title: Determining attenuation properties of interfering fast and slow ultrasonic waves in cancellous bone.
abstract: Previous studies have shown that interference between fast waves and slow waves can lead to observed negative dispersion in cancellous bone. In this study, the effects of overlapping fast and slow waves on measurements of the apparent attenuation as a function of propagation distance are investigated along with methods of analysis used to determine the attenuation properties. Two methods are applied to simulated data that were generated based on experimentally acquired signals taken from a bovine specimen. The first method uses a time-domain approach that was dictated by constraints imposed by the partial overlap of fast and slow waves. The second method uses a frequency-domain log-spectral subtraction technique on the separated fast and slow waves. Applying the time-domain analysis to the broadband data yields apparent attenuation behavior that is larger in the early stages of propagation and decreases as the wave travels deeper. In contrast, performing frequency-domain analysis on the separated fast waves and slow waves results in attenuation coefficients that are independent of propagation distance. Results suggest that features arising from the analysis of overlapping two-mode data may represent an alternate explanation for the previously reported apparent dependence on propagation distance of the attenuation coefficient of cancellous bone.
authors.affiliation: Department of Physics, Washington University in Saint Louis, Saint Louis, Missouri 63130, USA.
authors.forename: Amber M
authors.initials: AM
authors.lastname: Nelson
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Hoffman
authors.forename: Christian C
authors.initials: CC
authors.lastname: Anderson
authors.forename: Mark R
authors.initials: MR
authors.lastname: Holland
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Nagatani
authors.forename: Katsunori
authors.initials: K
authors.lastname: Mizuno
authors.forename: Mami
authors.initials: M
authors.lastname: Matsukawa
authors.forename: James G
authors.initials: JG
authors.lastname: Miller
mesh_terms: D000818:Animals; D016477:Artifacts; D002417:Cattle; D003198:Computer Simulation; D005270:Femur Head / Q000000981:diagnostic imaging*; D008962:Models, Theoretical; D009038:Motion; D009716:Numerical Analysis, Computer-Assisted; D012815:Signal Processing, Computer-Assisted; D013016:Sound; D013997:Time Factors; D014465:Ultrasonics / Q000379:methods*; D014463:Ultrasonography