[en] Objective: To assess the diagnostic potential of MR- PWI and MR-DWI in differentiating benign from malignant bone tumors. Methods: MR- PWI and MR- DWI were performed on 39 patients by using GE Signa 1.5 T MR imager. The perfusion imaging was started with GRE- EPI sequence, signal intensities were measured on delineated ROI and TIC was gotten using the Functool 2 software system Type of TIC, signal decreasing in first- pass period, maximum slope of TIC and signal difference between two standard states were compared between benign and malignant bone tumors MR-DWI was performed with SE-EPI fast scan sequence with diffusion in three directions ADC values were obtained and compared on delineated ROI using the Functool 2 software system. The resultant data were analyzed with software (SPSS, version 13.0). Subjective overall performance of two techniques was evaluated with Receiver Uperating Characteristic (ROC) analysis. Results: 1.MR-PWI: 1.The patterns of TIC of most benign bone tumors (17/21) were type Ⅰ and Ⅱ, and that of all malignant bone tumors were type Ⅲ and Ⅳ. 2.There were significant differences in signal decreasing in first- pass period [(17.52±.37)% vs. (52.42±5.74)%], maximum slope of TIC [(4.69±2.84)% s"-"1 vs. (9.63±4.05)%·s"-"1] and signal difference between two standard states [(6.87±3.34)% vs. (31.75±1.09)%] between benign and malignant groups. And their diagnostic accuracy was 82.1%, 79.5% and 87.2% respectively. 3. 4 highly vascularized benign bone tumors were mistaken in diagnosis as malignant ones according to their perfusion characteristics. 2. MR-DWI: There was significant difference between ADC of benign and malignant groups [(1.86±0.38)×10"-"3 mm"2/s vs. (1.44±0.26))×10"-"3 mm"2/s] when b value was 300 s/mm"3. The diagnostic accuracy was 79.5% when ADC value less than 1.63)×10"-"3 mm"2/s was considered as malignant ones. 3 The diagnostic accuracy of MR-PWI and MR-DWI were 89.7% and 79.5% respectively. Conclusion: MR-PWI is the better valuable technique than MR-DWI in differentiation benign from malignant bone tumors. To suspicious highly vascularized bone tumors. MR-PWI combining with MR-DWI lead to higher diagnostic accuracy. (authors)