The BRATS2017 dataset. It contains 285 brain tumor MRI scans, with four MRI modalities as T1, T1ce, T2, and Flair for each scan. The dataset also provides full masks for brain tumors, with labels for ED, ET, NET/NCR. The segmentation evaluation is based on three tasks: WT, TC and ET segmentation.
Source: Scribble-based Hierarchical Weakly Supervised Learning for Brain Tumor Segmentation
Homepage: https://www.med.upenn.edu/sbia/brats2017/data.html