title: Acousto-mechanical and thermal properties of clotted blood.
abstract: The efficacy of ultrasound-assisted thrombolysis as an adjunct treatment of ischemic stroke is being widely investigated. To determine the role of ultrasound hyperthermia in the process of blood clot disruption, the acousto-mechanical and thermal properties of clotted blood were measured in vitro, namely, density, speed of sound, frequency-dependent attenuation, specific heat, and thermal conductivity. The amplitude coefficient of attenuation of the clots was determined for 120 kHz, 1.0 MHz, and 3.5 MHz ultrasound at room temperature (20 +/- 2 degrees C). The attenuation coefficient ranged from 0.10 to 0.30 Np/cm in porcine clots and from 0.09 to 0.23 Np/cm in human clots. The experimentally determined values of specific heat and thermal conductivity for porcine clotted blood are (3.2 +/- 0.5) x 10(3) J/kg x K and 0.55 +/- 0.13 W/m x K, respectively, and for human clotted blood are (3.5 +/- 0.8) x 10(3) J/kg x K and 0.59 +/- 0.11 W/m x K, respectively. Measurements of the acousto-mechanical and thermal properties of clotted blood can be helpful in theoretical modeling of ultrasound hyperthermia in ultrasound-assisted thrombolysis and other high-intensity focused ultrasound applications.
authors.affiliation: Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221-0011, USA.
authors.forename: Volodymyr M
authors.initials: VM
authors.lastname: Nahirnyak
authors.forename: Suk Wang
authors.initials: SW
authors.lastname: Yoon
authors.forename: Christy K
authors.initials: CK
authors.lastname: Holland
mesh_terms: D000818:Animals; D001777:Blood Coagulation / Q000502:physiology*; D002151:Calorimetry; D003720:Densitometry; D005342:Fibrinolysis / Q000502:physiology; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006358:Hot Temperature; D006801:Humans; D008954:Models, Biological; D011994:Recombinant Proteins / Q000627:therapeutic use; D020521:Stroke / Q000097:blood / Q000628:therapy; D013552:Swine; D013814:Thermal Conductivity; D015912:Thrombolytic Therapy / Q000379:methods; D010959:Tissue Plasminogen Activator / Q000235:genetics / Q000627:therapeutic use; D014464:Ultrasonic Therapy
chemical_list: D005343:Fibrinolytic Agents; D011994:Recombinant Proteins; D010959:Tissue Plasminogen Activator