title: Optimal configuration of respiratory navigator gating for the quantification of left ventricular strain using spiral cine displacement encoding with stimulated echoes (DENSE) MRI.
abstract: To determine the optimal respiratory navigator gating configuration for the quantification of left ventricular strain using spiral cine displacement encoding with stimulated echoes (DENSE) MRI.
  
  
  
  Two-dimensional spiral cine DENSE was performed on a 3 Tesla MRI using two single-navigator configurations (retrospective, prospective) and a combined "dual-navigator" configuration in 10 healthy adults and 20 healthy children. The adults also underwent breathhold DENSE as a reference standard for comparisons. Peak left ventricular strains, signal-to-noise ratio (SNR), and navigator efficiency were compared. Subjects also underwent dual-navigator gating with and without visual feedback to determine the effect on navigator efficiency.
  
  
  
  There were no differences in circumferential, radial, and longitudinal strains between navigator-gated and breathhold DENSE (P = 0.09-0.95) (as confidence intervals, retrospective: [-1.0%-1.1%], [-7.4%-2.0%], [-1.0%-1.2%]; prospective: [-0.6%-2.7%], [-2.8%-8.3%], [-0.3%-2.9%]; dual: [-1.6%-0.5%], [-8.3%-3.2%], [-0.8%-1.9%], respectively). The dual configuration maintained SNR compared with breathhold acquisitions (16 versus 18, P = 0.06). SNR for the prospective configuration was lower than for the dual navigator in adults (P = 0.004) and children (P < 0.001). Navigator efficiency was higher (P < 0.001) for both retrospective (54%) and prospective (56%) configurations compared with the dual configuration (35%). Visual feedback improved the dual configuration navigator efficiency to 55% (P < 0.001).
  
  
  
  When quantifying left ventricular strains using spiral cine DENSE MRI, a dual navigator configuration results in the highest SNR in adults and children. In adults, a retrospective configuration has good navigator efficiency without a substantial drop in SNR. Prospective gating should be avoided because it has the lowest SNR. Visual feedback represents an effective option to maintain navigator efficiency while using a dual navigator configuration.
  
  
  
  2 J. Magn. Reson. Imaging 2017;45:786-794.
authors.affiliation: Department of Electrical and Computer Engineering, University of Kentucky, Lexington, Kentucky, USA.|Department of Pediatrics, University of Kentucky, Lexington, KY, USA.
authors.forename: Sean M
authors.initials: SM
authors.lastname: Hamlet
authors.affiliation: Department of Pediatrics, University of Kentucky, Lexington, KY, USA.|Institute for Advanced Application, Geisinger Health System, Danville, Pennsylvania, USA.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Haggerty
authors.affiliation: Department of Pediatrics, University of Kentucky, Lexington, KY, USA.|Institute for Advanced Application, Geisinger Health System, Danville, Pennsylvania, USA.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Suever
authors.affiliation: Department of Pediatrics, University of Kentucky, Lexington, KY, USA.|Department of Biomedical Engineering, University of Kentucky, Lexington, Kentucky, USA.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Wehner
authors.affiliation: Department of Pediatrics, University of Kentucky, Lexington, KY, USA.
authors.forename: Kristin N
authors.initials: KN
authors.lastname: Andres
authors.affiliation: Department of Biomedical Engineering, University of Kentucky, Lexington, Kentucky, USA.
authors.forename: David K
authors.initials: DK
authors.lastname: Powell
authors.affiliation: MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, USA.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhong
authors.affiliation: Department of Pediatrics, University of Kentucky, Lexington, KY, USA.|Institute for Advanced Application, Geisinger Health System, Danville, Pennsylvania, USA.|Department of Biomedical Engineering, University of Kentucky, Lexington, Kentucky, USA.|Department of Physiology, University of Kentucky, Lexington, Kentucky, USA.|Department of Medicine, University of Kentucky, Lexington, Kentucky, USA.
authors.forename: Brandon K
authors.initials: BK
authors.lastname: Fornwalt
mesh_terms: D000293:Adolescent; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D055119:Elastic Modulus / Q000502:physiology; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D013314:Stress, Mechanical; D013718:Tensile Strength / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology*; D055815:Young Adult
keywords: DENSE; breathholds; navigator efficiency; respiratory navigator; signal-to-noise ratio; strain