Abstract: Objective To differentiate malignant and degenerative benign bone disease using ^99mTc-citrate scintigraphy.Methods Thirty-nine patients(92 lesions)with confirmed malignant bone disease or degenerative benign bone disease were studied,for which the results of ^99mTc-methylene diphosphonate(^99mTc-MDP)scintigraphy were positive.^99mTc-citrate seintigraphy was performed within a time interval of 2-7 days after ^99mTc-MDP scinfigraphy.Visual analysis and semiquantitative analysis were apphed.Each lesion was scored as malignant or benign,which was independently verified,using conventional techniques (histopathology,X-ray,CT,MRI and clinical follow up).Results In visual analysis of ^99mTc-citrate imaging,most malignant lesions(35/48,72.92%)clearly showed high radioactivity accumulation,while most benign lesions(39/44,88.64%)had not obviously visible uptake of ^99mTc-citrate.In semiquantitative analysis of ^99mTc-citrate image,malignant lesions demonstrated a higher lesion-to-background radioisotope uptake ratio (RUR)than that of benign degenerative lesions(1.47±0.42 vs.1.09±o.38,t=2.887,P<0.01),while RUR of ^99mTc-MDP in the two groups is of the same(1.96±0.25 vs.1.87±0.21,t=1.178,P>0.20).Conclusion ^99mTc-citrate scintigraphy is a promising method to differentiate malignant from benign degenemfive lesions Seen as areas of increased activity on ^99mTc-MDP bone seintigraphy.