No new imaging is required for this patient with ankylosing spondylitis. She is currently feeling well, continues to respond well to treatment, and has normal inflammatory markers, making new imaging unnecessary. As with any test, imaging to follow disease activity should be performed only if clearly indicated by the clinical situation (for example, if the result is likely to change management). According to the 2010 Assessment of SpondyloArthritis international Society/European League Against Rheumatism (ASAS/EULAR) guidelines, serial imaging of patients with ankylosing spondylitis can be part of a comprehensive monitoring plan that also includes patient history (such as questionnaires like the Bath Ankylosing Spondylitis Functional Index [BASFI] or Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]), clinical parameters (such as physical examination findings like the Schober test), and laboratory tests (such as erythrocyte sedimentation rate and C-reactive protein). The ASAS/EULAR recommendations state that spinal radiography should not be repeated more frequently than every 2 years unless absolutely necessary in specific cases. The Schober test measures range of motion of the lumbar spine and is an inexpensive and noninvasive physical examination tool for assessing spine involvement and progression; greater than 4 cm is normal.

Bone scan, CT, MRI, and plain radiography may demonstrate evidence of inflammation and/or progression of disease, but without a clear indication may unnecessarily expose the patient to radiation and to expense. This patient is feeling well, has intact activities of daily living, and had radiographs less than 2 years ago; therefore, no additional imaging is necessary at this time.