Made available in DSpace on 2014-06-11T19:31:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-01-11Bitstream added on 2014-06-13T18:42:06Z : No. of bitstreams: 1 medeiros_fp_dr_jabo.pdf: 528893 bytes, checksum: cbab22416837a8e3c00b0b9c8ebee7f2 (MD5) / A utilização da ultrassonografia vem se tornando cada vez mais frequente na prática da anestesia regional raquidiana e peridural em pacientes humanos, pois oferece maior segurança e eficácia em relação às técnicas convencionais. Até o presente momento, publicações científicas a cerca do emprego desta modalidade diagnóstica como método de imagem auxiliar em bloqueios de neuroeixo são escassos na medicina veterinária. Objetivou-se com este estudo: padronizar a imagem ultrassonográfica do espaço intervertebral lombossacro em cães quanto à topografia, ecogenicidade, ecotextura e interrelações entre as estruturas visibilizadas; avaliar a confiabilidade da ultrassonografia em predizer a profundidade do espaço peridural, por meio da mensuração da distância entre a pele e a porção ventral do ligamento amarelo, e avaliar efeito da idade, peso e escore corporal na qualidade das imagens ultrassonográficas. Procedeu-se a varredura ultrassonográfica do espaço intervertebral lombossacro em 19 cães, em cortes longitudinal mediano, longitudinal paramediano e transversal. Foi possível identificar as estruturas anatômicas nestes diferentes planos de imagem, e as médias e os desvios padrão das medidas obtidas por meio da ultrassonografia em corte longitudinal e transversal, e da medida obtida pós-punção peridural foram, respectivamente, 2,66 ± 1,09cm, 2,75 ± 1,11cm e 2,81 ± 1,27cm. Concluiu-se que a ultrassonografia é uma técnica eficaz quanto à localização e identificação das estruturas anatômicas lombossacras, e permite determinar com precisão a profundidade do espaço peridural. O plano longitudinal paramediano possibilita a avaliação das estruturas anatômicas enquanto o plano mediano permite a localização do espaço intervertebral lombossacro. Para determinar a profundidade do espaço peridural é recomendado... / The ultrasonography has been spreadly used in the practice of spinal and epidural regional anesthesia in human patients because it offers greater safety and efficacy compared to conventional techniques. To date, studies about the use of this method as a imaging diagnostic tool in neuraxial blocks are scarce in veterinary medicine. The aim of this study was to standardize the ultrasound image of the lumbosacral intervertebral space in dogs, regarding the topography, echogenicity, echotexture and the relations among its structures; to evaluate the ultrasound accuracy in predicting the depth of the epidural space, by measuring the distance between the skin and the ventral portion of the ligamentum flavum and to evaluate the effects of age, body weight and body condition on the quality of ultrasound images. Ultrasound evaluation of lumbosacral intervertebral space was performed in 19 dogs in three planes, such as median longitudinal, paramedian longitudinal and transverse. It was possible to identify anatomic structures in these different image planes. The means and standard deviations of the measurements obtained by ultrasonography in both longitudinal and transversal planes, and the measurement obtained after epidural puncture were, respectively, 2,66 ± 1,09cm, 2,75 ± 1,11cm and 2,81 ± 1,27cm. In conclusion, ultrasonography is an effective technique to locate and to identify the anatomic lombossacral structures, and it is valuable to accurately determine the depth of the epidural space. The paramedian longitudinal plane enables the assessment of anatomical structures while the median plane allows the location of the lumbosacral intervertebral space. The transverse plane is recommended to determine the depth of the epidural space. In this study, it was also noticed that there is no effect of age on the quality of ultrasound... (Complete abstract click electronic access below)

Orientador: Júlio Carlos Canola / Coorientador: Fábio Futema / Banca: Georgea Bignardi Jarretta / Banca: Márcia Rita Fernandes Machado / Banca: Andrigo Barboza De Nardi / Banca: Gustavo Garkalns de Souza Oliveira / Resumo: A utilização da ultrassonografia vem se tornando cada vez mais frequente na prática da anestesia regional raquidiana e peridural em pacientes humanos, pois oferece maior segurança e eficácia em relação às técnicas convencionais. Até o presente momento, publicações científicas a cerca do emprego desta modalidade diagnóstica como método de imagem auxiliar em bloqueios de neuroeixo são escassos na medicina veterinária. Objetivou-se com este estudo: padronizar a imagem ultrassonográfica do espaço intervertebral lombossacro em cães quanto à topografia, ecogenicidade, ecotextura e interrelações entre as estruturas visibilizadas; avaliar a confiabilidade da ultrassonografia em predizer a profundidade do espaço peridural, por meio da mensuração da distância entre a pele e a porção ventral do ligamento amarelo, e avaliar efeito da idade, peso e escore corporal na qualidade das imagens ultrassonográficas. Procedeu-se a varredura ultrassonográfica do espaço intervertebral lombossacro em 19 cães, em cortes longitudinal mediano, longitudinal paramediano e transversal. Foi possível identificar as estruturas anatômicas nestes diferentes planos de imagem, e as médias e os desvios padrão das medidas obtidas por meio da ultrassonografia em corte longitudinal e transversal, e da medida obtida pós-punção peridural foram, respectivamente, 2,66 ± 1,09cm, 2,75 ± 1,11cm e 2,81 ± 1,27cm. Concluiu-se que a ultrassonografia é uma técnica eficaz quanto à localização e identificação das estruturas anatômicas lombossacras, e permite determinar com precisão a profundidade do espaço peridural. O plano longitudinal paramediano possibilita a avaliação das estruturas anatômicas enquanto o plano mediano permite a localização do espaço intervertebral lombossacro. Para determinar a profundidade do espaço peridural é recomendado... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The ultrasonography has been spreadly used in the practice of spinal and epidural regional anesthesia in human patients because it offers greater safety and efficacy compared to conventional techniques. To date, studies about the use of this method as a imaging diagnostic tool in neuraxial blocks are scarce in veterinary medicine. The aim of this study was to standardize the ultrasound image of the lumbosacral intervertebral space in dogs, regarding the topography, echogenicity, echotexture and the relations among its structures; to evaluate the ultrasound accuracy in predicting the depth of the epidural space, by measuring the distance between the skin and the ventral portion of the ligamentum flavum and to evaluate the effects of age, body weight and body condition on the quality of ultrasound images. Ultrasound evaluation of lumbosacral intervertebral space was performed in 19 dogs in three planes, such as median longitudinal, paramedian longitudinal and transverse. It was possible to identify anatomic structures in these different image planes. The means and standard deviations of the measurements obtained by ultrasonography in both longitudinal and transversal planes, and the measurement obtained after epidural puncture were, respectively, 2,66 ± 1,09cm, 2,75 ± 1,11cm and 2,81 ± 1,27cm. In conclusion, ultrasonography is an effective technique to locate and to identify the anatomic lombossacral structures, and it is valuable to accurately determine the depth of the epidural space. The paramedian longitudinal plane enables the assessment of anatomical structures while the median plane allows the location of the lumbosacral intervertebral space. The transverse plane is recommended to determine the depth of the epidural space. In this study, it was also noticed that there is no effect of age on the quality of ultrasound... (Complete abstract click electronic access below) / Doutor

Orientador: Hamilto Akihissa Yamamoto / Coorientador: Carlos Márcio da Nóbrega de Jesus / Banca: José Carlos Souza Trindade Filho / Banca: Victor Augusto Sanguinetti Scherrer Leitão / Banca: Reinaldo José Rafaelli / Banca: Fernandes Denardi / Resumo: Objetivo: Avaliar a utilidade do uso de 10,12 e 16 fragmentos em biópsias de próstata na positividade para câncer de próstata (CaP) bem como quanto o Antígeno Prostático Específico (PSA), volume prostático, escore de Gleason, detecção de Neoplasia Intraepitelial Prostática de Alto Grau (NIPAG) e Proliferação Atípica de Pequenos Ácinos (ASAP). Métodos: É um estudo prospectivo e controlado, realizado em uma amostra consecutiva de 354 pacientes com diferentes indicações para biópsia prostática que foram submetidos ao procedimento analisando a positividade de câncer de próstata com a coleta de 10 fragmentos (base, terço médio, ápice, face medial (zona de transição) e face látero-lateral, bilateralmente) comparando com 12 fragmentos (base, terço médio, ápice e nas regiões mais laterais da base, terço médio e ápice, bilateralmente) e o total global de 16 fragmentos. Também comparada a positividade com 10, 12 e 16 fragmentos quanto ao PSA, volume prostático, escore de Gleason, NIPAG e ASAP. Resultados: Entre os 351 pacientes selecionados para biópsia de próstata, a positividade para 10 fragmentos foi de 102 pacientes (29.06%), 12 fragmentos foi de 99 pacientes (28.21%) e 16 fragmentos foi de 107 pacientes (30.48%) (p = 0.79).Os protocolos de biópsia de próstata (10,12 e 16 fragmentos) foram comparados com o PSA estratificado, volume prostático estratificado, escore de Gleason, detecção de NIPAG e ASAP não havendo diferença entre os grupos aferidos. Conclusão: O protocolo com 10 fragmentos não apresentou diferença de positividade em relação aos protocolos de 12 e 16 fragmentos, demonstrando ser um bom método para realização de primeira biópsia / Abstract: Objective: To evaluate the utility of 10,12 and 16 fragments in prostate biopsies positive for the prostate cancer (PCa) as well as the Prostate Specific Antigen (PSA), prostate volume, Gleason score, Prostatic Intraepithelial Neoplasia Detection High Grade (NIPAG) and Atypical Small Acinar Proliferation (ASAP). Methods: It is a prospective controlled study performed with a sample of 354 consecutive patients with different indications for prostate biopsy who underwent the procedure analyzing the positivity of prostate cancer with the collection of 10 cores (base, middle third, apex, medial (transition zone) and latero-lateral, bilaterally) compared with 12 cores (base, middle third, apex and in areas more lateral to the base, middle third and apex, bilaterally) and the global total of 16 cores. It also was compared the positivity with 10, 12 and 16 cores, concerning the PSA, prostate volume, Gleason score, NIPAG and ASAP. Results: Among 351 patients screened for prostate biopsy positivity to 10 cores was 102 patients (29.06%), 12 cores of 99 patients (28.21%) and 16 cores of 107 patients (30.48%) (p = 0.798). The prostate biopsy protocols (10, 12 and 16 cores) were compared with the stratified PSA, stratified prostate volume,Gleason score, detection NIPAG and ASAP, there was no statistical difference. Conclusion: The protocol with 10 cores showed no difference in positivity in relation to 10 and 16 cores protocols, proving to be a good method for performing first biopsy / Doutor

Thesis (MTech (Sports Science Radiology))--Cape Peninsula University of Technology, 2006 / The knee is one ofthe most complicated joints in the body. The deep infrapatellar bursa being only a small water-pocket and forming a small part of the knee. The deep infrapatellar bursa can get inflamed and cause great discomfort, especially to professional sportsmen and -women. If such a inflammation is present, a common treament option are to inject a cortisone solution into the bursa for quick relieve and healing. This study was performed to investigate the specific ultrasound features of a normal deep infrapatellar bursa. Thus enableing more specific and accurate diagnosis of deep infrapatellar bursitis or not, which in turn leads to quicker recovery ofthe patients. A total of280 males and females from various population groups were recruited for the study. Subjects were categorized into different subgroups depending on their gender, ethnicity, competitiveness in sport, sport type practised and previous knee problems. These subgroups enabled a more individual specific DIB measurement. A high frequency ultrasound examination ofboth knees ofall recruits were performed. The deep infrapatellar bursa was located by slightly flexing the knee and applying not to much pressure with the probe whilst scanning. Three measurements, antero-posterio (AP), cranio-caudal (CC) and width measurements, were recorded ofeach individuals left and right deep infrapatellar bursa (DIB). The results ofthe DIB measurements were compared to results from a ultrasound study perfonned in Gennany and a favourable comparison could be made. MRI studies of the DIB performed in Turkey and Switzerland differed greatly from those of this study and Germany. This study could serve as a valuable source ofreference to sonographer, radiologist and orthopaedic surgeons when investigating the deep infrapatellar bursa. A statistical significant difference was shown for males having a larger DIB than female, for competitive sports people having a larger Dill than non-competitive sports people and also inactive people; and rugby players (as a sport type) have larger DIBs than cricketers, runners, soccer players and cyclists. Another surprising factor was the amazing ultrasound detection rate of the deep infrapatellar bursa, which allows for future easy and confident assessing of the DIB by ultrasound.

Thesis: B.S., Massachusetts Institute of Technology, Department of Biology, 1976 / Includes bibliographical references. / by Ann B. Mansfield. / B.S. / B.S. Massachusetts Institute of Technology, Department of Biology

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Clinical practice guidelines (CPGs) are viewed by many people with interests in health care as valuable tools for reducing practice variations that undermine patient outcomes and increase medical costs. However, guidelines themselves vary in quality. Assessment tools generally base quality measures on strength of guidelines' evidence base, but particularly for newly emerging applications of ultrasound, standards for measuring guideline quality are controversial. The validity of a guideline is considered likely when strong research-based evidence supports its recommendations, but for newer medical procedures such as emerging ultrasound applications, available evidence is sparse. Existing assessment tools must be modified if they are effectively to measure the validity of these guidelines built on immature evidence. Focusing on ways document drafting affects CPG validity, this study rated six guidelines using the Appraisal of Guidelines Research and Evaluation (AGREE) tool which was customized according to categories of guideline purposes and their differing features of validity. Fine-tuning AGREE in this way may create a more consistent, informative method of evaluating guidelines for emerging applications, and standards established in such an instrument may be useful as a template during the guideline development process. Results from my analyses illuminate several common omissions that weakened documents. Most guidelines did not describe an updating procedure or identify areas for future research, but results also highlighted some highly effective techniques for building validity. Notable examples include providing full credentials for expert drafters, and embedding statement references directly in the text. From the results of the analysis, I conclude that, although the adapted assessment tool I used needs additional adjustment, it may refine analysis of guidelines for emerging ultrasound guidelines and conversely serve as a useful tool during their development process.

Breast cancer is the most common cancer in women, accounting for almost one-thirdof new cancer diagnoses in the United States. The mortality rate has decreased by 42% since 1989 due to early diagnosis, improvements in imaging techniques and treatment regimens. Despite all the advances in imaging modalities, there is still a need for a non-invasive, nonionizing, and low-cost diagnosis technique with high sensitivity and specificity to reduce the rate of invasive biopsies. For individuals diagnosed with locally advanced breast cancer and early-stage breast cancer, neoadjuvant chemotherapy (NACT) has become the standard of care. Pathologic complete response (pCR) is the ideal outcome of NACT, which is correlated with the prognosis and overall survival of the patients. The pCR is achieved in only about 15-20% of patients determined at the time of surgery; therefore, most patients receive a treatment that is not beneficial for them and has considerable side effects. Thus, early detection and monitoring of breast tumor response to NACT is critical for treatment planning and improving overall survival. Ultrasound-based elasticity imaging techniques have gained interest in the clinic due to their potential to provide qualitative and/or quantitative information about tissue stiffness, which is presently not unachievable with standard ultrasonography. These techniques rely on the fact that a breast tumor’s stiffness or Young’s modulus is higher than that of the surrounding normal tissues. In this dissertation, the clinical feasibility of a technique called harmonic motion imaging (HMI) for breast tumor classification, as well as for NACT response prediction and monitoring of solid tumors is investigated. HMI is an ultrasound-based elasticity imaging technique that evaluates the mechanical properties of the underlying tissues by inducing amplitude modulated (AM) displacements at a specific frequency. First, we investigated whether HMI can characterize and differentiate human breast tumors based on their relative stiffness. We enrolled female patients with benign and malignant tumors and imaged them with a clinical HMI system. The malignant tumors were found to be associated with lower HMI displacements or higher stiffness than the benign tumors. Then, in order to verify our clinical findings, we estimated HMI displacements in the postsurgical breast specimens from the same subjects and compared them against the in-vivo estimations. Our findings indicated that HMI successfully differentiated tumors from the surrounding tissue in both ex-vivo and in-vivo conditions, with an excellent correlation between the results in the two different settings. Second, we introduced and characterized a new HMI setup consisted of a multi-element focused ultrasound transducer (FUS) with electronic beam steering capability. Therefore, instead of mechanical translation of the HMI setup, the acoustic force could be electronically steered in the volumetric space to accelerate the data acquisition. A pulse sequence was developed to drive the HMI transducers assembly, the FUS and imaging transducer, using a single ultrasound data acquisition system to have a compact setup that is more applicable for clinical settings. The data acquisition was further improved by investigating the effect of AM frequencies on the quality of the HMI images and tumor detection. We found that higher AM frequencies are needed in order to improve the detection and characterization of small and stiff inclusions. On the contrary, soft and large inclusions are better resolved at lower AM frequencies. Lastly, we investigated the feasibility of using HMI for early prediction of response to neoadjuvant chemotherapy in cancer mouse models and breast cancer patients. We acquired longitudinal HMI images from pancreatic and breast cancer murine tumors during treatment with chemotherapeutic drugs and monitored the changes in the mechanical properties of the tumors. The tumors were found to soften when responsive to treatment, followed by the stiffness increase in the case of drug resistance. However, the untreated mice underwent steady stiffening of the tumors. Next, we imaged breast cancer patients at different timepoints during their chemotherapy treatment. We found that tumors in the patients who achieved pCR had higher pre-treatment stiffness and higher softening from pre-treatment to a short-interval follow-up on treatment compared to the ones in patients with residual cancer cells at the completion of treatment. These findings indicate the promising potential of HMI in the early prediction of solid tumor response to chemotherapy interventions.

No description available.

Heart disease remains the leading cause of death globally, and prevalence has nearly doubled over the past three decades. It is estimated that up to 90% of cardiovascular events are preventable, but early detection and treatment is crucial. In this dissertation, we report on the optimization of the ultrasound-based cardiac strain imaging technique known as Myocardial Elastography (ME), a method for the detection of the most common and most lethal forms of heart disease: Coronary Artery Disease (CAD) which affects the major coronary arteries, and Coronary Microvascular Disease (CMD) which affects smaller coronary vessels. CAD has historically been the primary focus of clinical cardiac imaging, whereas CMD has been under-diagnosed due to a lack of awareness and challenges associated with imaging at the microvascular level. Ultrasound-based cardiac strain imaging has been shown capable of detecting functional changes due to CAD and may be effective in CMD detection, although the latter has not yet been sufficiently investigated. However, the diagnostic accuracy of strain imaging is reduced by noise from transcostal imaging, known as clutter, and by the limited lateral resolution of high framerate ultrasound. These factors preclude accurate strain imaging in up to 30% of patients. Myocardial elastography is a precise high framerate strain imaging technique that analyzes radiofrequency (RF) signals to quantify myocardial deformation. We hypothesize that ME can effectively image and diagnose the functional effects of CMD and CAD, and that novel beamforming and clutter-filtering techniques can improve ME imaging and strain estimation quality, thereby increasing diagnostic accuracy. To improve disease detection, Stress ME (S-ME) was proposed as a method to compare strain measurements at rest to strain during induced cardiac stress. A novel strain difference (Δ𝜺) metric was presented and investigated in a canine model of induced acute ischemia, as well as in a human CAD patient study with validation by myocardial perfusion imaging. In the canine model, flow-limiting stenosis was induced by partial ligation in N=2 canines, and stenosis was found to significantly reduce Δ𝜺 in the affected myocardial regions. In the clinical study, radial and circumferential ME strain and radial Δ𝜺 was measured in N=49 myocardial segments from 8 patients suspected to have ischemia or infarction due to CAD. The median Δ?, radial strain, and circumferential strain magnitudes were lowest in infarcted regions and highest in regions with normal perfusion, while measurements in ischemic regions fell in between. ROC analysis of radial strain metrics revealed that Δ𝜺 had the highest AUC for detecting ischemia (AUC=0.788 p<0.01) and infarction (AUC=0.792, p<0.05), followed by radial strain during stress (ischemia AUC=0.774 p<0.05, infarct AUC=0.758 p<0.05) while the AUC was lowest when considering only the radial strain at rest (ischemia AUC=0.52 p>0.05, infarct AUC=0.58 p>0.05). The results thus indicate that S-ME may improve detection of mild CAD cases that are functionally asymptomatic at rest. Despite these promising findings, accurate strain imaging remains hindered by clutter noise and poor image quality. Two complementary techniques were thus developed to improve image quality and strain estimation in high frame rate cardiac strain imaging; a novel Sliding Window implementation of the Minimum Variance beamformer (SWMV) was proposed to enhance speckle quality, while a spatiotemporal singular value decomposition filter (SVD) was developed to increase tissue visibility and contrast by suppressing static clutter signals using automated cutoff selection. SWMV and SVD were shown to effectively improve image quality in simulation studies and phantom imaging experiments. In vivo performance evaluation consisted of applying SWMV beamforming and SVD filtering techniques to a dataset of N=70 strain images from 13 patients suspected to have CAD. CCTA imaging was used for validation of strain estimation. Tracking was improved in 92% of cases with a median improvement of 15% in displacement estimation accuracy as evaluated by an intersection-over-union (IoU) metric. The proposed techniques also improve agreement with CCTA results; ROC analysis shows improved AUC with SWMV+SVD compared to DAS when comparing healthy regions to those with any degree of stenosis (AUC 0.64 vs 0.56) as well as when comparing healthy to severely stenosed regions (AUC 0.69 vs 0.60). The observed results point to significant improvement in strain estimation reliability due to SWMV beamforming combined with SVD processing. The final aim and the overarching goal of this work is a culmination of the previous sections for a clinical evaluation of ME as a diagnostic tool for CAD and CMD. In this clinical study, the enhanced ME technique utilizing SWMV and SVD filtering was applied to a cohort of N=201 patients with suspected coronary disease. All patients underwent invasive angiography or noninvasive cardiac imaging in the form of coronary computed tomography or nuclear stress testing. In addition, demographic information and patient clinical history were collected and accounted for in a multivariate statistical analysis. A K-nearest-neighbor (KNN) classifier was trained to distinguish between healthy and stenosed myocardial regions, and achieved an AUC of 0.91, with sensitivity of 86% and a specificity of 85% after training with 10-fold cross validation. CMD was also shown to significantly reduce regional strain measurements. This retrospective study identified the clinical factors which impact strain, and assessed the potential advantages of incorporating ME imaging to the existing clinical imaging pipeline for CAD and CMD diagnosis.