Hounsfield Units measured in low dose CT reliably assess vertebral trabecular bone density changes over two years in axial spondyloarthritis.

Autor: Marques ML; Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands; Department of Rheumatology, Coimbra University Hospital, Coimbra, Portugal. Electronic address: mary.lucy.marques@gmail.com., da Silva NP; Department of Radiology, Coimbra University Hospital, Coimbra, Portugal., van der Heijde D; Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands. Electronic address: mail@dvanderheijde.nl., Reijnierse M; Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands. Electronic address: m.reijnierse@lumc.nl., Baraliakos X; Rheumazentrum Ruhrgebiet Herne, Ruhr-University Bochum, Germany. Electronic address: Xenofon.Baraliakos@elisabethgruppe.de., Braun J; Rheumazentrum Ruhrgebiet Herne, Ruhr-University Bochum, Germany. Electronic address: juergen.braun@elisabethgruppe.de., van Gaalen F; Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands. Electronic address: F.A.van_Gaalen@lumc.nl., Ramiro S; Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands; Department of Rheumatology, Zuyderland Medical Center, Herleen, the Netherlands.
Jazyk: angličtina
Zdroj: Seminars in arthritis and rheumatism [Semin Arthritis Rheum] 2023 Feb; Vol. 58, pp. 152144. Date of Electronic Publication: 2022 Nov 30.
DOI: 10.1016/j.semarthrit.2022.152144
Abstrakt: Objectives: To describe low dose Computed Tomography (ldCT) Hounsfield Units (HU) two-year change-from-baseline values (expressing trabecular bone density changes) and analyse their inter-reader reliability per vertebra in radiographic axial spondyloarthritis (r-axSpA).
Methods: We used 49 patients with r-axSpA from the multicentre two-year Sensitive Imaging in Ankylosing Spondylitis (SIAS) study. LdCT HU were independently measured by two trained readers at baseline and two years. Mean (standard deviation, SD) for the change-from-baseline HU values were provided per vertebra by reader. Intraclass correlation coefficients (ICC; absolute agreement, two-way random effect), Bland-Altman plots and smallest detectable change (SDC) were obtained. Percentages of vertebrae in which readers agreed on the direction of change and on change >|SDC| were computed.
Results: Overall, 1,053 (98% of all possible) vertebrae were assessed by each reader both at baseline and two years. Over two years, HU mean change values varied from -23 to 28 and 29 for reader 1 and 2, respectively. Inter-reader reliability of the two-year change-from-baseline values per vertebra was excellent: ICC:0.91-0.99; SDC:6-10; Bland-Altman plots were homoscedastic, with negligible systematic error between readers. Readers agreed on the direction of change in 88-96% and on change >|SDC| in 58-94% of vertebrae, per vertebral level, from C3 to L5. Overall, similar results were obtained across all vertebrae.
Conclusion: LdCT measurement of HU is a reliable method to assess two-year changes in trabecular bone density at each vertebra from C3-L5. Being reliable across all vertebrae, this methodology can aid the study of trabecular bone density changes over time in r-axSpA, a disease affecting the whole spine.
Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest in relation to this study.
(Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE