D Hart, B F Wall, M C Hillier and P C Shrimpton
Publication date: December 2010
This report presents the results of a study of frequency and collective dose for medical and dental X-ray examinations in the UK in 2008. The frequency data were collected from the radiology information systems (RIS) at a sample of 29 NHS Trusts in England. The total number of medical and dental X-ray examinations carried out in the UK, both inside and outside the NHS, is estimated by extrapolation to be 46 million in 2008, a 10% rise on the number for the financial year 1997/98. Combining effective doses (2007 definition) for specific X-ray examinations with the frequency of those examinations gives an estimate of collective dose for the UK in 2008 of 24,700 man Sv (+ 12%). A very similar figure of 24,250 man Sv is obtained if the 1991 definition of effective dose is used. The UK per caput dose is therefore around 0.4 mSv per year, which has increased by 23% over that for 1997/98. This increase is mainly due to the greater prevalence of computed tomography (CT) examinations, which now account for 68% of the collective dose from all medical and dental X-ray examinations. Conventional radiographic and fluoroscopic examinations contribute only 19% of the collective dose, despite constituting 90% of all X-ray examinations. Angiography and interventional procedures contribute about 5% and 8%, respectively, to the UK collective dose from all X-ray examinations. Despite the increase in the annual UK per caput dose from 0.33 to 0.4 mSv, it is still low in comparison with other countries having similar levels of
healthcare. This is due to both a lower frequency of X-ray examinations per head of population and generally lower doses per examination in the UK.
Last reviewed: 31 December 2010