Feasibility of Swept Synthetic Aperture Ultrasound Imaging

Nick Bottenus, Will Long, Haichong K. Zhang, Marko Jakovljevic, David P. Bradway, Emad Boctor, Gregg E. Trahey

Research output: Contribution to journalArticle

Abstract

Ultrasound image quality is often inherently limited by the physical dimensions of the imaging transducer. We hypothesize that, by collecting synthetic aperture data sets over a range of aperture positions while precisely tracking the position and orientation of the transducer, we can synthesize large effective apertures to produce images with improved resolution and target detectability. We analyze the two largest limiting factors for coherent signal summation: aberration and mechanical uncertainty. Using an excised canine abdominal wall as a model phase screen, we experimentally observed an effective arrival time error ranging from 18.3 ns to 58 ns (root-mean-square error) across the swept positions. Through this clutter-generating tissue, we observed a 72.9% improvement in resolution with only a 3.75 dB increase in side lobe amplitude compared to the control case. We present a simulation model to study the effect of calibration and mechanical jitter errors on the synthesized point spread function. The relative effects of these errors in each imaging dimension are explored, showing the importance of orientation relative to the point spread function. We present a prototype device for performing swept synthetic aperture imaging using a conventional 1-D array transducer and ultrasound research scanner. Point target reconstruction error for a 44.2 degree sweep shows a reconstruction precision of 82.8 μm and 17.8 μm in the lateral and axial dimensions respectively, within the acceptable performance bounds of the simulation model. Improvements in resolution, contrast and contrast-to-noise ratio are demonstrated in vivo and in a fetal phantom.

Original languageEnglish (US)
Article number7398120
Pages (from-to)1676-1685
Number of pages10
JournalIEEE Transactions on Medical Imaging
Volume35
Issue number7
DOIs
Publication statusPublished - Jul 1 2016

    Fingerprint

Keywords

  • Aberration
  • beamforming
  • image quality
  • image resolution
  • mechanical tracking
  • synthetic aperture
  • ultrasound imaging

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Computer Science Applications
  • Radiological and Ultrasound Technology
  • Software

Cite this

Bottenus, N., Long, W., Zhang, H. K., Jakovljevic, M., Bradway, D. P., Boctor, E., & Trahey, G. E. (2016). Feasibility of Swept Synthetic Aperture Ultrasound Imaging. IEEE Transactions on Medical Imaging, 35(7), 1676-1685. [7398120]. https://doi.org/10.1109/TMI.2016.2524992