The radiological confirmation of sacro-iliitis is essential for the early diagnosis of ankylosing spondylitis. Conventional radiography is too insensitive to detect early changes in these joints, and radionuclide scintigraphy is a non-specific, though highly sensitive, technique. This study describes a preliminary survey of the use of computed tomography (CT) of the sacro-iliac joints in the diagnosis of early sacro-iliitis. Patients were selected for study from a routine rheumatology clinic. Entry criteria included a clinical suspicion of sacro-iliitis and normal or equivocal findings on conventional radiography. Twenty-two patients were selected for study. Nine had normal plain films and normal CT; four had equivocal plain films with conclusive evidence of sacro-iliitis on CT; in two cases, conventional radiographs were normal but CT showed clear evidence of sacro-iliitis; two other patients had equivocal findings on straight X-ray examination but normal CT. Computerized tomography of the sacro-iliac joints can be useful in the early diagnosis of sacro-iliitis if conventional radiography is equivocal or normal. Further controlled studies are necessary to establish the sensitivity and specificity of the technique.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.