TY - JOUR T1 - Definition for Rheumatoid Arthritis Erosions Imaged with High Resolution Peripheral Quantitative Computed Tomography and Interreader Reliability for Detection and Measurement JF - The Journal of Rheumatology JO - J Rheumatol SP - 1935 LP - 1940 DO - 10.3899/jrheum.160648 VL - 43 IS - 10 AU - Cheryl Barnabe AU - Dominique Toepfer AU - Hubert Marotte AU - Ellen-Margrethe Hauge AU - Andrea Scharmga AU - Roland Kocijan AU - Sebastian Kraus AU - Stephanie Boutroy AU - Georg Schett AU - Kresten Krarup Keller AU - Joost de Jong AU - Kathryn S. Stok AU - Stephanie Finzel AU - the SPECTRA Collaboration Y1 - 2016/10/01 UR - http://www.jrheum.org/content/43/10/1935.abstract N2 - Objective. High-resolution peripheral quantitative computed tomography (HR-pQCT) sensitively detects erosions in rheumatoid arthritis (RA); however, nonpathological cortical bone disruptions are potentially misclassified as erosive. Our objectives were to set and test a definition for pathologic cortical bone disruptions in RA and to standardize reference landmarks for measuring erosion size.Methods. HR-pQCT images of metacarpophalangeal joints of RA and control subjects were used in an iterative process to achieve consensus on the definition and reference landmarks. Independent readers (n = 11) applied the definition to score 58 joints and measure pathologic erosions in 2 perpendicular multiplanar reformations for their maximum width and depth. Interreader reliability for erosion detection and variability in measurements between readers [root mean square coefficient of variation (RMSCV), intraclass correlation (ICC)] were calculated.Results. Pathologic erosions were defined as cortical breaks extending over a minimum of 2 consecutive slices in perpendicular planes, with underlying trabecular bone loss and a nonlinear shape. Interreader agreement for classifying pathologic erosions was 90.2%, whereas variability for width and depth erosion assessment was observed (RMSCV perpendicular width 12.3%, axial width 20.6%, perpendicular depth 24.0%, axial depth 22.2%; ICC perpendicular width 0.206, axial width 0.665, axial depth 0.871, perpendicular depth 0.783). Mean erosion width was 1.84 mm (range 0.16–8.90) and mean depth was 1.86 mm (range 0.30–8.00).Conclusion. We propose a new definition for erosions visualized with HR-pQCT imaging. Interreader reliability for erosion detection is good, but further refinement of selection of landmarks for erosion size measurement, or automated volumetric methods, will be pursued. ER -