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A Varian 4 MeV isocentric therapy accelerator has been modified to perform also as a CT scanner. The goal is to provide low cost computed tomography capability for use in radiotherapy. The system will have three principal uses. These are (i) to provide 2- and 3-dimensional maps of electron density distribution for CT assisted therapy planning, (ii) to aid in patient set up by providing sectional views of the treatment volume and high contrast scout-mode verification images and (iii) to provide a means for periodically checking the patients anatomical conformation against what was used to generate the original therapy plan. The treatment machine was modified by mounting an array of detectors on a frame bolted to the counter weight end of the gantry in such a manner as to define a 'third generation' CT Scanner geometry. The data gathering is controlled by a Z-80 based microcomputer system which transfers the x-ray transmission data to a general purpose PDP 11/34 for processing. There a series of calibration processes and a logarithmic conversion are performed to get projection data. After reordering the projection data to an equivalent parallel beam sinogram format a convolution algorithm is employed to construct the image from the equivalent parallel projection data. Results of phantom studies have shown a spatial resolution of 2.6 mm and an electron density discrimination of less than 1% which are sufficiently good for accurate therapy planning. Results also show that the system is linear to within the precision of our measurement (≈ .75%) over a wide range of electron densities corresponding to those found in body tissues. Animal and human images are also presented to demonstrate that the system's imaging capability is sufficient to allow the necessary visualization of anatomy.

Globally there is a lack of radiologists, which results in unreported radiographic examinations, or a delay in reporting on radiographic images even in emergency situations. In order to mitigate and alleviate the situation, and optimise the utilisation of radiographers a red dot system was introduced in the United Kingdom, which later aided in the transformation of the role of radiographers in terms of formal reporting of various radiographic examinations. Although there is a shortage of medical practitioners and radiologists in South Africa the extended role of radiographers has not been yet realised for radiographers. At present, radiographers and medical practitioners work in collaboration to interpret and report on radiographic examinations informally, to facilitate effective and efficient patient management, but this is done illegally because the regulations defining the scope of the profession of radiography does not allow for such practice, putting radiographers and organisations at risk of litigation. In order to gain an in-depth knowledge of the phenomena, to enable the researcher to provide recommendations to the Professional Board of Radiography and Clinical Technology (PBRCT) of the Health Professions Council of South Africa (HPCSA), a qualitative, exploratory, descriptive, and contextual research study was undertaken. Radiographers and medical practitioners were interviewed in order to elicit rich descriptions of their experiences regarding reporting of trauma related radiographic images in the after-hours trauma units. Data were gathered using in-depth semi-structured interviews, and the data were analysed using kesch’s method of thematic synthesis. Three themes emerged from the data, namely the challenges radiographers and medical practitioners face in the after-hours trauma units respectively, with regards to reporting of trauma related adiographs, and suggestions were proposed to optimize the participation of radiographers with regard to trauma related radiographs in these units. A thick description and literature control was done using quotes from participants. Measures to ensure trustworthiness and ethical research practices were also implemented. Thereafter, recommendations were put forward for the PBRCT of the HPCSA, using current literature and inferences made from the findings of the study.

This study discusses reject film analyses (RFAs) before and after the implementation of a quality improvement intervention. RFAs were undertaken to investigate the effect of the introduction and use of exposure charts (ECs) on department and student reject rates of extremity radiographs. Methods: A quantitative comparative pre and post-treatment research design was used. Data was collected from the x-ray departments of two training hospitals in Windhoek, Namibia over a five month period. A retrospective RFA was conducted to determine the department and student reject rates for both departments before intervention. Emphasis was placed on exposure related reject films. ECs were compiled and introduced at Katutura State Hospital (venue B) by the researcher. The students were instructed to use these charts. At Windhoek Central Hospital (venue A) no ECs were used. A prospective RFA was conducted to establish department and student reject rates at both hospitals after the intervention at venue B. Results: During the retrospective phase the department reject rate for venue A was 21 percent while the student reject rate was 23 percent. At venue B 24 percent and 26 percent were scored respectively. Students at venue A produced rejected radiographs due to overexposure (49 percent) and underexposure (23 percent), whilst 37 percent was recorded for both causes at venue B. At venue A, 35 percent of films were rejected due to incorrect mAs selection, at venue B the figure was 42 percent. Undiagnostic radiographs due to inaccurate kV selection comprised 62 percent for venue A and 59 percent for venue B. During the prospective phase the department reject rate for venue A was 20 percent and that of the students was 19 percent. For venue B 12 percent and 11 percent were scored respectively. At venue A radiographs rejected due to over and underexposure were 43 percent and 33 percent respectively while those at venue B were 33 percent and 34 percent. Incorrect mAs selection caused 33 percent of discarded films at venue A and 38 percent at venue B. The figures for inaccurate kV selection were 68 percent and 62 percent for venues A and B. Conclusions: The introduction and use of ECs lowered the student reject rate at venue B in the prospective phase.