In ionographic imaging, the ions produced in a high-pressure, high-Z gas are normally collected on an insulating foil. If a deformable dielectric gel is used as a collecting electrode, then the electrostatic image can be visualized by optically projecting the gel deformation onto a screen. In the present work, we have evaluated the imaging performance of such an ionographic system in terms of its sensitivity and resolution capabilities. X-ray images of a sharp lead edge formed on a thin silicone elastomer were optically projected and recorded on x-ray films. The edge profiles were obtained at different values of x-ray exposure, elastomer thickness, gas pressure, and collecting voltage across the chamber. These profiles were processed to obtain the sensitivity and resolution of the system at different operating conditions. Images of some test objects are shown using this system in order to demonstrate its clinical potential.