Quantitative Analysis Of The Value Of DCE-MRI In The Diagnosis Of Rheumatoid Arthritis

Objective: To investigate the value of dynamic contrast-enhanced MRI（DCE-MRI）in quantitative analysis of the activity of rheumatoid arthritis Meterials and methods:1.Case date:38 cases of RA were recruited from July 2016 to January 2017 in the Second Affiliated Hospital of Dalian Medical University.5 male,33 female,mean age,55.6 years,according to the European League Against Rheumatism（EULAR）DAS28 classification criteria for evaluation of RA inflammatory activity definition are divided into three groups,including highly active inflammation group 12 cases.In moderate activity period 20 cases,in the clinical remission group 6 cases.2.MR equipment and technology:2.1 MR Scanning equipment and parameters:All patients underwent conventional and DCE-MRI at Siemens MAGNETOM Verio 3.0T MR.The scanning sequence includes:conventional,MR（T1WI,FS-PDWI,FS-T2WI）,DWI（0s/mm2,800s/mm2）and T1-3D-VIBEDCE-MRI.Conventional precontrast images and a total of six variable flip angles（VFAS）precontrast images with five angles of 2°,4°,6°,8°,10°,12° were obtained with three dimensional volumetric interpolated breathhold examination（3D-VIBE）sequence first,and then continuous scanning 40 phase of DCE-MRI,and scanning 3 phase before the injection of the contrast,finally,conventional contrast imaging with 3D-VIBE sequence were scanned.2.2 DCE-MRI imaging post-processing:DCE-MRI multi turning angle and dynamic enhancement data were transmitted to the hemo dynamic software Omni Kinetics for image post-processing.Firstly,the T1 values are calculated for each sequence image of the multi turn angle,which is used for the multi period dynamic enhancement of the time luminance signal to the time contrast concentration signal,and then the dynamic enhancement sequence data is introduced.Observation of the DCE-MRI images,and to determine the shape of radial artery,radial artery as input artery,manual delineation of size 3×3 pixels of the region of interest（region of,interest,ROI）;ensure that ROI do not exceed the delineation of artery vessel wall,blood vessels in the center of the cross section of location click Curving to obtain the individual arterial input function（individual arterial input function,INd-AIF）;enhanced MR synovial thickening was observed dynamically,avoid bone,blood vessels,tendons,fat and joint effusion structure,combined with K^trans pseudo color,manually select ROI,size is about 30⁸0 pixels,we selected 2 most significant parts of synovial enhancement were measured by hemodynamic Extended Tofts Linear（ETL）model fitting calculation,the corresponding quantitative parameters acquisition.3.Observational indexes:3.1The MRI manifestations:The average number of synovial thickening and synovial thickness,bone destruction,joint effusion,thickening of the tendon sheath3.2 DCE-MRI quantitative parameter:volume transfer constant(K^trans),（volume of extravascular extracellar space per unit volum of tissue,Ve）（min-1）,（rate constant between extravascular extracellular space and plasma,Kep）,（fractional plasma volume,Vp）（ml/ml）4.Statistical Analysis（SPSS17.0,P=0.05）4.1 Single factor analysis of variance was used to compare the differences of K^trans,Kep,Ve,Vp between the high activity group,moderate activity group and clinical remission group.The correlation between quantitative parameters and ESR、CRP was evaluated by Pearson correlation analysis;using Spearman rank correlation analysis with DAS28;4.2 The diagnosis of DCE-MRI K^trans and the average value of synovial thickness on RA high activity group threshold,the sensitivity and specificity of the receiver operating characteristic curve（Recevier Operator Characteristic curve,ROC）were statistically analyzed.Result:1.The Morphological changes of RA1.1 Synovial thickening:12 cases of high activity group,17 cases of moderate activity group and 9 cases of clinical remission group showed synovial thickening.1.2 Bone destruction:12 cases of high activity group,10 cases of moderate activity group and 2 cases of clinical remission group showed bone destruction.1.3 Hydrathrosis:11 cases of high activity group,13 cases of moderate activity group and 1 case of clinical remission group showed hydrathrosis.1.4 Tenosynovial thickening:10 cases of high activity group,11 cases of moderate activity group and 3 cases of clinical remission group showed tenosynovial thickening.2.The signal change of RA2.1 The signal changes of synovitisHigh activity group: on T1 WI,10 cases showed low signal,2 cases showed equisignal;on PDWI,11 cases showed high signal,1case showed slightly high signal;on DWI,12 cases showed high signal;on enhanced images,12 cases showed obvious enhancement.Moderate activity group: on T1 WI,10 cases showed low signal,7cases showed equisignal;on PDWI,14 cases showed high signal,3 cases showed slightly high signal;on DWI,14 cases showed high signal,3 cases showed slightly high signal;on enhanced images,10 cases showed obvious enhancement,7cases showed moderate enhancement.Clinical remission group: on T1 WI,6 cases showed low signal,3 cases showed equisignal;on PDWI,7 cases showed high signal,2cases showed slightly high signal;on DWI,7 cases showed high signal,2 cases showed slightly high signal;on enhanced images,4 cases showed obvious enhancement,5 cases showed moderate enhancement.2.2 Abnormal signal changes of bone destruction:High activity group: on T1 WI,11 cases showed low signal,1 cases showed equisignal;on PDWI,9 cases showed high signal,3 cases showed slightly high signal;on DWI,10 cases showed high signal,2 cases showed slightly high signal;on enhanced images,7 cases showed obvious enhancement,5 cases showed moderate enhancement.Moderate activity group: on T1 WI,9 cases showed low signal,1 case showed equisignal;on PDWI,8 cases showed high signal,2 cases showed slightly high signal;on DWI,8 cases showed high signal,2 cases showed slightly high signal;on enhanced images,3 cases showed obvious enhancement,.7 cases showed moderate enhancement.Clinical remission group: on T1 WI,2 cases showed low signal;on PDWI,2 cases showed high signal;on DWI,2 cases showed high signal;on enhanced images;2 cases showed moderate enhancement2.3 The signal changes of joint effusionHigh activity group: on T1 WI,7 cases showed low signal,4 case showed equisignal;on PDWI,11 cases showed high signal;on DWI,11 cases showed high signal;on enhanced images,11 cases showed no obvious enhancement.Moderate activity group: on T1 WI,9 cases showed low signal,4 cases showed equisignal;on PDWI,13 cases showed high signal;on DWI,12 cases showed high signal;on enhanced images,13 cases showed no obvious enhancement.Clinical remission group: on T1 WI,1 cases showed low signal;on PDWI,1 cases showed high signal;on DWI,1 case showed high signal;on enhanced images,1 case showed no obvious enhancement.2.4 Abnormal signal changes of tendon sheath:High activity group:on T1 WI,10 cases showed low signal;on PDWI,10 cases showed high signal;on DWI,10 cases showed high signal;on enhanced images,6 case showed slight enhancement,4 cases showed moderate enhancement.Moderate activity group:on T1 WI,11 cases showed low signal;on PDWI,11 cases showed high signal;on DWI,11 cases showed high signal;on enhanced images,6 case showed slight enhancement,5 cases showed moderate enhancement.Clinical remission group: on T1 WI,3 cases showed low signal;on PDWI,3 cases showed high signal;on DWI,3 cases showed high signal;on enhanced images,3 case showed slight enhancement,1 case showed moderate enhancement.3.Synovial thickening and the average number of synovial thickness: 38 cases of patients with DAS28,the average thickness of synovial ESR was positively correlated,correlation coefficients were 0.005 and 0.035（P<0.05）,but no correlation with CRP（P>0.05）.4.Quantitative parameters of DCE-MRI were compared between RA high activity group,moderate activity group and clinical remission group.The differences of K^trans were statistically significant（P<0.05）.K^trans can be used to identify the clinical remission group and the high activity group（P<0.05）,but not the clinical remission group and the moderate activity group,the moderate activity group and the high activity group（P>0.05）.5.DCE-MRI quantitative parameters of correlation between K^trans and DAS28,ESR,CRP was positive,the correlation coefficients were 0.718,0.472,0.315（P<0.05）.6.The area under the ROC curve of DCE-MRI K^trans value was 0.986,the diagnostic threshold was 0.0646,the sensitivity and specificity were 91.70% and 100%,respectively.The area under the ROC curve of average synovial thickness was 0.732,the diagnostic threshold was 7.32,the sensitivity and specificity were respectively 91.70%,83.33%.Conclusions:1.Quantitative parameters of K^trans DCE-MRI can be the activity evaluation of RA。Under the ETL model,the radial artery for the individual arterial input function,value of K^trans can identify the RA inflammatory highly activity group and the clinical remission group;K^trans>0.0646,RA synovitis is highly active,sensitivity and specificity were 91.70% and 100%.2.The diagnostic effect of DCE-MRI on RA activity of K^trans was higher than that of mean synovial thickness.