Ultrasound is a valuable tool to monitor wound healing. In this report, ultrasound is used to determine the features in the B-scans that correspond to a bruise. High frequency ultrasound scans show clear and distinct features that correspond to a laceration or a late stage pressure ulcer. This is because of the extensive damage and the rupture of the epidermis in both the cases. This study assumes significance because it is an effort to find such artifacts in the ultrasound scans of bruises caused by blunt forces where the epidermis remains intact. In this study, the structure of the skin was visualized using a 20 MHz ultrasound scanner. Skin thickness and echogenicity changes may result due to blood extravasations or edema. The thickness and the echogenicity values are plotted against time to determine the trend in the variation of these parameters. We see an intraday and a daily fluctuation of skin thickness and echogenicity albeit with no distinct trend on a day to day basis or between subjects. The results also give us a good estimation of the variation observable in these parameters in the event of an injury. A snapshot analysis is also performed, which describes qualitatively the structural changes in the B-scan of the bruise site compared to the control site. There are six different types of qualitative changes which can appear in the B-scan of a bruised site compared to the control. In the event of an injury, usually, more than one of these changes is manifested in the scan of a bruise. Skin thickness and echogenicity vary considerably due to a number of physiological factors which can seldom be controlled. Therefore, these parameters can give conclusive evidence of a bruise only if the change between a bruised region and a control region is much greater than the daily, normal variations. Snapshot analysis can help detect a bruise or a deep tissue injury. Further work involves the application of pattern recognition or face recognition algorithms to automate the detection.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 66-69). Also available in electronic version. Access restricted to campus users.

Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Hasler, Paul; Committee Co-Chair: Degertekin, Levent; Committee Member: Anderson, David; Committee Member: Ayazi, Farrokh; Committee Member: Brand, Oliver; Committee Member: Hesketh, Peter. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Photothermal cancer therapy is a potential alternative to surgery and involves selective tissue destruction using thermal energy. Targeted photoabsorbers, used in conjunction with matching a continuous wave laser, make photothermal therapy both noninvasive and tumor-specific. However, to become clinically relevant, there is a need to develop an imaging technique to identify tissue composition and to detect the presence of photoabsorbers in the tumor volume before therapy; to monitor the temperature rise during therapy; and to assess the tumor damage after therapy. In this study, a combined ultrasound and photoacoustic imaging system was designed to assist photothermal therapy. The imaging system was tested on tissue mimicking phantoms, ex-vivo porcine tissue samples, ex-vivo mice and in-vivo mice. First, ultrasound imaging was utilized to differentiate between water-based and lipidbearing tissue. A combined ultrasound and photoacoustic imaging system was then assembled to identify the presence and spatial location of gold nanoparticles. Multiwavelength photoacoustic imaging was used to further confirm the presence of nanoparticles. Temperature monitoring algorithms, using both temperature-dependent time shifts in ultrasound signals and amplitude changes in photoacoustic signals, were developed. Finally, photothermal therapy was carried out on tumor-bearing nude mice using in-vivo ultrasound and photoacoustic imaging to identify the tumor boundary, detect the nanoparticles and monitor the temperature elevation. The results of the studies show that ultrasound and photoacoustic imaging provide complementary and clinically relevant information. Overall, there is potential of using the ultrasound and photoacoustic imaging system to plan, guide and monitor photothermal therapy. / text

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

No description available.

[Truncated abstract] In women, as in other mammals, the ability to successfully lactate depends on both complete functional development of the mammary gland and the stimulation of the milk ejection reflex to enable the suckling young to remove stored milk. Prior to my studies, Sir Astley Cooper’s carried out the most comprehensive investigation of the gross anatomy of the lactating human breast in 1840. I have used ultrasound to image the anatomy of the breasts of fully breastfeeding women (1-6 months, n=22) with particular emphasis on the distribution of the main milk ducts, glandular and adipose tissue. Scanning of the milk duct system demonstrated that the anatomy in the region of the areola and nipple is different to that depicted in standard anatomical textbooks. The main milk ducts were small (diameter, left: 1.9 ± 0.6 mm; right: 2.1 ± 0.7 mm), superficial (depth, left: 4.50 ± 1.98 mm; right: 4.74 ± 1.59 mm) and branched close to the nipple (within 8.20 ± 6.27 mm, left; 7.00 ± 3.98 mm, right) (mean ± SD). The lactiferous sinuses (described in current textbooks) were not observed and the number of main ducts detected at the base of the nipple was less than the quoted 15-20 (9.4, range 4-18). Quantitative descriptions of the morphology of either the lactating or, indeed, the non-lactating breasts have not been attempted using ultrasound. I developed a systematic approach to ultrasound imaging of the breast that provided a semi-quantitative description of the distribution of glandular and adipose tissues within the lactating breast. Approximately two thirds of the breast was comprised of glandular tissue. Intraglandular fat was identified as hypoechoic transects within the hyperechoic glandular tissue. Over 65% of the glandular tissue together with 50% of the intraglandular fat and 25% of the subcutaneous fat was located within a 30 mm radius of the base of the nipple. The absence of lactiferous sinuses and the arrangement of tissue within a 30 mm radius of the nipple suggested that the current conceptualisation of sucking dynamics of the infant requires revision. Successful milk removal depends on the stimulation of the milk ejection reflex and currently subjective assessments of milk ejection such as the mother’s sensations and an alteration in the infants sucking and swallowing are used clinically to confirm milk ejection whereas in research two stressful invasive procedures; changes blood oxytocin and intra-ductal pressure have been used. I have developed a non-invasive ultrasound technique to detect milk ejection in women

Tez (Tıpta Uzmanlık) - Süleyman Demirel Üniversitesi, Tıp Fakültesi, Radyodiagnostik Anabilim Dalı, 2006. / Bibliyografya var.

Thesis (M.D.)--University of Hong Kong, 1992. / Includes bibliographical references (leaf 189-216).