title: Second-order motion-compensated spin echo diffusion tensor imaging of the human heart.
abstract: OBJECTIVE
  Myocardial microstructure has been challenging to probe in vivo. Spin echo-based diffusion-weighted sequences allow for single-shot acquisitions but are highly sensitive to cardiac motion. In this study, the use of second-order motion-compensated diffusion encoding was compared with first-order motion-compensated diffusion-weighted imaging during systolic contraction of the heart.
  
  
  METHODS
  First- and second-order motion-compensated diffusion encoding gradients were incorporated into a triggered single-shot spin echo sequence. The effect of contractile motion on the apparent diffusion coefficients and tensor orientations was investigated in vivo from basal to apical level of the heart.
  
  
  RESULTS
  Second-order motion compensation was found to increase the range of systolic trigger delays from 30%-55% to 15%-77% peak systole at the apex and from 25%-50% to 15%-79% peak systole at the base. Diffusion tensor analysis yielded more physiological transmural distributions when using second-order motion-compensated diffusion tensor imaging.
  
  
  CONCLUSIONS
  Higher-order motion-compensated diffusion encoding decreases the sensitivity to cardiac motion, thereby enabling cardiac DTI over a wider range of time points during systolic contraction of the heart.
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland.
authors.forename: Christian T
authors.initials: CT
authors.lastname: Stoeck
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland.|Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom.
authors.forename: Constantin
authors.initials: C
authors.lastname: von Deuster
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland.
authors.forename: Martin
authors.initials: M
authors.lastname: Genet
authors.affiliation: Centre for Medical Imaging, University College London, London, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Atkinson
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland.|Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kozerke
mesh_terms: D057791:Cardiac Imaging Techniques / Q000379:methods*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D012815:Signal Processing, Computer-Assisted
keywords: diffusion tensor imaging; in vivo cardiac DTI; myocardial microstructure; spin-echo