Imaging in Psoriatic Arthritis

Psoriatic arthritis (PsA), a chronic inflammatory arthritis associated with psoriasis, is often associated with significant inflammation and joint damage leading to a decrease in quality of life measures. Plain radiographs have traditionally been used to detect and estimate the extent of joint damage. Newer imaging modalities such as ultrasound and MRI however, have provided the ability to detect joint damage earlier and measure the extent of joint damage more accurately, than with radiographs. These imaging modalities also provide a sensitive means of assessing for the presence of and quantifying the amount of inflammation. Furthermore, these imaging modalities can help with the identification of enthesitis, tendonitis, and dactylitis, features that can help make a diagnosis of PsA. Additionally, MRI and scintigraphy can help in the early detection and assessment of sacroiliitis and axial disease. In addition to benefits with diagnosis and prognosis, recent advances in imaging techniques have led to their increased use in the assessment of efficacy of novel therapies for psoriatic arthritis. Imaging modalities therefore allow for early detection, assessment of joint inflammation and joint damage as well as in the estimation of disease activity of PsA and thereby enable the clinician to treat PsA early, adequately, and safely.