The application of radioimmune imaging techniques to the evaluation of non-neoplastic disease is largely based on the same principles as tumor imaging; specificity and high affinity of antibodies. Currently the most common non-tumor applications of antibody imaging are the detection of clots (peripheral and pulmonary emboli), myocardial necrosis (myocardial infarction, myocarditis and cardiac transplant rejection) and focal sites of infection/inflammation. In the area of injection imaging, both antigen-specific and non-specific properties of antibodies have been successfully exploited in imaging studies. While the number of non-tumor applications of antibodies are far fewer than the number of tumor studies, in many cases, they appear to be more reliable. The basis for the reliability of antibodies for detecting non-neoplastic lesions is probably related to the availability of abundant antigen, lack of antigen modulation and enhanced permeability at the lesion site. These observations suggest that there will be rapid proliferation of work in this area.