Project Summary This administrative supplement is requested to support research continuity and retention of the scientific aims outlined in a K25 NIAAward #1K25AG076864, titled "Development and Application of T1rho Dispersion Imaging of Aging Muscle." The principal investigator is currently managing a high-risk pregnancy and childbirth-related life events that may temporarily affect her research productivity and the success of her K25 grant. The aims of the parent grant are (1) to develop R1p (R1p = 1/T1p - the spin-lattice relaxation rates in the rotating frame) dispersion imaging at weak locking field frequency, a novel approach that can quantify degenerative changes in microvasculature and abnormal macromolecule accumulation in muscle fiber membranes, (2) to validate extracted-MRI indices using gold-standard ex vivo methods through a longitudinal study of skeletal muscle in F344 rats to establish the pathophysiological relevance of these novel MRI biomarkers with aging, and (3) to translate R1p dispersion imaging to human research, utilizing a clinical 3T MRI scanner to assess skeletal muscle changes with healthy aging. The parent grant has enabled successful completion of Aim 1 and Aim 2, and partial progress toward Aim 3. To fully accomplish the objectives outlined in Aim 2, additional computational analysis of histological data is necessary. To support this activity, I have established a collaboration with experts at the Digital Histology Shared Resource (DHSR), in partnership with the Translational Pathology Shared Resource (TPSR) at Vanderbilt University Medical Center. This collaboration will enable cost-effective computational quantification of ex vivo biomarkers, which are essential for interpreting MRI-derived indices from Aim 2. This supplement is also vital for advancing Aim 3 by ensuring continuity of human research activities during a temporary reduction in the principal investigator's availability and productivity. A research assistant (RA) will be