Quantitative DCE-MRI Study On The Activity Of Sacroiliac Arthritis In Ankylosing Spondylitis

Objective:1.To explore the feasibility of using quantitative Dynamic contrast enhanced magnetic resonance imaging（DCE-MRI）to distinguish between the active and inactive phases of sacroiliac arthritis;2.The clinical BASDAI activity score was used AS the standard to analyze the correlation between different quantitative parameters and AS activity,and to evaluate and distinguish the effectiveness of various parameters in the active and inactive stages of the diseaseMethods:Part Ⅰ:A total of 25 patients diagnosed with early ankylotic spondylitis in yijishan hospital affiliated to wannan medical college from Mar.2017 to Dec.2018 were collected.According to the early diagnosis criteria,the duration of the disease was less than half a year,the clinical manifestations and laboratory examinations were in line with the diagnostic criteria of ankylospondylitis,and no other abnormal imaging manifestations were found in the sacroiliac joints by X-ray and CT examination.Among them,15 were males and 10 were females,ranging in age from 14 to 63 years old,with an average age of 30.7±11.9 years.15 cases in the normal control group were collected,ranging from 17 to 41 years old,with an average age of 27.53±7.02.The values of quantitative parameters(K^trans,K_ep,V_e,V_p)in the four groups of DCE-MRI in the bone marrow area under the sacroiliac joint surface were measured,and the differences of the values of quantitative parameters between the early group and the normal control group were compared.Part Ⅱ:In this part,a total of 41 patients in clinical diagnosis of ankylosing spondylitis patients,divided into active（13 cases of male,female 8 cases）.They ranged in age from 14 to 47 years with an average age of 27.95±9.17 and inactive group（male11,female 9）They ranged in age from 21 to 63 years with an average age of 36.7±11.54,according to the clinical BASDAI score,and refer to the erythrocyte sedimentation rate,c-reactive protein test results.The DCE-MRI values of the bone marrow area under the sacroiliac joint surface were measured to analyze the differences between the two groups.The correlation between each parameter and the BASDAI score was analyzed,and the sensitivity,specificity and Youden index of each parameter in the active and inactive stages were compared using the subject operating curve（ROC）.Results:Results 1:By measuring the DCE-MRI quantitative parameters in the bone marrow area under the sacroiliac joint surface of patients with early ankylosing spondylitis and the normal group,the results showed that:in the early group,K^transrans was0.652（0.477-1.079）,K_epp was 0.693（0.396-0.987）,V_e was 0.447（0.183-0.847）,V_p was0.051（0.017-0.230）.K^transrans was 0.503±0.411,K_epp was 0.619±0.379,V_e was0.221（0.042⁰.702）,V_p was 0.083（0.008⁰.187）.After statistical analysis,compared between the two groups,there were significant statistical differences in parameters K^trans（P<0.05）,but no statistical significance in parameters K_ep,V_e and V_p.Results 2:Among the 41 patients with sacroiliac arthritis,21 were in the active stage（M 13,F 8）and 20 were in the inactive stage（M 11,F9）.There was no significant difference in gender between the two groups.There were statistically significant differences in age,ESR,CRP and BASDAI scores between the active group and the inactive group.The test statistical values were-2.69,-2.5653,-2.6474 and-5.569,respectively.The P values<0.05,indicating there was statistically significant differences between these group.Each quantitative parameter of DCE-MRI of the sacroiliac joint bone in the active group and the inactive ankylosing spondylitis was determined.The results were as follows:K^transrans was 0.806（0.509¹.753）,K_epp was1.185±0.483,V_e was 0.663±0.228,V_p was 0.055（0.033⁰.200）.K^transrans was0.388（0.197⁰.798）,K_epp was 0.877±0.443,V_e was 0.244（0.135⁰.441）,V_p was0.132（0.048⁰.371）.The index values of K^trans,K_epp and V_e in the active group were significantly higher than those in the inactive group.The comparison test statistics of K^trans,K_epp and V_e in the active group and the inactive group were-3.1690,2.1300 and-3.7431,respectively.Therefore,it is believed that K^trans,K_epp and V_e in the intensified group and the unintensified group are significantly different.However,there was no significant difference in V_p between the active group and the inactive group（P>0.05）.By analyzing the correlation between DCE-MRI quantitative parameters and BASDAI score,it is concluded that K^transrans and V_e are correlated with BASDAI score,withcorrelationcoefficientsof0.5240（P=0.0004）and0.5301（P=0.0004）,respectively.K^trans,V_e and BASDAI scores had significant positive correlation.The aucs of the ROC curves of quantitative parameters K^trans,K_ep,V_e and V_p in the diagnosis of ankylospondylitis in the active stage and the remission stage were 0.7905,0.6595,0.8429 and 0.6226,respectively.The sensitivity was 95.2%,57.1%,85.7%and 75%,and the specificity was 55.6%,75%,80%and 52.4%.The ROC curve analysis of each quantitative parameter value of ankylosing spondylitis showed that the area under the corresponding curve of V_e was the largest,and the maximum area was 0.8429.When the V_e threshold was 0.4470,the diagnostic sensitivity and specificity were 85.7%and80%,respectively.Conclusion:1.DCE-MRI quantitative study has high value in the diagnosis of early ankylosing spondylitis and anthraquinone,in which K^transrans is the most sensitive;2.DCE-MRI can quantitatively evaluate the quantitative parameters of ankylospondylitis,such as the active stage and the rest stage,K^trans,K_ep,V_e,and BASDAI score,which have a strong correlation.The ROC joint curve shows that V_e value is the larges under the curve corresponding to the quantitative parameter and the maximum area is 0.8429.When V_e was setting at a critical value of 0.4470,the sensitivity and specificity for the diagnosis of sacroiliac arthritis activity were 85.7%and 80% respectively.