Options for Assessing Joints and Entheses in Psoriatic Arthritis by Ultrasonography and Magnetic Resonance Imaging: How to Move Forward.

Psoriatic arthritis (PsA) is a heterogeneous disease with various manifestations of musculoskeletal inflammation. Recent advances in imaging, including ultrasound (US) and magnetic resonance imaging (MRI), allow for the accurate evaluation of the extent of inflammation and damage in the peripheral joints, spine, and entheses. The development and validation of outcome measures are critical steps in creating standardized evaluations of musculoskeletal inflammation and damage in psoriatic patients. At the 2017 meeting of the Group for Research and Assessment of Psoriasis and PsA (GRAPPA), recent work on outcome measures from the GRAPPA US and MRI working groups was summarized. The GRAPPA US group has been developing and validating a sonographic enthesitis scoring system in PsA. The GRAPPA MRI group focuses on the evaluation of whole-body MRI for the assessment of musculoskeletal inflammation in the joints and entheses in patients with PsA.