Prognostic significance of magnetic resonance imaging changes of the sacroiliac joints in spondyloarthritis--a followup study.
OBJECTIVE
To evaluate the prognostic significance of sacroiliac joint (SIJ) changes by magnetic resonance imaging (MRI) based on 2-7 years of followup of patients with axial spondyloarthritis (SpA).


METHODS
Ninety-four patients (50 women, 44 men) with axial SpA obtained MRI of the SIJ from 1998-2004. They were examined at followup after 25-95 months (mean 51), including MRI and radiography of the SIJ and the spine. The Danish scoring method was used to quantify the activity and chronic SIJ changes by MRI. The activity score included subchondral edema and/or enhancement, while chronic changes encompassed erosions and subchondral fatty marrow deposition (FMD).


RESULTS
The MR score values for chronic SIJ changes increased significantly during followup, and were most pronounced in HLA-B27-positive patients and patients fulfilling the modified New York criteria for ankylosing spondylitis (AS) at followup. SIJ activity scores >or= 2, total chronic scores >or= 1, erosion scores >or= 1, and FMD scores >or= 4 at baseline were significantly related to progression of chronic SIJ changes. Activity score values >or= 3 at baseline had a sensitivity of 0.83, specificity of 0.75, and accuracy of 0.80 in relation to the presence of AS at followup. The similar values for total chronic SIJ scores >or= 4 at baseline were 0.86, 0.75, and 0.82, respectively, and for erosion scores >or= 2 they were 0.88, 0.75, and 0.83.


CONCLUSIONS
The occurrence of manifest SIJ activity by MRI or chronic changes at baseline was related to progression of chronic changes and the presence of AS at followup.
Department of Radiology and the Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark.
Karen Berenth
KB
Madsen
Berit
B
Schiøttz-Christensen
Anne Grethe
AG
Jurik
D000273:Adipose Tissue / Q000473:pathology; D000293:Adolescent; D000328:Adult; D001853:Bone Marrow / Q000473:pathology; D001855:Bone Marrow Diseases / Q000150:complications / Q000473:pathology; D002908:Chronic Disease; D004487:Edema / Q000150:complications / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011859:Radiography; D012446:Sacroiliac Joint / Q000000981:diagnostic imaging / Q000473:pathology*; D013131:Spine / Q000000981:diagnostic imaging; D013167:Spondylitis, Ankylosing / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D055815:Young Adult