The Diagnosis Research Of The Sacroiliac Joints In Ankylosing Spondylitis By MRI

Objective:To investigate the diagnostic value of the sacroiliac joints in ankylosing spondylitis (AS) by MRI imaging, and to provide evidence for the clinical diagnosis of the disease and for the assessment of severity of the condition.Materials and Methods:Thirty patients with AS and20healthy volunteers were enrolled in this study. All patients fulfilled the2009ASAS classification criteria for AS. All patients underwent pelvic ray films and MR sequence scan (STIR, T1WI, T2WI and3D-WATS). According to the clinical disease activity index (BASDAI) score, patients with AS were divided into three groups: the static group, the suspicious activity group and the activity group. Classification of the patients on plain film and activity ability of the sacroiliac joint on MRI scoring system (SPARCC) score were compared using difference analysis and correlation studies between three groups. We also analysed the sacroiliac joint cartilage lesions, the fat signal and the thickness of fat deposition of MRI image in patients with AS, which is compared with that of plain film. Furthermore, all healthy volunteers (the control group) were underwent MR scan with the same parameters as that of the AS group. The manifestation of the MR imaging the sacroiliac joint cartilage beteen two groups were compared. The thickness of the sacroiliac joint cartilage in the control group were measured.Results:1,A significant difference of the scores of SPARCC of AS patients in the three patient groups were observed (p<0.05), and the SPARCC scores as well as the BASDAI scores was positively correlated in the three groups (rs0.66, P<0.05).2, We found no or mild fat deposition on MR imaging in AS patients with sacroiliac joint plain films grading Ⅰ-Ⅱ level, moderate or severe fat deposition with plain films grading III level and severe fat deposition with plain films grading IV level.3, We observed irregular thickening, distorting and interruption in sacroiliac joint cartilage with AS patients in3-D-WATS sequence. This sequence could distinguish the normal sacral side of the cartilage, iliac side of the cartilage and their interval. The thickness of the cartilage in the sacral side [(1.38±0.17) mm] is significantly greater than that of the iliac side [(0.81±0.16) mm] in the control group (t=10.90, P>0.001).Conclusion:In AS patients with sacroiliac joints lesions, the SPARCC score of bone marrow edema can determine the activity of ankylosing spondylitis, and the extent of fat deposition in the sacroiliac joint can reflect the severity of the disease.3D-WATS sequence show the damage to the cartilage of the sacroiliac joint, and provide imaging evidence for the early diagnosis of ankylosing spondylitis.