Figure 1.
Architecture of Proposed Methodology.
Figure 1.
Architecture of Proposed Methodology.
Figure 2.
Contrast Stretched Colour Image.
Figure 2.
Contrast Stretched Colour Image.
Figure 3.
Gamma Correction.
Figure 3.
Gamma Correction.
Figure 4.
Parametric Image Transformation.
Figure 4.
Parametric Image Transformation.
Figure 5.
Original Inception Module (Adopted from [
29]).
Figure 5.
Original Inception Module (Adopted from [
29]).
Figure 6.
Working Principle of 3-Layer CNN (Adopted from [
50]).
Figure 6.
Working Principle of 3-Layer CNN (Adopted from [
50]).
Figure 7.
Layers in DenseNet169 (Adopted from [
51]).
Figure 7.
Layers in DenseNet169 (Adopted from [
51]).
Figure 8.
Architecture of EfficientNet-B2 (Adopted from [
53]).
Figure 8.
Architecture of EfficientNet-B2 (Adopted from [
53]).
Figure 9.
Validation and Training metrics for InceptionV3. (a) Validation and Training Accuracy for InceptionV3. (b) Validation and Training Loss for InceptionV3.
Figure 9.
Validation and Training metrics for InceptionV3. (a) Validation and Training Accuracy for InceptionV3. (b) Validation and Training Loss for InceptionV3.
Figure 10.
Validation and Training Metrics for 3-layer CNN. (a) Validation and Training Accuracy for 3-layer CNN. (b) Validation and Training Loss for 3-layer CNN.
Figure 10.
Validation and Training Metrics for 3-layer CNN. (a) Validation and Training Accuracy for 3-layer CNN. (b) Validation and Training Loss for 3-layer CNN.
Figure 11.
Validation and Training Metrics for DenseNet169. (a) Validation and Training Accuracy for DenseNet169. (b) Validation and Training Loss for DenseNet169.
Figure 11.
Validation and Training Metrics for DenseNet169. (a) Validation and Training Accuracy for DenseNet169. (b) Validation and Training Loss for DenseNet169.
Figure 12.
Validation and Training Metrics for EfficientNetB2. (a) Validation and Training Accuracy for EfficientNetB2. (b) Validation and Training Loss for EfficientNetB2.
Figure 12.
Validation and Training Metrics for EfficientNetB2. (a) Validation and Training Accuracy for EfficientNetB2. (b) Validation and Training Loss for EfficientNetB2.
Figure 13.
Confusion Matrix for InceptionV3, 3-layer CNN, DenseNet169, and EfficientNetB2.
Figure 13.
Confusion Matrix for InceptionV3, 3-layer CNN, DenseNet169, and EfficientNetB2.
Figure 14.
The left panel displays the ROC curve illustrating the classifier’s ability to distinguish between Leigh’s disease and non-Leigh cases, achieving an AUC of 1.00, indicating perfect discrimination with no overlap between classes. The right panel shows the calibration curve, which assesses the reliability of the predicted probabilities. The curve closely aligns with the diagonal (perfect calibration), and a Brier Score of 0.000 confirms a high confidence level in the alignment between the predicted and actual class distributions. Together, these results demonstrate that the model is highly accurate and well-calibrated, mitigating overfitting and trivial classification concerns, and reinforcing its clinical applicability for cardiac risk assessment in Leigh’s disease.
Figure 14.
The left panel displays the ROC curve illustrating the classifier’s ability to distinguish between Leigh’s disease and non-Leigh cases, achieving an AUC of 1.00, indicating perfect discrimination with no overlap between classes. The right panel shows the calibration curve, which assesses the reliability of the predicted probabilities. The curve closely aligns with the diagonal (perfect calibration), and a Brier Score of 0.000 confirms a high confidence level in the alignment between the predicted and actual class distributions. Together, these results demonstrate that the model is highly accurate and well-calibrated, mitigating overfitting and trivial classification concerns, and reinforcing its clinical applicability for cardiac risk assessment in Leigh’s disease.
Figure 15.
Morphological biomarker comparison between patients with Leigh’s disease and non-diseased controls based on cardiac MRI-derived features. Area, aspect ratio, and extent were computed from segmented cardiac regions. Error bars indicate standard deviation.
Figure 15.
Morphological biomarker comparison between patients with Leigh’s disease and non-diseased controls based on cardiac MRI-derived features. Area, aspect ratio, and extent were computed from segmented cardiac regions. Error bars indicate standard deviation.
Figure 16.
This figure illustrates the structural and computational evidence of cardiac involvement in Leigh’s disease through cardiac MRI, morphological quantification, segmentation, and model explainability. In (a), cardiac MRI scans from patients with Leigh’s disease reveal evident morphological abnormalities, including thickened ventricular walls, loss of myocardial uniformity, and asymmetric chamber geometry—hallmarks of hypertrophic cardiomyopathy secondary to mitochondrial dysfunction. In contrast, the control image shows preserved ventricular shape and consistent myocardial texture. A binary segmentation of the left ventricle shows an extracted area of 212,097 pixels2, reflecting pathological myocardial expansion. In (b), the anatomical regions of the left atrium (LA) and left ventricle (LV) are highlighted, with visible LV enlargement and subtle LA compression. Grad-CAM heatmaps across both subfigures reveal high activation in the anterolateral or anteroseptal segments of the myocardium, confirming that the deep learning model localised structurally compromised regions relevant for risk stratification. These visualisations support cardiac imaging and AI-based interpretation to stratify cardiac complications in Leigh’s disease.
Figure 16.
This figure illustrates the structural and computational evidence of cardiac involvement in Leigh’s disease through cardiac MRI, morphological quantification, segmentation, and model explainability. In (a), cardiac MRI scans from patients with Leigh’s disease reveal evident morphological abnormalities, including thickened ventricular walls, loss of myocardial uniformity, and asymmetric chamber geometry—hallmarks of hypertrophic cardiomyopathy secondary to mitochondrial dysfunction. In contrast, the control image shows preserved ventricular shape and consistent myocardial texture. A binary segmentation of the left ventricle shows an extracted area of 212,097 pixels2, reflecting pathological myocardial expansion. In (b), the anatomical regions of the left atrium (LA) and left ventricle (LV) are highlighted, with visible LV enlargement and subtle LA compression. Grad-CAM heatmaps across both subfigures reveal high activation in the anterolateral or anteroseptal segments of the myocardium, confirming that the deep learning model localised structurally compromised regions relevant for risk stratification. These visualisations support cardiac imaging and AI-based interpretation to stratify cardiac complications in Leigh’s disease.
![Cardiogenetics 15 00019 g016]()
Figure 17.
Cardiac MRI analysis demonstrating structural abnormalities and model-based detection in Leigh’s disease. (a) Short-axis MRI shows LV wall thickening consistent with hypertrophic remodelling. (b) Control subject displays preserved LV morphology with a clearly defined anteroseptal region. (c) Segmentation output delineates myocardial boundaries with an estimated area of 212,097 px2. (d) Grad-CAM activation highlights attention on the anteroseptal wall, suggesting learned pathologic focus. This figure supports the explainability and clinical relevance of the proposed model.
Figure 17.
Cardiac MRI analysis demonstrating structural abnormalities and model-based detection in Leigh’s disease. (a) Short-axis MRI shows LV wall thickening consistent with hypertrophic remodelling. (b) Control subject displays preserved LV morphology with a clearly defined anteroseptal region. (c) Segmentation output delineates myocardial boundaries with an estimated area of 212,097 px2. (d) Grad-CAM activation highlights attention on the anteroseptal wall, suggesting learned pathologic focus. This figure supports the explainability and clinical relevance of the proposed model.
Figure 18.
Diagnostic imaging workflow for Leigh’s disease. This schematic outlines the stepwise cardiac evaluation process, beginning with initial echocardiographic assessment. In cases where echocardiographic findings are inconclusive or insufficient—common in Leigh’s disease due to subtle myocardial changes—cardiac MRI (CMRI) is recommended for its superior spatial resolution and tissue characterization capabilities. Advanced CMRI enables the identification of myocardial fibrosis, ventricular dysfunction, and hypertrophic changes that may be overlooked with ultrasound-based methods, thereby enhancing diagnostic precision and guiding subsequent clinical decisions for treatment and monitoring.
Figure 18.
Diagnostic imaging workflow for Leigh’s disease. This schematic outlines the stepwise cardiac evaluation process, beginning with initial echocardiographic assessment. In cases where echocardiographic findings are inconclusive or insufficient—common in Leigh’s disease due to subtle myocardial changes—cardiac MRI (CMRI) is recommended for its superior spatial resolution and tissue characterization capabilities. Advanced CMRI enables the identification of myocardial fibrosis, ventricular dysfunction, and hypertrophic changes that may be overlooked with ultrasound-based methods, thereby enhancing diagnostic precision and guiding subsequent clinical decisions for treatment and monitoring.
Figure 19.
CMRI Imaging Output in Leigh’s Disease. The diagram illustrates common cardiac abnormalities detectable by CMRI but often missed by echocardiography. Left Ventricular Hypertrophy (LVH) and regions of delayed gadolinium enhancement (fibrosis) reflect early myocardial remodelling and subclinical tissue damage, respectively. These indicators are critical for diagnosing cardiomyopathy in Leigh’s disease patients, especially when echocardiographic results are inconclusive.
Figure 19.
CMRI Imaging Output in Leigh’s Disease. The diagram illustrates common cardiac abnormalities detectable by CMRI but often missed by echocardiography. Left Ventricular Hypertrophy (LVH) and regions of delayed gadolinium enhancement (fibrosis) reflect early myocardial remodelling and subclinical tissue damage, respectively. These indicators are critical for diagnosing cardiomyopathy in Leigh’s disease patients, especially when echocardiographic results are inconclusive.
Figure 20.
Grad-CAM interpretability analysis showing original MRI input (left), focused heatmap (centre), and superimposed visualisation (right). The highlighted regions correlate with clinically relevant brain structures often affected in Leigh’s disease, supporting model transparency and localisation capacity in deep learning-based risk stratification.
Figure 20.
Grad-CAM interpretability analysis showing original MRI input (left), focused heatmap (centre), and superimposed visualisation (right). The highlighted regions correlate with clinically relevant brain structures often affected in Leigh’s disease, supporting model transparency and localisation capacity in deep learning-based risk stratification.
Figure 21.
Side-by-side feature embedding visualizations of cardiac MRI images using VGG16-extracted features projected via PCA, t-SNE, and UMAP. Distinct clustering of Leigh’s disease and non-Leigh samples validates the model’s ability to capture diagnostic features.
Figure 21.
Side-by-side feature embedding visualizations of cardiac MRI images using VGG16-extracted features projected via PCA, t-SNE, and UMAP. Distinct clustering of Leigh’s disease and non-Leigh samples validates the model’s ability to capture diagnostic features.
Table 1.
Comparative analysis and summary.
Table 1.
Comparative analysis and summary.
Author | Objective | Dataset | Accuracy |
---|
Kazemivalipour et al. [39] | Classification and segmentation of brain tumors | 41 MRI images | 98% |
Kharrat et al. [40] | Classification of brain tumour into normal, malignant, and benign | 83 MRI images | 98.14% |
Deepak et al. [9] | Classification of glioma, pituitary, and meningioma | 3064 MRI images | 98% |
Das et al. [8] | Categorization of brain tumors | 3064 MRI images | 94.39% |
Paul et al. [41] | Classification of brain tumors | 3064 MRI images | 91.43% |
Hemanth et al. [42] | Classification of normal and abnormal MR brain images | 220 MR images | 94.5% |
Table 2.
Dataset description.
Table 2.
Dataset description.
Classes | Number of Images | Number of Augmented Images |
---|
Leigh’s Disease | 80 | 2000 |
No Leigh’s Disease | 91 | 2000 |
Total | 171 | 4000 |
Table 3.
The Table of Experimental Setup.
Table 3.
The Table of Experimental Setup.
Model | InceptionV3, 3-layer CNN, DenseNet169, EfficientNetB2 |
Number of Classes | Leigh’s Disease, No Leigh’s Disease |
Image Size | 224 × 224 |
Optimizer | Adam |
Batch Size | 64 |
Loss Function | Sparse Categorical Crossentropy |
Table 4.
Validation and Training Accuracy for Inceptionv3.
Table 4.
Validation and Training Accuracy for Inceptionv3.
Epoch | Validation Accuracy | Training Accuracy |
---|
1 | 0.7917 | 0.6518 |
2 | 0.9323 | 0.8314 |
3 | 0.8802 | 0.8867 |
4 | 0.8958 | 0.8968 |
5 | 0.8854 | 0.9113 |
6 | 0.9375 | 0.9066 |
7 | 0.9688 | 0.9353 |
8 | 0.9349 | 0.9438 |
9 | 0.9531 | 0.8873 |
10 | 0.9609 | 0.9028 |
11 | 0.9245 | 0.9400 |
12 | 0.9635 | 0.9463 |
13 | 0.9583 | 0.9732 |
14 | 0.9401 | 0.9527 |
15 | 0.9635 | 0.9457 |
Table 5.
Validation and Training Loss for Inceptionv3.
Table 5.
Validation and Training Loss for Inceptionv3.
Epoch | Validation Loss | Training Loss |
---|
1 | 0.7413 | 12.0866 |
2 | 0.2298 | 0.6635 |
3 | 0.2966 | 0.3161 |
4 | 0.2970 | 0.2953 |
5 | 0.3494 | 0.2371 |
6 | 0.1818 | 0.2509 |
7 | 0.0984 | 0.1576 |
8 | 0.1852 | 0.1358 |
9 | 0.1293 | 0.4085 |
10 | 0.0983 | 0.2932 |
11 | 0.2050 | 0.1662 |
12 | 0.0926 | 0.1371 |
13 | 0.1073 | 0.0743 |
14 | 0.1659 | 0.1300 |
15 | 0.0945 | 0.1378 |
Table 6.
Validation and Training Accuracy for 3-layer CNN.
Table 6.
Validation and Training Accuracy for 3-layer CNN.
Epoch | Validation Accuracy | Training Accuracy |
---|
1 | 0.6745 | 0.6544 |
2 | 0.7760 | 0.7841 |
3 | 0.8099 | 0.8182 |
4 | 0.8542 | 0.8466 |
5 | 0.8932 | 0.8684 |
6 | 0.9062 | 0.8886 |
7 | 0.9219 | 0.8965 |
8 | 0.9167 | 0.9078 |
9 | 0.9453 | 0.9239 |
10 | 0.8698 | 0.9182 |
11 | 0.9427 | 0.9129 |
12 | 0.9505 | 0.9438 |
13 | 0.9583 | 0.9460 |
14 | 0.9714 | 0.9646 |
15 | 0.9635 | 0.9675 |
Table 7.
Validation and Training Loss for 3-layer CNN.
Table 7.
Validation and Training Loss for 3-layer CNN.
Epoch | Validation Loss | Training Loss |
---|
1 | 0.4813 | 178.3378 |
2 | 0.3998 | 0.4334 |
3 | 0.3313 | 0.3764 |
4 | 0.3007 | 0.3342 |
5 | 0.2307 | 0.2846 |
6 | 0.2194 | 0.2575 |
7 | 0.2098 | 0.2448 |
8 | 0.1872 | 0.2261 |
9 | 0.1599 | 0.1725 |
10 | 0.2805 | 0.1906 |
11 | 0.1566 | 0.2231 |
12 | 0.1564 | 0.1382 |
13 | 0.1474 | 0.1327 |
14 | 0.1088 | 0.0962 |
15 | 0.1566 | 0.0839 |
Table 8.
Validation and Training Accuracy for DenseNet169.
Table 8.
Validation and Training Accuracy for DenseNet169.
Epoch | Validation Accuracy | Training Accuracy |
---|
1 | 0.9349 | 0.8722 |
2 | 0.9714 | 0.9182 |
3 | 0.9766 | 0.9403 |
4 | 0.9740 | 0.9470 |
5 | 0.9896 | 0.9451 |
6 | 0.9844 | 0.9416 |
7 | 0.9844 | 0.9596 |
8 | 0.9766 | 0.9593 |
9 | 0.9818 | 0.9650 |
10 | 0.9870 | 0.9583 |
11 | 0.9870 | 0.9640 |
12 | 0.9870 | 0.9694 |
13 | 0.9896 | 0.9700 |
14 | 0.9870 | 0.9643 |
15 | 0.9792 | 0.9700 |
Table 9.
Validation and Training Loss for DenseNet169.
Table 9.
Validation and Training Loss for DenseNet169.
Epoch | Validation Loss | Training Loss |
---|
1 | 0.2596 | 0.3373 |
2 | 0.0922 | 0.2034 |
3 | 0.0685 | 0.1648 |
4 | 0.0641 | 0.1324 |
5 | 0.0474 | 0.1376 |
6 | 0.0476 | 0.1344 |
7 | 0.0440 | 0.1108 |
8 | 0.0541 | 0.1068 |
9 | 0.0413 | 0.0915 |
10 | 0.0349 | 0.0958 |
11 | 0.0329 | 0.0948 |
12 | 0.0317 | 0.0798 |
13 | 0.0318 | 0.0848 |
14 | 0.0285 | 0.0815 |
15 | 0.0370 | 0.0850 |
Table 10.
Validation and Training Loss for EfficientNetB2.
Table 10.
Validation and Training Loss for EfficientNetB2.
Epoch | Validation Loss | Training Loss |
---|
1 | 0.1312 | 0.8622 |
2 | 0.0818 | 0.0961 |
3 | 0.1006 | 0.0609 |
4 | 0.0532 | 0.0560 |
5 | 0.0349 | 0.0377 |
6 | 0.0160 | 0.0229 |
7 | 0.0148 | 0.0244 |
8 | 0.0169 | 0.0205 |
9 | 0.0227 | 0.0342 |
10 | 0.0131 | 0.0243 |
11 | 0.0282 | 0.0286 |
12 | 0.0077 | 0.0313 |
13 | 0.0110 | 0.0128 |
14 | 0.0029 | 0.0128 |
15 | 0.0021 | 0.0159 |
Table 11.
Accuracy Comparison Across Models.
Table 11.
Accuracy Comparison Across Models.
Model | Accuracy (%) | Error Rate (%) | Validation Accuracy (%) |
---|
InceptionV3 | 94.6 | 5.4 | 94.2 |
3-layer CNN | 96.8 | 3.2 | 96.5 |
DenseNet169 | 98.2 | 1.8 | 98.0 |
EfficientNetB2 | 99.1 | 0.9 | 99.0 |
Table 12.
Performance Metrics for Models.
Table 12.
Performance Metrics for Models.
Model | Accuracy (%) | Precision (%) | Recall (%) | F1-Score (%) |
---|
InceptionV3 | 94.2 | 93.8 | 94.4 | 94.1 |
3-layer CNN | 95.6 | 95.3 | 95.7 | 95.5 |
DenseNet169 | 98.4 | 98.1 | 98.6 | 98.3 |
EfficientNetB2 | 99.2 | 99.0 | 99.3 | 99.1 |
Table 13.
5-Fold Cross-Validation Sensitivity Analysis for Leigh’s Disease Detection.
Table 13.
5-Fold Cross-Validation Sensitivity Analysis for Leigh’s Disease Detection.
Metric | Value |
---|
Number of Folds | 5 |
Mean Sensitivity | 1.0000 |
Sensitivity Standard Deviation | 0.0000 |
Table 14.
Overall Model Accuracy Comparison.
Table 14.
Overall Model Accuracy Comparison.
Deep Learning Model | Test Accuracy | Accuracy |
---|
InceptionV3 | 0.95 | 0.92 |
3-layer CNN | 0.97 | 0.97 |
DenseNet169 | 0.98 | 0.97 |
EfficientNetB2 | 0.99 | 0.99 |
Table 15.
Analysis of Ensemble Learning.
Table 15.
Analysis of Ensemble Learning.
Model Name | Test Accuracy | Accuracy |
---|
EfficientNetB2 + DenseNet169 | 100% | 99.88% |
EfficientNetB2 + InceptionV3 | 100% | 99.97% |
DenseNet169 + CNN | 100% | 98.96% |
InceptionV3 + CNN | 99.66% | 99.83% |
EfficientNetB2 + CNN | 99.32% | 99.97% |
Inception + Xception | 95.98% | 96.43% |
ResNet50 + DenseNet | 100% | 100% |
EfficientNetB2 + DenseNet169 + CNN | 99.76% | 99.8% |
ResNet50 + InceptionV3 + DenseNet169 | 99.78% | 99.56% |
CNN + InceptionV3 + DenseNet169 | 99.76% | 99.98% |
Table 16.
Model-by-Model Comparison of Proposed Framework with State-of-the-Art Methods in Cardiac MRI Classification.
Table 16.
Model-by-Model Comparison of Proposed Framework with State-of-the-Art Methods in Cardiac MRI Classification.
Study | Model | Classification Task | Accuracy |
---|
Our Study (2025) | InceptionV3 | Leigh’s disease vs. healthy controls | 95.3% |
Our Study (2025) | 3-layer CNN | Leigh’s disease vs. healthy controls | 93.7% |
Our Study (2025) | DenseNet169 | Leigh’s disease vs. healthy controls | 96.8% |
Our Study (2025) | EfficientNetB2 | Leigh’s disease vs. healthy controls | 97.4% |
Our Study (2025) | EfficientNetB2 + DenseNet169 | Leigh’s disease vs. healthy controls | 97.9% |
Our Study (2025) | EfficientNetB2 + InceptionV3 | Leigh’s disease vs. healthy controls | 97.6% |
Our Study (2025) | DenseNet169 + CNN | Leigh’s disease vs. healthy controls | 96.4% |
Our Study (2025) | InceptionV3 + CNN | Leigh’s disease vs. healthy controls | 96.1% |
Our Study (2025) | EfficientNetB2 + CNN | Leigh’s disease vs. healthy controls | 96.9% |
Our Study (2025) | Inception + Xception | Leigh’s disease vs. healthy controls | 95.7% |
Our Study (2025) | ResNet50 + DenseNet | Leigh’s disease vs. healthy controls | 96.2% |
Our Study (2025) | EfficientNetB2 + DenseNet169 + CNN | Leigh’s disease vs. healthy controls | 98.5% |
Our Study (2025) | ResNet50 + InceptionV3 + DenseNet169 | Leigh’s disease vs. healthy controls | 98.3% |
Our Study (2025) | CNN + InceptionV3 + DenseNet169 | Leigh’s disease vs. healthy controls | 98.1% |
Slobodzian et al. (2024) [58] | U-Net + ResNet (multi-stage) | Multi-class: HCM, MI, DCM | 97.2% |
Lourenço et al. (2020) [59] | DNN integrating DE-CMR + clinical data | Myocardial disease vs. control | 95–100% |
Lim et al. (2021) [60] | CardiSort (2-head CNN) | Imaging sequence and view classification | Up to 98.1% |
Paciorek et al. (2024) [61] | DenseNet-161 | Cardiac pathologies vs. healthy controls using LGE PSIR MRI | 88% |
Isensee et al. (2017) [62] | Ensemble of U-Net architectures + MLP | Multi-class cardiac disease classification using cine MRI | 94% |
Xiong et al. (2020) [63] | Dual CNNs (ROI localization + segmentation) | Left atrium segmentation in LGE-MRI | Dice score: 93.2% |
Avendi et al. (2016) [64] | CNN + RNN | Left ventricle segmentation + function classification | 94.6% |
Jacob et al. (2025) [65] | Variational Autoencoder | Multi-class: NORM, DCM, HCM, IHD | 77.8% |
Liu et al. (2023) [66] | Successive Subspace Learning (SSL) | Multi-class: Healthy, DCM, HCM, MI, RV | 95.1% |
Shad et al. (2023) [67] | Self-supervised contrastive model | 35 cardiovascular conditions (multi-label) | Not specified |
Table 17.
Statistical Morphological Summary of Cardiac MRI Images.
Table 17.
Statistical Morphological Summary of Cardiac MRI Images.
Label | Area | Aspect Ratio | Extent |
---|
Mean | Std | Mean | Std | Mean | Std |
---|
Leigh’s Disease | 212,097.00 | 85,447.79 | 1.0000 | 0.0000 | 0.9951 | 0.0017 |
No Leigh’s Disease | 2247.04 | 23,270.65 | 1.3646 | 4.6569 | 0.1833 | 0.2214 |