Free-running simultaneous myocardial T1/T2 mapping and cine imaging with 3D whole-heart coverage and isotropic spatial resolution

Magn Reson Imaging. 2019 Nov;63:159-169. doi: 10.1016/j.mri.2019.08.008. Epub 2019 Aug 16.

Abstract

Purpose: To develop a free-running framework for 3D isotropic simultaneous myocardial T1/T2 mapping and cine imaging.

Methods: Continuous data acquisition with 3D golden angle radial trajectory is used in conjunction with T2 preparation of varying echo times and inversion recovery (IR) pulses to enable simultaneous myocardial T1/T2 mapping and cine imaging. Data acquisition is retrospectively synchronized with ECG signal, and 1D respiratory self-navigation signal is extracted from the k-space center of all radial spokes. Respiratory binning is performed based on the estimated respiratory signal, enabling estimation and correction of 3D translational respiratory motion. Using high-dimensionality patch-based undersampled reconstruction with dictionary-based low-rank inversion, whole-heart T1/T2 maps and cine images can be generated with 2 mm isotropic spatial resolution. The proposed technique was validated in a standardised phantom and ten healthy subjects in comparison to conventional 2D imaging techniques.

Results: Phantom T1 and T2 measurements demonstrated good agreement with 2D spin echo techniques. Septal T1 estimated with the proposed technique (1185.6 ± 49.8 ms) was longer than with a conventional breath-hold 2D IR-prepared sequence (1044.3 ± 26.7 ms), whereas T2 measurements (47.6 ± 2.5 ms) were lower than a breath-hold 2D gradient spin echo sequence (52.0 ± 1.8 ms). Precision of the proposed 3D mapping was higher than conventional 2D mapping techniques. Ejection fraction measured with the proposed 3D approach (63.8 ± 6.8%) agreed well with conventional breath-held multi-slice 2D cine (62.3 ± 6.4%).

Conclusions: The proposed technique provides co-registered 3D T1/T2 maps and cine images with isotropic spatial resolution from a single free-breathing scan, thereby providing a promising imaging tool for whole-heart myocardial tissue characterization and functional evaluation.

Keywords: 3D radial; Cine imaging; Joint T1/T2; Myocardial T1 mapping; Myocardial T2 mapping.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Breath Holding
  • Electrocardiography / methods*
  • Female
  • Heart / diagnostic imaging*
  • Humans
  • Image Interpretation, Computer-Assisted / methods*
  • Imaging, Three-Dimensional / methods*
  • Magnetic Resonance Imaging, Cine / methods*
  • Male
  • Motion
  • Phantoms, Imaging
  • Reproducibility of Results
  • Retrospective Studies