Objective To investigate the application significance of 3.0T MR three dimensional double-echo steady state(3D-DESS) and three dimensional-true fast imaging with steady-state procession(3D-True FISP) sequences in diagnosis of wrist cartilage of rheumatoid arthritis (RA).Methods 26 patients who were clinically diagnosed with RA underwent wrist MR scans with 3D-DESS and 3D-True FISP sequences, while both sequences' scanning were achieved on 20 of them.340 articular-surface morphological conditions' were observed,which were divided into level 0, level 1 and level 2 damages according to morphological performance,and recorded on 3D-DESS and 3D-True FISP sequence respectively.The diagnostic differences in the number of lesions were compared for two sequences.Results The numbers were 79 and 50 for level 1 damage and 23 and 33 for level 2 damage on 3D-DESS and 3D-True FISP sequence respectively (P<0.05).The artifacts were showed in 14 patients on 3D-True FISP,and only two patients on 3D-DESS.Conclusion 3D-DESS sequence does better than 3D-True FISP in displaying RA wrist cartilage,which is able to provide certain help for treatment and prognosis evaluation of RA.

Objective To evaluate the value of DTI in mild articular cartilage injury in patellofemoral joint.Methods The DTI and arthroscopy data of 82 patients wih routine MRI diagnosed as mild articular cartilage injury were analyzed retrospectively.According to the results of arthroscopy,40 cases of mild articular cartilage injury with Outerbridge classification Ⅰ or Ⅱ were divided into experimental group,and 33 cases with normal patellofemoral articular cartilage were divided into control group.There were 8 articular cartilage injury patients with Outerbridge classification Ⅲ or Ⅳ in patello-femoral join were excluded.The DTI data were analyzed compared with arthroscopy.Results Arthroscopy detected 62 lesions of cartilage injury in experimental group.Totally 49 lesions (49/62,79.03 ％) were detected by ADC pseudocolor image and 51 lesions (51/62,82.25 ％) were detected by FA pseudocolor image.The DTI pseudocolor images of articular cartilage injury showed uneven levels.The red or pink levels can been observed.Compared with the control group,ADC value increased and FA value decreased significantly in experimental group (both P＜0.05).Conclusion DTI can clearly display and detect mild articular cartilage injury in patellofemoral joint,which provide valuable information for early cartilaginous injury.