Quantitative Contrast-Enhanced Ultrasound Assessment of Renal Microcirculation and Function in a Rat Model of...

This study aims to investigate the utility of quantitative contrast-enhanced ultrasound (CEUS) in both assessing renal perfusion and monitoring renal function in a rat model of sepsis-associated acute kidney injury (S-AKI).

Thirty-six healthy Sprague-Dawley rats were divided into a sepsis model group (with severe and mild subgroups) and a sham-operated control group (Sham). The model subgroups underwent cecal ligation and puncture to induce S-AKI, while the Sham group received only a laparotomy without ligation or puncture. Jugular venous blood was collected to measure serum creatinine (Scr) and uric acid (UA) levels. CEUS was performed to evaluate renal perfusion and time-intensity curves were analyzed to derive perfusion parameters. The relationships between these CEUS-derived parameters and the serum biomarkers were examined. Finally, kidney tissue samples were harvested for pathological analysis to confirm AKI.

In the sepsis model rats, the time-based perfusion parameters-time to peak (TTP), rise time (RT), fall half-time (FHT) and mean transit time (MTT)-were all significantly longer than in the Sham group (all p < 0.05). Scr and UA levels correlated positively with TTP, MTT, RT and FHT (Scr: r = 0.695, 0.669, 0.704, 0.394; UA: r = 0.810, 0.798, 0.586, 0.351; all p < 0.05). Histopathological examination of renal tissues in the model subgroups revealed changes consistent with AKI, with the severe subgroup exhibiting more pronounced renal damage than the mild subgroup.

Quantitative CEUS can effectively evaluate renal perfusion in rats with S-AKI and is valuable for detecting and monitoring changes in renal function.