Patient dose and image quality in five standard x-ray examinations.

Patient doses and image quality in five standard x-ray examination projections (22-36 measurements per each projection) have been measured, using homogeneous phantoms. The means and range of variation for the entrance skin air kerma values were: abdomen AP 5.2 mGy (1.1-21 mGy), chest PA 0.27 mGy (0.035-0.84 mGy), lumbar spine AP 8.4 mGy (2.9-28 mGy), skull LAT 3.1 mGy (1.1-7.7 mGy), and thoracic spine AP 7.9 mGy (1.3-22 mGy). Considerable variation was found in image quality parameters: film optical densities, image contrasts, and resolutions as well as in exposure values, tube voltages, exposure times, and in half-value thicknesses. The study indicated the need to standardize medical x-ray examination techniques in different x-ray departments. The measuring method can be used for comparing the patient dose and image quality of an individual x-ray unit to the doses and image quality in general use. The results can be used as the reference values for quality control of x-ray equipment.