Navigator artifact reduction in three-dimensional late gadolinium enhancement imaging of the atria

Magn Reson Med. 2014 Sep;72(3):779-85. doi: 10.1002/mrm.24967. Epub 2013 Oct 22.

Abstract

Purpose: Navigator-gated three-dimensional (3D) late gadolinium enhancement (LGE) imaging demonstrates scarring following ablation of atrial fibrillation. An artifact originating from the slice-selective navigator-restore pulse is frequently present in the right pulmonary veins (PVs), obscuring the walls and making quantification of enhancement difficult. We describe a simple sequence modification to greatly reduce or remove this artifact.

Methods: A navigator-gated inversion-prepared gradient echo sequence was modified so that the slice-selective navigator-restore pulse was delayed in time from the nonselective preparation (NAV-restore-delayed). Both NAV-restore-delayed and conventional 3D LGE acquisitions were performed in 11 patients and the results compared.

Results: One patient was excluded due to severe respiratory motion artifact in both NAV-restore-delayed and conventional acquisitions. Moderate to severe artifact was present in 9 of the remaining 10 patients using the conventional sequence and was considerably reduced when using the NAV-restore-delayed sequence (ostial PV to blood pool ratio, 1.7 ± 0.5 versus 1.1 ± 0.2, respectively [P < 0.0001]; qualitative artifact scores, 2.8 ± 1.1 versus 1.2 ± 0.4, respectively [P < 0.001]). While navigator signal-to-noise ratio was reduced with the NAV-restore-delayed sequence, respiratory motion compensation was unaffected.

Conclusions: Shifting the navigator-restore pulse significantly reduces or eliminates navigator artifact. This simple modification improves the quality of 3D LGE imaging and potentially aids late enhancement quantification in the atria.

Keywords: artifact; late gadolinium enhancement imaging; navigator; pulmonary veins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Artifacts
  • Contrast Media
  • Echo-Planar Imaging / methods*
  • Heart Atria / anatomy & histology*
  • Humans
  • Image Enhancement / methods
  • Image Processing, Computer-Assisted / methods
  • Imaging, Three-Dimensional / methods
  • Organometallic Compounds
  • Pulmonary Veins / anatomy & histology*
  • Signal-To-Noise Ratio

Substances

  • Contrast Media
  • Organometallic Compounds
  • gadobutrol