Transfer Learning for Brain Tumor Segmentation

TL;DR

This paper introduces a transfer learning approach using pretrained encoders in fully convolutional networks to improve automatic brain tumor segmentation in MRI scans, achieving more stable training and better accuracy.

Contribution

It presents a novel application of transfer learning with pretrained encoders in FCNs for brain tumor segmentation, enhancing training stability and segmentation performance.

Findings

Improved dice scores and Hausdorff distances with pretrained encoders.

Stable training process for complex MRI data.

Validated on clinical dataset.

Abstract

Gliomas are the most common malignant brain tumors that are treated with chemoradiotherapy and surgery. Magnetic Resonance Imaging (MRI) is used by radiotherapists to manually segment brain lesions and to observe their development throughout the therapy. The manual image segmentation process is time-consuming and results tend to vary among different human raters. Therefore, there is a substantial demand for automatic image segmentation algorithms that produce a reliable and accurate segmentation of various brain tissue types. Recent advances in deep learning have led to convolutional neural network architectures that excel at various visual recognition tasks. They have been successfully applied to the medical context including medical image segmentation. In particular, fully convolutional networks (FCNs) such as the U-Net produce state-of-the-art results in the automatic segmentation of brain tumors. MRI brain scans are volumetric and exist in various co-registered modalities that serve as input channels for these FCN architectures. Training algorithms for brain tumor segmentation on this complex input requires large amounts of computational resources and is prone to overfitting. In this work, we construct FCNs with pretrained convolutional encoders. We show that we can stabilize the training process this way and achieve an improvement with respect to dice scores and Hausdorff distances. We also test our method on a privately obtained clinical dataset.