This study aims to enhance the visualization of deep cerebrovascular structures and blood flow in the aging brain, a key factor in understanding the pathogenesis of vascular cognitive impairment and dementia (VCID) and Alzheimer's disease (AD). We hypothesized that functional ultrasound (fUS) imaging through a polymethylpentene window could provide high-resolution insights into cerebral blood flow (CBF) in older mice. Employing this method, we replaced the skull of elderly (24-month-old C57BL/6) mice with a transparent window, allowing for consistent, non-invasive fUS imaging over time. We utilized ultrasound localization mapping (ULM) with a microbubble (approximately 10 micrometers (μm)) suspension for detailed mapping of microvascular vessels and flows. Data were analyzed using a FIJI-based platform to interpret high-quality ULM images. Our results demonstrate this novel method's effcacy in revealing intricate vascular details, proving its utility for longitudinal CBF assessments in physiological research in preclinical murine models and aging. This study was supported by the following funding sources: NIH R03AG070479, K01AG073614, R21AG080775, American Heart Association, Hevolution/AFAR. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.