Brain cancer detection is the identification of malignant brain tumors using diagnostic tools like optical spectroscopy and AI.Brain cancer detection using artificial intelligence includes segmentation (delineation) of tumors on MRI images. Convolutional neural networks (CNN) with the U-Net architecture are most effective, processing 3D volumes and classifying each voxel as healthy tissue, necrosis, edema, or tumor. Models are pre-trained on large datasets (e.g., BraTS) with slice-by-slice annotation. The key challenge is distinguishing glioblastoma from metastases and non-tumor formations (abscess, demyelination). Additionally, radiomics (extraction of multiple quantitative features from images) and diffusion-weighted MRI are used.
The development of computer-aided brain cancer diagnosis began with expert systems in the 1980s that used thresholding and texture filters. In 1998, the first CAD package for MRI appeared, and in the 2010s, public BraTS (Brain Tumor Segmentation Challenge) competitions accelerated progress. The pivotal moment was the victory of convolutional networks in 2015 (DeepMedic). Since 2018, U-Net-based models and its 3D modifications became the standard. In the 2020s, the FDA approved several AI systems (e.g., icobrain) to assist in clinical decisions, although widespread adoption is hindered by scanner and protocol variability.
A typical pipeline: (1) preprocessing — intensity normalization, skull stripping, registration to an atlas; (2) an input 3D patch from four channels (T1, T1c, T2, FLAIR) is fed into a U-Net encoder that extracts hierarchical features from edges to texture; (3) the decoder restores spatial resolution with skip connections, outputting probability maps for each class; (4) the loss function is usually a combination of Dice Loss and cross-entropy, accounting for class imbalance; (5) post-processing — removal of small false spots using connected components and morphological operations. To increase robustness, activation consistency is checked under small distortions of the input image (test-time augmentation). The integrated system visualizes the segmentation in the clinician's interface, providing quantitative metrics (volume, radiomics).
Helps doctors diagnose at an early stage, reduces the number of false alarms, and precisely determines tumor boundaries before surgery or radiation.
Some algorithms can detect a tumor 6–12 months earlier than a radiologist by analyzing barely noticeable changes in signal intensity on consecutive scans.


















