title: A study of the display pixel-based focusing method in ultrasound imaging.
abstract: This paper presents a new beamforming technique, in which ultrasound waves are focused at the display pixels on the Cartesian coordinates, rather than sampling points located on the uniformly-separated scanlines on either the polar or Cartesian coordinates. Consequently, this method does not require a digital scan converter (DSC) and therefore completely eliminates the distortions due to the DSC. A new imaging system based on the proposed method is also presented, which is advantageous over conventional systems in hardware complexity, especially when high-density imaging is required. The new method can also be used effectively to achieve high frame rates for real-time 3D imaging and cardiac applications. To verify the proposed method, we modified a commercial ultrasound scanner and performed experiments with a 3.5 MHz convex array and a 7.5 MHz linear array. The experimental results with in vivo and in vitro data show that the proposed technique provides much smoother and finer images than the conventional dynamic focusing methods.
authors.affiliation: Department of Electronic Engineering, Sogang University, Medical Imaging Research Center, Seoul, Korea. heroica@medison.com
authors.forename: J S
authors.initials: JS
authors.lastname: Hwang
authors.forename: T K
authors.initials: TK
authors.lastname: Song
mesh_terms: D006801:Humans; D007091:Image Processing, Computer-Assisted; D019047:Phantoms, Imaging; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods