The production of good quality radiographs is a complex process, given the high level of image quality required (Sniureviciute & Adliene, 2005: 260). Exposure of patients to x-rays, a factor in the production of quality radiographs also entails a risk of radiation injury. In 2006, computerized radiography (CR) was introduced at The Nairobi Hospital to try and reduce the film reject rate, decrease repeats, reduce financial costs of consumables like x-ray films and processing chemicals. However, to date, no formal film reject analysis has been conducted at The Nairobi Hospital. Four years after the incorporation of CR, there is apparently, still a significant number of film rejects, implying operational costs may still be high. The cause of film rejects and overall reject cost is not known. This has led to the research question: “Has the film reject rate in the A & E x-ray unit at The Nairobi Hospital reduced following incorporation of CR?” A quantitative, retrospective, descriptive study involving a reject film analysis of rejected radiographs in the Accident and Emergency (A&E) x-ray unit in the Nairobi Hospital, Kenya was conducted. The researcher collected data for a period of 6 months between 2/12/07 and 28/05/08 using a purpose-designed data collection form. All rejected x-ray films during the study period were included. Capture and analysis of the collected data was completed by the researcher using SPSS 10 and EPINFO computer packages. Permission to conduct the study was obtained from The Nairobi Hospital Education Committee and due consideration to patient and radiographer confidentiality was maintained throughout the study. A total of 851(2.5 percent) x-ray films were collected during the study period. Four hundred and fourteen (2.6 percent) radiographs and 437 (2.5 percent) radiographs were rejected prior to and after the incorporation of CR respectively. Chest radiographs were the most frequently rejected accounting for 277(66.9 percent) and 123 (28.1 percent) prior to and after the incorporation of CR respectively. The most frequently rejected film size was 35x35cm prior to the incorporation of CR (61.6 percent) and 26x35cm film size after the incorporation of CR (91.3 percent). The most frequent cause of film rejects was radiographer causes both prior to and after the incorporation of CR accounting for 496 (58.3 percent). The film reject rate did not significantly reduce after the incorporation of CR, suggesting that there are other factors which contribute to reject rate, other than CR. The study also shows that higher film consumption does not necessarily lead to high reject rates. The percentage value on annual rejects did not change after the incorporation of CR and a demonstrated increase in the annual cost of purchasing x-ray films was attributed to an increase in annual consumption after the incorporation of CR, and also to the higher cost of digital x-ray films. Despite some identified limitations to this study, some recommendations, which included conduction of regular reject analyses and regular continuing professional development with respect to radiographic technique amongst others, were suggested.

No description available.

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in ful filment of the requirements for the degree of Master of Science in Engineering. Johannesburg, May 2018 / This work was aimed at the advancement of the Laser Shock Peening (LSP) process for aeronautical applications. This involved developing a robust strategy for residual stress measurements to various depths in LSP treated samples with different thicknesses and then to perform a parametric analysis of the LSP process. For the residual stress measurement part of the study, aluminium alloy 7075 samples with thicknesses of 10, 6, 3 and 1.6 mm were treated with LSP and the residual stresses were measured using various complementary techniques: Incremental Hole Drilling (IHD), Neutron Diffraction (ND), Synchrotron Energy-Dispersive X-Ray Diffraction (ED-XRD), Laboratory XRD (L-XRD) and Synchrotron Angle-Dispersive XRD (AD-XRD). The results compared favourably and it was concluded that to obtain a complete depth profile in the subsequent work, the residual stresses would need to be measured using at least three methods: one for near the surface, one at intermediate depths and one at greater depths. For the parametric analysis phase of the study, aluminium alloy 7075 samples with thicknesses of 10 and 1.6 mm were treated with LSP; the following LSP parameters were varied: Power Intensity (PI), Spot Size (SS) and %Overlap. The residual stresses were measured using L-XRD, IHD and ED-XRD. In addition to this, the following were investigated: the sample deformation, the surface integrity, the microhardness, and the microstructure under a Scanning Electron Microscope (SEM). A clear trend in the residual stress depth profile as well as the additional characterisations was observed as the parameters varied. This work will form part of a database of LSP results for various alloys that can be used for engineering residual stress profiles using optimal parameter selection for specific industrial applications and as benchmark for the development of LSP Finite Element tools. / MT 2018

Thirty six consecutive patients with primary sclerosing cholangitis (PSC), 20 males median age 42 years, were studied in order to define prognostic variables and determine the influence of surgery on outcome. Presentation was usually with insidious cholestasis or recurrent cholangitis. Twenty six patients (72 per cent) had associated inflammatory bowel disease (ulcerative colitis 20, Crohn's disease 2, unclassified 4). Thirty two patients were followed prospectively for up to nine years. Twenty three remained either stable or had slowly progressive disease. Of the remaining nine patients, seven died (five from end-stage liver failure and two from cholangiocarcinoma) and two patients underwent liver transplantation. Actuarial survival at five years was 52 per cent. A raised serum bilirubin concentration was the only variable at presentation that independently predicted a poor outcome. Cholangiograms were available for detailed assessment in thirty PSC patients. Neither the extent of biliary involvement nor the presence of surgical correctable ("dominant") strictures in the extrahepatic ductal system were of prognostic importance. Six patients who developed obstructive jaundice associated with advanced liver disease underwent surgical drainage operations for dominant biliary strictures, but this did not seem to prevent progression of the disease. Two patients who progressed to end-stage liver disease went on to liver transplantation and were alive with functioning grafts at seven and fourteen months respectively. Nine patients with asymptomatic PSC were followed prospectively for up to twelve years. None of these patients developed overt liver disease but serum bilirubin levels became mildly elevated in two patients. It is concluded that symptomatic PSC is a progressive disease with a poor prognosis. Patients with advanced liver disease due to PSC should be considered directly for liver transplantation. In contrast, asymptomatic PSC patients may remain symptom-free for many years.

Indiana University-Purdue University Indianapolis (IUPUI)

Indiana University-Purdue University Indianapolis (IUPUI) / The purpose of this study was to determine whether angular and linear measurements from tracings of a Panorex radiograph provide a valid comparison to bony relationships identified on the lateral cephalometric headplate of the same individual. A pilot study was performed on a dried skull to identify selected skeletal landmarks on Panorex radiographs. Using these landmarks, fifteen measurements of bony relationships of the head were completed on each radiograph. Values obtained on a lateral headplate were compared with measurements on the same patient's Panorex radiograph for a group of forty-eight children. The data were recorded on standard IBM punch cards and submitted for statistical analysis to the Research Computation Center of Indiana University-Purdue University at Indianapolis. The data support the conclusion that angular and linear measurements from a tracing of a Panorex radiograph cannot be compared directly or in a proportional manner to similar measurements from a tracing of a lateral headplate of the same individual. Although there was significant correlation of comparative measurements for the sample group as a whole, there was wide variation from individual to individual.

Indiana University-Purdue University Indianapolis (IUPUI) / An exploratory study was conducted in order to identify what information patients have and/or want to have about an arteriogram prior to the procedure being performed, and to evaluate the effectiveness of a prearteriogram teaching program in providing this information. The final sample consisted of nine adult patients who were hospitalized and scheduled for arteriography (except for cerebral arteriograms). Data were collected over a two-and-a-half month period utilizing a prearteriogram and a postarteriogram questionnaire. Subjects were contacted prior to the arteriogram and asked to complete part of the prearteriogram questionnaire. The Singer Caramate (Model SP-2) was then used to present the prearteriogram teaching program (a cassette tape recording with accompanying slides) to the subjects. The program. provided the subjects with information about the arteriogram, including preparation for the procedure, how the procedure was performed, and postprocedural care. The subjects then completed the remainder of the prearteriogram questionnaire. Within 48 hours of the completion of the arteriogram the subjects were again contacted and asked to complete the postarteriogram questionnaire. Results of this study indicated that these subjects had very little, if any, information about the arteriogram prior to the procedure being performed, but that they did desire information about the preparation for the test, the procedure itself, and postprocedural care. Most of the subjects in the study indicated that they acquired information about the arteriogram from the prearteriogram teaching program, and that this program was helpful to them in preparing them for the arteriogram. The majority of the subjects also recommended that future patients scheduled for arteriograms be given this informati.on by presenting the program to them prior to the procedure. Thus, the investigator postulated that the presentation of information in an audio-visual program prior to an arteriogram is an effective means of providing information about the procedure to patients.

No description available.

Indiana University-Purdue University Indianapolis (IUPUI) / Sixteen adult human skulls with "normal occlusion" were examined with the Panorex to determine its ability to record the mesio-distal axial inclinations and the mesio-distal diameters of the posterior teeth. This study indicates that the Panorex can be used as a qualitative and quantitative instrument in the study of the mesio-distal axial inclinations of the posterior teeth. A series of means and standard deviations for each posterior tooth as interpreted by the Panorex was developed. Individual measurements of posterior teeth as seen on the Panorex can now be related and compared to these standards so that they are valuable in the diagnosis, treatment, and evaluation of orthodontic cases. Further research is necessary, however, to accurately interpret the mesio-distal diameters of the posterior teeth as seen on the Panorex if these measurements are to be used for arch length analysis.

No description available.