Guidewire tip detection in the percutaneous coronary intervention is important. It assists physicians in navigating and is a prerequisite for clinic applications such as surgical skill assessment and robot assisted surgery. Nevertheless, accurate detection is not a trivial task due to the noisy background of the 2D X-ray image and the thin, deformable structure of the tip. In this paper, an automatic method based on cascaded convolution neural networks is proposed to segment the tip in the 2D X-ray image. The main contribution of the method is to use a cascade detection-segmentation structure to overcome the noisy background and the large deformation of the tip, achieve robust, high-precision segmentation. On the other hand, sufficient annotated training samples are necessary for convolution neural network models, while pixel-level annotating is tedious and time consuming. Accordingly, a novel data augmentation algorithm is introduced to improve the model generalization and performance, reduce the cost of data annotation. Evaluations were conducted on a dataset consisting of 22 different sequences of 2D X-ray images, 15 sequences for training and 7 sequences for evaluation. The proposed approach obtained tip precision of 0.532 pixels, F1score of 0.939, false tracking rate of 0.800%, and missing tracking rate of 9.900% on the test set. And the running speed is 4-5 frames per second.

Detection of surgical devices, in particular of guide-wire detection, is prerequisite during image-guided navigation in percutaneous coronary intervention (PCI). Guide-wire detection is a challenging task for following reasons: (i) X-ray images have a low signal-to-noise rate (SNR); (ii) there is a high similarity between guide-wires and some other adjacent anatomical skeletons' contours; (iii) guide-wires have various shapes and their motion is complex and nonlinear. Traditionally, guide-wires are detected using curve fitting method, and third-order B-spline curve model is always used to fit guide-wires, while B-spline fitting method has some obvious shortcomings such as it is a semi-automatic method which needs manual initialization, and it is not a real-time method because of high computational complexity. Recently, with the availability of large annotated datasets and the accessibility of hardware resources with GPUs, it is succeeded in detecting general objects with convolutional neural networks (ConvNet). In this paper, we present a novel image-based fully-automatic and real-time approach with ConvNet for guide-wires detection. ConvNet method is robust to guide-wires' various poses and other structures' effects. We evaluate our method on 22 different sequences of X-ray images. The detection accuracy evaluated by average precision (AP) reaches 89.2% and the detection speed achieves 40fps. Our experiment result shows a promising for accurate and real-time guide-wires detection in PCI navigation with ConvNet model.