title: Erythrocytes, as well as microbubble contrast agents, are important factors in improving thermal and therapeutic effects of high-intensity focused ultrasound.
abstract: Erythrocytes, as well as microbubble contrast agents, are important factors in improving thermal effect of high-intensity focused ultrasound (US), or HIFU, and increasing the coagulation volume produced by HIFU irradiation. In vitro experiments used human plasma with various concentrations of human erythrocytes in combination with or without Levovist. In vivo experiments used eight Japan white rabbits with three degrees of anemia. Using a 2.17-MHz transducer, HIFU was applied for 60 s, and the temperature rise and the volume of coagulation necrosis was evaluated. There was a significant correlation between the HIFU-induced temperature rise and hematocrit, with a correlation coefficient of 0.998 (p=0.0001). Although the temperature rise was smaller at low hematocrit, it was significantly increased by adding Levovist in the suspension (p<0.01). The mean volume of coagulation necrosis was significantly greater in the rabbits with higher hematocrits (p<0.01), and that in the moderate anemia group was significantly increased by using Levovist (p<0.01).
authors.affiliation: Department of Surgical Oncology, The University of Tokyo, Tokyo, Japan. ktakegami-tky@umin.ac.jp
authors.forename: Kenji
authors.initials: K
authors.lastname: Takegami
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kaneko
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Watanabe
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Maruyama
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Nagawa
mesh_terms: D000740:Anemia / Q000503:physiopathology; D000818:Animals; D001777:Blood Coagulation / Q000187:drug effects / Q000502:physiology; D001831:Body Temperature / Q000187:drug effects; D003287:Contrast Media / Q000494:pharmacology*; D004912:Erythrocytes / Q000502:physiology*; D005260:Female; D006400:Hematocrit; D006358:Hot Temperature; D006801:Humans; D008099:Liver / Q000503:physiopathology; D045423:Microbubbles; D009336:Necrosis; D011134:Polysaccharides / Q000494:pharmacology*; D011817:Rabbits; D014464:Ultrasonic Therapy / Q000379:methods*
chemical_list: D003287:Contrast Media; D011134:Polysaccharides; C059891:SHU 508