title: Finite beam-width ray model for geometric spectral broadening.
abstract: The purpose of the study was to compare measured spectral width and maximum frequency with that predicted from ray models of geometric spectral broadening. Zero and finite beam-width models were used. Spectral data were acquired from a string phantom using two commonly-used linear array systems. Beam width and Doppler aperture sizes were measured using a needle hydrophone. The results showed that the experimentally measured data agreed best with the finite beam-width model. The zero beam-width model was in error by up to 50% for calculated spectral width, and up to 10% for maximum frequency. It is concluded that spectral width and maximum frequency are best calculated using the finite beam-width model, and that ultrasound manufacturers could improve the variation in spectral broadening measured at different locations on a single machine by adjusting the aperture size to give a constant subtended angle and beam width.
authors.affiliation: Department of Medical Physics and Medical Engineering, Royal Infirmary, Edinburgh, UK. P.Hoskins@ed.ac.uk
authors.forename: P R
authors.initials: PR
authors.lastname: Hoskins
authors.forename: P J
authors.initials: PJ
authors.lastname: Fish
authors.forename: S D
authors.initials: SD
authors.lastname: Pye
authors.forename: T
authors.initials: T
authors.lastname: Anderson
mesh_terms: D008962:Models, Theoretical; D019047:Phantoms, Imaging; D014465:Ultrasonics