X-ray field collimation in diagnostic radiology.

A comprehensive study of radiographic practice within radiodiagnostic departments throughout Wales is currently being carried out under the auspices of the College of Radiographers and the Royal College of Radiologists. This paper reports on collimation practices observed in more than 2000 individual patient radiographs involving seven types of examination. Film dimensions are compared to those of the X-ray field and the unnecessary irradiation of radiosensitive organs consequent upon inappropriate collimation is considered. The suitability of film sizes frequently chosen for particular projections is also examined.