Three-dimensional late gadolinium-enhanced mr imaging of the left atrium: A comparison of spiral versus Cartesian k-space trajectories.

Abstract

To investigate the feasibility of high-resolution late gadolinium enhancement (LGE) imaging using a 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. Nine healthy subjects and ten 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.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). The feasibility of spiral LGE in the left atriumhas 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 to the Cartesian scan.