The value of super microvascular imaging and shear wave elastography in evaluating synovial lesions in knee osteoarthritis

Objective This study investigates the value of super microvascular imaging (SMI) and shear wave elastography (SWE) in evaluating the relationship between synovial tissues and disease severity in knee osteoarthritis (KOA) patients. Materials and Methods Patients with KOA who visited our hospital between August 2022 and May 2023 were enrolled. WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) scores, X-ray images (Kellgren-Lawrence grading), power Doppler imaging (PDI), SMI, and SWE were evaluated for each patient. Results A total of 54 patients were enrolled. SMI detected more synovial blood flow than PDI (79.62% vs. 62.96%, p < 0.001). SMI upgraded 22.22% of PDI from level 0 to level 1, 31.48% from level 1 to level 2, and 9.26% from level 2 to level 3. There was a positive correlation between WOMAC scores and Kellgren-Lawrence grading (KLG), (r = 0.79, p < 0.001). PDI showed no significant correlation with WOMAC scores (r = 0.26, p = 0.06) or KLG (r = 0.12, p = 0.40). SMI also showed no significant correlation with WOMAC scores (r = 0.26, p = 0.05) or KLG (r = 0.06, p = 0.67). However, A significant correlation was showcased between PDI (r = 0.38, p = 0.04), SMI (r = 0.47, p < 0.001) and the WOMAC pain scores. Additionally, SWE exhibited significant positive correlations with WOMAC scores (r = 0.74, p < 0.001) and KLG (r = 0.84, p < 0.001). Conclusion In patients with KOA, SMI improved the detection of synovial blood flow and is significantly superior to PDI, offering a more sensitive tool for assessing synovial blood flow. SWE of synovial tissue showed a positive correlation with disease severity, providing a novel tool for assessing the severity of the disease.