The role of imaging in the evaluation of joint involvement in 102 consecutive patients with systemic lupus erythematosus

Objective: To assess the prevalence of joint involvement in consecutive patients with systemic lupus erythematosus (SLE) by means of clinical assessment, joint US and MRI and to evaluate the sensitivity and specificity of physician evaluation of joint involvement. Methods: At enrolment, patients underwent a complete physical examination including a 44-joint count, and hand deformities were scored. On the day of enrolment, each patient underwent a non-dominant hand-wrist ultrasound (US) examination and a non-dominant hand-wrist MRI study without contrast injection. Results: One hundred and two patients (F 95, M 7) were enrolled. By physician examination hand or wrist involvement was diagnosed in 23.5%. At least one pathological finding was revealed by US examination at wrist and/or hand joints in 55%. We found a low sensitivity (46.5%) with high specificity (93.2%) of the physician assessment for the evaluation of joint involvement.The MRI imaging showed at least one erosion in 47.3% patients at the hand and in 98.9% at the wrist; in healthy subjects erosions were found in 19.6% and 97.8% at the hand and wrist, respectively. Conclusions: In conclusion, (i) physicians tend to underestimate the severity of joint involvement in SLE; (ii) US assessment shows a high prevalence of joint and tendon involvement; and (iii) the MRI evaluation shows a high prevalence of damage, suggesting that joint involvement in SLE could be more severe than expected.