title: Effect of Carbon Dioxide on the Twinkling Artifact in Ultrasound Imaging of Kidney Stones: A Pilot Study.
abstract: Bone demineralization, dehydration and stasis put astronauts at increased risk of forming kidney stones in space. The color-Doppler ultrasound "twinkling artifact," which highlights kidney stones with color, can make stones readily detectable with ultrasound; however, our previous results suggest twinkling is caused by microbubbles on the stone surface which could be affected by the elevated levels of carbon dioxide found on space vehicles. Four pigs were implanted with kidney stones and imaged with ultrasound while the anesthetic carrier gas oscillated between oxygen and air containing 0.8% carbon dioxide. On exposure of the pigs to 0.8% carbon dioxide, twinkling was significantly reduced after 9-25 min and recovered when the carrier gas returned to oxygen. These trends repeated when pigs were again exposed to 0.8% carbon dioxide followed by oxygen. The reduction of twinkling caused by exposure to elevated carbon dioxide may make kidney stone detection with twinkling difficult in current space vehicles.
authors.affiliation: Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA. Electronic address: jcsimon@uw.edu.
authors.forename: Julianna C
authors.initials: JC
authors.lastname: Simon
authors.affiliation: Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.
authors.forename: Yak-Nam
authors.initials: YN
authors.lastname: Wang
authors.affiliation: Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.
authors.forename: Bryan W
authors.initials: BW
authors.lastname: Cunitz
authors.affiliation: Department of Radiology, University of Washington Medical Center, Seattle, Washington, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Thiel
authors.affiliation: Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.
authors.forename: Frank
authors.initials: F
authors.lastname: Starr
authors.affiliation: Department of Biostatistics, Indiana University Schools of Public Health and Medicine, Indianapolis, Indiana, USA.
authors.forename: Ziyue
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Bailey
mesh_terms: D000818:Animals; D016477:Artifacts; D002245:Carbon Dioxide / Q000008:administration & dosage / Q000494:pharmacology*; D004195:Disease Models, Animal; D007669:Kidney Calculi / Q000000981:diagnostic imaging*; D010865:Pilot Projects; D012680:Sensitivity and Specificity; D013552:Swine; D014463:Ultrasonography / Q000379:methods*
chemical_list: D002245:Carbon Dioxide
keywords: Bubbles; Carbon dioxide; Doppler; Kidney stones; Space; Twinkling artifact; Ultrasound