| 摘要 |
A process is disclosed for producing an ultrasonographic image using an element containing a catalyst and a diffusion barrier. When the element is placed into contact with a solution containing a catalyst poison and ultrasound is imagewise applied, the catalyst is selectively poisoned in ultrasonically exposed areas. Thereafter the unpoisoned catalyst remaining is employed to form a viewable image. The catalyst can be electrically biased to avoid poisoning during extended contact with the catalyst poisoning solution in the absence of ultrasound. In one form the catalyst can be generated using a photographic silver halide emulsion.
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