title: Radiography and abdominal CT compared with sacroiliac joint CT in the diagnosis of sacroiliitis.
abstract: Background The presence of structural sacroiliitis is strong evidence for the diagnosis of spondyloarthritis (SpA). Purpose To assess the performance of abdominal computed tomography (CT) and pelvic plain radiography for the diagnosis of structural sacroiliitis compared with sacroiliac CT (SI joint CT) considered the reference technique in patients with SpA. Material and Methods All SpA patients eligible for biologic treatment were selected from 2005 to 2012. An assessment of sacroiliitis was based on radiography according to the modified New York criteria and on abdominal CT and SI joint CT scans depending on the presence of erosion on at least two consecutive slices. A senior rheumatologist and radiologist independently scored the grade and diagnosis of structural sacroiliitis for the three imaging modalities. After a consensus reading of conflicting examinations (radiography and CT), a final diagnosis of structural sacroiliitis was attained. Results Of the 72 patients selected, sacroiliitis was diagnosed on radiography, abdominal CT, and SI joint CT in 40, 31, and 44 patients, respectively. Inter-reader agreements for the grade of sacroiliitis were substantial for the three imaging modalities, with a weighted kappa range of 0.63-0.75 (95% confidence interval [CI], 0.52-0.83), and they were moderate for the diagnosis of sacroiliitis, with a kappa range of 0.50-0.55 (95% CI, 0.32-0.74). The sensitivity and specificity were 79.1% and 70.5%, respectively, for radiography and 82.1% and 100%, respectively, for abdominal CT. Conclusion This study demonstrates the relevance of abdominal CT for the diagnosis of structural sacroiliitis, with good sensitivity and excellent specificity. These imaging techniques avoid unnecessary examinations.
authors.affiliation: 1 Department of Rheumatology, CHU Nancy Brabois, Vandoeuvre-les-Nancy cedex, France.
authors.forename: Julian
authors.initials: J
authors.lastname: Melchior
authors.affiliation: 2 Department of Radiology, University Hospital of Hadassah, Jerusalem, Israel.
authors.forename: Yusef
authors.initials: Y
authors.lastname: Azraq
authors.affiliation: 1 Department of Rheumatology, CHU Nancy Brabois, Vandoeuvre-les-Nancy cedex, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Chary-Valckenaere
authors.affiliation: 1 Department of Rheumatology, CHU Nancy Brabois, Vandoeuvre-les-Nancy cedex, France.
authors.forename: Anne-Christine
authors.initials: AC
authors.lastname: Rat
authors.affiliation: 3 Department of Radiology, Imagerie Guilloz, CHU Nancy Central, Nancy, France.
authors.forename: Pedro
authors.initials: P
authors.lastname: Texeira
authors.affiliation: 3 Department of Radiology, Imagerie Guilloz, CHU Nancy Central, Nancy, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Blum
authors.affiliation: 1 Department of Rheumatology, CHU Nancy Brabois, Vandoeuvre-les-Nancy cedex, France.
authors.forename: Damien
authors.initials: D
authors.lastname: Loeuille
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography / Q000379:methods*; D011860:Radiography, Abdominal / Q000379:methods*; D015203:Reproducibility of Results; D012446:Sacroiliac Joint / Q000000981:diagnostic imaging*; D058566:Sacroiliitis / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Spondyloarthritis; computed tomography (CT); conventional radiography; structural sacroiliitis