NUSG is a visualization method suitable for evaluating the subunits of the nail. The main purpose of this study is to identify NUSG properties in patients with PsA and healthy controls. The investigators recruited patients with PsA according to the CASPAR criteria and sex- and age-matched healthy controls into the study. NUSG parameters were examined by grayscale and power Doppler techniques for all of the fingernails and first toenails (12 nails); and five scorings including nail plate impairment score (NPIs), nail plate thickness score (NPTs), nail bed thickness score (NBTs), nail thickness score (NTs), and the Doppler activity score (DAs) were calculated. The investigators compared the PsA and control groups in terms of the NUSG scorings and also documented the discriminative performances (with receiver operating characteristic curve analysis) of the scorings. Then, the feasibility and reliability analysis of the NUSG scorings were performed. Finally, the association between the NUSG scores and participant characteristics, including sex, age, body weight, height, labor market participation, smoking, hemoglobin, disease duration, history of dactylitis, current enthesitis, radiographic sacroiliitis, C reactive protein, minimal disease activity, Disease Activity Index for Psoriatic Arthritis, Nail Psoriasis Severity Index, and Psoriasis Area Severity Index were explored.
