Quantifying computed radiography (CR) and digital radiography (DR) image quality and patient dose for pediatric radiology.

摘要

With the advent of digital imaging modalities, there is a potential for dose reduction especially for pediatric patients due to the wide dynamic range and the image processing capabilities of digital systems. A Canon digital radiography (DR) system and an Agfa computed radiography (CR) system are currently in use at Shands Hospital at the University of Florida. Using objective measures of image quality (modulation transfer function (MTF), noise power spectrum (NPS), and integral detective quantum efficiency (IDQE)), these systems can be evaluated and compared for pediatric chest imaging. Using MIRD tissue-equivalent pediatric phantoms constructed at the University of Florida, organ absorbed and effective doses of chest examinations can be measured. With these measurements, a relationship between image quality and dose is used to predict appropriate techniques used for pediatric chest imaging.;The radiographic techniques developed in this research for the Agfa CR system were identical to the radiographic techniques that a technologist would select for a patient the same size and weight of the pediatric phantoms. The method for predicting appropriate radiographic techniques is useful for setting up new systems such as the Canon DR system at Shands at the University of Florida which is not used on patients under 4 years of age. This research determined that the Canon DR system had superior image quality, as measured by the HDQE, at lower doses than the Agfa CR system at standard resolution.