[Comparative animal experiments on tissue compatibility and measurement of radioactivity of various roentgen contrast media].

In a comparative study the tissue reaction of several X-ray contrast materials was examined by subcutaneous and intraperitoneal application on rats. There were tested Bariumsulphate (BaSO4) and three Zircondioxyde (ZrO2) samples of several manufactures (cubic and monocline ZrO2-Feldmühle; Optipur-Merck). In the histologic evaluation no inflammatory signs could be seen. In case of BaSO4 the tissue reaction was more distinct than in the ZrO2 samples. Within the tested ZrO2 samples the differences were small; the cubic ZrO2 showed the slightest, the monocline one the relatively strongest cellular reaction. We also measured the radioactive emission by the contrast media. Here the monocline and--first of all--the cubic ZrO2 showed an alarming radioactive emission (radium 3000-11,500 Bq/kg). Only the Optipur (Merck) was free of radiation and can so be recommended for human implantation. Also the BaSO4 had no measurable radioactive Emission. Therefore only these two X-ray contrast media can be recommended for human implantation.