High Resolution MRI with a Spiral k-Space Trajectory: Atrial Wall Imaging and Late Gadolinium Enhancement for the Assessment of RF Ablation Lesion Transmurality in the Left Atrium.

Benjamin R. Knowles¹, Claudia Prieto¹, Reza Razavi¹, Tobias Schaeffter¹

Current late gadolinium enhancement (LGE) techniques for the visualisation of RF ablation lesions do not reach sufficient resolution to determine if ablation lesions are transmural, We have formed a strategy to assess ablation lesion transmurality using the combination of high resolution LGE and atrial wall imaging. Both MR scans use a spiral k-space trajectory as this trajectory is a highly efficient sampling scheme. Off-resonance effects are corrected for. High-resolution LGE images are compared to the lower resolution Cartesian LGE currently in use. Thickness measurements of the atrial wall and of the enhancing areas are conducted in order to assess transmurality.