title: Quantitative and qualitative analysis of in vivo Doppler signal enhancement of FS-069.
abstract: OBJECTIVE
  In vivo lifetime of ultrasound (US) contrast agents is still limited and thus a cause for ongoing investigations of new substances. The purpose of this study was to determine the time intensity changes of the Doppler signals obtained within the femoral vein after two different doses of a new microsphere-based ultrasound contrast agent.
  
  
  METHODS
  Twenty-four healthy male volunteers (mean age, 29; average weight, 76 kg) were included in this study. All underwent a triplex Doppler US examination after an intravenous bolus injection of 0.3 mL and 1.0 mL Optison. To examine the signal enhancement characteristics of this contrast agent the audio signal of the pulsed-wave spectral Doppler US was measured quantitatively using an audio analyzer, whereas velocity-encoded color Doppler examinations were scored qualitatively (score 0-3).
  
  
  RESULTS
  The mean maximal enhancement of the audio signal at a dose of 1.0 mL FS-069 was significantly higher than with a bolus of 0.3 mL FS-069 (29 +/- 2 dB vs. 26 dB +/- 2 dB, P < 0.001). The time-intensity curves after each bolus injection yielded an early peak (one minute after the injection) followed by constantly decreasing signal intensities. The scoring of the velocity-encoded color Doppler US revealed an optimal enhancement (score 2) for 3 minutes and 20 seconds (0.3 mL Optison) and for 6 minutes (1.0 mL Optison), respectively.
  
  
  CONCLUSIONS
  This study showed the capability of triplex Doppler ultrasound signal enhancement after Optison. 1.0 mL Optison proved to be the more appropriate dose for an optimal signal enhancement than 0.3 mL Optison.
authors.affiliation: Department of Radiology, Medical School and University Hospital of Graz, Austria. gottfried.schaffler@kfunigraz.ac.at
authors.forename: G J
authors.initials: GJ
authors.lastname: Schaffler
authors.forename: C H
authors.initials: CH
authors.lastname: Kugler
authors.forename: G
authors.initials: G
authors.lastname: Schreyer
authors.forename: G
authors.initials: G
authors.lastname: Graber
authors.forename: M M
authors.initials: MM
authors.lastname: Uggowitzer
mesh_terms: D000328:Adult; D000418:Albumins; D003287:Contrast Media; D005268:Femoral Vein / Q000000981:diagnostic imaging*; D005466:Fluorocarbons; D006801:Humans; D008297:Male; D008863:Microspheres; D008875:Middle Aged; D011446:Prospective Studies; D018608:Ultrasonography, Doppler / Q000379:methods*
chemical_list: D000418:Albumins; D003287:Contrast Media; C099458:FS 069; D005466:Fluorocarbons