Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Experimental methods D-PO01 - Featured Poster Session (ID 11) Poster

D-PO01-177 - Intra-procedural Guidance Of RF Ablative Treatment In The Left Atrium Using Non-contrast-enhanced MRI (ID 951)

Abstract

Background: Incompletely ablated tissue can lead to arrhythmia recurrence after RF catheter ablation (RFCA). Non-contrast-enhanced T1-weighted (T1w) MRI can indicate tissue ablated to necrosis, while real-time MRI (rtMRI) can be used for catheter navigation.
Objective: To apply rtMRI and T1w for catheter navigation, intra-procedural ablation lesion assessment and target guidance.
Methods: Left atrial RFCA was performed in five swine in a 1.5T MRI (Siemens Healthineers AG) using a sheath and catheter with four active tracking coils (Abbott Inc). Lesion images were acquired using T1w 3D respiratory-gated inversion recovery. Catheters were navigated using rtMRI with color highlighting of catheter coil signals. Each ablation was placed along the LA roof, followed by T1w imaging. Volume renderings of lesion enhancement were imported to the navigation display to guide further ablation. The first two lesions were separated by a gap, which was then targeted.
Results: rtMRI ran at 3 frames per second and 3D T1w required about 10 minutes for 44 slices. Figure shows T1w (top row) and rtMRI (bottom row), with catheter coils in red (distal), green, blue and yellow (proximal). Necrotic lesions were visibly enhanced in T1w (C,E,G, cyan arrows) and imported for navigation to additional targets (D,F,H). Image (F) shows the initial gap, which was then targeted using the integrated display for additional ablations (H).
Conclusion: We demonstrate two feedback mechanisms which may be of benefit in RFCA treatment: 1) rtMRI for catheter navigation with anatomical context, and 2) T1w imaging for assessment of lesions and guidance of ablation targeting, without need for contrast agent.

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