publications by Gregg E. Trahey.


Papers Published

  1. Smith, S.W. and Trahey, G.E. and Von Ramm, O.T., Phased array ultrasound imaging through planar tissue layers, Ultrasound Med. Biol. (UK), vol. 12 no. 3 (1986), pp. 229 - 43 [0301-5629(86)90314-5] .
    (last updated on 2007/04/13)

    Abstract:
    Conventional ultrasound imaging devices are designed based on the assumption of a homogeneous tissue medium of constant acoustic velocity=1540 m/sec. However, the body consists of tissue layers of varying thicknesses and velocities which range from 1470 m/sec in fat to 3200 m/sec in skull bone. Refraction effects from these layers degrade ultrasound image quality. In this paper, pulse-echo ultrasound imaging is modeled as imaging an organ of interest through an intervening planar tissue layer, such as liver through fat in the abdomen or brain through skull bone in the adult head. Refraction effects from planar tissue layer interfaces are analyzed using Snell's law and measured using phantoms. The authors also introduce an on-line phased array correction technique based on planar tissue layers to restore ultrasound image quality. The authors conclude that fat/organ planar interfaces do not degrade image quality significantly. However, refraction effects at a skull/brain planar interface degrades resolution and target acquisition and introduces geometric distortion. The authors' plane layer phased array correction technique significantly improves image quality in phantoms through lucite aberrators and improves adult cephalic ultrasound image quality when used through the top of the adult skull. The correction technique is robust even in the presence of inaccurate estimates of skull thickness

    Keywords:
    acoustic imaging;biomedical ultrasonics;patient diagnosis;