Computed tomography in the evaluation of sacroiliac arthritis.

Computed tomography (CT) in the evaluation of the sacroiliac joints was compared with conventional radiography in a double-blind study. CT did not increase the probability of detecting sacroiliitis. Because only a few patients were evaluated near the onset of their disease, the sensitivity of CT as compared with that of routine radiography in detecting early morphological changes remains undetermined. An inexperienced observer may find it easier to evaluate CT scans than conventional radiographs of the sacroiliac joint; however, with optimal images, an experienced radiologist does not need CT to evaluate the sacroiliac joint in clinical practice.