Detection Of The Activity Of Sacroiliitis With Ankylosing Spondylitis Through Magnetic Resonance Imaging

Objective1. To investigate the correlation of SPARCC obtained through MR imaging and clinical activity in index score inthe activity of ankylosing spondylitis.2. To evaluate the value of judging for the activity in AS by diffusion-weighted sequences (DWI) and enhance sequences MRI (DCE-MRI), To explore the correlation of Apparent diffusion coefficient(ADC) values, intensive rate and the clinical activity index in sacroiliitis (SIJ) of ankylosing spondylitis.3. To evaluate the sensitivity and specificity of DWI and CE MRI in differentiatingthe active sacroiliitis from chronic sacroiliitis in patients with ankylosing spondylitis.4. Feaibility and assessment of IVIM to differentiate active sacroiliitis and ankylosing spondylitis.Materials andMethodes1. MR examinations were performed to Seven patients enrolled with application of biological agents (etanercept or Andes), before taking, after taking three months, six months, nine months and 12 months respectively. SPARCC score was adopted for MRI. SPARCC score and T2WI signal intensity were measured. By use of the bath ankylosing spondylites disease activity index score (B ASDAI) score, the correlation of the changes of SPARCC score, T2 signal intensity and BASDAI score were assessed. The correlation of ESR and CPR was also assessed.2. Fifty-six patients prospectively choiced and diagnosed were divided into two groupsas:active group (n=32) and chronic group (n=24) by rheumatologist according to BASDAI and laboratory parameters.Twenty healthy adults were as control group. The values of ADC and intensive rate of all sacroiliac joints were measured on MRI. BASDAI score were got by Bath ankylosing spondylitis disease activity index. ESR, CPR and were got by laboratory. Statisticaly to analysis whether the parameters were significantly different amang AS active, chronic, and the control group.to assess the correlation of the values of ADC, intensive rate and BASDAI score, ESR, CPR and in sacroiliac joint.3. Ninety-six patientswho fulfilled the modified New York criteria were divided into two groups as active group (n=60) and chronic group (n=36) by rheumatologist according tothe Bath AS disease activity index (BASDAI) and laboratory parameters. Twenty-one healthy volunteers were enrolled into control group. The DWI and CE MRI examinations were performed on participants of all groups. Intensive rate(ASI)and apparent diffusion coefficient(ADC) values were obtained. One-way analysis of variance (one-way ANOVA) was performed for the comparison of all parameters among the three groups. ROC curve analyses were performed to assess the utility of the measures for the detection of active groupfromchronic group.4. Forty-one patients were divided into two groups:active group (n=20) and chronic group (n=21) according to bath ankylosing spondylitis disease activity index (BASDAI) and laboratory parameters. In addition, Twenty-one healthy volunteers were chosen as control group. Tissue diffusivity (Dslow), perfusion fraction (f), and pseudo-diffusion coefficient (Dfast) values were obtained for all the three groups. One-way analysis of variance and receiver operating characteristic analysis were performed for all parameters.Results1. The results show that there was a positive correlation (r=0.888, P<0.05) between the changes of SPARCC score and BASDAI score. Meanwhile, there was also a positivecorrelation (r=0.670, P<0.05) between the changes of the changes of T2 signal signal and BASDAI scores.2. The values of ADC and intensive rate were significantly different among AS active, chronic and the control group.There were the significant correlation between the values of ADC, intensive rate and BASDAI score.3. Optimal cut-off values (with respective area under the curve, sensitivity and specificity) were△SI=1.44 (0.814,81.67%,80%); ADC value=1.15×10-3mm2/s (0.73, 76.67%,71.43%) between active and chronic group. Pairwise comparisons showed no significant difference on area under the curve of △SI and ADC values, and ADC values could further increase the diagnostic sensitivity and specificity in differentiating the active group from the chronic group as CE MRI.4. There was good interobserver agreement on the measurements between the 2 observers. The optimal cut-off values (with respective AUC, sensitivity, specificity, positive likelihood ratio and negative likelihood ratio) between active and chronic group were Dslow=0.53×10-3 mm2/s (0.976,90%,95.2%,18.9,0.10); f=0.09 (0.545,20%,95.5%,4.2,0.84), and these between chronic and control group were f= 0.09 (0.935,95.24%,80.95%,5,0.059).Conclusion1. The changes of SPARCC score changes value can quantitatively be used to detect treatment effects in patients with AS, to provide for patients with a visibility observation.2. Diffusion-weighted sequences and Contrast-enhanced sequences is superior to other methods in judging the activity in AS.combined with clinical activity index, The accuracy can significantly be improved to explore whether the activities of AS are.3. DWI and CE MRI perform equally well. DWI and conventional MR, which are convenient and economical, should be considered together in assessing disease activity of AS and in avoiding nephrogenic systemic fibrosis (NSF) that might be caused by contrast agents.4. Dslow and f of IVIM DW-MRI in AS show significant difference in the values of diffusion of water molecules and fractional perfusion-related volume among the three groups.