Time-efficient three-dimensional transmural scar assessment provides relevant substrate characterization for ventricular tachycardia features and long-term recurrences in ischemic cardiomyopathy

Figures

• 

  Figure 1. Study flowchart. LGE-CMR: late gadolinium-enhanced cardiac magnetic resonance, ROI: region of interest, SI: signal intensity, VT: ventricular tachycardia.

• 

  Figure 2. Myocardial segmentation and generation of patient-specific scar-volume reconstructions in 3D models. (A,B) Identification and segmentation of the endocardium and epicardium of 2D (A) and 3D (B) LGE-CMR sequences from the same patient after initial automatic processing and fine manual segmentation. (C) Representative 3D models with scar volume reconstructions obtained from 2D and 3D LGE-CMR sequences in (A), (B). Acquisition shifts in 2D slices were corrected using the contours of the 3D-acquired shell.

• 

  Figure 3. Three-dimensional transmural-based scar assessment. (A) Long-axis and short-axis views of 2D and 3D LGE-CMR images from the same patient. (B) Resolution upsampling from 2D images and representative 3D-upsampled and 3D-acquired myocardial models. (C) Wall segmentation for scar transmurality analysis at different layers. (D) Representative transmurality map from a 3D-upsampled model with a short axis view at high-magnification to illustrate the 3D methodology for transmural-based scar assessment. LV: left ventricle.

• 

  Figure 4. Three-dimensional transmural scar assessment in patients. (A) Long axis view of representative 3D and 2D LGE-CMR images from the same patient. (B) Sample scar transmurality maps from the 3D and 2D LGE-CMR images showed in (A). (C) Myocardial thickness comparison between 2D and 3D LGE-CMR images. (D) Pearson correlation coefficients of scar transmurality, scar thickness and myocardial thickness between 3D-acquired and 3D-upsampled models in patients. LV: left ventricle.

• 

  Figure 5. Patient-specific scar volume reconstruction and correlation analysis with the cycle length of ventricular tachycardia episodes. (A) Scar volume comparisons between 3D- and 2D-LGE-CMR reconstructions. (B) Left ventricular (LV) myocardial volume comparisons between 3D- and 2D-LGE-CMR reconstructions. (C) Representative case of 2D- and 3D-LGE-CMR scar reconstructions and the associated ventricular tachycardia (VT) episodes on admission and during the electrophysiological (EP) study. (D,E) correlation analysis between the cycle length of spontaneous (D) /inducible (E) VT episodes and scar volumes from 3D (D) and 2D-LGE-CMR (E) reconstructions. RV: right ventricle.

• 

  Figure 6. Correlation analysis of transmural scar assessment with the cycle length of ventricular tachycardia episodes. (A) Representative 3D-acquired and 3D-upsampled models with transmurality (TsM) maps and the associated ventricular tachycardia (VT) episodes on admission and during the electrophysiological (EP) study. (B,C) Correlation analysis between the cycle length (CL) of spontaneous VT episodes and scar areas for wall transmurality < 0.2 (for 3D-upsampled models), < 0.1 (for 3D-acquired models) and < 0.2 [for original 2D LGE-CMR slices, in (C)]. (D) Pearson correlation coefficients between scar assessment at sequential TsM thresholds and the CL of spontaneous VT episodes. (E) 3D visualization of scar areas (in blue) using < 0.2 (for 3D-upsampled models) and < 0.1 (for 3D-acquired models) transmurality criteria in the sample case shown in (A).

• 

  Figure 7. Clinical value of transmural scar assessment in ventricular tachycardia recurrences after long-term follow up. (A) Scar areas quantification on 3D-acquired (left) and 3D-upsampled (right) models using < 0.1 and < 0.2 transmurality criteria, respectively, in patients with and without ventricular tachycardia (VT) recurrences. (B) Scar volumes quantification from 3D-acquired and 2D LGE-CMR sequences in patients with and without VT recurrences. (C,D) Scar tissue quantification in the regions with 3D transmurality < 0.1 (for 3D-acquired models) (C) and < 0.2 (for 3D-upsampled models) (D).