This study presents a multi-modality image registration method that evaluates left atrial scarring after radiofrequency
(RF) ablation for pulmonary vein (PV) isolation. Our group has recently developed a delayed enhancement magnetic
resonance imaging (DE-MRI) method with the potential to visualize and monitor non-invasively post-ablation scarring
in the left atrium and the PV ostia. We wished to compare the 3D configuration of scarring in the DE-MRI image and the
ablation points recorded by electroanatomical mapping (EAM) system, hypothesizing that scarring detected by DE-MRI
overlaps with ablation points recorded by the EAM system used in the procedure.
<b>Methods and Results:</b> Three data sets, DE-MRI images and pulmonary vein MR angiography (PV-MRA) images, and
EAM data (CARTO-XP, Biosense-Webster, Inc., Diamond Bar, CA) from a patient who underwent PV ablation, were
used for the multi-modal image registration. Contrast-enhanced MR imaging was performed 38 days after the ablation
procedure. PV-MRA and DE-MRI were fused by intensity-based rigid registration. Scar tissue was extracted from the
DE-MRI images using multiple threshold values. EAM data was further fused with segmented PV-MRA by the iterative
closest point algorithm (ICP). After registration, the distance from PV-MRA to the scar was 2.6 ± 2.1 mm, and from
ablation points to the surface of the scar was 2.5 ± 2.3 mm. The fused image demonstrates the 3D relationship between
the PV ostia, the scar and the EAM recording of ablation points.
<b>Conclusion:</b> Multimodal data fusion indicated that the scar tissue lesion after PV isolation showed good overlap with the