De-aliasing for signal restoration in Propeller MR imaging

Magn Reson Imaging. 2017 Feb:36:12-15. doi: 10.1016/j.mri.2016.10.016. Epub 2016 Oct 27.


Purpose: Objects falling outside of the true elliptical field-of-view (FOV) in Propeller imaging show unique aliasing artifacts. This study proposes a de-aliasing approach to restore the signal intensities in Propeller images without extra data acquisition.

Materials and methods: Computer simulation was performed on the Shepp-Logan head phantom deliberately placed obliquely to examine the signal aliasing. In addition, phantom and human imaging experiments were performed using Propeller imaging with various readouts on a 3.0 Tesla MR scanner. De-aliasing using the proposed method was then performed, with the first low-resolution single-blade image used to find out the aliasing patterns in all the single-blade images, followed by standard Propeller reconstruction. The Propeller images without and with de-aliasing were compared.

Results: Computer simulations showed signal loss at the image corners along with aliasing artifacts distributed along directions corresponding to the rotational blades, consistent with clinical observations. The proposed de-aliasing operation successfully restored the correct images in both phantom and human experiments.

Conclusion: The de-aliasing operation is an effective adjunct to Propeller MR image reconstruction for retrospective restoration of aliased signals.

Keywords: Aliasing artifacts; Propeller MR imaging; Signal re-distribution; Signal restoration.

Publication types

  • Technical Report

MeSH terms

  • Artifacts
  • Computer Simulation
  • Image Interpretation, Computer-Assisted / methods*
  • Image Processing, Computer-Assisted / methods*
  • Magnetic Resonance Imaging / methods*
  • Phantoms, Imaging
  • Retrospective Studies