The Histologic Effects of Four Commonly Used Media for Excretory Urography and an Attempt to Modify the Responses

The authors studied the histologic effects of subcutaneous and intramuscular injections of Conray 60%, Conray 400, Hypaque, and Renografin 60 alone and diluted with saline, water, procaine, and hyaluronidase. All four media produced an acute inflammatory response which was minimal at six hours and peaked between twenty-four and forty-eight hours. Chronic inflammatory cells, muscle atrophy, and scar formation were present at eight weeks. Despite clinical impressions, Renografin produced a heightened histologic reaction. Hyaluronidase appreciably increased the inflammatory reaction with more coagulation necrosis and scarring. No advantage resulted from diluting the medium with water or saline, or adding procaine.