'It's grim up north' : a comparative study of the subjectivities of gay HIV positive men in an urban and rural area

This comparative study of the experiences of gay HIV positive men living in urban and rural areas explores the dynamic interrelationship between lived experience and service provision. The literature in this field has drawn on a familiar stereotype - the urban, sexually active, gay man. This man - and his community - does not exist in a rural environment in the way it is assumed nor does it necessarily fit the experience of gay men in London. By creating a link between the questions of subjectivity and the question of how we improve services, I argue that a mechanistic construction of need may follow an assumed urban model which may not hold for all men in an urban setting, nor for men in rural areas. Gay HIV positive men are faced with new psycho-social dilemmas in relation to the virus, including unpredictability of outcome, as well as the complexity and burden of the current treatment. They engage in a constant process of renegotiating their sense of themselves in space, time and relationships. Through the use of narrative methodology, my research builds a new perspective on the experience of these individuals which can help to shape the services and policies of the future. The stories of 21 gay HIV positive men were gathered and analysed in relation to five areas of focus: community/space, relationships, identity, health and services. Rural participants were less able to build and maintain a politically strong identity and rural services need to create strategies to enable gay men to draw on the strength of a collective voice. 'Doing for' services, prevalent in rural areas, may be appropriate for the very ill but can perpetuate a culture of helplessness. The healthist discourse adopted by London services promotes individualism and responsibility. Services for HIV positive men in all areas need to hold the dynamic between 'doing for' services for the sick and dying and a healthist discourse for those who can look to their future.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A New Concept for a Low-Dose Stationary Tomographic Molecular Breast Imaging Camera Using 3D Position Sensitive CZT Detectors

Pixelated CZT detectors have been used in a variety of molecular imaging applications for many years. The interplay of gamma camera and collimator geometric design, gantry motion, and image reconstruction determines the image quality and dose-time-FOV trade-offs. In particular, Molecular Breast Imaging (MBI) has been shown to provide excellent diagnostic results in patients with dense breast tissue, but higher than mammography patient dose and long imaging time impede its wide adoption. We propose a new transformative system concept combining the advantages of CZT detectors (superior energy and position resolution and depth of interaction sensing), multi-pinhole collimation and novel image reconstruction to mitigate those drawbacks without compromising diagnostic content. The closely spaced pinholes allow tomographic image reconstruction, improve sensitivity and angular sampling, but result in significant multiplexing. Novel de-multiplexing algorithms have been developed to mitigate the adverse multiplexing artefacts using the DOI. GATE simulations of the new camera demonstrate a potential to reduce the patient dose by at least a factor of 5 in comparison to planar MBI, thus reducing the dose to the level of an average mammography scan. The first prototype has been built at Kromek with 3D position sensitive CZT detectors and is being evaluated using an "activity-painting"setup with a point 57Co source. Initial results demonstrate the expected performance improvement with the use of sub-pixelisation and DOI. The next steps of the development will include accurate evaluation of the image quality and the dose reduction followed by building a larger scale clinical prototype using optimised detector design

Design of an Ultra-low-dose, Stationary, Tomographic Molecular Breast Imaging System

Molecular Breast Imaging (MBI) has been shown to have high sensitivity in detection of cancer, even in patients with dense breasts where conventional mammography has issues. However the technique has limited acceptance due to the relatively high radiation dose and long imaging time. Improved lesion detection can be achieved using tomography, however this normally involves detector motion and complex mechanics. Our goal is to develop a low-dose stationary tomographic MBI system with similar or better sensitivity for lesion detection to conventional planar MBI. The proposed system utilizes state-of-the-art cadmium zinc telluride (CZT) detectors based on 2mm pixels, with sub-pixelization and depth of interaction (DOI) capability, combined with densely packed multi-pinhole collimators. Use of closely-spaced pinholes improves efficiency and angular sampling, but results in significant multiplexing. De-multiplexing algorithms have been developed that take advantage of the DOI acquisition to achieve tomographic reconstruction using two opposing planar detectors which apply mild compression to the breast. Simulation studies of multiple lesions with clinically realistic contrast have been used to demonstrate the feasibility of the design and to characterize the expected performance. Reconstruction without de-multiplexing resulted in significant artefacts. De-multiplexing without DOI had limited success but with DOI resulted in artefact-free images, with good contrast and axial plane definition. Lesion detectability was preserved even with reduction of acquisition time (or radiation dose) by a factor of 4. Further optimization has potential for even greater dose reduction. A prototype system is currently being constructed to validate these findings

Challenges in Optimization of a Stationary Tomographic Molecular Breast Imaging System

A prototype Molecular Breast Imaging (MBI) system is currently under development, motivated by the need of a practical low-dose system for use in patients with dense breast tissue, where conventional mammography is limited. The system is based on dual opposing CZT detector arrays and multi-pinhole collimators which allow for multiplexing in the projection data. We have performed optimization of various design parameters based on either contrast-to-noise ratio (CNR) in the reconstructed images or area under the localization receiver operating characteristics curve (LROC-AUC) obtained using the scan statistic model. The optimizations were based on simulated data, and the parameters investigated were pinhole size and opening angle, pinhole separation and collimator-to-detector separation. The two optimization approaches resulted in similar design parameters, allowing for reconstruction of tomographic images with high CNR and lesion detectability, which can lead to a reduced dose or scan time as compared to planar MBI

Empowerment and advocacy: reflections on action research with Bangladeshi and Pakistani families who have children with severe disabilities

The concepts of empowerment and advocacy, and how they impinge on power relationships for service providers working with black and Asian communities, are explored through the findings of a 20-month project carried out between 2000 and 2001 with 19 Pakistani and Bangladeshi families who have children with severe disabilities in Birmingham. This action research project evaluated an advocacy project designed to improve the quality of life for Pakistani and Bangladeshi families with at least one child with severe disabilities. The objectives included improving access to resources, services, information and support in ways which were non-stigmatising, and which were sensitive to the particular needs of the children and their carers. The present paper discusses four main themes: (1) advocacy and empowerment in practice; (2) issues of the efficacy of advocacy and of consultation within advocacy; (3) individual empowerment versus the families' needs; and (4) cultural and gender issues which emerged from the analysis of the study. The authors identify features of empowerment which must be addressed in advocacy services which are sensitive to ethnic differences. These issues must be addressed if services are to reap their potential to make a positive impact on the lives of the most vulnerable and powerless members of the community