Measurement of x-ray exposures using mailed thermoluminescent dosimeters

Thermoluminescent dosimeters (TLD) have been sent by mail to all hospitals in Nova Scotia to survey the radiographic and fluoroscopic x-ray exposures to patients, For each radiographic system a TLD was placed in the x-ray field during a routine abdominal radiographic procedure on an average size patient (20 cm AP). The TLD was not visible on the film and in no way effected the examination. Fluoroscopic exposure rates were measured using TLD and a 20 cm water phantom. The dosimeter was exposed for one minute using technique factors for an abdomen of average size. The average abdominal exposure to a 20 cm thick patient on 137 different radiographic units was .74 R. The average fluoroscopic exposure rat to a 20 cm water phantom using 54 different fluoroscopic systems was 5.4 R/min.