"Glioma Segmentation Model Based on 2D Multimodal Magnetic Resonance Imaging Using a U-Net Transfer Learning Network"

Abstract

"The segmentation of gliomas in magnetic resonance imaging (MRI) is a clinical challenge, especially in clinical settings where access to high-end equipment and computing power is limited. In this paper, we propose a two-phase segmentation framework based on transfer learning applied to multimodal 2D MRI (T1-weighted and T2-FLAIR). The first phase focuses on brain/background separation using U-Net, achieving Dice coefficients greater than 0.95 and false negative rates of less than 1.5% after post-processing. In the second phase, tumor segmentation is developed using a factorial design that combines two architectures (U-Net and Attention U-Net), two input resolutions (120?×?120 and 32?×?32), configurations with and without clinical context, and both modalities, generating a total of 16 models. The results show that the inclusion of clinical context and 32?×?32 centered crops systematically improve performance, achieving a Dice score of 0.9322 and an IoU of 0.8730. In addition, weighted multimodal fusion of T1ce and T2-FLAIR, with ? parameter adjustment, consistently outperformed the performance of each modality separately. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2026."