[Evaluation of the cases of benign disease with high accumulation on the examination of 18F-fluorodeoxyglucose PET].

In this study 39 cases of abdominal benign disease were examined by PET using 18F-fluorodeoxyglucose (FDG), and 11 cases of them (i.e. 4 cases of liver abscess, 1 of pelvic abscess, 1 of omental abscess, 2 of chronic pancreatitis, 1 of inflammatory pseudotumor of liver, 1 of retroperitoneal leiomyoma and 1 of solid and cystic tumor of pancreas) which showed as high accumulation of FDG as malignant lesion were investigated of their clinical and pathological feature. We used Ci/Cp ratio as index to express the accumulation of FDG in the lesion, which was calculated from radioactivities of the lesion (Ci) and the plasma (Cp) at 60 mins after injection of FDG. The Ci/Cp ratio of the 11 cases was 3.64 +/- 0.77. The pathological feature of the 9 inflammatory cases was high accumulation of inflammatory cells and that of the 2 benign tumor cases was solid proliferation of tumor cells. The serum of the 9 inflammatory cases showed high CRP value. It was considered that the high accumulation of FDG in inflammatory lesions was due to piles of FDG uptake of the many inflammatory cells, while the 2 benign tumors of high accumulation were considered that the tumor cell had as high glucose metabolism as malignancies.