Fig. 4.

Hypoxia imaging with radiolabelled 2-nitroimidazole. a Chemical structure of [¹⁸F]fluoroetanidazole. The nitro moiety is necessary for hypoxia selective retention. b Cellular uptake of [¹⁸F]fluoroetanidazole in RIF-1 cell line culture grown under normoxia or hypoxia (nitrogen gas). The amount of radioactivity bound to cells was counted. c Imaging of [¹⁸F]fluoroetanidazole by PET showing tracer localisation in HT1080 (subclone 1-3C) xenograft. A 0.5-mm transverse slice of the 30–60 min image acquired in a small animal PET scanner is shown. Arrow, tumour. Courtesy of EOA

Published in Br J Cancer 2004 (Barthel et al.) (Color figure online)