The document describes using Mask R-CNN to detect brain tumors from MRI scans. It discusses how Mask R-CNN works, including its convolutional and pooling layers. The methodology section explains that the model uses a region proposal network to identify regions of interest, an object detection branch to classify ROIs as tumor or non-tumor, and a segmentation mask to identify tumor boundaries. The results found a mean precision of 0.81, recall of 0.74, and F1 score of 0.83, showing Mask R-CNN can accurately detect and segment brain tumors from MRI images.