the sonographer. Another technique uses features within the images themselves to form an estimate of each image's relative location. However, these techniques are not well accepted for diagnostic use because they are not always reliable. The final method for acquiring position and orientation information is to use a six Degree-of-Freedom (6 DoF) tracking system. Commercially available 6 DoF tracking systems use magnetic fields, ultrasonic ranging, or optical tracking to measure the position and orientation of a target. Although accurate, all of these systems have fundamental limitations in that they are relatively expensive and they all require sensors or transmitters to be placed in fixed locations to provide a fixed frame of reference. The goal of the work presented here is to create a probe tracking system for freehand 3D ultrasound that does not rely on any fixed frame of reference. This system tracks the ultrasound probe using only sensors integrated into the probe itself. The advantages of such a system are that it requires no setup before it can be used, it is more portable because no extra equipment is required, it is immune from environmental interference, and it is less expensive than external tracking systems. An ideal tracking system for freehand 3D ultrasound would track in all 6 DoF. However, current sensor technology limits this system to five. Linear transducer motion along the skin surface is tracked optically and transducer orientation is tracked using MEMS gyroscopes. An optical tracking system was developed around an optical mouse sensor to provide linear position information by tracking the skin surface. Two versions were evaluated. One included an optical fiber bundle and the other did not. The purpose of the optical fiber is to allow the system to integrate more easily into existing probes by allowing the sensor and electronics to be mounted away from the scanning end of the probe. Each version was optimized to track features on the skin surface while providing adequate Depth Of Field (DOF) to accept variation in the height of the skin surface. Orientation information is acquired using a 3 axis MEMS gyroscope. The sensor was thoroughly characterized to quantify performance in terms of accuracy and drift. This data provided a basis for estimating the achievable 3D reconstruction accuracy of the complete system. Electrical and mechanical components were designed to attach the sensor to the ultrasound probe in such a way as to simulate its being embedded in the probe itself. An embedded system was developed to perform the processing necessary to translate the sensor data into probe position and orientation estimates in real time. The system utilizes a Microblaze soft core microprocessor and a set of peripheral devices implemented in a Xilinx Spartan 3E field programmable gate array. The Xilinx Microkernel real time operating system performs essential system management tasks and provides a stable software platform for implementation of the inertial tracking algorithm. Stradwin 3D ultrasound software was used to provide a user interface and perform the actual 3D volume reconstruction. Stradwin retrieves 2D ultrasound images from the Terason t3000 portable ultrasound system and communicates with the tracking system to gather position and orientation data. The 3D reconstruction is generated and displayed on the screen of the PC in real time. Stradwin also provides essential system features such as storage and retrieval of data, 3D data interaction, reslicing, manual 3D segmentation, and volume calculation for segmented regions. The 3D reconstruction performance of the system was evaluated by freehand scanning a cylindrical inclusion in a CIRS model 044 ultrasound phantom. Five different motion profiles were used and each profile was repeated 10 times. This entire test regimen was performed twice, once with the optical tracking system using the optical fiber bundle, and once with the optical tracking system without the optical fiber bundle. 3D reconstructions were performed with and without the position and orientation data to provide a basis for comparison. Volume error and surface error were used as the performance metrics. Volume error ranged from 1.3% to 5.3% with tracking information versus 15.6% to 21.9% without for the version of the system without the optical fiber bundle. Volume error ranged from 3.7% to 7.6% with tracking information versus 8.7% to 13.7% without for the version of the system with the optical fiber bundle. Surface error ranged from 0.319 mm RMS to 0.462 mm RMS with tracking information versus 0.678 mm RMS to 1.261 mm RMS without for the version of the system without the optical fiber bundle. Surface error ranged from 0.326 mm RMS to 0.774 mm RMS with tracking information versus 0.538 mm RMS to 1.657 mm RMS without for the version of the system with the optical fiber bundle. The prototype tracking system successfully demonstrated that accurate 3D ultrasound volumes can be generated from 2D freehand data using only sensors integrated into the ultrasound probe. One serious shortcoming of this system is that it only tracks 5 of the 6 degrees of freedom required to perform complete 3D reconstructions. The optical system provides information about linear movement but because it tracks a surface, it cannot measure vertical displacement. Overcoming this limitation is the most obvious candidate for future research using this system. The overall tracking platform, meaning the embedded tracking computer and the PC software, developed and integrated in this work, is ready to take advantage of vertical displacement data, should a method be developed for sensing it.

Orientador: Marcus Antônio Rossi Feliciano / Coorientador: Ricardo Andrés Ramirez Uscategui / Coorientador: Vivian Tavares de Almeida / Banca: Mirela Tinucci Costa / Banca: Leandro Nassar Coutinho / Resumo: A incidência de neoplasmas mamários em cadelas tem aumentado o seu diagnóstico juntamente com a sobrevida desses animais e a avaliação completa das mamas e anexos é fundamental para o diagnóstico adequado. Uma característica dos neoplasmas mamários é a grande capacidade de desenvolver metástase e os linfonodos regionais por serem responsáveis pela drenagem das mamas, desenvolvem um papel importante na disseminação de células tumorais, sendo um fator prognóstico negativo para os pacientes. O desenvolvimento de novas técnicas para detecção do linfonodo sentinela e identificação prévia de alterações contribuem positivamente na sobrevida do paciente. Todavia, a maioria dos métodos utilizados para o diagnóstico conclusivo são métodos invasivos. Sendo assim, este estudo prospectivo visou avaliar a sensibilidade e especificidade das técnicas ultrassonográficas para avaliação de linfonodos locoreginais em cadelas com tumores mamários (Modo-B, Doppler em cores e Elastografia Acoustic Radiation Force Impulse - ARFI), pela diferenciação da malignidade (livres, reativos e metastáticos) Linfonodos axilares (n = 96) e inguinais (n = 100) ipsilaterais de cadeias mamárias de 100 cadelas acometidas foram avaliados por meio da ultrassonografia modo-B (comprimento, altura, relação eixo curto/longo, forma, ecotextura e ecogenicidade), Doppler em cores (presença ou ausência de vascularização) e Elastografia ARFI (rigidez, padrão, deformabilidade, velocidade de cisalhamento e profundidade). As var... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The incidence of mammary neoplasms in bitches has increased their diagnosis along with a survival of the animals and a complete evaluation of the mammarys and appendages is fundamental for the proper diagnosis. A characteristic of mammary neoplasms is a great capacity to develop regional metaphors and lymph nodes because they are responsible for the production of breasts, they play an important role in the dissemination of tumor cells, being a negative prognostic factor for the patients. The development of new techniques for lymph node detection and the preventive identification of positive contributions to patient survival. However, most of the methods used for conclusive diagnosis are invasive methods. (B-mode, Doppler in nuclei and Acoustic Radiation Force Impulse Elastography - ARFI), by the difference in the literature, reactive and metastatic measurements of malignancy (lp, Doppler color and Elastography). Axillary lymph nodes (n = 96) and inguinal lymph nodes (n = 100) ipsilateral mammary chains of 100 bitches were reassessed by means of B-mode ultrasonography (length, height, short / long axis, shape, ecotexture and echogenicity), core Doppler (presence or absence of vascularization) and ARFI Elastography (stiffness, pattern, deformability, shear velocity and depth). The variables that obtained the significant difference have cut-off value, sensitivity, specificity, area over the curve and accuracy. The shear velocity obtained by ARFI elastography showed 95% sensitivi... (Complete abstract click electronic access below) / Mestre

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 158-162).

Thesis (M. Phil.)--University of Hong Kong, 2010. / Includes bibliographical references (p. 67-[70]). Also available in print.

By integrating three complementary imaging techniques - ultrasound, elasticity and photoacoustic imaging, a hybrid imaging system utilizing an array transducer is proposed for various biomedical imaging applications including cancer detection, diagnosis and therapy monitoring. Simultaneous imaging of the anatomy (ultrasound imaging), changes in biomechanical properties (elasticity imaging) and cancer-induced angiogenesis (photoacoustic imaging) of tissue is based on many synergistic features of these modalities and may result in a unique and important imaging tool. In this study, numerical analysis and experimental studies are presented to demonstrate the feasibility, to evaluate the performance, and also to improve the quality of the combined array-based ultrasound, elasticity and photoacoustic imaging system. To estimate spatial resolution, a point source was imaged using ultrasound and photoacoustic imaging modes. Then, several tissue mimicking phantoms were examined using ultrasound, photoacoustic and elasticity imaging. In elasticity imaging, ultrasound frames were acquired during deformation of the tissue. To reduce the data acquisition time of the system, high frame rate imaging was used. High frame rate imaging is possible by transmitting a broader and less focused ultrasound beam but the image quality is sacrificed. Thus, we compared the quality of the high frame rate and conventional ultrasound images. In photoacoustic imaging, acoustic transients are generated simultaneously in the entire volume of the laser irradiated tissue. Hence, image formation (beamforming) algorithms were developed based on the characteristics of the photoacoustic signals. Then, adaptive beamforming method is suggested to improve the image quality of the photoacoustic imaging. The results of the numerical analyses and experimental studies clearly indicate that ultrasound, elasticity and photoacoustic imaging techniques complement each other and together provide critical information needed for the reliable detection and diagnosis of diseases. / text

published_or_final_version / Medicine / Master / Doctor of Medicine

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences