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AP versus PA positioning in lumbar spine computed radiography : Image quality and individual organ doses

Davey, E and England, A 2015, 'AP versus PA positioning in lumbar spine computed radiography : Image quality and individual organ doses' , Radiography, 21 (2) , 188 - 196.

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Purpose: Radiological imaging examinations must be optimised in order to ensure that the radiation dose is kept as low as reasonably possible (ALARP). The aim of this study was to compare anteroposterior (AP) and posteroanterior (PA) projections of the lumbar spine, at various kVp increments, in order to establish optimum parameters. Methods: An anthropomorphic phantom was imaged in both the AP/PA projections and at various kVp increments. Acquisitions were undertaken using a Wolverson Acroma X-ray unit and processed using an Agfa computed radiography (CR) unit. The entrance surface dose was recorded and converted to effective and organ doses using PCXMC 2.0 software. Five observers were then asked to evaluate the images, using a two-alternative force choice (2AFC) approach and a scale based on EC guidelines. Results: The PA projection lowered the mean effective dose by 19.8% and also the mean absorbed dose to the stomach (70.4%), colon (61.1%), remainder tissues (33.2%), ovaries (7.3%) and testes (15.9%). However, this was at the expense of slightly inferior image quality, not statistically significant. For AP projections, a higher kVp is a further option for dose reduction. Conclusion: Dose optimisation requires the production of an image that is acceptable for the purpose intended. Based on ALARP, and when taking into consideration the dose reductions in this study, it may now be time to routinely use PA projections when imaging the lumbar spine. The use of a higher kVp should also be considered as an option but would be more useful for AP projections.

Item Type: Article
Uncontrolled Keywords: Computed radiography
Themes: Health and Wellbeing
Schools: Schools > School of Health Sciences > Centre for Health Sciences Research
Journal or Publication Title: Radiography
Publisher: Elsevier
Refereed: Yes
ISSN: 1078-8174
Related URLs:
Funders: University of Salford
Depositing User: Dr Andrew England
Date Deposited: 07 Jul 2015 14:35
Last Modified: 01 Jun 2016 01:38

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