Imaging in clinical trials for psoriatic arthritis: a scoping review

Psoriatic arthritis (PsA) is a chronic inflammatory condition principally affecting the skin and musculoskeletal system, associated with comorbidities and decreased quality of life. Imaging is crucial for diagnosis, monitoring progression, and evaluating treatment efficacy; therefore, it plays an important role in PsA clinical trials. In this review, we aimed to characterize how imaging modalities and advances in imaging techniques are being used specifically in the PsA clinical trial literature. Following the Arksey and O'Malley framework for scoping reviews, we conducted a comprehensive search of multiple literature databases, from January 1, 2000, to June 27, 2024. We captured 1961 articles and after deduplication, title and abstract screening, and full-text review, 53 studies were included. Radiographs were the most used imaging modality (n = 32/53, 60%), and radiographic progression was frequently measured using the PsA-modified Sharp/van der Heijde score. MRI (n = 16/53, 30%) was used in evaluating peripheral and axial disease, with more recent adoption of validated scoring systems (PsAMRIS and SPARCC). Ultrasound (n = 11/53, 21%), including power Doppler, was used to assess soft tissue inflammation. Standardized scoring systems (e.g. GLOESS) were used in a minority of ultrasound-based studies. Multimodality imaging (n = 7/53, 13%) and CT (n = 2/53, 4%) was uncommon. The development of PsA-specific scoring systems for radiographs and MRI has been instrumental in advancing imaging assessment in PsA. However, their application remains limited, particularly in ultrasound, where further standardization is needed. Future clinical trials should focus on increasing the adoption of PsA-specific scoring systems, exploring advanced techniques (e.g. DCE-MRI), and multi-modal imaging to improve PsA disease monitoring.