Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 14 of 14 for “"Quantitative Ultrasound (QUS)"”.
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Toward model-free and reference-free quantitative ultrasound
Current spectral-based quantitative ultrasound (QUS) techniques rely on a reference or a calibration signal to obtain system-independent ultrasonic scattering parameters. Adoption of QUS clinically has been hindered by (1) the need to limit clinical ultrasonic scanner settings to account for a …
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A FPGA/DSP based ultrasound system for tumor detection
… of detection of size and location of tumor using ultrasound transmission. The system utilizes Quantitative Ultrasound (QUS) which means sending an ultrasound signal from a transmitter and receiving it at multiple receivers. This received signal is analyzed for echogenic as well as echolucent …
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Quantitative ultrasonic characterization of diffuse scatterers in the presence of structures that produce coherent echoes
Quantitative ultrasound (QUS) techniques that parameterize the backscattered signal power spectrum have demonstrated significant promise for ultrasonic tissue characterization. Some QUS parameters, including the effective scatterer diameter (ESD) and the effective acoustic concentration (EAC) that …
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Using quantitative ultrasound for epidemiological research : associations with risk factors for low bone mineral density in South African premenopausal women
Quantitative Ultrasound (QUS) measurement at the calcaneum is a convenient, cost effective and noninvasive method of determining bone strength well suited to community-based research in countries with limited resources. Although only moderately correlated with dual X-ray absorptiometry (DEXA) …
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Quantitative Ultrasound Characterization and Monitoring of Locally Advanced Breast Cancer
… clinically significant. In this thesis, novel ultrasound backscatter signal analysis and machine learning techniques were developed to characterize breast tumours and detect early changes correlated to response. In the first study, tumour cell death was induced in human breast cancer …
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Improving ultrasonic imaging using novel coded excitation techniques
In ultrasound imaging, the axial resolution depends on the source bandwidth. Recently, a novel coded excitation and pulse compression technique, known as Resolution Enhancement Compression (REC), was developed. REC enhances the -6 dB bandwidth of an ultrasonic imaging system. In this dissertation, …
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Three-dimensional acoustic impedance map analysis of soft tissue
… Additionally, 3DZMs were compared with quantitative ultrasound (QUS) techniques. A chemically fixed section of rabbit liver was scanned ultrasonically, then used to create 3DZMs. ESD estimates were made using the fluid-filled sphere form factor. Twenty-four 3DZMs of volume 300x300x300 …
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Quantitative ultrasound assessment of thermal therapy in liver
Quantitative ultrasound (QUS) is a promising technique for non-invasive tissue characterization. In this work, the potential of QUS to assess thermal therapy in liver tissue was examined. Specifically, the QUS parameters of attenuation slope, effective scatterer size (ESD), effective acoustic …
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Risk assessment for osteoporotic fractures among men and women from a prospective population study: the EPIC-Norfolk study
… dual-energy X-ray absorptiometry (DXA) and quantitative ultrasound (QUS). We found that that the predictive power of QUS is comparable to, and independent of, predictive power of DXA. In summary, my studies have added to our knowledge about some novel and easy-to-use risk factors of …
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Bone speed of sound in overweight and normal-weight girls and adolescents
… measured for one week using accelerometry. Using quantitative ultrasound (QUS; Sunlight Omnisense™), bone SOS was measured at the distal radius and mid-tibia. No differences were found between groups in daily total energy, calcium or vitamin D intake. However, all groups were below the recommended …
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Exercise in Youth and Long-Term Effects on Bone and Joints
… (DXA), peripheral computed tomography (pQCT) and quantitative ultrasound (QUS) at follow-up. The second study used DXA. Fracture incidence was evaluated in two retrospective cohort studies, one including 397 former male soccer players and 1368 age-matched controls and the second 709 former male …
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Bone properties and skeletal maturity in adolescent males, as assessed by quantitative ultrasound
… skeletal maturity in children. Recently, quantitative ultrasound (QUS) technologies have been developed to examine bone properties and skeletal maturity in a safe, noninvasive and cost-effective manner. Objective: The purpose of this study was to compare bone properties and skeletal …
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Using two-dimensional impedance maps to study acoustic properties of tissue microstructure
Quantitative ultrasound (QUS) imaging represents a set of techniques for estimating acoustic properties of tissue microstructure that have confirmed potential for identifying disease and monitoring therapy. In one approach to QUS, the backscatter coefficient (BSC) from a tissue is utilized to …
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Deep structure ultrasound imaging using fundamental and third harmonic coded excitation techniques
A novel coded excitation method, combining Golay coding with fundamental and third harmonic 1, 3 chirps with resolution enhancement compression (REC) and frequency compounding, increases the axial resolution, lateral resolution, penetration depth and the contrast-to-noise ratio (CNR) for an …