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A three dimensional model for generating the texture in B-scan ultrasound imagesGoodsitt, Mitchell M. January 1982 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1982. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 226-230).
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Architecture and algorithms for a fully programmable ultrasound system /York, George W. P. January 1999 (has links)
Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 110-118).
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Development of a field-deployable voice-controlled ultrasound scanner systemSebastian, Dalys. January 2004 (has links)
Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: field use; ultrasound scanner; speech recognition; wearable. Includes bibliographical references (p. 165-166).
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In vivo characterization of ultrasonic backscattering from normal and abnormal lungsJafari, Farhad. January 1900 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 261-265).
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A sensing system for two dimensional acoustical imagingLefley, Paul W. January 1989 (has links)
No description available.
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Ultrasonic phased arrays for robotics modelling and experimental implementationPomeroy, Simon January 1989 (has links)
No description available.
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Ultrasonic phased arrays for use in imaging and automatic vehicle guidanceMunro, W. S. H. January 1990 (has links)
No description available.
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An evaluation of transvaginal ultrasound in the assessment of endometrial thickness in black South African patients presenting with postmenopausal uterine bleedingMoodley, Premla January 2004 (has links)
Dissertation submitted in full compliance with the requirements for the Master's degree in Technology: Radiography, Durban Institute of Technology, Durban, 2004. / The object of this study was to use Transvaginal ultrasound to evaluate the thickness of the endometrium to exclude endometrial abnormality in Black South African women with postmenopausal uterine bleeding. Transvaginal ultrasound is an excellent diagnostic method for assessing endometrial pathology. The study was carried out at the Gynaecological Ultrasound Department, King Edward VIII Hospital. The study included 76 Black women with postmenopausal uterine bleeding. The thickness of the endometrium was measured by Transvaginal ultrasound. The measurement included both endometrial layers (double-layer technique). The Transvaginal ultrasound measurement was compared with the histopathological diagnosis of the biopsy specimens. At the end of the investigation, findings obtained were 3.9% non-representative, 44.8% endometrial adenocarcinomas, 14.5% benign polyp, 3.9% chronic Endometritis, 17.1% benign endometrium, 5.3% endometrial hyperplasia, 9.2% atrophic endometrium, 3.9% myometrial invasion and 1.3% Malignant Mixed Mullerian Tumour. In this study, the thickness of the endometrial echo varied from 5mm to 35mm, with a mean of 18,2mm. When the thickness of the endometrial echo was compared with the histopathological results, the mean value for non-representative was 7.83mm, much lower than the thickness of an active endometrium (13.25mm). In cases with atrophic endometrium, the thickness ranged from 6mm to 30mm with a mean of 15.86mm. The mean value obtained for cases with endometrial adenocarcinoma was 20.32mm (range 11 to 35mm). The sensitivity, specificity and accuracy of Transvaginal ultrasound for detecting endometrial malignancy were 100% if the cutoff limit of 4mm was used
In conclusion, this study using Transvaginal ultrasound demonstrated that a thickness limit greater than 8mm was considered in detecting malignancy. No malignant endometrium was thinner than 5mm. Therefore in women with postmenopausal uterine bleeding and an endometrium less than 4mm, it may be justified not to perform further investigations. Transvaginal ultrasound is a simple,
well-tolerated safe and reliable method for identifying endometrial thickness in postmenopausal Black South African women. / M
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Adaptive clutter filter design for micro-ultrasound color flow imagingof small blood vesselsCheung, Ka-hei., 張嘉熹. January 2010 (has links)
published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy
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Adaptive flow detector and estimator for ultrasound high frame rate vector flow imagingChan, Lok-sang, 陳樂生 January 2011 (has links)
Cardiovascular diseases is a leading cause of death worldwide and improvement of the
corresponding screening tool is the best way to deal with this clinical problem. In this thesis
we attempted to develop a framework of ultrasound high frame rate vector flow imaging
(VFI) by emphasizing on the design of corresponding flow detector and flow estimator. We
believe that the high temporal resolution and the complex blood flow visualization ability of
high frame rate VFI enables it to be further developed as a reliable flow imaging modality
for cardiological examination.
In order to achieve high temporal resolution, fast data acquisition algorithm was applied
in the framework. Doppler signals acquired using this acquisition algorithm have two
unique characteristics comparing with conventional data acquisition algorithm: (1) widen
spectral bandwidth and (2) greater clutter to blood signal ratio. These signal characteristics
give rise to unique signal processing. In addition, complex blood flow pattern, which
is common in cardiological examination, induces extra challenges in implementing high
frame rate VFI. In this thesis, flow detector which is adaptive to different flow scenarios
and high dynamic range 2D flow estimator were presented.
The proposed flow detector employes K-means++ clustering algorithm to classify clutter
components from acquired Doppler signals. As a performance analysis, Field II simulation
studies were performed by a parabolic flow phantom (flow velocity: 10mm/s to
200mm/s; tissue motion: 10mm/s; beam-flow angle: 60?). The post-filtered Doppler power
map and BCR were used as qualitative and quantitativemeasures of detectors performance.
Analyzed result has indicated that, as compared with clutter downmixing detector and
eigen-based detector, the proposed flow detector could classify and suppress clutter component
more effectively. Results also suggested that the proposed flow detector is more
adaptive to slow flow scenarios where existing flow detectors failed to distinguish between
blood and clutter components.
For the proposed flow estimator, it was characterized by the interpolation of speckle
tracking results in Lagrangian reference frame. The estimation bias and RMS error were
calculated for different flow scenarios (flow velocity: 100mm/s to 500mm/s; beam-flow
angle: 15? to 60?). It was found that the proposed flow estimator provides higher dynamic
range than conventional speckle tracking-based flow estimator. Nonetheless, it is also observed
that the estimation variances and errors increases in slow flow scenarios.
In order to demonstrate the medical potential of the proposed high frame rate VFI
framework. A carotid bifurcation simulation model with realistic blood flow pattern calculated
using computational fluid dynamic software was applied in the performance evaluation
study. In the VFI image obtained, complex blood flow pattern was readily visualized.
In contrast, conventional ultrasound flow imaging was only able to estimate axial velocity
map and thus lead to many ambiguities in analyzing the complex blood flow pattern. It
proved that ultrasound high frame rate VFI has the potential to be further developed into a
new cardiological examination technique. / published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy
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