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This study investigated arch dimension changes associated with growth and tooth wear in Australian Aboriginals aged from age 8 to 15 years using 2D and 3D digital imaging systems. Serial dental casts of Australian Aboriginals from Yuendumu were used in the study. The sample comprised 25 females and 24 males for whom casts were available at ages of 8, 12 and 15 years ( a total of 294 dental study casts). The primary method of data acquisition involved obtaining digital photographs and digitizing the images using an Apple IIGS computer and customised software program. A subset of 40 dental stone models (5 individuals at ages 8, 12, 15 and 18 years) were duplicated and scanned using the Minolta Vivid 900 laser surface scanner at the DSIRO Laboratories, National University Singapore. The 3-D images were digitised using the Rapidform software package (Inus, technology, Seoul, Korea). Study variables included mesiodistal crown diameters, arch widths, arch depths and arch lengths. Mesiodistal crown dimensions in males tended to be larger than those in females. All arch dimensions were significantly larger in males than females. Upper and lower Intercanine width increased from age 8 to age 12 years but did not change thereafter. Upper and lower intermolar widths increased with age from 8 years to 15 years while arch depth decreased. No significant reduction in arch lengths was found from age 12 to 15 years. The two imaging systems were comparable in their measurement reliability, although the 2D method provided consistently larger crown diameters than the 3D method. Changes in arch dimensions with age in the Aboriginal sample were similar to those reported for other populations. However, no measurable change was detected in arch length over time, even though the Aboriginals had abrasive diets that would be expected to contribute to interproximal wear. It was concluded that the 2D and 3D imaging methods were suitable for clinical use but would require further refinement for research projects aimed at assessing minor changes in arch lengths associated with interproximal wear. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1347947 / Thesis (D.Clin.Dent.) -- University of Adelaide, School of Dentistry, 2008

Thesis (MTech (Radiography))--Cape Peninsula University of Technology, 2006 / This research was performed to obtain consensus of opinion on the clinical competencies required of newly qualified diagnostic radiographers in South Africa in an attempt to improve alignment between educational practices, assessment practices and workplace requirements. Methods: The Delphi technique, an effective group communication process was employed to recruit a panel of experts representing the radiography profession in South Africa. Three rounds of structured questionnaires together with controlled feedback were sent to the panel members for comment. The same four point Likert scale was employed in all three rounds of the questionnaire. Consensus of opinion was predetermined at >75% agreement for each clinical competency. Results: Response rates for rounds I, 2 and 3 were: 84% (n=49), 78% (n=45) and 69% (n = 40) respectively. Of the 109 clinical competencies listed in the first round questionnaire, 94 (86%) achieved consensus as being necessary clinical competencies required of newly qualified diagnostic radiographers. The remainders were further investigated in terms of whether they should be excluded or included in role extension possibilities. An additional 22 clinical competencies were also suggested by the panel in round I and further developed in subsequent rounds

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Medical imaging technologies such as MRI, CT, PET, etc. enable the use of higher resolution 3D digital image data for research and clinical treatment. The new technologies provide improved spatial resolution at the cost of increased data processing time. Manual identification of anatomical landmarks is still a common practice in many neuroimaging and other medical imaging applications but it is labor-intensive, subjective, and suffers from intra-/inter- rater inconsistency. This work explored one way of estimating a landmark constellation automatically, consistently, and efficiently. The proposed method demonstrated a successful application on how to effectively utilize image processing in tackling clinical challenges. It is shown that the cooperation of spatial localization using linear model prediction with evolutionary principal components and local search estimation using statistical shape models is capable of effectively extracting important landmark detection information from both morphometric relationships of landmarks and consistent intensity distribution of images. It is accurate (compared to 1.6 mm root mean squared errors of manual labeling of brain landmarks), consistent, reliable in predicting many salient midbrain point landmarks such as ac, pc, MPJ, etc. in a longitudinal, multisubject environment, and throughout large datasets with different modalities and image information such as orientation, spacing, and origin. The framework of linear model estimation method using evolutionary principal components and the idea of local search using statistical shape models are generalized to the detection task for arbitrary number of landmarks in other organs, creatures, or even any other physical objects in the world as long as the landmarks present intensity consistency and satisfy regularity in spatial organization.

Orientador: Sheila Canevese Rahal / Resumo: O trabalho teve por objetivo comparar, por meio de exames de imagem e avaliações histológicas, dois parafusos de interferência bioabsorvíveis implantados em ovinos. Foram utilizados 22 ovinos, misto de Santa Inês, adultos, fêmeas, com massa corpórea média de 42,3 kg. Em todos os animais, o membro pélvico direito recebeu o parafuso de PDLLA (70% de L-lactídeo e 30% de DL-lactídeo) e o membro pélvico esquerdo recebeu parafuso de PDLLA 70/30 + β-TCP (30% de beta fostato tricálcico), os quais foram aplicados na região metafisária distal do fêmur por acesso lateral. Os animais foram submetidos à eutanásia, de acordo com o tempo de observação e permanência dos implantes, como segue: 1 mês (n=6), 4 meses (n=5), 7 meses e meio (n=6), 18 meses (n=5). Pelo exame radiográfico, o local de inserção do parafuso PDLLA mostrava-se inicialmente como área radiolucente circular, que progressivamente apresentou-se menos definido e com presença de radiopacidade central. Pela tomografia computadorizada (TC) havia área de hipodensidade no período inicial, que com o passar do tempo apresentou aumento da densidade no eixo central. No último tempo de avaliação, a microTC mostrou acentuado aumento da densidade do parafuso, principalmente nas regiões corticais. Na avaliação histologia o parafuso estava degradado, com áreas de formação óssea discretas e outras mais evidentes. O parafuso de PDLLA/β-TCP foi facilmente identificado nas avaliações iniciais pelos exames de imagem, sendo tanto radiopaco como h... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study aimed to compare two bioabsorbable interference screws implanted in sheep. Twenty-two Santa Inês mixed sheep, adults, females, mean body mass of 42.3 kg were used. In all sheep, the right hind limb received PDLLA screw (70% L-lactide and 30% D,L-lactide) and the left hind limb received PDLLA70/30 + β-TCP (30% beta-tricalcium phosphate) screw, which were applied in the distal metaphyseal region of the femur by lateral access. The animals were submitted to euthanasia, according to observation time and permanence of the implants, as follows: 1 month (n = 6), 4 months (n = 5), 7.½ months (n = 6), 18 months (n = 5). On radiographs, the PDLLA screw insertion site was initially visibilized as a circular radiolucent area, which progressively was less defined and had central radiopacity. Computed tomography (CT) showed an area of hypodensity in the early period, and over time showed increased density in the central axis. At the last evaluation time, the microCT showed a marked increase in screw density, especially in the cortical regions. In the histology, the screw was degraded, with discrete bone formation areas and others more evident. The PDLLA/β-TCP screw was easily identified in the initial evaluations by imaging exams, being radiopaque and hyperdense, with progressive loss of definition by radiographic examination and density change on CT. In the last evaluation, the screw remained hypodense and surrounded by discrete bone tissue on microCT. Histologically, its centr... (Complete abstract click electronic access below) / Doutor