A radiofluorinated 2-nitroimidazole derivative with hypoxia-specific tracer activity. 18F-fluoroazomycin arabinoside is reduced under hypoxic conditions and is often seen in various malignant tumors, forming highly reactive intermediates. In its reduced form, 18F-fluoroazomycin arabinoside covalently binds to macromolecules, thereby accumulating in hypoxic cells and allowing radioisotopic imaging of these particular cells. Compared to 18F-misonidazole, 18F-fluoroazomycin arabinoside has a lower octanol:water partition coefficient; it therefore has less tendency to accumulate in lipophilic tissues and exhibits a faster renal clearance, leading to an improved imaging ability of hypoxic tissue. Check for active clinical trials using this agent. (NCI Thesaurus)