| BackgroundOver the past decade, magnetic resonance(MR) has been gradually and widely used in rheumatology, which provided new method and ideas for early diagnosis of some rheumatic diseases. In2009, new classification criteria for RA was developed by the European League Against Rheumatism(EULAR) and the American College of Rheumatology(ACR). In the same year, new classification criteria for axial SpA were also established by the Assessment of SpondyloArthritis international Society (ASAS). The two criterias include MR for the detection of synovitis in RA and sacroiliitis in axial SpA, respectively.ObjectiveThe authors retrospectively determined:(1) To compare the difference in diagnosis and differential diagnosis of synovitis in RA between MR and clinical examination and to evaluate the diagnostic performance of2010ACR/EULAR classification criteria and1987ACR criteria.(2)To compare the ability between MR and X ray examination in detecting the structural damage lesions of sacroiliac joint in axial SpA patients.Methods(1)122patients with early arthritis presented with affected joints swollen and tenderness from Nanfang Hospital from March2009to June2011were included, and among them,34patients who had received MR scan were analysized, the diseases without synovitis incidating RA were summarized. Among the above patients with MR synovits, the number of synovitis detected by MR and clinical examination was made a comparision, respectively. After excluding the patients without synovitis incidating RA, the diagnostic ability of the two criterias was evaluated with methotrexate or leflunomide treatment within1year and expert opinion RA at1year as’gold standard’, respectively.(2)35patients with ankylosing spondylitis(AS) and7patients with non-radiographic axial spondyloarthritis(nr-axSpA) from Nanfang Hospital from May2009to March2011were analysized. The score was made by a blinded radiologist for the structural damage lesions(including bone erosion, sclerosis, and joint space) of sacroiliac joint referring to1984modified New York criteria(mNY-criteria) scoring method for radiological sacroiliitis on MR and X ray images. Then, the difference of score between MR and X ray examination was analysized. Inter-rater MR score reproducibility was determined by two independent radiologists on MR images(including T1-weighted images, T1-weighted and fat suppression images, T2-weighted and fat suppression images). Interobserver reproducibility was assessed by intraclass correlation coefficient and limits of agreement analysis (Bland and Altman). Results(1) By MR examination,23.5%of the patients with early arthritis who had joints swollen and tenderness were diagnosed as non RA, whose diagnosis were tenosynovitis(n=4), pigmented villonodular synovitis(n=2), psoriatic arthritis(n=1), paraproxymal interphalangeal collagen deposition(n=1). The finding of "normal MRI with synovitis on clinical examination" was observed in18joints, versus positive findings in35joints. MRI revealed synovitis significantly more often than clinical examination(123vs106; P value=0.027).5patients among the above cases did not satisfy the2010ACR/EULAR criteria at baseline according to clinical examination for synovitis, while2of5patients did when according to MR for synovitis. The sensitivity of the2010ACR/EULAR classification and1987ACR criteria was0.87and0.63(’gold standard’ methotrexate or leflunomide use),0.91and0.76(’gold standard’ expert opinion RA).The specificity of the two criterias was0.67and0.81(’gold standard’ methotrexate or leflunomide use),0.56and0.92(’gold standard’ expert opinion RA). The discriminative ability of the two criterias was similar with areas under the curve of0.89and0.86(’gold standard’ methotrexate or leflunomide use),0.87and0.92(’gold standard’ expert opinion RA). According to expert opinion at1year,17of39patients without RA meet the2010ACR/EULAR classification criteria at baseline. The diagnosis of them were undifferentiated arthritis(n=7), psoriatic arthritis(n=5), Sjogren’s syndrome(n=2), Systemic Lupus Erythematosus(n=1), self-limiting arthritis(n=2), respectively.3of39patients without RA meet the1987ACR criteria at baseline. They were all psoriatic arthritis. There were4patients (expert opinion RA at1year) with normal serological markers who did not satisfy the2010criteria among60patients who met1987ACR criteria.(2)The mean difference in bone erosion score on T1-weighted sequence, T1-weighted sequence and fat suppression, T2-weighted sequence and fat suppression between readers were0(0.32),-0.05(0.30) and0.02(0.27), respectively. Interobserver intraclass correlation coefficients for mNY-criteria scoring method for radiological sacroiliitis on the three sequences were0.99,1.00and0.99, respectively. There was no statistically significant interreader difference in bone erosion scores for the three sequences(P value<0.001). The mean difference in joint space scores on T1-weighted sequence, T1-weighted sequence and fat suppression, T2-weighted sequence and fat suppression between readers were0.03(0.28),0(0.33) and-0.02(0.41), respectively. Interobserver intraclass correlation coefficients for mNY criteria scoring method on the three sequences were0.98,0.97and0.97, respectively. There was no statistically significant interreader difference in bone erosion scores for the three sequences(P value<0.001). The mean difference in sclerosis scores on T1-weighted sequence, T1-weighted sequence and fat suppression, T2-weighted sequence and fat suppression between readers were-0.05(0.32),0(0.33) and-0.02(0.35), respectively. Interobserver intraclass correlation coefficients for mNY criteria scoring method on the three sequences were0.97,0.99and0.96, respectively. There was no statistically significant interreader difference in bone erosion scores for the three sequences(P value<0.001).There was no statistically significant score difference in bone erosion score between the three sequences and X ray examination(P value=0.284, P value=0.347, P value=0.082). The score in joint space on T1-weighted sequence and T2-weighted sequence plus fat suppression was significantly smaller than that of X ray examination(P value=0.007, P value<0.001), while there was no statistically significant score difference between T1-weighted sequence plus fat suppression and X ray examination(P value=0.080).The score in bone sclerosis on T1-weighted sequence and T2-weighted sequence plus fat suppression was significantly smaller than that of X ray examination(P value<0.001, P value<0.001), while there was no statistically significant score difference between T1-weighted sequence plus fat suppression and X ray examination(P value=0.162). The incidence of fat depositon on T1-weighted sequence and bone marrow edema on T2-weighted sequence plus fat suppression were46.2%(18/39) and50.0%(21/42),respectively, while the incidence of both fat deposition and bone marrow edema was33.3%(13/39).Conclusion(1) In the process of classification diagnosis of early RA, MR can make up for the deficiencies of the clinical examination in the diagnosis of synovitis, which is benefical to diagnose RA with2010ACR/EULAR criteria. The sensitivity of the2010ACR/EULAR criteria was higher than the1987ACR criteria, while the specificity was lower. The discriminative ability of the two criterias was similar. The use of the2010ACR/EULAR criteria may lead to a revoked classification as RA in patients with other arthritis or some connective tissue diseases, so the followup was necessary in clinical practice. Moreover, the use of the2010ACR/EULAR criteria combined with1987ACR criteria may avoid the undiagnosis of patients with RA with normal serological markers.(2) According to the radiological sacroiliitis scoring method in modified New York criteria of AS, the interrater reproducibility of MR scores was perfect. The structural damage lesion of sacroiliac joint could be evaluated on T2-weighted sequence plus fat suppression in MR, which performed similarly with X ray examination. While T1-weighted sequence and T2-weighted sequence did not due to a high proportion of fat deposition and bone marrow edema in sacroiliac joint. |
PDF Full Text Request