Rapid time-resolved magnetic resonance angiography via a multiecho radial trajectory and GraDeS reconstruction

Magn Reson Med. 2013 Feb;69(2):346-59. doi: 10.1002/mrm.24256. Epub 2012 Apr 3.

Abstract

Contrast-enhanced magnetic resonance angiography is challenging due to the need for both high spatial and temporal resolution. A multishot trajectory composed of pseudo-random rotations of a single multiecho radial readout was developed. The trajectory is designed to give incoherent aliasing artifacts and a relatively uniform distribution of projections over all time scales. A field map (computed from the same data set) is used to avoid signal dropout in regions of substantial field inhomogeneity. A compressed sensing reconstruction using the GraDeS algorithm was used. Whole brain angiograms were reconstructed at 1-mm isotropic resolution and a 1.1-s frame rate (corresponding to an acceleration factor > 100). The only parameter which must be chosen is the number of iterations of the GraDeS algorithm. A larger number of iterations improves the temporal behavior at cost of decreased image signal-to-noise ratio. The resulting images provide a good depiction of the cerebral vasculature and have excellent arterial/venous separation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms*
  • Blood Flow Velocity
  • Brain / pathology
  • Brain / physiopathology*
  • Cerebrovascular Circulation*
  • Cerebrovascular Disorders / pathology
  • Cerebrovascular Disorders / physiopathology*
  • Computer Systems
  • Contrast Media
  • Gadolinium*
  • Humans
  • Image Enhancement / methods
  • Image Interpretation, Computer-Assisted / methods*
  • Magnetic Resonance Angiography / methods*
  • Reproducibility of Results
  • Sensitivity and Specificity

Substances

  • Contrast Media
  • Gadolinium