ANTERIOR CHEST WALL INFLAMMATION BY WHOLE BODY MRI IN PATIENTS WITH SPONDYLOARTHRITIS: FREQUENCY OF INVOLVEMENT AND ASSOCIATION BETWEEN CLINICAL AND IMAGING FINDINGS

Background: Inflammatory involvement of the anterior chest wall (ACW) has a substantial impact on the quality of life in patients with spondyloarthritis (SpA). However, ACW involvement is often neglected in clinical routine and data on ACW inflammation by clinical examination and by various imaging modalities are controversial. Whole body (WB) MRI is a promising imaging method to assess also the ACW without additional inconvenience for the patients. Objectives: To describe the frequency and distribution of ACW inflammation by WB MRI in SpA patients; to assess the association between imaging and clinical findings; to evaluate the performance of a WB MRI scoring system for the ACW. Methods: The ACW of 122 consecutive SpA patients (95 with ankylosing spondylitis (AS) and 27 with inflammatory back pain (IBP)) and 75 healthy controls was scanned by sagittal and coronal WB MRI. The MR images were scored independently in random order by 7 readers blinded to patient identifiers. Active and structural inflammatory lesions of the ACW were recorded on a web-based scoring form. ACW pain by patient self-report, ACW tenderness on physical examination according to the Maastricht ankylosing spondylitis enthesitis score and MRI lesions were analyzed descriptively. Kappa statistics served to assess inter-observer reliability and the agreement between clinical and imaging findings. Results: ACW pain or tenderness was present in 26% with little difference between AS and IBP patients. Bone marrow edema (BME), erosion and fat infiltration were recorded in 49.5%, 36.8% and 33.7% of the AS patients, in 25.9%, 25.9% and 3.7% of the IBP patients, and in 9.3%, 12.0% and 5.3% of the controls, respectively. The most frequently affected joint by MRI lesions was the manubriosternal joint. The inter-reader agreement by kappa values for 7 observers and for the 3 MRI lesions BME, erosion and fat infiltration was 0.52, 0.48 and 0.46, respectively, being highest (0.65) for BME of the manubriosternal joint. The agreement between patient self-reports of pain and ACW tenderness upon clinical examination was moderate with a kappa value of 0.5. The kappa values between clinical and MRI inflammation ranged from -0.18 to 0.25 for all SpA patients. The highest agreement between MRI lesions and clinical evaluation (0.33 for BME) was observed in the IBP group for the patient self-reports of pain. Conclusions: Clinical and WB MRI signs of ACW inflammation were found in 26% and up to 44% of SpA patients, respectively. Assessing ACW inflammation by WB MRI showed a moderate to substantial reliability. The agreement between clinical and imaging findings was poor, most likely due to subclinical inflammation. Disclosure of Interest: None DeclaredCitation: Annals of the Rheumatic Diseases, volume 70, supplement 3, year 2011, page 81Session: Abstract Session: Clinical aspects of spondyloarthritis – what is new? (Oral Presentations )