Convolutional Neural Networks (CNNs) have been recently employed to solve problems from both the computer vision and medical image analysis fields. Despite their popularity, most approaches are only able to process 2D images while most medical data used in clinical practice consists of 3D volumes. In this work we propose an approach to 3D image segmentation based on a volumetric, fully convolutional, neural network. Our CNN is trained end-to-end on MRI volumes depicting prostate, and learns to predict segmentation for the whole volume at once. We introduce a novel objective function, that we optimise during training, based on Dice coefficient. In this way we can deal with situations where there is a strong imbalance between the number of foreground and background voxels. To cope with the limited number of annotated volumes available for training, we augment the data applying random non-linear transformations and histogram matching. We show in our experimental evaluation that our approach achieves good performances on challenging test data while requiring only a fraction of the processing time needed by other previous methods.

本文提出了一种基于全卷积神经网络的三维图像分割方法，通过优化Dice系数的目标函数，应对前景和背景体素数量极不平衡的情况，并通过数据增强技术提高数据样本的数量和多样性，实验结果表明该方法在肺部三维图像分割任务中取得了较好的性能。

V-Net: 用于体积医学影像分割的全卷积神经网络