Fluorine F-18 HX4

**Semantic type:** Pharmacologic Substance

**Definition:** A 2-nitroimidazole labeled with the positron-emitting radioisotope fluorine F 18. HX4, the 2-nitroimidazole moiety of [F-18]HX4, is selectively bioreduced and bound in hypoxic tumor cells, permitting the imaging of hypoxic tumor cells with positron emission tomography (PET).

**Synonyms:** - Fluorine F 18 HX4 - [F-18]HX4