Lightweight Quantum-Enhanced ResNet for Coronary Angiography Classification: A Hybrid Quantum-Classical Feature Enhancement Framework
Jingsong Xia
TL;DR
We address the challenge of operator-dependent interpretation in coronary angiography and the limits of purely classical feature mappings by proposing a lightweight hybrid quantum–classical framework (LQER) that inserts a small 4-qubit PQC into the high-level feature space of a ResNet backbone. A linear projection reduces a rich ResNet feature to a compact representation, which is then processed by a shallow quantum circuit and fused back with classical features for final prediction. Empirical results on LRSE-Net datasets show that LQER achieves accuracy of 0.950 and AUC of 0.987, substantially outperforming purely quantum or classical baselines, while maintaining a CPU-friendly, end-to-end training regime. This work demonstrates a practical pathway for deploying quantum feature enhancement in medical imaging, offering potential for real-time intraoperative support and deployment in resource-constrained clinical environments.
Abstract
Background: Coronary angiography (CAG) is the cornerstone imaging modality for evaluating coronary artery stenosis and guiding interventional decision-making. However, interpretation based on single-frame angiographic images remains highly operator-dependent, and conventional deep learning models still face challenges in modeling complex vascular morphology and fine-grained texture patterns.Methods: We propose a Lightweight Quantum-Enhanced ResNet (LQER) for binary classification of coronary angiography images. A pretrained ResNet18 is employed as a classical feature extractor, while a parameterized quantum circuit (PQC) is introduced at the high-level semantic feature space for quantum feature enhancement. The quantum module utilizes data re-uploading and entanglement structures, followed by residual fusion with classical features, enabling end-to-end hybrid optimization with a strictly controlled number of qubits.Results: On an independent test set, the proposed LQER outperformed the classical ResNet18 baseline in accuracy, AUC, and F1-score, achieving a test accuracy exceeding 90%. The results demonstrate that lightweight quantum feature enhancement improves discrimination of positive lesions, particularly under class-imbalanced conditions.Conclusion: This study validates a practical hybrid quantum--classical learning paradigm for coronary angiography analysis, providing a feasible pathway for deploying quantum machine learning in medical imaging applications.
