Validation of Handheld Ultrasound Devices for Point of Care Use in Rheumatology Study- Focus on Synovitis, Doppler Activity, Erosions, and Tendon Lesions

OBJECTIVE: Ultrasonography (US) is essential in rheumatology, but conventional systems are costly and not easily portable. Handheld US offers affordable, portable options, yet their diagnostic validity in Psoriatic Arthritis (PsA) is unclear. This study assessed the concurrent validity of handheld US devices in PsA by evaluating agreement with a gold-standard scanner in detecting elementary lesions. METHODS: PsA patients meeting Classification Criteria for PsA and presenting ≥ tender and swollen joint underwent same-day US with handheld (Clarius-HD3 L20/L15) and gold-standard (GE Logiq E9/E10) systems using a standardized protocol. A blinded assessor scored anonymized images for synovitis, Doppler signals, erosions, and tendon/tenosynovitis based on OMERACT definitions. Inter-device agreement was analyzed using Cohen's kappa (lesion detection), weighted kappa (lesion scoring), and intraclass correlation (ICC) per patient. RESULTS: Thirty patients were included. Between devices, agreement for detecting synovitis was moderate (κ = 0.46-0.50). For Doppler activity, moderate agreement was found with Clarius-L15 (κ = 0.42) and fair agreement with Clarius-L20 (κ = 0.37). Erosions showed moderate-to-substantial agreement (κ for L15= 0.57, L20= 0.62), whereas tendon inflammation had no-fair (κ for L15=0.16, -0.05). Per-patient agreement showed poor (Global OMERACT-EULAR Synovitis Score - GLOESS) and moderate agreement (Doppler) for L15, and good (GLOESS) and moderate (Doppler) agreement for L20, when compared with the gold-standard device. CONCLUSION: Handheld US devices demonstrated moderate agreement with high-end scanners in identifying and grading synovitis and erosions, suggesting promising potential for clinical application. However, sensitivity for Doppler activity and tendon lesions remains lower, emphasizing the need for continued optimization and validation.