RESUMO
OBJECTIVE: The comparison between different techniques to quantify the 3-dimensional size of inflammatory bone erosions in rheumatoid arthritis(RA) patients. METHODS: Anti-cyclic citrullinated peptide antibody(ACPA) positive RA patients received high-resolution peripheral quantitative computed tomography (HR-pQCT) scans of the metacarpophalangeal joints (MCP). Erosions were measured by three different segmentation techniques: (1) manual method with calculation by half-ellipsoid formula, (2) semi-automated modified Evaluation Script for Erosions (mESE), and (3) semi-automated Medical Image Analysis Framework (MIAF) software. Bland & Altman plots were used to describe agreement between methods. Furthermore, shape of erosions was classified as regular or irregular and then compared to the sphericity obtained by MIAF. RESULTS: A total of 76 erosions from 65 RA patients (46 females/19 males), median age 57 years, median disease duration 6.1 years and median disease activity score 28 of 2.8 units were analyzed. While mESE and MIAF showed good agreement in the measurement of erosion size, the manual method with calculation by half-ellipsoid formula underestimated erosions size, particularly with larger erosions. Accurate segmentation is particularly important in larger erosions, which are irregularly shaped. In all three segmentation techniques irregular erosions were larger in size than regular erosions (MIAF: 19.7 vs. 3.4mm3; mESE: 15.5 vs. 2.3mm3; manual = 7.2 vs. 1.52mm3; all p < 0.001). In accordance, sphericity of erosions measured by MIAF significantly decreased with their size (p < 0.001). CONCLUSION: MIAF and mESE allow segmentation of inflammatory bone erosions in RA patients with excellent inter reader reliability. They allow calculating erosion volume independent of erosion shape and therefore provide an attractive tool to quantify structural damage in individual joints of RA patients.
Assuntos
Anticorpos Antiproteína Citrulinada/sangue , Artrite Reumatoide/diagnóstico por imagem , Articulação Metacarpofalângica/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Idoso , Artrite Reumatoide/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Índice de Gravidade de DoençaRESUMO
OBJECTIVE: To search for evidence of secondary osteoarthritis (OA) in patients with rheumatoid arthritis (RA) in a cross-sectional and longitudinal setting, and to relate osteophyte formation to functional outcome. METHODS: Anti-citrullinated protein antibody (ACPA)-positive RA patients underwent high-resolution peripheral quantitative computed tomography of the hand. Cross-sectional and longitudinal measurements were performed. The number and size (volume) of osteophytes as well as bone erosions were documented. The relationship of osteophytes to bone erosions and to demographic and disease-specific data was evaluated by multiple logistic regression models. RESULTS: A total of 202 ACPA-positive RA patients were enrolled in the cross-sectional part of the study, and a total of 77 ACPA-positive RA patients were enrolled in the longitudinal analysis (interval of 1.5 years between baseline and follow-up assessment). The mean ± SD number of osteophytes per patient was 1.3 ± 2.3, and the mean ± SD osteophyte volume per patient was 2.6 ± 4.9 mm(3) . The total number of erosions was significantly correlated with the total number of osteophytes (P < 0.001), and the total volume of erosions was significantly correlated with the total volume of osteophytes (P < 0.001). Moreover, the number of osteophytes was related to age (P < 0.001) and disease duration (P = 0.001), while the volume of osteophytes was related to age (P = 0.001), disease duration (P < 0.001), and function as measured by the Health Assessment Questionnaire (P = 0.013). Multivariate regression analyses showed an independent association between osteophytes and erosions. In the longitudinal analysis, the mean number (P = 0.033) and volume (P < 0.001) of osteophytes increased significantly in RA patients during their disease course. CONCLUSION: Age, disease duration, and bone erosions are associated with osteophytes, indicating development of secondary OA in patients with RA.