Pulmonary vein inflow artifact reduction for free‐breathing left atrium late gadolinium enhancement

Two‐dimensional “pencil‐beam” navigator, placed on the right hemidiaphragm, is used for free‐breathing late gadolinium enhancement of the left atrium in patients with atrial fibrillation. The pencil‐beam navigator creates an inflow artifact in the right pulmonary veins and atrial wall that may obscure local pulmonary vein and left atrium scars. To reduce this artifact, we propose a large slab right hemidiaphragm projection navigator that measures the respiratory motion while reducing the associated inflow artifact. Eighteen subjects underwent pulmonary vein late gadolinium enhancement using the pencil‐beam and projection navigator. Subjective inflow and respiratory motion artifact scores (1 = severe, 2 = moderate, 3 = mild, and 4 = none) from two blinded readers were compared. The artifact scores were 3.8 ± 0.4 and 2.1 ± 0.7 for the projection and pencil‐beam navigators, respectively (P < 0.001). Respiratory motion artifact scores were similar between the two techniques (3.0 ± 0.5 vs. 3.1 ± 0.5 for projection vs. pencil‐beam navigator). The proposed method greatly reduces the inflow artifact in free‐breathing pulmonary vein late gadolinium enhancement while allowing adequate respiratory motion compensation. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.