APPLICATIONS OF LOW-FIELD MAGNETIC RESONANCE IMAGING IN A RHEUMATOLOGY DEPARTMENT

Background: Low-field MRI (LF-MRI) is a useful Imaging technique for the diagnosis and in the follow-up of high-impact rheumatologic pathology . However, the use of the Low-field MRI is not widespread due to the high cost and the use of other techniques such as Musculoskeletal sonography . The Rheumatology Unit of the HUVM owns a Musculoskeletal Imaging Unit (ECO /MRI) and a standardized protocol for LF-MRI , which is performed by a rheumatologist applied in a routine clinical practice. We describe the patterns of use of LF-MRI by general rheumatologists in their routine clinical practice. Objectives: Perform an analysis of the use of LF-MRI in a Rheumatology department to the assessment of joint inflammatory activity. Correlate the results of the analyses in patients without diagnosis or patients with unclear diagnosis. Methods: Retrospective analysis using the medical records of the patients referred to the Musculoskeletal Imaging Unit from January to June 2018. The main variables collected were reason for referral as well as previous and final diagnosis after LR-MRI. An evaluation on the usefulness of MRI is made twelve months later to establish the diagnosis. Results: The global population studied of 114 patients were referred to for LF-MRI. 81 females (71%). The 80% of the patients with previous diagnostic 40% Rheumatoid Arthritis (RA), 24% Psoriatic Arthritis (PAs), 16% other rheumatic diseases, and the remaining 20% with an unclear diagnosis. The most frequent reasons for referral were: 1) A total of patients (female and male) was referred to assessment of inflammatory activity prior to the change of treatment and 2) assessment of subclinical activity in patients with optimized treatment. A total of 23 patients (16 female; 7 male), were referred for diagnostic evaluation or differential diagnosis: 7 arthralgias, 6 suspected psoriatic arthritis, 6 with undiagnosed joint inflammation, 2 for differential diagnosis, 1 suspected of juvenile idiopathic arthritis (JIA), and 1 tendinitis. ( Table 1 ) Table 1. Undiagnosed patients. Post-imaging diagnosis. TENO SYNO-VITIS NO DIAG AR MONO ART-HRITIS OA CARPAL TUNNEL RULE OUT PAs GOUT SpA PLAN-TAR FASCII-TIS JIA PAs OS TRI-GO-NUM ARTHRALGIAS 1 1 1 0 0 1 0 2 0 1 0 0 0 SWOLLEN JOINT WITHOUT DIAGNOSIS 0 1 1 1 2 0 0 0 0 0 0 0 1 DIFFERENTIAL DIAGNOSIS 0 0 1 0 1 0 0 0 0 0 0 0 0 SUSPECTED PAs 0 2 1 0 0 0 1 0 1 0 0 1 0 SUSPECTED JIA 0 0 0 0 0 0 0 0 0 0 1 0 0 TENDINITIS WITHOUT DIAGNOSIS 1 0 0 0 0 0 0 0 0 0 0 0 0 Total 2 4 4 1 3 1 1 2 1 1 1 1 1 Conclusion: The results of our study shown that the addition of the LF-MRI into clinical practice and performed by a rheumatologist is a useful tool in the diagnosis and evaluation of the degree of disease activity in patients with joint inflammatory pathology. The main test-indication of these techniques is to assess the degree of activity of the disease. In a 20% of the cases, the LF-MRI was requested for diagnostic evaluation in patients without a clear diagnosis. The long-term follow-up studies that correlate symptoms with structural damage are necessary to define remission more accurately and evaluate the efficiency of different treatment options. REFERENCES: [1]Hunt L, Eugénio G, Grainger AJ. Magnetic resonance imaging in individuals at risk of rheumatoid arthritis. Best Pract Res Clin Rheumatol. 2017 Feb;31(1):80-9. [2]Mandl P, Ciechomska A, Terslev L, Baraliakos X, Conaghan PG, D’Agostino MA, et al. Implementation and role of modern musculoskeletal imaging in rheumatological practice in member countries of EULAR. RMD Open. 2019 Jun 25;5(2):e000950. [3]Gorbachova T, Melenevsky Y, Cohen M, Cerniglia BW. Osteochondral Lesions of the Knee: Differentiating the Most Common Entities at MRI. Radiographics. 2018 Sep-Oct;38(5):1478-95. Disclosure of Interests: None declared Citation: Ann Rheum Dis, volume 80, supplement 1, year 2021, page 1420Session: Diagnostics and imaging procedures (Publication Only)