In vivo pressure measurements of lithotripsy shock waves in pigs
In vivo pressure measurements of lithotripsy shock waves in pigs
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DOI：
10.1016/s0301-5629(97)00270-6
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发表时间：
1998-02-01
影响因子：
2.9
通讯作者：
Crum, LA
中科院分区：
文献类型：
--
作者：
Cleveland, RO;Lifshitz, DA;Crum, LA
碎石术中的结石粉碎和组织损伤对肾脏内的声场很敏感，但对体内冲击波的了解有限。我们用25微米直径的聚偏氟乙烯薄膜构成的小型水听器，在直径21毫米的环上测量了猪体内的碎石冲击波。用一层薄薄的硅橡胶将膜与猪液电隔离。在猪肾两侧切开后，将水听器放置在猪肾周围。将水听器放置在左肾的前表面(冲击波入口)或后表面(冲击波出口)。使用透视成像将水听器垂直于冲击波进行定向。对于每头猪，电压设置(12-24千伏)和冲击波焦点在肾脏内的位置是不同的。在猪体内测得的波形与在水中测得的波形非常相似，但峰值压力约为水中的70%。体内焦域为82 mm×20 mm，大于体外测量的焦域(57 mm×12 mm)。似乎是组织中的非线性效应和不均衡性的结合扩大了碎石机的范围。冲击波上升时间约为100 ns，大大超过在水中测量的上升时间，这归因于组织中更高的吸收。(C)1998年世界医学和生物学超声联合会。
Stone comminution and tissue damage in lithotripsy are sensitive to the acoustic field within the kidney, yet knowledge of shock waves in vivo is limited. We have made measurements of lithotripsy shock waves inside pigs with small hydrophones constructed of a 25-mu m PVDF membrane stretched over a 21-mm diameter ring. A thin layer of silicone rubber was used to isolate the membrane electrically from pig fluid. A hydrophone was positioned around the pig kidney following a flank incision. Hydrophones were placed on either the anterior (shock wave entrance) or the posterior (shock wave exit) surface of the left kidney. Fluoroscopic imaging was used to orient the hydrophone perpendicular to the shock wave. For each pig, the voltage settings (12-24 kV) and the position of the shock wave focus within the kidney were varied. Waveforms measured within the pig had a shape very similar to those measured in water, but the peak pressure was about 70% of that in water. The focal region in vivo was 82 mm x 20 mm, larger than that measured in vitro (57 mm x 12 mm). It appeared that a combination of nonlinear effects and inhomogeneities in the tissue broadened the focus of the lithotripter. The shock rise time was on the order of 100 ns, substantially more than the rise time measured in water, and was attributed to higher absorption in tissue. (C) 1998 World Federation for Ultrasound in Medicine & Biology.