Comparative Study of the 18F-FDG PET/CT Imaging Characteristics in Isometabolic Liver Lesions

1400 Objectives: The aim of this study was to compare and analysis the imaging characteristics of isometabolic liver lesions in 18F-FDG PET/CT imaging. Methods Prospective study was conducted in patients with isometabolic liver lesions in 18F-FDG PET/CT imaging from November 2014 to May 2015 in nuclear medicine department of our hospital. The clinical data were retrospectively followed-up and analyzed. According to the pathologic diagnosis,clinical diagnosis,imaging examination result and the follow-up result, these isometabolic liver lesions were divided into benign and malignant group. The clinical data and imaging characteristics of 18F-FDG uptake and factors influencing isometabolism were reviewed and the specificity factors to improve the diagnostic value of 18F-FDG PET/CT imaging were found. Results 73 cases of isometabolic liver lesions in 69 patients were enrolled in this study which included 7 malignant lesions and 66 benign lesions (2 cases of liver cell dysplasia, 50 cases of liver cyst and 14 cases of liver hemangioma). Isometabolism was defined as no difference in SUVmean between lesions and the right lobe of the liver (P>0.05). The 7 malignant lesions performed the low density shadow in CT, and 2 of the ambulant liver carcinomas had the increased SUVmax in delay imaging. Both liver cysts and hepatic hemangioma perform low density shadow with clear edge, and respective present none enhanced, quick in quick out in the enhanced CT. The 2 cases of LCD respective performed the unclear edged low density shadow and clear edged high density shadow. The lesion size, T/Nmax and CT value of isometabolic liver lesions had significant statistical differences (P 0.05). Conclusion Hepatocellular carcinoma, liver metastasis,liver cyst, hepatic hemangioma, liver cell dysplasia can all present as isometabolic liver lesions in 18F-FDG PET/CT imaging. The Lesion size, T/Nmax and CT value do help to diagnosis the benign and the malignant liver isometabolic lesions.