title: Bubble dynamics involved in ultrasonic imaging.
abstract: In clinical ultrasound, blood cells cannot be differentiated from surrounding tissue, due to the low acoustic impedance difference between blood cells and their surroundings. Resonant gas bubbles introduced in the bloodstream are ideal markers, if rapid dissolution can be prevented. Ultrasound contrast agents consist of microscopically small bubbles encapsulated by an elastic shell. These microbubbles oscillate upon ultrasound insonification. Microbubbles with thin lipid shells have demonstrated highly nonlinear behavior. To enhance diagnostic ultrasound imaging techniques and to explore therapeutic applications, these medical microbubbles have been modeled. Several detection techniques have been proposed to improve the detectability of the microbubbles. A new generation of contrast agents, with special targeting ligands attached to the shells, may assist the imaging of nonphysical properties of target tissue. Owing to microbubble-based contrast agents, ultrasound is becoming an even more important technique in clinical diagnostics.
authors.affiliation: Institute for Medical Engineering, Department of Electrical Engineering & Information Technology, Ruhr-Universität Bochum, Building IC, 6/146, D-44780 Bochum, Germany. michiel.postema@rub.de
authors.forename: Michiel
authors.initials: M
authors.lastname: Postema
authors.forename: Georg
authors.initials: G
authors.lastname: Schmitz
mesh_terms: D001773:Blood Cells / Q000000981:diagnostic imaging; D003287:Contrast Media / Q000494:pharmacology*; D006801:Humans; D007089:Image Enhancement; D007090:Image Interpretation, Computer-Assisted; D008024:Ligands; D008055:Lipids / Q000737:chemistry; D045423:Microbubbles; D008863:Microspheres; D012542:Scattering, Radiation; D013010:Sonication; D014465:Ultrasonics; D014463:Ultrasonography / Q000379:methods*
chemical_list: D003287:Contrast Media; D008024:Ligands; D008055:Lipids