[Radiologic study of the thorax using the digital method (FCR 101). Evaluation of various parameters as related to exposure].
A computed radiography system with solid state detectors (FCR 101) was employed to evaluate the quality of digital images, with optimal and progressively lowered doses, in the study of the chest. Routine chest radiographs of in patients with no pathologic conditions of the chest were studied. The patients were divided into 3 groups: each patient in group A underwent two radiographs, one at 100% and the other at 50% exposure; patients in group B were imaged with 100% and 25% doses, and those in group C received 50% and 25% exposure. Several parameters were employed for image evaluation, and a value was given to each of them (1 = good, 2 = sufficient, 3 = insufficient). Upon comparison of the average values obtained, we observed that the digital technique allowed a most accurate and well-defined representation of the examined parameters at 100% exposure dose and that a 50% reduction did not decrease the informative content in the least. A 25% reduction, however, determined a high degree of background noise and a subsequent, though slight, loss of information.