Thesis (MTech (Radiography))--Cape Peninsula University of Technology, 2006 / A prospective cohort study was done on Human Immunodeficiency Virus (HIV) infected and uninfected women attending Khayelitsha Midwifery Obstetric Unit (MOU) and Gugulethu MOU from June 2003 to December 2004, primarily to establish whether there is an association between HIV infection and Intra-uterine growth restriction (lUGR). B-Mode real time ultrasound imaging was used to monitor fetal growth from ±22 weeks to 36 weeks gestational age. Birth weight, gestational age at delivery, gender, placental weight, and maternal complications were also included. Maternal factors considered included age, weight parity, singleton versus multiple pregnancy, previous IUGR or preterm delivery, previous fetal abnormality, social habits viz. cigarette smoking, alcohol and drug use, and vascular disease viz. Diabetes, hypertension, renal disease, cardiac disease and collagen disease. A secondary objective was to establish whether the CD4 T-lymphocyte count possibly modulated the presence of IUGR. All HIV infected women were given antiretroviral therapy according to the standard Protocol of the Provincial Government of Western Cape (2002). The research questions were: • Does maternal HIV infection increase the risk of intrauterine growth restriction and associated preterm delivery? • Does the immune status of (CD4 T-lymphocyte count) of HIV infected pregnant women modulate fetal growth? The primary objective of this study was to establish whether there is an association between HIV infection and IUGR, and hence that HIV infection leads to an adverse perinatal outcome. Ultrasound was used as a diagnostic tool to establish normal or abnormal fetal growth patterns. Anecdotal reports from health workers in the obstetric field suggested that IUGR and preterm delivery may be associated with low birth weight infants in HIV infected pregnant women. However, preterm delivery is associated with various other factors including low socio-economic status (poor nutrition), cigarette smoking, drug and alcohol abuse, previous history of preterm delivery, over distention of the uterus (hydramnios, multiple gestation), premature rupture of membranes, cervical incompetence, vaginal infections (bacterial vaginosis) and maternal disease e.g. hypertension, heart disease (Lizzi, 1993: Symmonds, 1992; Odendaal et aI, 2002). HIV is now thought to be an added factor. Afier doing a systematic review and meta-analysis of 31 studies, Brocklehurst and French (1998) reported that there is an association (although not strong) between HIV infection and adverse perinatal outcome in developed countries; but in developing countries, there is an increased risk of infant death. By excluding or controlling for confounding variables that could affect fetal growth, this study aimed to determine whether there is a significant association between HIV and fetal growth by comparing fetal growth in HIV infected and uninfected women from midsecond trimester to the time of delivery. A secondary objective was to establish whether there is an association between the immune status (CD4 T-lymphocyte count) of the mother and IUGR. The immune status of the mother is probably one of the most important factors affecting the fetus and perinatal outcome. As the mother's viral load increases, her immune system is increasingly compromised, resulting in the occurrence of HIV-related diseases, and a concurrent increase in fetal complications. In this study a CD4 T-lymphocyte count was used to assess the level of immunodeficiency of all the HIV infected participants. Ideally the test should have been done each time the participant was scanned so that the CD4 T-lymphoc)1e count could be monitored simultaneously with the fetal growth parameters, however due to financial constraints and ethical considerations, one test was done on each HIV infected women. This study was based at two MOU's where different antiretroviral therapy (ARVT) regimens were used. The one MOU offered Zidovudine (ZDV) to mothers from 34 weeks gestation to the onset of labour, and the other MOU offered Nevirapine (NVP) as a single dose to the mother at the onset of labour and to the neonate within 72 hours of birth (Provincial Government Western Cape, 2002). This presented an opportunity to compare two groups of HIV infected women on different regimes. The intention was to establish whether ZDV had an adverse effect on fetal growth and resulted in low birth weight. However, 6 months after the study started a revised Prevention of Mother to Child Transmission (PMTCT) Protocol was implemented where women at both MOU's received the same ARVT i.e. ZDV and NVP. This objective was therefore abandoned due to a change in the PMTCT Protocol in the Western Cape. The study was based at two Midwife Obstetric Units (MOU) in the Western Cape where the prevalence of HIV in pregnant women is relatively high i.e. 20 - 24 % (Mother-to-child transmission Monitoring Team, 2001), viz. Gugulethu MOU and Khayelitsha MOU. A prospective cohort study was done with the intention of recruiting a sample of 400 pregnant women, 200 HIV infected and 200 uninfected. The actual sample size was 415. The study group was 194 HIV infected women and the control group was 221 uninfected women. Confounding variables such as cigarette smoking, alcohol and drug abuse. multiple gestation. grand multipara pregnancy, history of IUGR or preterm delivery. fetal abnormality detected at the time of the first scan in the current pregnancy, and maternal vascular disease - were excluded. Confounding variables such as maternal age, maternal weight and gestational age were controlled. Ultrasound imaging was used as a diagnostic tool to establish normal and abnormal fetal growth patterns. A B-mode real time ultrasound unit was used to confirm the gestation age and rule out any obvious fetal abnormalities at 20-24 weeks gestation. Fetal growth scans were done at 28 weeks, 32 weeks and 36 weeks gestation to compare fetal growth patterns in the study and control groups. Fetal biometry used to monitor fetal growth included biparietal diameter (BPD), head circumference (HC), femur length (FL), abdominal circumference (AC) and estimated fetal weight (EFW). Amniotic fluid index (AFI), placental thickness & placental grading were also included. The following variables were analyzed post delivery: • Gestation age at delivery: Normal term delivery is considered to be at 37 - 42 weeks and premature delivery is considered to be less than 37 weeks gestation. The HIV infected and uninfected groups were compared to assess if there \vas a significant difference in the number of preterm deliveries. • Birth weight: The HIV infected and uninfected groups were compared to assess if there was a significant difference in the number of infants with low birth weight. • Perinatal complications: The HIV infected and uninfected groups were compared to assess if there was a significant difference in the number of perinatal complications and to assess if there was an association between the immune status (CD4 T-lymphocyte count) of HIV infected women and perinatal complications. Appropriate ethical principles in medical research were applied. The participant's autonomy, rights and best interests were always considered a priority. Informed consent was obtained from all the participants. Strict confidentiality was adhered to regarding any data collected throughout the study. The Research Ethics Committees at Cape Peninsula University of Technology and University of Cape Town granted ethics approval for the study. Statistical analysis was performed using the statistical package SPSS 12.0.

Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2016. / Ultrasound is widely used in most medical clinics, especially obstetrical clinics. It is a way of imaging methods that has important diagnostic value. Although useful in many different applications, diagnostic ultrasound is especially useful in antenatal (before delivery) diagnosis. The use of two-dimensional ultrasound (2DUS) in obstetrics has been established. However, there are many disadvantages of 2DUS imaging. Several researchers have published information on the significance of patients being shown the ultrasound screen during examination, especially during three- and four-dimensional (3D/4D) scanning. In addition, a form of ultrasound, called keepsake or entertainment ultrasound, has boomed, particularly in the United States. However, long-term epidemiological studies have failed to show the adverse effects of ultrasound in human tissues. Until now, there is no proof that diagnostic ultrasound causes harm in a human body or the developing foetus when used correctly. While ultrasound is supposed to be absolutely safe, it is a form of energy and, as such, has effects on tissues it traverses (bio-effects). The two most important mechanisms for effects are thermal and non-thermal. These two mechanisms are indicated on the screen of ultrasound devices by two indices: The thermal index (TI) and the mechanical index (MI). These are the purposes of this thesis: • evaluate end-users’ knowledge regarding the safety of ultrasound; • evaluate and make a comparison between acoustic output indices (AOI) in B-mode (2D) and three-dimensional (3D) ultrasound – those measured by thermal (TI) and mechanical (MI) indices; • assess the acoustic output indices (AOI) to benchmark current practice with a survey conducted by the British Medical Ultrasound Society (BMUS); and • review how to design 2D and 3D arrays for medical ultrasound imaging

No description available.

Diagnostic ultrasound has become invaluable to healthcare professions for the purpose of imaging soft tissue without the risk of exposure to damaging, ionizing radiation. However, the majority of commercially available transducers have rigid, fixed interfaces that cannot conform to the surface of the human body. Such limitations both introduce a potential air gap (requiring the application of ultrasound gel) and make long-term monitoring impractical. In this work, I propose a novel flexible 2D ultrasound phased array with adaptive phasing that is capable of compensating for the radius of curvature. I describe the phasing algorithm and illustrate the detrimental effect of a lack of phase correction through simulation. I conduct phase detection by using time of arrival (TOA) without additional external hardware. In addition to simulations, I provide details of the fabrication process of a flexible 16 by 16 element array. The manufactured array, with an operating frequency of 1.4MHz and bandwidth of 41.3%, was capable of generating pressures up to 600 kPa. Finally, I conduct an in-vivo human study to demonstrate the functionality of the array on a human humerus. Although visible without phase correction, the location of the bone can easily be tracked in real-time after applying the correction algorithm.

Thesis (MSc (Radiography))--Cape Peninsula University of Technology, 2019 / INTRODUCTION: The Breast Imaging Reporting and Data System (BI-RADS) was developed by the American College of Radiology (ACR). The BI-RADS is an internationally accepted method of assessing and reporting on mammograms and breast ultrasound images. The BI-RADS consists of a lexicon (descriptors) and assessment categories. The ACR aimed to standardise mammography reporting and placing the findings in the appropriate assessment category. The aim of this study was to establish the accuracy of the BI-RADS assessment categories for mammography and breast ultrasound images in women diagnosed with breast cancer. METHOD: Data were retrieved from 77 patients who were diagnosed with breast cancer from 1 January 2013 to 31 December 2014. Seven did not meet the inclusion criteria and were excluded. The study sample size was 70 (n=70) patients. All mammography reports included a BI-RADS assessment category of all patients diagnosed with breast cancer within the study period. These reports were analysed and compared with histopathology results. The BI-RADS assessment category and descriptors were collected from the mammogram reports; the histopathology report indicated the type of breast cancer. All reports were obtained from the patients' folders at the research site. In addition, questionnaires were distributed among radiologists to assess whether their experience and training had an influence on the accuracy of reporting in the BI-RADS assessment categories. Descriptive and inferential statistical analysis was used for data analysis. RESULTS: The most common malignancy diagnosed was invasive ductal carcinoma with a total of 70% (n=54), followed by ductal carcinoma in situ with 10.4% (n=8) and invasive lobular carcinoma with 9.1% (n=7). The histology results confirmed breast cancer for all BI-RADS 4 and 5 assessment categories. The mammogram was able to detect 93.5% of abnormalities and breast ultrasound 84.4% of abnormalities in this study sample. Breast ultrasound was used as an adjunct to mammography and hence an overall combined diagnostic rate was 100%. Mammography descriptors: The more common malignancy findings were spiculated mass margin, 35.1% (n=27). Ultrasound descriptors: The more common malignancy findings were hypoechoic echo pattern, 55.8% (n=43). There was no significant association (p=0.152) between the radiologists' years of experience and BI-RADS 3, 4 and 5 assessment category reporting. Of the 15 responses, 67% agreed that the BI-RADS standardises breast imaging reporting and reduces confusion, 33% agreed that the BI-RADS allows better communication between radiologists and referring physicians, and 40% agreed that the BI-RADS clarifies further management for patients by helping to stratify risk management. CONCLUSION: The outcome of this study indicated that the use of BI-RADS assessment categories is useful for predicting the likelihood of malignancy when used correctly. The outcome of BI-RADS 4 and BI-RADS 5 had a positive predictive value of 100%, which corresponded well with histology results. The descriptor findings suggested that spiculated mass margins, irregular-shaped masses, hypoechoic echo pattern and posterior shadowing were high predictors of malignancy and warranted a placement in the BI-RADS 5 assessment category.

With over half a century of medical ultrasound support, proven efficacy, and increased popularity, why is it that over half our planet’s population does not have access to ultrasound imaging? In 2015 when I joined the doctoral program, I embarked to not only understand this problem but to provide a solution. This document will walk you through this journey, detailing the challenge of creating my very own ultrasound system with the purpose of it being highly accessible to people who need it the most. I had the vision to take this further; not only did I aim to create an open-source portable ultrasound- I also wanted to see this in the hands of users. This dissertation will show you how collaboration between students of varying disciplines can help propel research to the point of product development. A full ultrasound system including both hardware and software has been developed and tested using commercial ultrasound phantoms. This document will present progress chronologically, starting with the first attempts at using audible piezoelectric buzzers to generate a signal, where the first proof of concept is met. In this dissertation, you will follow the continuous development of a 1) ultrasound analog circuit, 2) mechanical transducer probe, 3) analog signal acquisition system, and 4) imaging software coupled with the user interface. The open-source portable ultrasound research has been successful in providing both hardware and software solutions, combined as a single package in an end-to-end integrated system. This has never been done before. During a time when “data is gold”, this project has also created an open platform where users can collect and share data, enabling collaborations and propulsion of open-access medical screening technologies. This research has developed the lowest-cost 3D scanning ultrasound transducer that we know of at this time. This is inherently novel and transcendental.

The following thesis will describe the investigation of the effect of nifedipine (a calcium antagonist) on the Doppler flow velocity waveform of the umbilical artery. The thesis is divided into two parts. The first section is a literature review of the three main aspects of the thesis namely: 1. The uteroplacental circulation in humans and the pathophysiology related to this circulation in hypertension and intrauterine growth retardation (IUGR). 2. The biokinetics of nifedipine and a review of the experiments that have been performed using the drug in human and animal models. 3. The principles of Doppler ultrasound and the literature pertaining to its use in the study of the uteroplacental circulation. The second part of the thesis is devoted to the effect of nifedipine on fetal umbilical artery Doppler waveform analysis. In the first ·stage of the investigation the effect of the drug on hypertensive mothers has been examined, and in the second stage the effect on fetuses that have an increased resistance index of the umbilical artery Doppler waveform.

[Truncated abstract] Transrectal ultrasound (TRUS) has become the urologist’s primary tool for diagnosing and staging prostate cancer due to its real-time and non-invasive nature, low cost, and minimal discomfort. However, the interpretation of a prostate ultrasound image depends critically on the experience and expertise of a urologist and is still difficult and subjective. To overcome the subjective interpretation and facilitate objective diagnosis, computer aided analysis of ultrasound images of the prostate would be very helpful. Computer aided analysis of images may improve diagnostic accuracy by providing a more reproducible interpretation of the images. This thesis is an attempt to address several key elements of computer aided analysis of ultrasound images of the prostate. Specifically, it addresses the following tasks: 1. modelling B-mode ultrasound image formation and statistical properties; 2. reducing ultrasound speckle; and 3. extracting prostate contour. Speckle refers to the granular appearance that compromises the image quality and resolution in optics, synthetic aperture radar (SAR), and ultrasound. Due to the existence of speckle the appearance of a B-mode ultrasound image does not necessarily relate to the internal structure of the object being scanned. A computer simulation of B-mode ultrasound imaging is presented, which not only provides an insight into the nature of speckle, but also a viable test-bed for any ultrasound speckle reduction methods. Motivated by analysis of the statistical properties of the simulated images, the generalised Fisher-Tippett distribution is empirically proposed to analyse statistical properties of ultrasound images of the prostate. A speckle reduction scheme is then presented, which is based on Mallat and Zhong’s dyadic wavelet transform (MZDWT) and modelling statistical properties of the wavelet coefficients and exploiting their inter-scale correlation. Specifically, the squared modulus of the component wavelet coefficients are modelled as a two-state Gamma mixture. Interscale correlation is exploited by taking the harmonic mean of the posterior probability functions, which are derived from the Gamma mixture. This noise reduction scheme is applied to both simulated and real ultrasound images, and its performance is quite satisfactory in that the important features of the original noise corrupted image are preserved while most of the speckle noise is removed successfully. It is also evaluated both qualitatively and quantitatively by comparing it with median, Wiener, and Lee filters, and the results revealed that it surpasses all these filters. A novel contour extraction scheme (CES), which fuses MZDWT and snakes, is proposed on the basis of multiresolution analysis (MRA). Extraction of the prostate contour is placed in a multi-scale framework provided by MZDWT. Specifically, the external potential functions of the snake are designated as the modulus of the wavelet coefficients at different scales, and thus are “switchable”. Such a multi-scale snake, which deforms and migrates from coarse to fine scales, eventually extracts the contour of the prostate

MSCAGR (Animal Science) / Department of Animal Science / The main purpose of this study was to assess the efficiency of ultrasonography in monitoring reproductive organs, pregnancy diagnosis, and foetal gender identification and to verify its reliability by laparoscopy and laparotomy, where applicable. Reproductive organs, pregnancy diagnosis and gender of the foetus were examined by A-mode ultrasound using 3.0 - 8.0 MHz trans-rectal transducer. A Sony Olympus Model laparoscope with a camera transducer was used to monitor the reproductive organs and pregnancy diagnosis. In monitoring the follicular dynamics, daily ultrasonography (ULTS) scanning was done for 17 days in sheep and for 21 days in both goats and cattle. Follicles of diameter ≥ 3 mm were selected for analysis of growth, ovulation and regression. For determining the efficiency of the techniques, laparoscopy (LAPSC) and laparotomy (LAPT) were used on days 3 and 10 of the goats and sheep oestrous cycle. The follicles were grouped into three categories according to their diameter as 3 - 4.9 mm, 5 - 7.9 mm and ≥ 8 mm, whereas the follicles of cattle were grouped as 3 - 4.9 mm, 5 - 9.9 mm and ≥ 10 mm. Early pregnancy diagnosis examinations were carried out from day 18 post insemination until pregnancy was confirmed. Foetal gender examinations were conducted from day 40 of pregnancy until the day the gender of the foetus was confirmed. Follicular development was accompanied by the occurrence of waves of follicular growth at different period of the oestrous cycle. The first follicular wave emerged on day 1.0 ± 0.4 in goats, 1.2 ± 0.4 in sheep and 2.2 ± 0.4 in cattle. The maximum diameter of the dominant follicles of observed follicular waves in goats was 7.3 ± 0.4 mm, 6.6 ± 0.2 mm, 7.3 ± 0.2 mm; in sheep was 6.4 ± 0.4 mm, 6.6 ± 0.4 mm and 6.7 ± 0.7 mm and in cattle was 13.1 ± 0.8 mm, 14.2 ± 0.6 mm and 15.7 ± 0.6 mm in wave 1, 2 and 3, respectively. However, the maximum size of the dominant follicle of the ovulatory wave in cattle was larger than the dominant follicles of both first and second waves, but in goats and sheep the dominant follicles were of similar size throughout the waves. In cattle, the ovulatory wave was shorter (p ˂ 0.05) than the duration of the first and second waves, while in sheep and goats were similar throughout the waves. In goats the total number of follicles counted in right and left ovaries under category 3 - 4.9 mm was lower with ULTS and LAPSC than with LAPT method (p ˂ 0.05). In sheep the mean number of follicles between 3 - 4.9 mm category in both right and left ovaries were different (p ˂ 0.05) between ULTS and LAPT. However, for categories 5 - 7.9 mm and ≥ 8 mm in both goats and sheep the mean numbers of follicles observed by all techniques were similar (p ˃ 0.05). In goats, pregnancy diagnosis accuracy improved from zero percent on day 18 to 100% on day 26 - 28, in sheep pregnancy diagnosis was 40% on day 18 and improved to 100% on day 20 - 22 vi of gestation. In cattle accuracy of pregnancy diagnosis was not possible at day 18 and gradually increased to 100% on day 30 - 32 of gestation. Out of 5 (100%) goat’s foetuses whose gender was determined, the diagnosis was correct in 100% (3/3) of the male foetuses and 100% (2/2) of the female foetuses. In sheep two foetuses were sexed as males while the other three were sexed as females and were both 100%. Out of 60% (3/5) of foetuses examined in cattle, 1 (100%) was identified as male and the remaining 2 (100%) were identified as females. The results obtained confirmed that the accuracy for foetal gender by ultrasonography was 100% in all foetuses observed. The current study demonstrated that trans-rectal ultrasonography examination is an efficient method for monitoring follicular dynamics, diagnosing pregnancy and foetal gender identification and that it is as reliable as laparoscopy and laparotomy where they were applied together. / NRF

Thesis (M.Tech.: Chiropractic)-Dept. of Chiropractic, Durban Institute of Technology, 2005 xiv, 99 leaves / Plantar Fasciitis (PF), also called ‘the painful heel syndrome’, is a common cause of heel pain (Barrett and O’Malley, 1999:2200), accounting for between 7% and 10% of all running injuries (Batt and Tanji, 1995:77; Chandler and Kibler, 1993:345). Primarily an overuse injury, resulting from tensile overload, it involves inflammation and micro-tears of the plantar fascia at its insertion on the calcaneus (Lillegard and Rucker, 1993:168; Barrett and O’Malley, 1999:2200). The body’s attempt to heal these micro-tears leads to chronic inflammation and the formation of adhesions (Ambrosius and Kondracki, 1992:30). Transverse friction massage has been found to be beneficial in the treatment of PF (Hyde and Gengenbach, 1997:478,481; Hertling and Kessler, 1996:137). Cyriax (1984) and Prentice (1994) state the effect of frictions to include the breakdown of adhesions (scar tissue), as well as preventing the formation of further adhesions. Graston Technique Instrument-assisted Soft Tissue Mobilisation (GISTM), based on the principles of frictions, aims to break down adhesions, realign collagen fibres and aid in the completion of the inflammatory process (Carey-Loghmani, 2003:31, 51-62; Hammer, 2001). Enabling us to see changes on ultrasonography, which has been found to be an objective, non-invasive way of evaluating PF (Wall and Harkness, 1993:468; Tsai et al, 2000:259; Cardinal et al, 1996:258). These changes include decreased thickness of the fascia. The aim of the study was to see the effect of GISTM on PF in runners, in terms of ultrasonography, and identify any correlation between these findings and other objective and subjective findings.