DRRNet: Dense Residual Refine Networks for Automatic Brain Tumor Segmentation.

Glioma is one of the most common and aggressive brain tumors. Segmentation and subsequent quantitative analysis of brain tumor MRI are routine and crucial for treatment. Due to the time-consuming and tedious manual segmentation, automatic segmentation methods are required for accurate and timely treatment. Recently, segmentation methods based on deep learning are popular because of their self-learning and generalization ability. Therefore, we propose a novel automatic 3D CNN-based method for brain tumor segmentation. In order to better capture the contextual information, we design the network architecture based on u-net and replace the simple skip connection with encoder adaptation blocks. To further improve the performance and reduce computational burden at the same time, we also use dense connected fusion blocks in decoder. We train our model with generalised dice loss function to alleviate the problem of class imbalance. The proposed model is evaluated on the BRATS 2015 testing dataset and obtains dice scores of 0.84, 0.72 and 0.62 for whole tumor, tumor core and enhancing tumor, respectively. Our model is accurate and efficient, achieving results that comparable to the reported state-of-the-art results.

Computer-Aided Grading of Gliomas Combining Automatic Segmentation and Radiomics.

Gliomas are the most common primary brain tumors, and the objective grading is of great importance for treatment. This paper presents an automatic computer-aided diagnosis of gliomas that combines automatic segmentation and radiomics, which can improve the diagnostic ability. The MRI data containing 220 high-grade gliomas and 54 low-grade gliomas are used to evaluate our system. A multiscale 3D convolutional neural network is trained to segment whole tumor regions. A wide range of radiomic features including first-order features, shape features, and texture features is extracted. By using support vector machines with recursive feature elimination for feature selection, a CAD system that has an extreme gradient boosting classifier with a 5-fold cross-validation is constructed for the grading of gliomas. Our CAD system is highly effective for the grading of gliomas with an accuracy of 91.27%, a weighted macroprecision of 91.27%, a weighted macrorecall of 91.27%, and a weighted macro-F1 score of 90.64%. This demonstrates that the proposed CAD system can assist radiologists for high accurate grading of gliomas and has the potential for clinical applications.