Information gain at reduced exposure time using a prototype video-enhancement device.

An experimental imaging device based on analogue video-enhancement was evaluated by comparing the information yield of three different screen/film radiographic combinations with that from conventional viewing methods. Twenty radiographic images of variable density for each screen/film combination were produced by exposing a test object for between 0.1 and 6.6 s and examined by 10 observers in two trials. Perceptibility curves were generated from the data to measure the information yield of each system. Multiple non-parametric t tests demonstrated no loss of information with the experimental device in the diagnostically useful exposure range (15-60 impulses). In addition, this range was extended, with the faster film/screen combinations, to lower exposures (8-12 impulses), suggesting that the device also has the potential to reduce radiation exposure.