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Updated: Jun 7, 2025
Author Spotlight: Enhancing Rheumatoid Arthritis Research Through HR-pQCT Imaging Analysis
Published on: October 6, 2023
Detecting new erosions in rheumatoid arthritis over one year - Radiography and high-resolution computed tomography of
Josephine Therkildsen1, Rasmus Klose-Jensen1, Mathias Hänel1
1Department of Rheumatology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, Aarhus N, Central Denmark Region, 8200, Denmark; Department of Clinical Medicine, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, Aarhus N, Central Denmark Region, 8200, Denmark.
Objective:
To compare the number of new erosions in two metacarpophalangeal (MCP) joints over one year assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT) and conventional radiography (CR). Furthermore, to estimate the diagnostic accuracy of erosive progression by CR with HR-pQCT as the reference standard.
Methods:
Paired sets of image data were available from patients with RA (n=310), who underwent HR-pQCT and CR, including the 2nd and 3rd MCP joints only of the dominant hand at baseline and at the one-year follow-up. Erosion number was determined using HR-pQCT and CR. Erosive volume was estimated from segmented HR-pQCT images, and erosion scores were obtained by the Sharp/van der Heijde method from CR. Erosive progression was defined as an increase in total erosion number or a study-specified increase in total erosive volume or total erosion score.
Results:
At baseline, 250 erosions were identified by CR compared to 1864 erosions by HR-pQCT. After one year, 3 new erosions were detected by CR compared to 66 new erosions by HR-pQCT. Erosive progression was identified in 40 patients using HR-pQCT and in 3 patients using CR. With HR-pQCT as reference, CR had a sensitivity of 2.5% (95% CI: 0.1-13.2%) and a specificity of 99.3% (95% CI: 97.3-99.9%) for detecting erosive progression.
Conclusion:
HR-pQCT identified more than 20 times the number of new erosions, and more than 10 times as many patients with erosive progression than CR. HR-pQCT is a sensitive tool for monitoring new erosions and erosive progression over one year in RA.
