R@ hne-18-2-deoxy-2-fIuoro-D-glucose ([18F] FDG) uptake and distributionin an expenmentaily induced inflammatorytissue were investigated. Rats were subcutaneouslyinocu lated withturpenthe oil to induce inflamma@ onand used for tissue disthbu@ onstud@ sand autoradkgraphy. lime@ ursestudy of [18F] FDGtissue distribution showed that the uptake in inflammatorytissue increased graduallyuntil60 mm and then decreased. A longftudinalstudy of [†8FJFDGtissue distributionshowed thatthe uptakeincreasedprogressivelyto a peak 4 days after inoculationand then decreased. On the fourth day postinoculation, a section of inflammatorytissue showed tharacterisbc changes of chronic inflammation. Macro-and micro-autoradiographyshowed a high density of silvergrains in the abscesswall cons@ bngof an inflammatorycell layerand granulationtissue. Graincountingon micro-autoradiographyof the abscess wall showed that the highest grain densfty was foundinthe marginalzone ofyoung fibroblasts, endothelialcells of vessels and phagocytesof neutrophilsand macrophages, followed by that in the neutrophil layer and granulation tissue. Our results indicatethat [18F] FDGPET may be useful in detecting and monftedng chronic inflammatory processes.