Hynynen K, Colucci V, Chung A, Jolesz F
Department of Radiology, Brigham and Women's Hospital, Boston, MA 02115, USA.
Ultrasound Med Biol. 1996;22(8):1071-7. doi: 10.1016/s0301-5629(96)00143-3.
The purpose of this work was to test the hypothesis that reproducible and sustainable arterial occlusion can be induced by focused ultrasound energy deposition noninvasively within deep tissue. An MRI-compatible focused ultrasound transducer was used to sonicate a branch of the renal artery (diameter about 0.6 mm) in vivo (nine rabbits). An intravenous MRI contrast agent bolus was injected about 30 min and up to 7 days after the sonication. After follow-up, in vitro magnification x-ray angiograms were obtained and the kidneys were fixed in formaldehyde for histologic study. The ultrasound pulses resulted in complete cessation of blood flow, as shown by the gradient echo images. In seven of the nine rabbits, a wedge-shaped unenhanced area was seen at the part of the kidney that was perfused by the vessel after the contrast agent injection. This area extended laterally (outside of the sonicated volume) to the cortical surface of the kidney. The x-ray angiograms showed that the artery was completely occluded. Postmortem histologic evaluation showed an infarcted tissue volume corresponding to the wedge shape seen in the images. This study showed that appropriately focused ultrasound can be used to close arteries noninvasively. This finding has significant clinical potential.
聚焦超声能量沉积可在深部组织内无创地诱导出可重复且可持续的动脉闭塞。使用一台与MRI兼容的聚焦超声换能器在体内（9只兔子）对肾动脉的一个分支（直径约0.6毫米）进行超声处理。在超声处理后约30分钟至7天内静脉注射MRI造影剂团注。随访后，获取体外放大X射线血管造影图像，并将肾脏固定在甲醛中进行组织学研究。梯度回波图像显示，超声脉冲导致血流完全停止。在9只兔子中的7只身上，在注射造影剂后，由该血管供血的肾脏部分出现了一个楔形无强化区域。该区域横向（超出超声处理体积）延伸至肾脏的皮质表面。X射线血管造影显示动脉完全闭塞。尸检组织学评估显示梗死组织体积与图像中所见的楔形相符。这项研究表明，适当聚焦的超声可用于无创闭合动脉。这一发现具有重大的临床潜力。
