Spatially Modulated Radiographic Illuminator

The objective of this project is to develop a system for the optimized viewing of medical x-ray film. Illuminators currently used to view radiographs have a fixed-area, spatially uniform light output. This allows extraneous light to degrade visual performance and limits the viewable film density range to the dynamic range of the eye at a given adaptation level. The proposed viewing system will provide spatially modulated illumination to reduce the range of light intensities transmitted through and around the x-ray image; thus, it will lessen optical glare, improve photoreceptor sensitivity and expand viewable film latitude without compromising contrast or resolution. Specifically, this approach to film viewing should reduce significant false-negative rate in detecting pulmonary nodules on chest films. To achieve these goals, the project will aim to develop 1) a large-area, flat-panel spatial light modulator, 2) a variable light source with sufficient intensity to enable photopic viewing of radiographs over a wide density range, and 3) a mechanism to provide automatic illumination control. No current technological embodiment can provide large-area spatial modulation of light at sufficient intensity for reading radiographs.