Project Summary Hadamard-encoded edited MRS allows simultaneous in vivo detection of multiple low-concentration neurometabolites in a single experiment. Methods developed in the last funded period of this grant are being applied in the HBCD study, a large national study of childhood development (~7,000 infants). In this renewal period, we will acquire the same acquisition protocol in a whole-lifespan cohort in order to reveal neurochemical changes in development and aging. Methodologically, we will then extend the utility of edited MRS into challenging areas of the brain by addressing the long-standing issue of out-of-voxel (OOV) echoes. We will optimize acquisitions to reduce the impact of OOV echoes for each challenging region and develop modeling strategies to minimize their impact on metabolite quantification. We will also develop intelligent acquisitions that can detect OOV signals in real-time as the sequence is being acquired and adjust the acquisition responsively to reduce OOV signals. Finally, we will continue the on-going work to disseminate methods developed during prior grant periods, upgrading code as scanners update and porting new advances back into older code so collaborators can benefit.