Intraoperative stenosis detection in X-ray coronary angiography via temporal fusion and attention-based CNN

Coronary artery disease (CAD), the leading cause of mortality, is caused by atherosclerotic plaque buildup in the arteries. The gold standard for the diagnosis of CAD is via X-ray coronary angiography (XCA) during percutaneous coronary intervention, where locating coronary artery stenosis is fundamental and essential. However, due to complex vascular features and motion artifacts caused by heartbeat and respiratory movement, manually recognizing stenosis is challenging for physicians, which may prolong the surgery decision-making time and lead to irreversible myocardial damage. Therefore, we aim to provide an automatic method for accurate stenosis localization.

In this work, we present a convolutional neural network (CNN) with feature-level temporal fusion and attention modules to detect coronary artery stenosis in XCA images. The temporal fusion module, composed of the deformable convolution and the correlation-based module, is proposed to integrate time-varifying vessel features from consecutive frames. The attention module adopts channel-wise recalibration to capture global context as well as spatial-wise recalibration to enhance stenosis features with local width and morphology information.

We compare our method to the commonly used attention methods, state-of-the-art object detection methods, and stenosis detection methods. Experimental results show that our fusion and attention strategy significantly improves performance in discerning stenosis (P<0.05), achieving the best average recall score on two different datasets.

This is the first study to integrate both temporal fusion and attention mechanism into a novel feature-level hybrid CNN framework for stenosis detection in XCA images, which is proved effective in improving detection performance and therefore is potentially helpful in intraoperative stenosis localization.