Browsing by Subject "Cardiomyopathies"

Now showing 1 - 3 of 3
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    Especies reactivas de oxígeno y su implicación en Biomedicina
    (Universidad de Murcia. Servicio de publicaciones, 2018) Lozano Picazo, Carmen María; Fernández-Belda, Francisco
    Las especies reactivas de oxígeno (ROS) actúan como regulador intracelular cuando se generan de forma controlada en puntos concretos de la célula. Modifican la función de proteínas mediante la oxidación reversible de cisteínas. Hay quinasas y fosfatasas de proteínas, factores de transcripción y canales iónicos que están regu-lados por ROS. Estrés oxidativo y daño celular aparecen cuando los mecanismos antioxidantes de protección son incapaces de mantener bajo el nivel intracelular de ROS. En estas condiciones, ROS inducen pérdida de viabilidad celular en patologías degenerativas de corazón y cerebro y promueven proliferación celular ilimitada en procesos tumorales. La alteración de la función mitocondrial juega un papel clave en la generación del estrés oxidativo y por tanto es una diana terapéutica preferente para evitar o aminorar los daños oxidativos producidos por ROS.
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    Improving a Deep Learning Model to Accurately Diagnose LVNC
    (Federico Guerra, 2023-12-12) Baron Yusti, Jaime Rafael; Bernabé García, Gregorio; González Férez, Pilar; García Carrasco, José Manuel; Casas, Guillem; González-Carrillo, Josefa; Ingeniería y Tecnología de Computadores
    Accurate diagnosis of Left Ventricular Noncompaction Cardiomyopathy (LVNC) is critical for proper patient treatment but remains challenging. This work improves LVNC detection by improving left ventricle segmentation in cardiac MR images. Trabeculated left ventricle indicates LVNC, but automatic segmentation is difficult. We present techniques to improve segmentation and evaluate their impact on LVNC diagnosis. Three main methods are introduced: (1) using full 800 × 800 MR images rather than 512 × 512; (2) a clustering algorithm to eliminate neural network hallucinations; (3) advanced network architectures including Attention U-Net, MSA-UNet, and U-Net++.Experiments utilize cardiac MR datasets from three different hospitals. U-Net++ achieves the best segmentation performance using 800 × 800 images, and it improves the mean segmentation Dice score by 0.02 over the baseline U-Net, the clustering algorithm improves the mean Dice score by 0.06 on the images it affected, and the U-Net++ provides an additional 0.02 mean Dice score over the baseline U-Net. For LVNC diagnosis, U-Net++ achieves 0.896 accuracy, 0.907 precision, and 0.912 F1-score outperforming the baseline U-Net. Proposed techniques enhance LVNC detection, but differences between hospitals reveal problems in improving generalization. This work provides validated methods for precise LVNC diagnosis.
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    Semi-Automatic Refinement of Myocardial Segmentations for Better LVNC Detection
    (MDPI, 2025-01-06) Barón, Jaime R.; Bernabé García, Gregorio; González Férez, Pilar; García Carrasco, José M.; Casas, Guillem; González Carrillo, Josefa; Ingeniería y Tecnología de Computadores
    Background: Accurate segmentation of the left ventricular myocardium in cardiac MRI is essential for developing reliable deep learning models to diagnose left ventricular non-compaction cardiomyopathy (LVNC). This work focuses on improving the segmentation database used to train these models, enhancing the quality of myocardial segmentation for more precise model training. Methods: We present a semi-automatic framework that refines segmentations through three fundamental approaches: (1) combining neural network outputs with expert-driven corrections, (2) implementing a blob-selection method to correct segmentation errors and neural network hallucinations, and (3) employing a cross-validation process using the baseline U-Net model. Results: Applied to datasets from three hospitals, these methods demonstrate improved segmentation accuracy, with the blob-selection technique boosting the Dice coefficient for the Trabecular Zone by up to 0.06 in certain populations. Conclusions: Our approach enhances the dataset’s quality, providing a more robust foundation for future LVNC diagnostic models.