DETERMINATION OF SURFACE AND ORGAN DOSES IN THE AMBER SYSTEM

Surface and organ doses were determined by means of thermoluminescence dosimetry with the Alderson Rando phantom and the patient, for the AM BER thoracic imaging system, sensitivity class 400, and the convention al grid screen stand, sensitivity class 200. The dose on entering the body, which varied according to object-dependent modulation of x-ray i ntensity, was 140 muGy for the mediastinum and 96 muGy for the lung in p. a. AMBER takes, and hence was comparable with the entrance dose of 132 muGy with the conventional grid screen stand. In lateral takes th e entrance doses were lower with the AMBER system (302 muGy) than with conventional takes (593 muGy). Exposure of the gonads at the AMBER sy stem for p.a. thoracic takes was lower than at the screen grid stand i n females (4 - 6 muGy). More unfavourable values were measured for the gonad exposure in males (2 - 0.8 mug).