Arrhythmia substrate identification using wideband motion-corrected late gadolinium enhancement magnetic resonance imaging in a swine model of myocardial infarction with taped implantable cardioverter-defibrillators

Figures

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  Figure 1. Conventional 3-dimensional late gadolinium enhancement with and without an ICD present. Left top row: Images with an ICD present demonstrate hyperintensity artifacts in the basal anterior wall. Bottom left row: Images without artifacts. Right: Scarmap demonstrating hyperintensities owing to fibrosis (orange arrow) and ICD (teal arrow). ICD = implantable cardioverter-defibrillator.

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  Figure 2. Sample images from pig datasets. A: GRE cine and WB-MOCO LGE with magnitude and PSIR reconstruction with implantable cardioverter-defibrillator present. Teal arrows indicate hyperintensity artifact, white arrows indicate signal void and phase boundary artifacts from the implantable cardioverter-defibrillator, and purple arrows indicate regions of scar. Top row: Basal slice. Bottom row: Apical slice. B: Sample short-axis and long-axis reformatted images for 2D, 2D-WB, and 3D LGE. 2D and 3D LGE demonstrate high image quality, but low scar-blood contrast. WB-MOCO LGE demonstrates poorer image quality outside of regions of fibrosis, but higher scar-blood contrast with clearer depiction of infarct. Hyperintensity artifacts in WB-MOCO LGE are indicated with black arrows. 2D = 2-dimensional; 3D = 3-dimensional; GRE = gradient echo; FB-MOCO = free-breathing motion-corrected; LGE = late gadolinium enhancement; PSIR = phase-sensitive inversion recovery; WB-MOCO = wideband motion-corrected.

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  Figure 3. Sample 3D scarmaps for 2-dimensional WB-MOCO LGE (top row) and 3D LGE (bottom row) in a noninducible pig. Two-dimensional LGE was nondiagnostic in this pig. Despite the lack of ventricular tachycardia induction, a heterogeneous tissue corridor is present in WB-MOCO and 3D LGE and occurs at similar positions and transmurality (60% vs 70%). 3D = dimensional; LGE = late gadolinium enhancement; WB-MOCO = wideband motion-corrected.

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  Figure 4. Sample 3D scarmaps for 2D LGE (left), 3D LGE (center), and 2D WB-MOCO LGE (right) in an inducible pig with 12-lead ECG of induced ventricular tachycardia (far right). The electrophysiologist interpreted the ventricular tachycardia circuit exit as being in the inferolateral apical region of the heart, corresponding to segment 16 and the inferior portion of segment 16. 2D and 3D LGE heterogeneous tissue corridors align with this interpretation, but the WB-MOCO LGE heterogeneous tissue corridor does not. 2D = 2-dimensional; 3D = 3-dimensional; ECG = electrocardiogram; LGE = late gadolinium enhancement; WB-MOCO = wideband motion-corrected.

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  Figure 5. Violin plots of the number of total heterogeneous tissue corridors (HTCs) per subject, true-positive HTCs per subject, and false-positive HTCs per subject for each LGE sequence. Left: Significant differences in total HTC count were observed between 2D and WB-MOCO LGE and 3D and WB-MOCO LGE. Center: No significant differences were observed in true-positive HTC count between sequences. Right: No significant differences were observed in false-positive HTC count between sequences. 2D = 2-dimensional; 3D = 3-dimensional; LGE = late gadolinium enhancement; WB-MOCO = wideband motion-corrected.

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  Figure 6. Segmental heatmap of heterogeneous tissue corridors (HTCs) identified in LGE sequences compared with EP-identified segments with ventricular tachycardia circuit exit. Spatial localization of magnetic resonance imaging–derived HTCs agrees qualitatively with segments of ventricular tachycardia circuit exit, with WB-MOCO LGE demonstrating the most number of segments containing HTCs. 2D = 2-dimensional; 3D = 3-dimensional; EP = electrophysiological; LGE = late gadolinium enhancement; WB-MOCO = wideband motion-corrected.