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FRI0589 Use of Ultrasonography and Tomosynthesis Can Improve the Diagnostic Performance of Early Rheumatoid Arthritis

Background The sensitivity and specificity of the 2010 American College of Rheumatology/European League Against Rheumatism classification criteria for rheumatoid arthritis (RA) have been reported to range between 62-74% and 71.4-78%, respectively1-3. Ultrasonography (US) assessment of synovitis improves the accuracy of the 2010 criteria4. Recent studies have demonstrated that tomosynthesis is superior to radiography for the detection of bone erosion in patients with RA5. We have reported tomosynthesis is useful for evaluation of bone erosions in patients with early RA. Especially, the depiction of bone erosions of the wrists is greater and earlier with tomosynthesis than with radiography6. Objectives To determine the respective diagnostic efficiency for early RA with radiography (X-P), tomosynthesis (Tomo), US, and combinations of these imaging modalities. Methods One hundred patients with musculoskeletal symptoms who visited to our hospital from January 2012 to July 2014 were enrolled. Patients underwent clinical, laboratory, radiographic tests and US at baseline. The patient with RA was defined as who was prescribed a disease-modifying-anti-rheumatic drug. RA was classified according to the 2010 criteria using radiograph (① X-P), tomosynthesis (② Tomo), and/or Power Doppler (PD) score 2 in US and a score of >5/10 in the criteria (③ X-P+US, ④ Tomo+US). Results A total of 100 patients were enrolled. Mean age was 61.0 years old and mean duration of disease was 15.2 months. Sixteen patients did not present with any swollen joints and were not eligible for the 2010 criteria. Sixty-two patients of 84 who were eligible for the 2010 criteria were diagnosed as RA. Forty-nine of 62 patients with RA were satisfied with the 2010 criteria (score6), but 13 patients were not satisfied. Using Steinbrocker's staging system, 46 patients were Stage I and 16 patients Stage II assessed by X-P and 27 patients Stage I and 35 patients Stage II by Tomo. There is a difference of the stage between X-P and Tomo in 19 patients, and their mean duration of disease was 5.6 months. Twelve in 19 patients were satisfied with the 2010 criteria (score 6) and all of them were identified synovitis with PD score 2 in US. Seven patients in 19 were not satisfied with the 2010 criteria (score <6) and all of them were double negative for rheumatoid factor and anti- cyclic citrullinated peptide antibody and were identified synovitis with PD score 2 in US. Sensitivity and specificity, positive predictive value, negative predictive value, likelihood ratio, likelihood ratio negative of the classification criteria were ① (83.9%, 68.2%, 88.1%, 60%, 2.636, 0.237) vs ② (95.2%, 68.2%, 89.4%, 83.3%, 2.991, 0.071) vs ③ (95.2%, 68.2%, 89.4%, 83.3%, 2.991, 0.071) vs ④ (98.4%, 68.2%, 89.7%, 93.8%, 3.092, 0.024), shown at table 1, respectively. Conclusions Use of US and Tomo can improve the diagnostic performance of the 2010 criteria because of earlier detection of bone erosions and synovitis. References Van der Linden MP, et Al. Arthritis Rheum 2011,63: 37-42. Cander MZ, et Al. Ann Rheum Dis 2011,70; 949-955. Kaneko Y, et Al. Rheumatology 2011, 50; 1268-74. Nakagomi D et Al. Arthritis Rheum, 2013,65(4); 890-898. Canella C, et. Al. Radiology 2011,258(1): 199-205. Bohgaki M, et Al, EULAR 2014. Disclosure of Interest None declared