A national survey of doses to patients undergoing a selection of routine x-ray examinations in English hospitals

Wide variations have been observed for many of the measured and calculated doses during each examination, with range factors between the extreme values frequently in excess of 100 (average per capita annual dose of about 300 μSv). The majority of measurements in each case are, however, generally covered by a much smaller factor of less than five. Significant differences are also apparent between mean doses determined at the individual hospitals participating in the survey, with factors of over 10 not uncommon between corresponding mean values. The present measurements have included no assessment of image quality during examinations. (author)