Ensemble of Deep Learning Models for Accurate Segmentation of Left and Right Atria in Late Gadolinium-Enhanced Cardiac MRI of Atrial Fibrillation Patients

Grunnleggende konsepter

An ensemble of deep learning models, including UNet, ResNet, EfficientNet, and VGG, achieves superior performance in segmenting the left and right atria and their walls from late gadolinium-enhanced cardiac MRI data of atrial fibrillation patients.

Sammendrag

This work presents an ensemble approach that integrates multiple machine learning models to perform automatic bi-atrial segmentation from late gadolinium-enhanced cardiac MRI (LGE-MRI) data. The dataset consists of 200 multi-center 3D LGE-MRI scans labeled by experts, which were split into training, validation, and testing sets.
The ensemble model combines the strengths of four CNN architectures: UNet, ResNet, EfficientNet, and VGG. Each model was trained individually on the dataset, and the ensemble model was then trained to optimize a weighted combination of the sub-models' outputs.
The ensemble model was evaluated using the Dice Similarity Coefficient (DSC) and 95% Hausdorff distance (HD95) metrics on the left & right atrium wall, right atrium cavity, and left atrium cavity. On the internal testing dataset, the ensemble model achieved a DSC of 88.41%, 98.48%, 98.45% and an HD95 of 1.07, 0.95, 0.64 respectively, outperforming the individual sub-models.
The results demonstrate the effectiveness of the ensemble approach in improving segmentation accuracy compared to single models. This work contributes to advancing the understanding of atrial fibrillation and supports the development of more targeted and effective ablation strategies by providing reliable segmentation of atrial structures from LGE-MRI data.

Statistikk

The dataset consists of 200 multi-center 3D LGE-MRI scans, each labeled by three experts.
The scans have dimensions of either 40 × 640 × 640 or 40 × 576 × 576 and consist of three classes: left & right atrium wall, right atrium cavity, and left atrium cavity.
The 70 labeled training scans were split into internal training, validation, and testing datasets in a ratio of 84:8:8, resulting in 2587 training images, 246 validation images, and 247 testing images.

Sitater

"The ensemble model achieves the best results, with the highest Dice score and HD95 distance in each class by a considerable amount. This reflects the strength of a model ensemble, able to combine the strengths of multiple, individual models to attain superior results."
"Ultimately, this ensemble-based method offers a robust solution for automatic multi-class segmentation of the left and right atrium from LGE-MRI data, achieving high accuracy and precision as evidenced by the Dice and HD95 metrics."

Viktige innsikter hentet fra

Multi-Model Ensemble Approach for Accurate Bi-Atrial Segmentation in LGE-MRI of Atrial Fibrillation Patients

by Lucas Beveri... klokken arxiv.org 09-25-2024

https://arxiv.org/pdf/2409.16083.pdf

Dypere Spørsmål

How could the ensemble model be further improved, such as through the integration of additional architectures or the exploration of different ensemble techniques?

The ensemble model presented in this study demonstrates significant promise in achieving high accuracy for bi-atrial segmentation from LGE-MRI data. However, there are several avenues for further improvement. One potential enhancement is the integration of additional architectures that have shown success in other medical imaging tasks. For instance, incorporating models like DenseNet or attention-based architectures such as Vision Transformers (ViTs) could provide complementary strengths, particularly in capturing intricate features and contextual information within the LGE-MRI scans.
Moreover, exploring different ensemble techniques could yield further improvements. Techniques such as stacking, where the predictions of multiple models are used as input features for a higher-level model, could enhance the overall performance. Additionally, employing weighted averaging based on model performance during validation could help in optimizing the contribution of each model to the final prediction. Implementing techniques like bagging or boosting could also be beneficial, as they focus on reducing variance and bias, respectively, which may lead to more robust segmentation outcomes.

What are the potential limitations or challenges in applying this ensemble approach to other medical imaging tasks beyond atrial fibrillation?

While the ensemble approach has shown effectiveness in bi-atrial segmentation, its application to other medical imaging tasks may face several limitations and challenges. One significant challenge is the variability in imaging modalities and the characteristics of different anatomical structures. For instance, the features relevant for segmentation in LGE-MRI may not translate directly to other imaging techniques, such as CT or ultrasound, which may require different preprocessing and model architectures.
Additionally, the availability of labeled datasets can be a limiting factor. The success of the ensemble model relies heavily on the quality and quantity of training data. In many medical imaging tasks, especially those involving rare conditions, obtaining a sufficiently large and well-annotated dataset can be difficult. This scarcity can lead to overfitting, where the model performs well on training data but fails to generalize to unseen cases.
Furthermore, the computational complexity of ensemble models can pose challenges in terms of deployment in clinical settings. The need for significant computational resources for training and inference may limit the practicality of using such models in real-time applications, where rapid decision-making is crucial.

How could the insights gained from this work on bi-atrial segmentation be leveraged to develop more personalized treatment strategies for atrial fibrillation patients?

The insights gained from the bi-atrial segmentation work can significantly contribute to the development of personalized treatment strategies for atrial fibrillation (AF) patients. Accurate segmentation of the left and right atria, along with their walls and cavities, provides critical information regarding the extent and distribution of atrial fibrosis and scarring. This information is essential for tailoring ablation strategies, as it allows clinicians to identify specific areas of the atria that may be contributing to the arrhythmia.
By integrating the segmentation results with patient-specific clinical data, such as symptoms, comorbidities, and response to previous treatments, healthcare providers can develop more individualized treatment plans. For instance, the segmentation data can inform the selection of ablation targets, optimizing the procedure to focus on areas with significant fibrosis, thereby potentially increasing the success rates of the intervention.
Moreover, the ability to monitor changes in atrial structure over time through repeated imaging and segmentation can help in assessing treatment efficacy and making timely adjustments to the management plan. This dynamic approach to treatment, informed by precise imaging and segmentation, aligns with the broader trend towards personalized medicine, ultimately aiming to improve clinical outcomes and quality of life for AF patients.