title: Modification of intensity distributions from large aperture ultrasound sources.
abstract: The Fresnel-Kirchhoff diffraction theory has been used to model the acoustic fields produced by a variety of apodizations of large aperture, axially symmetric ultrasound sources. The forms of resulting intensity maxima and their resulting suitability for surgical lesioning of tissues are compared, through a "lesioning capability" and a "focal efficiency." Although only modest changes in intensity distribution are possible, some may have applications in making arrays of lesions for control of focal cancer and other pathologies.
authors.affiliation: Carleton University, Ottawa, Canada.
authors.forename: R L
authors.initials: RL
authors.lastname: Clarke
mesh_terms: D000162:Acoustics; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging; D012984:Software; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods*