Ablation of high intensity focused ultrasound combined with SonoVue on rabbit VX2 liver tumors: assessment with conventional gray-scale US, conventional color/power Doppler US, contrast-enhanced color Doppler US, and contrast-enhanced pulse-inversion harmonic US.
BACKGROUND
We investigated effects of high intensity focused ultrasound (HIFU) combined with contrast agent SonoVue on rabbit VX2 liver tumors by using conventional gray-scale ultrasonography (US), color/power Doppler (CD/PD) US, contrast-enhanced color Doppler (CE CD) US, and contrast-enhanced pulse-inversion harmonic (CE PIH) US.


METHODS
Fourteen days after implantation of VX2 tumors in livers of 50 rabbits, animals were randomly separated into two groups. Based on principles of HIFU, the volume of the tumor was divided into several parallel "planes" to be ablated. Before ablation on each "plane," 0.2 mL SonoVue was injected in bolus via ear veins of rabbits in group II and normal saline solution was administrated in group I. Conventional gray-scale US, CD US, PD US, CE CD US, and CE PIH US were performed before and after ablation.


RESULTS
Twenty-three surviving rabbits in each group underwent HIFU ablation. Conventional gray-scale US showed ablated areas diffusely hyperechoic. On CE PIH US, coagulated areas presented perfusion defect. Both conventional gray-scale US and CE PIH US showed the ablated volume in group II was larger than that in group I. CD US and PD US demonstrated residual vessels in periphery ablated areas in group I, but no residual vessels in group II. CE CD US and CE PIH US depicted less residual vessels in periphery ablated areas in group II than that in group I.


CONCLUSIONS
By enlarging ablated volume of tissue and reducing residual vessels, effects of HIFU ablation on rabbit VX2 liver tumors were enhanced by contrast agent SonoVue.
Luo
Wen
W
Department of Ultrasound, Xijing Hospital, Fourth Military Medical University, 15th Changle Xi Road, Xi'an, Shaanxi, 710032, China.
Zhou
Xiaodong
X
He
Guangbin
G
Li
Qiuyang
Q
Zheng
Xiaoying
X
Fan
Zhiyong
Z
Liu
Qing
Q
Yu
Ming
M
Han
Zenghui
Z
Zhang
Jun
J
Qian
Yunqiu
Y
D000818:Animals; D017115:Catheter Ablation; D003287:Contrast Media; D008114:Liver Neoplasms, Experimental / Q000000981:diagnostic imaging*; D009368:Neoplasm Transplantation; D010743:Phospholipids; D011817:Rabbits; D013459:Sulfur Hexafluoride; D014464:Ultrasonic Therapy; D018615:Ultrasonography, Doppler, Color
D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride