Sandra Hopkins Final Report.pdf - University of Surrey

1. IntroductionThe use of ionising radiation for clinical diagnosis is a long established method for the examinationof a variety of medical conditions. Different imaging modalities and complexities of examinationsmean that some procedures contribute more to patient dose than others. Figure 1 shows thecontribution of the collective dose from the 15 diagnostic examinations which provided the largestcontribution to the collective dose. It can be seen that, with the exception of Computed Tomography(CT), routine diagnostic coronary angiography provides the largest contribution to the collectivedose in the UK. Although the frequency of the examination is low (0.4%), the dose for eachexamination can be high. UK estimates calculate that this exam produces 5.6% of the totalcollective dose 1 . A more recent study for the European population estimates that this contributionhas increased 2 and this is attributed to the fact that this procedure can be performed on an outpatient basis and causes less trauma than surgical procedures. There have also been technicaldevelopments which have led to an increase in frequency such as the introduction of digitaldetectors and the evolution of stents. Coronary angiography is the standard technique for imagingthe left ventricle and coronary arteries. It is a routine diagnostic procedure with a clearly establishedmethod for performing it. Although patient doses are considered to be relatively high for adiagnostic procedure, using current imaging techniques it is unlikely to ever reach a level wheredeterministic effects could be considered a possibility. However, the results of a diagnosticexamination may indicate that treatment is required. This treatment could involve a more complexinterventional procedure such as a graft or insertion of a stent.Figure 1. Contribution to UK collective dose and frequency from the 15 exams making the biggest contribution to thecollective dose 1 .181614Collective DoseFrequency% contribution121086420CT abdomenBa EnemaCT chestCT pelvisCT HeadCoronary AngiographyAbdomenLumbar SpinePelvisMammographyIVUPTCAArteriographyHipCT Spine1