The invention relates to diagnostic, detection, screening and imaging methods. In various embodiments, methods of diagnosis, detection, screening and imaging include administering a cationic steroid antimicrobial or CSA to a subject having or at risk of having an infection or a hyperproliferative disorder (e.g., a tumor, cancer or neoplasia) in an amount effective to diagnose or detect the infection or the hyperproliferative disorder (e.g., a tumor, cancer or neoplasia) in the subject. In a particular aspect, a detectable CSA, namely CSA-13 labeled with 99mTc is used to detect the presence of an infection.
