Radiation dose in pelvic imaging

OBJECTIVE: To compare the radiation dose during pelvic x-ray examinations using computed radiography (CR) and film-screen (FS) radiography at various x-ray tube voltages (kV) and tube-current time product (mAs) values. METHODS: A pelvic phantom was imaged using FS and CR systems. The entrance surface dose was measured using an ionization chamber, and the gonadal dose and effective dose were calculated using the XDOSE program. The diagnostic quality of the images was assessed using a 5-point subjective scoring system. RESULTS: At standard kV values, the image quality did not vary significantly between the CR and the FS system, but at higher kV values, the CR images werefound to be of better quality than FS images. In addition, the lower limit of entrance skin dose consistent with diagnostically acceptable CR images was 50% lower than that for FS images. CONCLUSION: The gonadal dose and effective dose for pelvic x-ray examinations can be reduced by 50% when CR systems are used and appropriate exposure factors are established.