Quantitative Contrast-Enhanced Ultrasound Characterization of Perilesional Perfusion and Its Association with CD34-Positive Cell Density in a Rat Model of Hepatic Alveolar Echinococcosis

Hepatic alveolar echinococcosis (HAE) is characterized by infiltrative growth and remodeling of perilesional host tissue, including microvascular changes. We investigated whether quantitative contrast-enhanced ultrasound (CEUS) could characterize perilesional perfusion and its animal-level association with CD34-positive cell density in a standardized rat model. Twenty female Sprague Dawley rats underwent ultrasound-guided intrahepatic HAE modeling and CEUS 10 weeks later. Peak enhancement (PE), rise time (RT), time to peak (TTP), wash-in rate (WiR), wash-in perfusion index (WiPI), and wash-in area under the curve (WiAUC) were measured in the perilesional zone and reference liver parenchyma. CD34-positive cell density was quantified by digital pathology. The perilesional zone showed higher PE, WiR, WiPI, and WiAUC and shorter RT and TTP than the reference liver parenchyma (all FDR-adjusted p < 0.001). CD34-positive cell density correlated positively with PE (ρ = 0.696, FDR-adjusted p = 0.004), WiR (ρ = 0.525, FDR-adjusted p = 0.026), WiPI (ρ = 0.614, FDR-adjusted p = 0.012), and WiAUC (ρ = 0.534, FDR-adjusted p = 0.026), but not with RT or TTP. Within this experimental model, these findings indicate increased and accelerated perilesional perfusion and support quantitative CEUS as a contrast-enhanced imaging-based approach for characterizing its relationship with local microvascularity.