Whole-body MR imaging in psoriatic arthritis: additional value for therapeutic decision making

Purpose: In psoriatic arthritis (PsA) multiple locations may show inflammatory changes not always readily accessible to clinical exam. Often, clinical exam is inconclusive and the decision to initiate or adapt therapy is difficult. Whole body (WB)-MRI may help in this situation by providing a comprehensive overview of affected areas/joints. The purpose of this study was to make a proof of concept whether WB-MRI in psoriatic arthritis is feasible and can provide additional information compared to clinical examination alone with regard to therapeutic decision making in patients with PsA and inconclusive clinical situation.

Materials and methods: 30 patients with PsA and diffuse musculoskeletal pain were examined. A WB-MRI protocol was implemented on a 1.5 Tesla scanner using coronal and sagittal STIR- (TR: 5800, TE: 54, matrix 384(2) pixels, FOV 400 mm) and pre- and steady-state-post-Gadolinium-VIBE sequences (TR: 9.82, TE: 4.53, matrix 384×307 pixels, FOV: 400 mm). MRI was evaluated for image quality and inflammatory findings by two readers in consensus and compared to clinical exam.

Results: The WB-MR-exam was well tolerated by all patients. Image quality was rated good to excellent in 26 of 30 patients (86.6%). WB-MRI detected significantly (p<0.001) more areas of synovitis/enthesitis than clinical exam except for the hands and feet. MRI was able to detect unknown destructive bony changes in 10 patients (53%). In 22 patients (73.3%) the therapy regimen was modified, in 18 patients (62%) TNF-alpha-inhibitors were started.

Conclusion: Whole-body MRI (WB-MRI) may be integrated in the diagnostic work-up of patients with psoriatic arthropathy facilitating individual adaptation of therapeutic strategy.