During a seizure, there will be increased blood flow to the area where the seizure initially starts (seizure focus). SPECT is used to show an increase the blood flow in the brain during a seizure (ictal SPECT). A safe, very low-level radioactive compound is injected into your arm within seconds of the seizure onset, and the particles it emits are measured. The more blood that flows through a certain area, the more particles are emitted. It is used for seizure arising anywhere in the brain.