Radiographic image subtraction in gas ionography

The feasibility of radiographic image subtraction based on electrostatic imaging techniques is demonstrated. Ionographic latent images are essentially foil electrets with surface charge densities modulated by x-ray transmission through the object. Latent image charging at one polarity corresponding to the production of the primary image, and latent image discharging with the opposite polarity, are used to create the final latent image representing the region of interest. The technique is simple and could be in its present form applied to industrial radiography. Using high-pressure xenon ionographic chambers, the technique could be developed into a clinical tool as an inexpensive alternative to conventional digital radiography.