The Value Of 3D Space-DIR Sequence In Diagnosis Of Knee Joint Synovits At 3.0T MRI And Optimization Of The Sequence

Synovial of knee joint is the largest one in the whole body, also the one that prone to the disease in all synovial tissue. According to the pathological change of the disease is divided into synovitis, hyperplasia,metaplasia, infection, tumor etc, and synovitis is the most common pathological changes. No matter what reason causes to synovitis, the common expression is the synovial thickening.In this study we optimized a 3D Space Double Inversion Recovery(3D Space DIR)sequence which were used in brain scanning routinely, The timings to enhance the synovial contrast from the fluid components were TI1=1800ms and TI2=354ms for suppressing the water and fat signals. On this premise, highlighted synovial tissue. In our study, 120 cases of clinically suspected synovitis of knee joint scanning with 3.0T magnetic resonance(Magnetic Resonance Imaging, MRI). Scan sequence includes T1-Weighted imaging(T1WI), T2-Weighted imaging(T2WI), Proton Density Weighted Imaging(PDWI) and 3D Space DIR sequence. Uploading the picture to the workstation. The image of the experimental group(T1WI?T2WI?PDWI?3D Space-DIR) and the control group(T1WI?T2WI?PDWI)were analyzed and diagnosed by two chief physician with more than 10 years working experience.and measuring the thickness of the synovial membrane on T2 WI and 3D Space-DIR. The results obtained are used for statistical analysis, the last result were marked synovitis lesions, no synovitis lesions. And pathology as the gold standard, synovial thickness as index, Drawing ROC curve about experimental group and control group.And compare 3D Space-DIR and CE-T1 WI from subjective and objectiveevaluation.The results show that in 120 patients with pathologically proved, knee joint synovitis in 99 cases, 21 cases of non synovitis. The result of control group 89 cases were detected in 99 cases of patients with synovitis, 10 cases were not detected, 8 cases which were proved to be negative by pathology were diagnosed as positive. The result of experimental group show that 97 cases were detected in the 99 cases of patients with synovitis,2 cases were not detected, 3 cases which were proved to be negative by pathology were diagnosed as positive. The diagnostic senysitivity,specificity and accuracy of the conventional protocol and the experimental protocol were(89.9%, 62.0%, 85.0%) and(97.8%, 85.7%, 95.8%). The area under ROC curve of conventional protocol(AUC: 0.93, P<0.05) was higher than the experimental protocol(AUC: 0.77, P<0.05). Comparing CNR1,the difference was not statistically significant(t=-0.22,P>0.05)for 3D Space-DIR and CE-T1 WI. Comparing CNR2,the difference was not statistically significant(t=-0.23,P>0.05)for 3D Space-DIR and CE-T1 WI, the difference was not statistically significant(t=-0.22,P>0.05)for 3D Space-DIR and CE-T1 WI. The difference was not statistically significant(P>0.05)for the synovial thickness about 3D Space-DIR and CE-T1 WI. Thus, we can draw the following conclusions:(1)The 3D Space-DIR sequence which were usually used in brain scanning can be used in displaying knee synovitis by optimization.(2)The diagnostic capability of conventional protocol can be improved when 3D Space-DIR sequence was added in the diagnosis of knee joint synovitis at 3.0T MRI.(3)3D Space-DIR sequence can substitute CE-T1 WI in displaying knee synovitis to some extent.