The use of homemade microbubbles in detection of organ bleeding and enhancement of high-intensity focused ultrasound therapy

We investigated the feasibility of using homemade microbubbles in detection of internal bleeding, and for optimization of high-intensity focused ultrasound (HIFU) therapy. Homemade microbubbles were produced by sonicating albumin and dextrose saline solution with the presence of perfluorocarbon gas. Microbubbles were injected intravenously to reveal rabbit kidney and liver injuries. HIFU treatments were performed on liver lacerations for hemostatis and on intact liver for lesion production, with or without homemade microbubbles. The mean size of homemade microbubble was 4.7 um (range 1.2–7.1 μm). The concentration of microbubbles was 3.1*108 bubble/ml. Kidney and liver injuries were revealed by mosaic color flow at the injury sites. In treatment, the average hemostasis times normalized with the bleeding rate were 39 s/ml*min for HIFU only and 21 s/ml*min for HIFU+microbubbles treatments. The presence of microbubbles reduced 44 percent (p<0.05) time in producing the first formation of the blood coagulum. The HIFU lesion depth was reduced by 35 percent because microbubbles shield the postfocal region from HIFU exposure. Homemade microbubbles oscillate and collapse in ultrasound field, generating mosaic pattern thus revealing the bleeding site. It also shows potential in promoting HIFU hemostasis and shielding deep-tissue regions from HIFU exposures.