- MR Spectroscopy (MRS): 1H MRS is a noninvasive imaging technique that can easily be added to the conventional MRI sequences and is able to measure metabolism in the brain. Metabolic changes arising from pathology that can be visualized by MRS may not be apparent from anatomy. During a seizure, the metabolic demands exceed the supply of oxygen and nutrients to the portion of the brain that is undergoing the enhanced electric activity. Under these circumstances, metabolic changes can be detected by MRS, including the production of lactate and, if prolonged, the reduction of NAA, and an increase in Cho. These abnormalities can still be observed after seizure activity ceases. Another common clinical scenario for the use of MRS is temporal-lobe epilepsy (TLE) to help localize the source of the seizures.