Superb microvascular imaging enhances detection of microvascularity in plantar fasciosis: a clinical correlation...

To evaluate superb microvascular imaging (SMI) for detecting microvascularity in chronic plantar heel pain and to assess its clinical correlation in comparison with grayscale ultrasound and conventional Doppler, using a standardized clinical diagnosis as the reference standard.

In this prospective study, 29 patients (58 fasciae) with bilateral plantar fasciosis and 30 matched asymptomatic controls (60 fasciae) underwent ultrasound examinations. Assessments included grayscale parameters (thickness > 4 mm, swelling hypoechogenicity), color/power Doppler, and SMI. Pain and function were evaluated using the VAS and FAOS-derived impairment scores. Discriminative ability was assessed via receiver operating characteristic (ROC) curves.

Symptomatic fasciae had significantly greater fascial thickness (5.02 ± 1.29 mm vs. 3.27 ± 0.56 mm, p < 0.001) and exceeded 4 mm in 82.8%/9.3% (right/left) versus 6.7%/10.0% of controls. Color Doppler detected no signals; power Doppler identified flow in 10.3% of symptomatic fasciae. SMI detected microvascular flow in 41.4%/44.8% (right/left) of symptomatic fasciae versus none (0%) of asymptomatic control fasciae (p < 0.001). SMI-detected vascularity showed a moderate association with clinical disease status (right r = 0.494; left r = 0.510; p < 0.001). ROC analysis demonstrated good discriminative ability for fascial thickness (AUC = 0.886) and fair performance for SMI (AUC = 0.707), both outperforming power Doppler (AUC = 0.603).

SMI is substantially more sensitive than conventional Doppler for detecting microvascularity in plantar fasciopathy. However, grayscale fascial thickness retained the highest single-test discriminative ability, and many symptomatic fasciae remained SMI-negative. Therefore, SMI should be considered a complementary vascular assessment rather than a stand-alone diagnostic test. Larger multicenter studies are required to define its routine clinical role.