This is a request for funds for an Xradia VersaXRM-500 micro- and nano-computed tomography instrument. The requested instrument will expand the Cornell Micro-CT facility from in vivo scanning (25 micrometer resolution) to in vitro scanning (0.56 micrometer resolution) to meet the medical research needs of 10 principal investigators with NIH funding. The new instrument will be located within and managed by the Cornell University Microscopy and Imaging Facility, whose main focus is to support imaging needs on campus and in central New York. The Microscopy and Imaging Facility is located within the newly built, $160 million Weill Hall facility that was designed to the be the hub for Cornell's New Life Sciences Initiative. The Xradia VersaXRM- 500 device has novel capabilities including sub-micron resolution in specimens larger than 4mm in size and phase contrast enhanced computed tomography allowing visualization and assessment of soft tissues with or without contrast agents. The instrument will directly enhance the research needs of 9 major users, each of whom have found that existing imaging approaches are not sufficient for their current and future needs. The device will be used immediately to enhance research on a) the development and treatment of osteoporosis and other defects in bone;b) treatment of osteoarthritis;c) the development of lung cancer;e) uterine pre- eclampsia;d) congenital defects in the heart and will be used in future investigations on these health topics and others.