Psoriatic arthritis: lessons from imaging studies and implications for therapy.

Modern imaging may aid in the diagnosis, prognosis and monitoring of therapeutic response in psoriatic arthritis (PsA). Detection of osteitis and technical advances like whole body magnetic resonance imaging (MRI) exemplify the value of this technology. Areas covered: Ultrasound (US) provides a clinic-based tool for evaluating both joint pathologies and extra-articular structures (especially enthesitis) including skin and nail disease. Recent studies have demonstrated subclinical disease in psoriasis without arthritis, as well as in PsA, with implications for diagnosis and treatment classification. Modern imaging can also facilitate decisions on tapering of expensive biologics, though real-world clinical studies are still lacking. Expert commentary: The increase in novel PsA therapies should increase the utilization of modern imaging, providing both increased validation of imaging biomarkers as well as responsive outcome measures.