In the August issue of Pediatrics, Delpy et al1 provided a detailed description of changes in intracerebral, intracellular constituents before, during, and after severe ischemic events in rabbits using a nuclear magnetic resonance technique. The constituents, ATP, phosphocreatine (PCr), and sugar phosphates, are the basic energy substrates of the body. Intracellular pH was also monitored throughout. As the authors correctly point out, such noninvasive, in vivo biochemistry would be invaluable to the pediatric clinician, not only to gather direct metabolic information on the status of the brain, but also to increase knowledge about muscle.2 In fact, applications of this technique to other organs such as the liver,3 the kidney,4 and the heart5 are likely to be made soon.