Ultrafast ultrasound imaging reveals altered cerebral blood flow in newborn rats with hypoxic-ischemic encephalopathy.

Abstract

BACKGROUND: Hypoxic-ischemic encephalopathy (HIE) leads to poor neurological outcomes without timely treatment, yet early identification remains challenging. While cerebral blood flow (CBF) changes relate to HIE, specific early CBF or cerebral venous drainage (CVD) patterns are unclear. Recently, the advanced multi-angle plane wave high-frequency ultrafast Doppler (HF-μDoppler) imaging has shown promise for neonatal CBF/CVD assessment, aiding early diagnosis and intervention of HIE. METHODS: This study modified the Rice-Vannucci model to enable real-time observation of CBF/CVD changes during HIE. Using HF-μDoppler, we evaluated its feasibility and performance in assessing CBF/CVD under different conditions and stages of HIE, and explored specific early CBF/CVD alterations during HIE onset. RESULTS: This study validated the feasibility and sensitivity of HF-μDoppler for detecting CBF/CVD anomalies in HIE rats. We identified early-stage HIE-specific retrograde perfusion of the transverse sinus (TS) contralateral to carotid ligation, with reduced velocity and increased diameter on both sides compared to baseline. The contralateral TS showed lower velocity and smaller diameter than the ipsilateral side, with potential explanations discussed. CONCLUSION: HF-μDoppler is a promising imaging modality for reliable HIE assessment. The observed retrograde perfusion of TS may serve as a sensitive early biomarker for accurate HIE detection, supporting earlier clinical diagnosis and treatment. IMPACTS: HF-μDoppler can be used for CBF/CVD evaluation in HIE newborn rats. HF-μDoppler can detect sensitive biomarkers in the early stages of HIE. Transverse sinus' retrograde perfusion specifically occurs in HIE' early stages.