Spinal bone SPECT in chronic symptomatic ankylosing spondylitis.

Bone SPECT has acquired a useful role in the evaluation of acute and chronic back pain. Spinal pain is also a characteristic of chronic ankylosing spondylitis. The authors investigated the bone SPECT appearances of the lower thoracic and lumbar spine in 28 symptomatic patients with established ankylosing spondylitis, half of whom had complete ankylosis of the sacroiliac and one third complete ankylosis of the intervertebral joints. SPECT abnormalities were identified in 89%. Facetal joint uptake was found in 16 (57%) patients, of whom 7 (25%) had three or more, and 2 (7%) had seven or more active sites. The only other common site of uptake was in the vertebral body, in which 15 patients (54%) showed increased uptake with three or more sites found in 3 (11%) patients. The authors conclude that SPECT abnormalities in the lower thoracic and lumbar spine are frequently found in patients with ankylosing spondylitis, with the most common sites of abnormality in the facetal joints or vertebral body. Multiple sites of uptake in the facetal joints maybe striking in such patients and has not been previously described.