摘要
目的 探讨在不同剂量的高强度聚焦超声 (high intensityfocusedultrasound ,HIFU )辐照下 ,正常猪离体心肌组织焦点局部的温度变化及规律。方法 应用不同声强度 (110 0 0W /cm2 、15 80 0W /cm2和 2 2 2 0 0W /cm2 )、不同辐照时间 (1s、3s、5s、7s、10s、13s和 15s)的HIFU连续定点辐照猪离体心肌组织的不同部位 ,同时通过置于焦点中心的热电耦温度计连续测温 ,观察焦域的温度变化。结果 不同剂量下焦点中心所达到的最高温度分布范围为 (66.4± 11.2 )℃～ (85 .8± 7.4)℃。不同处理因素间的最高温度差异具有显著性意义 (P <0 .0 5 ) ,停止辐照后焦点的降温曲线下降趋势由快到慢。结论 不同剂量的HIFU均可使焦点中心达到组织发生不可逆变化所需的温度 ,HIFU剂量与焦域中心温度有关 。
Objective To explore the relationship of acoustic exposure dose and temperature in in vitro myocardial tissue exposed to high intensity focused ultrasound(HIFU).Methods The JC therapeutic apparatus ( 1.6 MHz) was separately used to selectively destroy the different parts in myocardial tissue of 10 fresh normal swine in vitro hearts. In this step, the myocardial tissue was exposed to HIFU for 1 s, 3 s, 5 s, 7 s, 10 s, 13 s, 15 s with the acoustic intensity of 11 000 W/cm 2, 15 800 W/cm 2, 22 200 W/cm 2, respectively. The temperature alteration in the focal field of swine hearts was detected by thermocouple probe which just located in the focal field under the B mode ultrasonic diagnosis system monitoring. Results It was observed that the highest temperature in focal field varied from ( 66.4 ± 11.2 )℃ to( 85.8 ± 7.4 )℃ under different HIFU dose. And significant difference was found among them (P< 0.05 ).After HIFU irradiation was stopped, the tendency of the temperature descending curve went down slowly. Conclusions The temperature in focal field can reach to that degree which lead to irreversible change in cells under different HIFU dose. And the temperature was related with the HIFU dose, but it was not direct proportion.
出处
《中华超声影像学杂志》
CSCD
2002年第7期424-426,共3页
Chinese Journal of Ultrasonography
基金
国家自然科学基金资助 (30 1 70 2 65)
