Visualization of the gall bladder of the dog by the Roentgen ray.

By injecting solutions of sodium iodide or Neo-silvol (Parke-Davis) into the gall bladder of the dog, the movements of the gall bladder and the fate of contained fluids may be easily studied fluoroscopically and by radiograph. Neo-silvol, a silver-proteiniodide compound, is particularly useful because it is not readily absorbed and is relatively non-irritating. Excellent radiographs of the gall bladder have been obtained after direct injection of 1 cc. of a 35 per cent solution of sodium iodide. The volume of the gall bladder in a medium sized dog is greater than 21/2 cc. Much more of the salt may therefore be used, and isotonicity still be preserved since sodium iodide is isotonic at about a concentration of 141/2 per cent. Proportionate amounts of Neosilvol may similarly be used. The presence of pneumoperitoneum remaining postoperatively or induced experimentally, is a distinct aid in visualization where it is desirable to use small concentrations of material.

The following observations have been made on six dogs while recovering from anesthesia, after anesthesia, or a number of days after operation. The total number of actual experimental hours of observation was between fifteen and twenty.

1. Spontaneous Expulsion.

Only once during the course of this series was there seen spontaneous expulsion of material from the gall bladder. This was in a cholecystostomized dog (No. 3361, May 29, 1923) which five days after a small bored rubber tube had been placed in the gall bladder wall, was taken to fluoroscopy. Four cc. of 150 per cent sodium iodide was injected through the tube. The gall bladder became beautifully outlined. During the next ten minutes the dog was standing comfortably on the platform on four iegs, or occasionally sitting down, nothing was seen to enter the duct and go into the duodenum.