From histology to sonography in synovitis: EURO-MUSCULUS/USPRM approach

Objectives: The aim of the present study was to propose a methodologically innovative sonographic approach for optimal evaluation of synovial tissues (starting from histopathology). Methods: Using high-frequency ultrasound probes and high-level ultrasound machines, we matched the histological microarchitecture of synovial tissues with multiple sonographic patterns in physiological and pathological conditions. Likewise, high-sensitive color/power Doppler assessments have also been performed to evaluate the microcirculation. Results: Modern equipment allows for a macroscopic classification of synovial pathologies recognizing different morphological patterns; however, intimal and subintimal layers of the synovium cannot be distinguished from each other on ultrasound. High-sensitive Doppler imaging clearly defines the microvascular pattern, especially in patients with hypertrophic synovial pathologies. Conclusions: In clinical practice, using adequate technological equipment i.e. high-frequency B-mode and high-sensitive Doppler imaging, detailed sonographic assessment of synovial tissues can be performed - defining the main sono-histological patterns.