Evaluation of image quality parameters of representative intraoral digital radiographic systems

Abstract

The aim of this study was to compare imaging properties of 20 intraoral digital systems objectively. Using a direct current x-ray source and a radiographic phantom, a series of radiographs was made from the lowest exposure time until the sensor saturated. Images were captured and stored. Incident exposures were measured using a radiation meter. Gray scale, spatial resolution, and contrast/detail detectability were evaluated. Presence of 7 distinct steps spanning the gray levels from 0 to 255 was used to define the exposure latitude. An "optimal" exposure, the lowest exposure where maximum spatial resolution and contrast/detail detectability were achieved, was determined. The systems varied greatly in latitude, "optimal" exposure, and image quality. This may not be readily apparent to the naked eye or when clinical images are compared. Objective assessment of image quality with a quality assurance tool makes it possible to evaluate and compare the various intraoral digital systems.