高强度聚焦超声辐照兔肌肉组织后B超灰度值与坏死体积的相关性研究

The study on the correlation between the volume of tissue necrosis and two dimensional ultrasound grey scale on rabbit muscle with high intensity focused ultrasound

目的探讨高强度聚焦超声辐照兔腿部肌肉后,其坏死体积与B超灰度值变化的关系。方法将05只新西兰大白兔按辐照时间分为0 s1、8 s3、0 s、40 s、50 s6、0 s7、0 s8、0 s、90 s1、00 s共10个组;治疗参数为功率140 W、频率0.8 MHz、焦距126 mm、治疗头直径150 mm;监测辐照过程中B超灰度值变化,治疗24 h后解剖兔腿部肌肉,观察其坏死情况。结果随着辐照时间的延长,B超灰度值逐渐增加,坏死体积也逐渐增加,差异具有显著性(P<0.01),坏死体积与灰度值呈正相关,r为0.982;当灰度值达到54.25±3.60时,坏死体积达(3.01±0.5)ml,此后随着B超灰度值的增加,坏死体积变化不明显(P>0.05),且灰度值达73.08以上时会出现HIFU辐照过量,甚至碳化现象。结论进行HIFU治疗时,B超灰度值与组织坏死体积之间存在一定的相关性,当灰度达到一定值时,组织坏死体积会达到饱和。

Objective To explore the relation between the necrosis volume and B ultrasound grey scale on rabbit muscle with high intensity focused ultrasound（HIFU）. Methods 60 new Zealand white rabbits were divided into 10 groups（0 s,18 s,30 s,40 s, 50 s, 60 s, 70 s, 80 s, 90 s, 100 s） according to the treating time. The treatment parameter of power 140 W, frequency 0.8 MHz, foci 126 mm, and diameter of treatment head 150 mm were elected. The grey scale during HIFU radiation and the necrosis of rabbit muscle after 24 hours with HIFU were observed by anatomy. Results With HIFU radiation prolonging,both two dimensional ultrasound grey scale and the necrosis volume of rabbit muscle tissue would be increased, the difference is significant（ P 〈 0.01 ）. The necrosis volume would be （3.01 ± 0.5）ml when two dimensional ultrasound grey scale was increased to 54.25 ± 3.60, and the correlation between the volume of necrosis and the grey scale is positive（ r 0.982） before it. With the grey scale increasing, the chance of the necrosis volume was not significant after it. The necrosis would appear HIFU overradiation, even charcoal when the grey scale was higher than 73.08. Conclusion The correlation between the volume of tissue necrosis and two dimensional grey scale for HIFU radiation was sure, the biggest volume of tissue necrosis would be present when the grey scale is increased to some scale.