Interlandmark measurements from lodox statscan images with application to femoral neck anteversion assessment

Includes abstract.Includes bibliographical references.Clinicians often take measurements between anatomical landmarks on X-ray radiographs for diagnosis and treatment planning, for example in orthopaedics and orthodontics. X-ray images, however, overlap three-dimensional internal structures onto a two-dimensional plane during image formation. Depth information is therefore lost and measurements do not truly reflect spatial relationships. The main aim of this study was to develop an inter-landmark measurement tool for the Lodox Statscan digital radiography system. X-ray stereophotogrammetry was applied to Statscan images to enable three-dimensional point localization for inter-landmark measurement using two-dimensional radiographs. This technique requires images of the anatomical region of interest to be acquired from different perspectives as well as a suitable calibration tool to map image coordinates to real world coordinates. The Statscan is suited to the technique because it is capable of axial rotations for multiview imaging. Three-dimensional coordinate reconstruction and inter-landmark measurements were taken using a planar object and a dry pelvis specimen in order to assess the intra-observer measurement accuracy, reliability and precision. The system yielded average (X, Y, Z) coordinate reconstruction accuracy of (0.08 0.12 0.34) mm and resultant coordinate reconstruction accuracy within 0.4mm (range 0.3mm – 0.6mm). Inter-landmark measurements within 2mm for lengths and 1.80 for angles were obtained, with average accuracies of 0.4mm (range 0.0mm – 2.0 mm) and 0.30 (range 0.0 – 1.8)0 respectively. The results also showed excellent overall precision of (0.5mm, 0.10) and were highly reliable when all landmarks were completely visible in both images. Femoral neck anteversion measurement on Statscan images was also explored using 30 dry right adult femurs. This was done in order to assess the feasibility of the algorithm for a clinical application. For this investigation, four methods were tested to determine the optimal landmarks for measurement and the measurement process involved calculation of virtual landmarks. The method that yielded the best results produced all measurements within 10 of reference values and the measurements were highly reliable with very good precision within 0.10. The average accuracy was within 0.40 (range 0.10 –0.80).In conclusion, X-ray stereophotogrammetry enables accurate, reliable and precise inter-landmark measurements for the Lodox Statscan X-ray imaging system. The machine may therefore be used as an inter-landmark measurement tool for routine clinical applications

The medical device development landscape in South Africa: Institutions, sectors and collaboration

A characterisation of the medical device development landscape in South Africa would be beneficial for future policy developments that encourage locally developed devices to address local healthcare needs. The landscape was explored through a bibliometric analysis (2000–2013) of relevant scientific papers using co-authorship as an indicator of collaboration. Collaborating institutions thus found were divided into four sectors: academia (A); healthcare (H); industry (I); and science and support (S). A collaboration network was drawn to show the links between the institutions and analysed using network analysis metrics. Centrality measures identified seven dominant local institutions from three sectors. Group densities were used to quantify the extent of collaboration: the A sector collaborated the most extensively both within and between sectors; local collaborations were more prevalent than international collaborations. Translational collaborations (AHI, HIS or AHIS) are considered to be pivotal in fostering medical device innovation that is both relevant and likely to be commercialised. Few such collaborations were found, suggesting room for increased collaboration of these types in South Africa

Focus areas of cardiovascular medical device research in South Africa

We investigated the focus of cardiovascular medical device research in South Africa over the 15-year period 2000 - 2014. Information drawn from journal articles was used for the analysis, with attention to articles describing a contribution to the development of a cardiovascular medical device, or a new application of an existing device. The findings suggest that research has focused on diagnostic and monitoring as well as prosthetic cardiovascular medical devices, with specific emphasis on vascular and valvular heart diseases

Collaboration and citation impact: Trends in health sciences research at the University of Cape Town

Against a background of substantial growth in publication output in health sciences at the University of Cape Town (UCT) over the past two decades, we examined the relationship between collaboration with domestic and foreign institutions and resulting citations of co-published work. We report on trends in authorship and citation impact for health sciences research at UCT across three 3-year periods: 1999–2001, 2006–2008 and 2013–2015. We examined numbers of collaborative publications with domestic and foreign co-authors; the status of collaboration with other African countries; the location of the ‘drivers’ of the research (with ‘drivers’ indicated by first or last authorship); and expected and observed citation counts – used as an indicator of impact – over time. We found that the relative citation rate of the set of UCT health sciences publications has increased; the set of 1999–2001 publications was less frequently cited than expected for the journals in which the publications appear, while the 2006–2008 and 2013–2015 sets were cited more frequently than expected. Relative citation rates were greater for papers for which UCT shared international co-authorship than for papers with UCT-only or domestic co-authorship. Our findings confirm reports in the literature of higher citation of internationally co-authored publications. We additionally found that the publications with the highest relative citation rates were driven by authors from foreign institutions. Significance: Methods are presented for extracting, measuring, analysing and representing the citation impact of collaborative research. The relative citation rate of health sciences publications produced by UCT has increased and copublication with international authors has increased. The findings confirm reports in the literature of higher citation of publications co-authored with international collaborators. An apparent influence of foreign drivers on citation impact, holds risk for South African science