Haemangioblastoma brain tumour. Coloured magnetic resonance angiography (MRA) scan of the brain of a 78 year old woman. The image shows the arterial blood supply (yellow) to the haemangioblastoma tumour (orange), which is affecting the left lobe of the cerebellum. Haemangoblastomas are formed from cells that line the blood vessels and are almost always benign. The main symptoms, such as headaches and sight problems, arise from increased pressure within the skull. Surgery is often the main form of treatment. MRA is a non-invasive technique to image blood vessels in the body that uses a combination of a very strong magnetic field and radiofrequency pulses to image the flow of blood.