Progress in spondylarthritis. Spondyloarthritis: lessons from imaging

The advent of magnetic resonance imaging (MRI) and advanced sonographic techniques has led to a resurgence of interest in the role of imaging in the evaluation and management of spondyloarthritis. Radiography remains the cornerstone of diagnosis although MRI is more sensitive in early stages of the disease. Inflammatory changes in the sacroiliac joints and spine can now be reliably quantified and can also predict the subsequent development of radiographic changes in the corresponding locations. MRI-based scoring systems for inflammation are highly responsive, facilitating proof-of-concept studies of new therapies for spondyloarthritis. Assessment of chronic changes is much less reliable using MRI, while assessment using radiography lacks sensitivity to change. Assessment of disease modification therefore remains a principle challenge in the development of new therapies for ankylosing spondylitis. Ultrasound may be the preferred approach to the assessment of peripheral inflammation, especially enthesitis. Scintigraphy and computed tomography offer few advantages over MRI.