Abstract: Objective To assess the clinical value of ¹⁸F-FDG PET/CT for the patients with ascites of unknown causes.Methods A total of 106 patients with ascites undergoing ¹⁸F-FDG PET/CT examination was retrospectively studied and ¹⁸F-FDG PET/CT imaging was interpreted by two ways.(1)PET/CT(localization):Diagnostic Results of PET/CT depended on the degree of ¹⁸F-FDG uptake in peritoneum with CT was trecoted as anatomical localization,and high ¹⁸F-FDG uptake in peritoneum was regarded as malignancy.(2)PET/CT(morphology):Morphological changes of peritoneum on CT imaging and the degree of ¹⁸F-FDG uptake on PET imaging were simultaneously considered when interpreting the diagnostic Results of PET/CT.Results In the differential diagnosis of ascites of unknown cause,the sensitivity,specificity and accuracy of PET/CT(localization)were 90.2%,71.1% and 82.1%,respectively.These values of PET/CT(morphology)were 95.1%,93.3% and 94.3%,and 85.2% of malignant ascites were found primary lesion.The specificity and accuracy of PET/CT(morphology)were higher than those of PET/CT(localization)(P=0.002,P＜0.001).Statistical difference was not found in both sensitivities.Conclusion PET/CT(morphology)had higher clinical value than PET/CT(localization)in the differential diagnosis of ascites with unknown cause,and had important significance in detecting primary cause of malignant ascites.

Key words: Ascites, Positron emission tomography, Tomography