title: Automated quantitative analysis of the shift of frequency spectra generated by attenuated signals from contrast microbubbles.
abstract: The ultrasound-induced harmonic microbubble response spectrum is known to shift to lower frequencies with increasing tissue attenuation. We hypothesized that this shift could be reproducibly detected in received broadband radiofrequency spectra. We used an automatic Gaussian curve-fitting technique to measure the mean harmonic response generated by three different contrast agents at six incremental levels of attenuation. Analytical curve fitting identified a consistent, reproducible, and statistically significant shift in mean harmonic frequency with increasing attenuation. The presented method could be a step toward attenuation estimation by contrast harmonic imaging; optimization of harmonic signal reception by ultrasound systems; and, ultimately, automatic detection of contrast agents in tissue.
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
authors.forename: Virginia B
authors.initials: VB
authors.lastname: Bartleson
authors.forename: Kjetil
authors.initials: K
authors.lastname: Viggen
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Asanuma
authors.forename: Randall R
authors.initials: RR
authors.lastname: Kinnick
authors.forename: Marek
authors.initials: M
authors.lastname: Belohlavek
mesh_terms: D000162:Acoustics; D000465:Algorithms; D003287:Contrast Media; D008863:Microspheres; D014465:Ultrasonics
chemical_list: D003287:Contrast Media