TY - JOUR T1 - Diagnostic Utility of Magnetic Resonance Imaging and Radiography in Juvenile Spondyloarthritis: Evaluation of the Sacroiliac Joints in Controls and Affected Subjects JF - The Journal of Rheumatology JO - J Rheumatol SP - 963 LP - 970 DO - 10.3899/jrheum.131064 VL - 41 IS - 5 AU - Jacob L. Jaremko AU - Lei Liu AU - Naomi J. Winn AU - Janet E. Ellsworth AU - Robert G.W. Lambert Y1 - 2014/05/01 UR - http://www.jrheum.org/content/41/5/963.abstract N2 - Objective. To compare the utility of radiography and magnetic resonance imaging (MRI) for the diagnosis of juvenile-onset spondyloarthritis in pediatric patients presenting with low back and/or sacroiliac (SI) pain of potentially inflammatory etiology. Methods. Radiographs and MRI studies of the SI joints in 26 patients with juvenile spondyloarthritis (JSpA) and 35 controls were assessed independently by 2 radiologists, with discrepancies arbitrated by a third. Radiographs and MRI were blinded and read in separate batches in random order. Results. Erosion was common and was the most useful diagnostic feature on radiography [positive likelihood ratio (LR) = 3.5] and was especially diagnostic of SpA on MRI (LR = 6.7). Subchondral sclerosis was common but was the least specific feature for both modalities. Joint space narrowing had some utility on radiography (LR = 2.0) and MRI (LR = 2.7) but was uncommon and had poor reader reliability. Bone marrow edema (LR = 3.1) and subarticular fat infiltration (LR = 4.5), detectable only on MRI, were both useful features. Global diagnostic impression of MRI (LR = 9.4) had very high utility for the diagnosis of JSpA, exceeding radiography (LR = 4.4) because of superior specificity. In addition, global diagnosis of SpA is much more reliably made on MRI (κ = 0.80) compared to radiography (κ = 0.30). Conclusion. Specificity and reliability of MRI of the SI joints are superior to radiography for the diagnosis of juvenile-onset SpA and, where available, MRI should replace radiography as the first line of investigation. ER -