title: Vascular effects of microbubble-enhanced, pulsed, focused ultrasound on liver blood perfusion.
abstract: The purpose of this study was to investigate the vascular effects of microbubble-enhanced pulsed high-pressure ultrasound on liver blood perfusion. In the presence of circulating lipid-shell microbubbles, a focused ultrasound transducer was used to transcutaneously treat eight livers of healthy rabbits for perfusion analysis and to treat three livers with the abdomen open for histologic analysis. Twenty-two livers treated with the ultrasound only (n = 11) or microbubbles only (n = 11) served as the controls. The focused ultrasound was operated at a frequency of 1.22 MHz with a peak negative pressure of 4.6 MPa. The liver blood perfusion was estimated by performing contrast-enhanced ultrasound and gray-scale quantification on the livers before and after treatment. A temporary, nonenhanced region occurred in all of the experimental livers. The regional contrast gray-scale values of the experimental group dropped significantly from 88.4 before treatment to 2.7 after treatment. The liver perfusion also demonstrated a gradual recovery over a 60-min period. The liver perfusion of the control groups remained the same after treatment. We found microvascular rupture, hemorrhage and swelling hepatocytes upon histologic examination of the experimental group. Regional liver blood perfusion can be temporarily blocked by microbubble-enhanced focused ultrasound with high-pressure amplitude. These vascular effects can be explained as acute microvascular injury of the liver and may have clinical implications.
authors: Department of Ultrasound, Xinqiao Hospital, The Third Military Medical University, Chongqing, China.
authors: Yuejuan
authors: Y
authors: Gao
authors: Shunji
authors: S
authors: Gao
authors: Baozhen
authors: B
authors: Zhao
authors: Yang
authors: Y
authors: Zhao
authors: Xing
authors: X
authors: Hua
authors: Kaibin
authors: K
authors: Tan
authors: Zheng
authors: Z
authors: Liu
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D019220:High-Energy Shock Waves; D008099:Liver / Q000000981:diagnostic imaging / Q000502:physiology* / Q000528:radiation effects*; D008102:Liver Circulation / Q000502:physiology* / Q000528:radiation effects*; D045423:Microbubbles; D011817:Rabbits; D011829:Radiation Dosage; D014463:Ultrasonography / Q000379:methods*