Cerebrovascular Segmentation from TOF-MRA using Model- and Data-driven Method via Sparse Labels

Cerebrovascular segmentation from time-of-flight magnetic resonance angiography (TOF-MRA) data is of great importance in blood supply structure analysis, diagnosis, and treatment of cerebrovascular pathologies. However, complete and accurate segmentation is still a challenge due to the complex image context and vascular morphology. The existing model-driven methods are often difficult to obtain prominent accuracy and robustness. Deep-learning based technology has achieved unimaginable success, but always faces the problem of insufficient labeled data. In this paper, a novel strategy is proposed to automate cerebrovascular segmentation, which integrates model- and data-driven methods. Firstly, the TOF-MRA data are sparsely labeled by three radiologists. Secondly, a semi-supervised mixture probability model is proposed to fit the cerebrovascular intensity distribution precisely, which starts from the sparse annotations and generates massive labeled points. Thirdly, mislabeled points are corrected by a Clean-Mechanism model, to acquire a well-labeled point-set of good quality. Finally, we construct and train a dilated dense convolution network (DD-CNN) by the resultant labeled point-set. The proposed method is validated on 109 clinical TOR-MRA data from a public dataset. Compared with the other state-of-the-art segmentation methods, our method segments cerebrovascular structure with better completeness and sensibility, especially for slender vascularity. The experimental results show that our method reaches an average dice score of 93.20%, which also indicates that the DD-CNN is very competent for cerebrovascular segmentation from TOF-MRA volume.