title: In vivo droplet vaporization for occlusion therapy and phase aberration correction.
abstract: The objective was to determine whether a transpulmonary droplet emulsion (90%, <6 microm diameter) could be used to form large gas bubbles (>30 microm) temporarily in vivo. Such bubbles could occlude a targeted capillary bed when used in a large number density. Alternatively, for a very sparse population of droplets, the resulting gas bubbles could serve as point beacons for phase aberration corrections in ultrasonic imaging. Gas bubbles can be made in vivo by acoustic droplet vaporization (ADV) of injected, superheated, dodecafluoropentane droplets. Droplets vaporize in an acoustic field whose peak rarefactional pressure exceeds a well-defined threshold. In this new work, it has been found that intraarterial and intravenous injections can be used to introduce the emulsion into the blood stream for subsequent ADV (B- and M-mode on a clinical scanner) in situ. Intravenous administration results in a lower gas bubble yield, possibly because of filtering in the lung, dilution in the blood volume, or other circulatory effects. Results show that for occlusion purposes, a reduction in regional blood flow of 34% can be achieved. Individual point beacons with a +24 dB backscatter amplitude relative to white matter were created by intravenous injection and ADV.
authors.affiliation: University of Michigan Health Systems, Department of Radiology, Ann Arbor 48109-0553, USA.
authors.forename: Oliver D
authors.initials: OD
authors.lastname: Kripfgans
authors.forename: J Brian
authors.initials: JB
authors.lastname: Fowlkes
authors.forename: Michael
authors.initials: M
authors.lastname: Woydt
authors.forename: Odd P
authors.initials: OP
authors.lastname: Eldevik
authors.forename: Paul L
authors.initials: PL
authors.lastname: Carson
mesh_terms: D000162:Acoustics; D000418:Albumins / Q000737:chemistry; D000818:Animals; D001769:Blood / Q000000981:diagnostic imaging; D002540:Cerebral Cortex / Q000098:blood supply*; D016461:Chemoembolization, Therapeutic / Q000379:methods; D003287:Contrast Media; D004285:Dogs; D004655:Emulsions / Q000737:chemistry; D005466:Fluorocarbons / Q000737:chemistry*; D007672:Kidney Cortex / Q000098:blood supply*; D014465:Ultrasonics; D014463:Ultrasonography
chemical_list: D000418:Albumins; D003287:Contrast Media; D004655:Emulsions; D005466:Fluorocarbons