The application of photographic reducers to autoradiographically intensified radiographs.

In autoradiographic intensification of underexposed images by the method of Askins, the lower densities are intensified by a much larger factor than the higher densities, thus decreasing the contrast of the intensified image. However, when the underexposed, developed, and processed image radiograph) is treated in a subtractive photographic reducer (potassium ferricyanide-sodium thiosulfate mixture) prior to activation with 35S thiourea, the fog is decreased greatly, thereby increasing the contrast of the intensified image. Of the six underexposed radiographys, involving both bone phantoms and various body regions studied after autoradiographic intensification, five were consistently rated adequate for their diagnostic certainty in comparison to the corresponding optimally exposed radiographs.