To investigate the acceptance of the high-resolution peripheral quantitative computed tomography (HR-pQCT) in rheumatoid arthritis (RA). The second objective was to investigate the motion artefacts of the metacarpophalangeal (MCP) joints with two different custom-made positioning devices.
Methods:Fifty patients with established RA had their MCP joints scanned by HR-pQCT with two different custom-made positioning devices and examined by conventional X-ray. Afterwards, the patients answered a questionnaire of imaging experience. The comparability of the erosion measures was investigated between the two different custom-made positioning devices by Bland-Altman plot, and intrareader repeatability by intraclass correlation coe cient. The motion artefacts were graded for each acquisition, and intrareader repeatability was investigated by Cohen's kappa coe cient.
Results:Forty percent of the patients preferred HR-pQCT imaging, only 6% preferred conventional X-ray. Seventy-four percent found it di cult to keep their ngers steady during the scan. Fifty percent of the patients reported the in atable immobilization device helped to keep their ngers steady while only 6% reported that it impaired their ability to do so. However, this difference was not re ected in the visual grading, as motion artefacts were sparse, and no clinically relevant difference could be observed. The intrareader repeatability and comparability for the erosion measures were excellent.
Conclusion:The high acceptance among patients adds to the feasibility of HR-pQCT imaging of MCP joints in patients with RA. The in atable immobilization device did not reduce motion-induced image degradation, as the overall visual grading for motion artefacts was low for imaging of the MCP joints in both acquisitions.MCP joints, might exacerbate the motion artefacts. However, motion-induced image degradation and the number of repeated acquisitions are rarely reported for the MCP joints [6][7][8][9].The objective of this study was two-fold. Firstly, the acceptance of HR-pQCT imaging in patients with established RA was investigated using a patient-reported experience measure questionnaire [10]. Secondly, we investigated the comparability and repeatability of motion artefacts and erosion measures of the 2 nd and 3 rd MCP joint for two different custom-made hand positioning devices.
Methods
Study design and populationPatients with rheumatoid arthritis, according to the ACR/EULAR (2010) classi cation criteria [11], were recruited from the outpatient clinic at the Department of Rheumatology, Aarhus University Hospital. Inclusion criteria were the ability to give consent, age ≥ 18 years and disease duration ≥ 5 years. Exclusion criteria were fracture or luxation of the MCP joints in both hands, evidence of active malignant disease, hypocalcemia, impaired renal function (Estimated glomerular ltration rate <35ml/min), untreated hypo-or hyperthyroidism or pregnancy.A full medical history was obtained, and a clinical examination was performed for all individuals. Speci cally, demog...