Doses to Patients from Medical X-ray Examinations in the UK - 2000 Review

In 1992 NRPB established a National Collation Centre for measurements of doses to patients made by x-ray departments throughout the UK. This report is the second in a series of five-yearly reviews of the national patient dose database and analyses the information collected during the period January 1996 to December 2000. It includes the results of 28,000 entrance surface dose (ESD) measurements and 13,000 dose-area product (DAP) measurements for single radiographs, and 140,000 DAP measurements and 128,000 records of the fluoroscopy time for complete examinations, collected from 371 hospitals throughout the UK. Information on the patient dose distributions and exposure conditions for over 30 types of examination and radiograph is presented. National reference doses based on the rounded third quartile values of these dose distributions are recommended and are seen to be about 20% lower than corresponding values in the previous (1995) review. They have approximately halved since the original UK national reference doses were derived from a survey in the mid-1980s. In this review reference doses have been derived for a larger number of examinations on adults than previously and, for the first time, for three examinations on children, with specific values for five standard-sized patients corresponding to new born babies, 1, 5, 10 and 15 year olds. NRPB gratefully acknowledges the co-operation of hospital physicists and radiology department staff in supplying patient dose data. The continued provision of data to the National Patient Dose Database will be essential in order to monitor the progress of patient dose reduction measures in the UK and to extend and revise national reference doses in the future.