Independent evaluation of deep learning models for detecting focal cortical dysplasia

Clinical Snapshot

Key Findings

• P Value: Not reported

• Effect Size: MELDGraph: 61% accuracy, MELDClassifier: 52% accuracy, DeepFCD: 56% accuracy

• Primary Outcome: Patient-level diagnostic accuracy for FCD detection

• Nnt Or Sensitivity: MELDClassifier: 91% sensitivity, 14% specificity; MELDGraph: 76% sensitivity, 47% specificity; DeepFCD: 62% sensitivity, 50% specificity

• Confidence Interval: Not reported

Clinical Application

Limited by poor diagnostic accuracy and low test-retest reliability across all three tools Relevant to Australian epilepsy centres, but poor performance suggests these tools not ready for routine clinical use. Would require validation against Australian neuroradiology standards and consideration of Medicare item numbers for MRI interpretation Epilepsy patients undergoing MRI evaluation for suspected focal cortical dysplasia

Abstract

The purpose of this study is to perform an independent assessment of three state-of-the-art tools for the detection of focal cortical dysplasia (FCD) from Magnetic Resonance images (MRI). These tools include DeepFCD, the Multi-center Epilepsy Lesion Detection (MELD) Classifier, and MELDGraph. T1-weighted and fluid-attenuated inversion recovery MRIs from 101 epilepsy patients with FCD and 101 epilepsy patients without FCD were retrospectively included. Classifiers were evaluated at patient-level by their ability to correctly identify the presence of any FCD lesions, and at lesion-level by their capacity to identify lesions within regions delineated by neuroradiologists in MRI reports. A calibrated threshold for DeepFCD prediction probabilities was empirically determined to improve classifier specificity. Classifier test-retest consistency was measured using the Dice coefficient on repeated MRI scans of 21 individuals. At patient-level, MELDClassifier achieved 52% accuracy (sensitivity=91%, specificity=14%), MELDGraph reached 61% accuracy (sensitivity=76%, specificity=47%) and DeepFCD performed with 56% accuracy (sensitivity=62%, specificity=50%) at an empirically determined threshold of 0.90. At lesion-level, MELDClassifier performed with a sensitivity of 70% and a positive predictive value (PPV) of 13%. MELDGraph reached 53% sensitivity and PPV of 36%, whereas the DeepFCD performed with 30% sensitivity and PPV of 19%. Test-retest reliability was low, with an average [min, max] Dice coefficient of 0.28 [0.0, 1.0] for MELDClassifier, 0.38 [0.0, 1.0] for MELDGraph, and 0.35 [0.05, 0.54] for DeepFCD. This study highlights the current limitations of using deep learning models in FCD diagnosis and emphasizes the need to enhance the tools' accuracy, reliability, and interpretability to improve clinical utility.

References

1. 1.Kaas, H., Prener, M., Ganz, M., Knudsen, G. M., Pinborg, L. H., & Beliveau, V. (2026). Independent evaluation of deep learning models for detecting focal cortical dysplasia. Epilepsy Research, 107778. https://doi.org/10.1016/j.eplepsyres.2026.107778