Lost image contrast in underexposed regions of x-ray films (radiographs) is a persistent and pervasive problem that compromises the reliability with which radiologists diagnose disease from radiographs. This is sometimes called the """"""""dynamic range"""""""" limitation of film. The X-Ray Light Equalizer (XLE) is an electro-optical device that boosts the contrast of underexposed regions of any radiographic film by supplementing X-ray exposure with additional light exposure, thereby extending the dynamic range of radiographic film and improving diagnostic accuracy. During Phase I, a prototype XLE device was constructed and tested. The results of that work indicated that: 1. virtually any x-ray film can be improved using light equalization; 2. contrast improve-ment by factors as large as 5 are possible with this approach; and 3. the prototype XLE significantly increased image contrast in underexposed regions of radiographic images of chest and head phantoms without noticeably affecting the adequately exposed areas of the same films. The primary goal of this Phase II research effort is to evaluate the clinical efficacy of light equalization radiography in the chest, portable and mammographic exams. Clinical prototypes of XLE devices for each of these three areas will be developed during Phase II. Observer studies will be carried out at the University of Chicago in chest and portable radiography.
