The imaging effect on rabbit's liver by SonoVue and Sonazoid in the high-frequency state with different mechanical indices

Objective The contrast enhancement of SonoVue and Sonazoid were compared in rabbit's liver with ultrasound frequency of7 MHz usinga rangingmechanical index(MI).Methods In the high frequency state (7 MHz),a total of 8 rabbits (weight 2.30±0.30 kg) were bolus injected with two contrast agents:Once the SonoVue (0.06 mL/kg) was injected,the MI was observed ranging from0.10 to0.55 (0.10,0.15,0.25,0.30,0.40,0.50,0.55);after injection of Sonazoid (0.045 mL/kg),MI was found ranging from 0.19 to 0.98 (0.19,0.40,0.62,0.78,0.98).The time-intensity curve (TIC) was drawn for quantitative analysis with a correlation between MI and perfusion parameters.Results In the same frequency:SonoVue group:the peak intensity (PI) reached a maximum at MI =0.15 following an increase of MI;rising-time(RT),time-to-peak(TTP) did not change significantly but MI≤0.25 (P0.05),and turned to be shorter with a continued increase of MI (P0.01);Sonazoid group:PI reached a maximum at MI =0.40 along with an increased MI;RT and TTP were not significantly changed (P0.05).Conclusion Due to different physical and chemical properties,the two ultrasonic contrast agents have different imaging effects in the high-frequency (7 MHz) state.