Scoring systems have been developed for radiographs and magnetic resonance imaging (MRI) in patients with ankylosing spondylitis (AS). Radiographic scores focus on chronic structural alterations, which occur slowly and show little sensitivity to change in the short-term. Recent clinical studies used the modified Stoke ankylosing spondylitis spine score (mSASSS), which evaluates the cervical and lumbar spine. TNF antagonists were found to modify the mSASSS, indirectly supporting a structural effect of these agents. MRI using specific sequences is a potent tool for evaluating inflammation, most notably at the spine. MRI has proved sensitive to change in patients taking TNF antagonists. An outcome measures in rheumatology clinical trials (OMERACT) task force is working on standardizing MRI scores for the spine and sacroiliac joints.