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Browsing by Author "McEntee, Mark"

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  • Paediatric CT optimisation utilising Catphanw 600 and age-specific anthropomorphic phantoms
    Publication . Santos, Joana; Batista, Maria; Foley, Shane; Paulo, Graciano; McEntee, Mark; Rainford, Loiuse
    The purpose of the study is to perform phantom-based optimisation of paediatric computed tomography (CT) protocols and quantify the impact upon radiation dose and image noise levels. The study involved three Portuguese paediatric centres. Currently employed scanning protocols for head and chest examinations and combinations of exposure parameters were applied to a Catphan(®)600 phantom to review the CT dose impact. Contrast-noise ratio (CNR) was quantified using Radia Diagnostic(®) tool. Imaging parameters, returning similar CNRs (<1) and dose savings were applied to three paediatric anthropomorphic phantoms. OsiriX software based on standard deviation pixel values facilitated image noise analysis. Currently employed protocols and age categorisation varied between centres. Manipulation of exposure parameters facilitated mean dose reductions of 33 and 28 % for paediatric head and chest CT examinations, respectively. The majority of the optimised CT examinations resulted in image noise similar to currently employed protocols. Dose reductions of up to 33 % were achieved with image quality maintained.
    2014Journal article Open access Show more
  • The establishment of computed tomography diagnostic reference levels in Portugal
    Publication . Santos, Joana; Foley, Shane; Paulo, Graciano; McEntee, Mark; Rainford, Louise
    The aims of this study were to investigate the frequency of Portuguese computed tomography (CT) examinations, identify protocol application and establish diagnostic reference levels (DRLs). CT departments (n=5211) were surveyed nationally (June 2011-January 2012) and CT protocol information and dose data were collected, as were retrospective age-categorised paediatric CT data from three national paediatric centres. The proposed national CT DRLs (CTDIvol) for adults were 75, 18, 14, 18, 17, 36, 22, 27 and 16 mGy for head, neck, chest, abdomen, pelvis, cervical, dorsal, lumbar and joints, respectively. The levels for paediatric head and chest examinations were as follows: 48 and 2 mGy (newborns), 50 and 6 mGy (5 y olds), 70 and 6 mGy (10 y olds) and 72 and 7 mGy (15 y olds). A limited number of current paediatric protocols aligned to recommended international age categorisations. Portuguese DRLs were generally higher than European recommendations, suggesting potential for optimisation. The need for greater standardisation of age-categorised paediatric protocols was identified.
    2014Journal article Open access Show more