Optimal Dual-VENC Unwrapping in Phase-Contrast MRI

IEEE Trans Med Imaging. 2019 May;38(5):1263-1270. doi: 10.1109/TMI.2018.2882553. Epub 2018 Nov 21.

Abstract

Dual-VENC strategies have been proposed to improve the velocity-to-noise ratio in phase-contrast MRI. However, they are based on aliasing-free high-VENC data. The aim of this paper is to propose a dual-VENC velocity estimation method allowing high-VENC aliased data. For this purpose, we reformulate the phase-contrast velocity as a least squares estimator, providing a natural framework for including multiple encoding gradient measurements. By analyzing the mathematical properties of both single- and dual-VENC problems, we can justify theoretically high/low-VENC ratios such that the aliasing velocity can be minimized. The resulting reconstruction algorithm was assessed using three types of data: numerical, experimental, and volunteers. In clinical practice, this method would allow shorter examination times by avoiding tedious adaptation of VENC values by repeated scans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Aorta, Thoracic / diagnostic imaging
  • Aorta, Thoracic / physiology
  • Blood Flow Velocity / physiology*
  • Humans
  • Image Processing, Computer-Assisted / methods*
  • Magnetic Resonance Imaging / methods*
  • Phantoms, Imaging