Nuclear magnetic resonance spectroscopy (MRS) and positron emission tomography (PET) scanning are the only two non-invasive methods available for obtaining metabolic data on inaccessible tissues such as the brain. MRS and PET scanning are powerful research techniques that provide strong evidence that neuropsychiatric lupus is a brain disorder characterized by profound metabolic alterations including impaired blood flow, ischemia, decreased aerobic metabolism, and progressive neuronal loss.