Beyond skin deep: total-body positron emission tomography to illuminate systemic inflammation in psoriatic arthritis

Psoriatic arthritis (PsA) is a systemic, immune-mediated disorder characterized by inflammation across peripheral and axial joints, entheses, skin, and nails. Given this heterogeneous manifestation, PsA presents unique challenges in clinical diagnosis and management. Conventional imaging, limited to localized, anatomical assessments, often fails to capture the full spectrum of PsA's systemic inflammatory burden, particularly subclinical disease. This review explores the emerging role of total-body positron emission tomography (TB-PET), offering a comprehensive assessment of molecular and metabolic processes across all affected tissues of the body in a single, short, low-dose scan. With PET radiotracers targeting glucose metabolism, T-cell trafficking, and macrophage activation, TB-PET may serve as a gateway to assess the spectrum and degree of inflammation in all the pathologic domains underlying PsA. Ultimately, by bridging molecular imaging with immunology and observable phenotypic features, TB-PET may open new avenues for understanding the pathophysiology of PsA, impacting both research paradigms and clinical strategies.