Dose reduction by the use of erbium filtration in a general radiographic room

The conventional aluminium filtration of a general purpose X-ray tube in a district general hospital was replaced by an erbium filter for a 2-month period. The resulting reduction in skin dose was measured for a number of examinations using thermoluminescent dosimetry. The change in effective dose equivalent was calculated from these measurements and compared with previous theoretical estimates. The use of the erbium filter had no effect on radiograph quality. It was concluded that the use of an erbium filter resulted in a worthwhile reduction in radiation dose, and was a cost-effective method of dose reduction.