title: Three-dimensional late gadolinium-enhanced MR imaging of the left atrium: a comparison of spiral versus Cartesian k-space trajectories.
abstract: OBJECTIVE
  To investigate the feasibility of high-resolution late gadolinium enhancement (LGE) imaging using a three-dimensional (3D) stack of spirals k-space trajectory for the detection of left atrial (LA) ablation lesions. LGE imaging inherently suffers from low SNR, so that improvements in spatial resolution and imaging time are challenging. The spiral trajectory offers greater acquisition efficiency, and this is used for increased spatial resolution.
  
  
  METHODS
  Nine healthy subjects and 10 pre/post pulmonary vein isolation patients underwent an MRI examination. A Cartesian 3D inversion-recovery gradient-echo sequence was performed followed by a 3D inversion-recovery gradient-echo with a spiral trajectory. Image quality, fat suppression and sharpness were graded by expert cardiologists.
  
  
  RESULTS
  No statistical significance was determined for SNR or image quality between the Cartesian and spiral images; however, fat suppression was significantly improved with the spiral approach (P = 0.002). The enhancement in the Cartesian scan was found to have significantly higher CNR (P = 0.02).
  
  
  CONCLUSIONS
  The feasibility of spiral LGE in the left atrium has been demonstrated. Similar image quality and sharpness were observed with both acquisitions. This spiral sequence has sub-millimeter spatial resolution improved fat suppression and maintains a comparable level of SNR compared with the Cartesian scan.
authors.affiliation: Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom; Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Knowles
authors.forename: Dana C
authors.initials: DC
authors.lastname: Peters
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Clough
authors.forename: Reza
authors.initials: R
authors.lastname: Razavi
authors.forename: Tobias
authors.initials: T
authors.lastname: Schaeffter
authors.forename: Claudia
authors.initials: C
authors.lastname: Prieto
mesh_terms: D000368:Aged; D004867:Equipment Design; D005260:Female; D005682:Gadolinium / Q000737:chemistry*; D006325:Heart Atria / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D011667:Pulmonary Veins / Q000473:pathology; D011846:Radio Waves; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D013997:Time Factors
chemical_list: D005682:Gadolinium
keywords: Cartesian; late gadolinium enhancement; left atrium; spiral