A method for determination of the depth of thrombi after injection of fibrinogen labelled with iodine 125.

By using a specific characteristic of 125I decay, the depth of thrombi located in the lower limb could be determined. Twelve thrombi in nine patients were studied with the method and their localization was in all cases confirmed by phlebography and clinical examination. The results of the phlebograms were in good agreement with those of the 125I-fibrinogen method. The present method offers a promising alternative to phlebography in the diagnosis of postoperative thrombosis.