Intraventricular hemorrhage (IVH) is a neurovascular complication due to premature birth that results in blood clots forming within the ventricles. Magnetic resonance–guided high-intensity focused ultrasound (MRgHIFU) has been investigated as a noninvasive treatment to lyse clots. The authors designed and constructed a robotic MRgHIFU platform to treat the neonatal brain that facilitates ergonomic patient positioning. The clot lysis efficacy of the platform is quantified using a brain phantom and clinical MRI system.

A thermosensitive brain-mimicking phantom with ventricular cavities was developed to test the clot lysis efficacy of the robotic MRgHIFU platform. Whole porcine blood was clotted within the phantom’s cavities. Using the MRgHIFU platform and a boiling histotripsy treatment procedure (500 W, 10-msec pulse duration, 1.0% duty cycle, and 40-second duration), the clots were lysed inside the phantom. The contents of the cavities were vacuum filtered, and the remaining mass of the solid clot particles was used to quantify the percentage of clot lysis. The interior of the phantom’s cavities was inspected for any collateral damage during treatment.

A total of 9 phantoms were sonicated, yielding an average (± SD) clot lysis of 97.0% ± 2.57%. Treatment resulted in substantial clot lysis within the brain-mimicking phantoms that were apparent on postsonication T2-weighted MR images. No apparent collateral damage was observed within the phantom after treatment. The results from the study showed the MRgHIFU platform was successful at lysing more than 90% of a blood clot at a statistically significant level.

The robotic MRgHIFU platform was shown to lyse a large percentage of a blood clot with no observable collateral damage. These results demonstrate the platform’s ability to induce clot lysis when targeting through simulated brain matter and show promise toward the final application in neonatal patients.

脑室内出血 (IVH) 是由于早产导致脑室内形成血块的神经血管并发症。磁共振引导的高强度聚焦超声 (MRgHIFU) 已被研究作为一种无创治疗来溶解凝块。作者设计并构建了一个机器人 MRgHIFU 平台来治疗新生儿大脑，有助于符合人体工程学的患者定位。使用脑模型和临床 MRI 系统量化该平台的凝块溶解功效。

开发了一种带有心室腔的热敏模拟大脑模型，以测试机器人 MRgHIFU 平台的凝块溶解功效。全猪血在幻影的腔内凝结。使用 MRgHIFU 平台和沸腾组织切片治疗程序（500 W、10 毫秒脉冲持续时间、1.0% 占空比和 40 秒持续时间），血块在模型内裂解。空腔的内容物被真空过滤，固体凝块颗粒的剩余质量用于量化凝块溶解的百分比。在治疗过程中，检查了模型腔体的内部是否有任何附带损伤。

总共对 9 个模型进行了超声处理，平均 (± SD) 凝块裂解率为 97.0% ± 2.57%。治疗导致在超声后 T2 加权 MR 图像上明显的仿脑幻影内的大量凝块溶解。治疗后在幻影内没有观察到明显的附带损伤。研究结果表明，MRgHIFU 平台成功地以具有统计学意义的水平裂解了 90% 以上的血块。

机器人 MRgHIFU 平台被证明可以溶解大部分血凝块，没有明显的附带损伤。这些结果证明了该平台在通过模拟大脑物质进行靶向时诱导凝块溶解的能力，并显示出最终应用于新生儿患者的希望。