Abstract: A system for use in determining a condition of a brain, the system including an input device for providing data representing a structure of the brain and a processor communicably connected to the input device. The processor is configured for measuring at east one geometric characteristic of the structure of the brain by reference to the data, determining a brain index value by reference to the at least one geometric characteristic, and, comparing the brain index value against at least one predetermined index whereby, based on a result of the comparison, a condition of the brain is able to be determined corresponding to the brain index value.