Non-invasive pulsed ultrasound enhances hematoma clearance and neurological recovery in experimental intracerebral hemorrhage

Background Intracerebral Hemorrhage (ICH) is a devastating stroke subtype. Accelerating hematoma clearance is a critical therapeutic goal. This study evaluated non-invasive pulsed ultrasound for enhancing hematoma clearance, edema resolution, and recovery post-ICH. Methods Twenty-nine rats with striatal autologous blood-induced ICH were randomized into control ( n = 11), 2 MHz ultrasound ( n = 7), and 8 MHz ultrasound ( n = 11) groups. Ultrasound treatment (60 min/day) was applied for 7 consecutive days following ICH induction. Hematoma volume and perihematomal edema (PHE) were assessed by T2-weighted imaging (T2WI) and susceptibility-weighted imaging (SWI) at days 1 and 7 post-ICH. Neurological function was assessed by corner turn and cylinder tests at baseline and days 1, 3, and 7. Results Non-invasive pulsed ultrasound significantly enhanced hematoma clearance (2 MHz: 47.7%; 8 MHz: 47.8% vs. control: 20.4%, p < 0.01) and PHE resolution (2 MHz: 53.9%; 8 MHz: 71.8% vs. control: 31.1%, p < 0.05). Behavioral tests showed reduced right-turn bias and forelimb asymmetry in ultrasound groups ( p < 0.05). No frequency difference was found. Conclusion Non-invasive pulsed ultrasound significantly enhances hematoma clearance, reduces edema, and improves functional recovery post-ICH, supporting its translational potential.