This proposal requests funds to purchase a MicroXCT-200 (High Resolution 3D X-Ray Microscope). This state-of-the-art instrument can acquire 3D images with submicron pixel resolution (PR) from relatively large pieces of intact biologic tissue. It will further the research objectives of multiple NIH-funded projects. Many of the projects have been using conventional MicroCT or Scanning Electron Microscopy (SEM) for their morphologic studies, but now require examining features of smaller size that cannot be reliably approached with MicroCT or SEM. The MicroXCT-200 (Xradia, Inc;Pleasanton, CA) will be placed in the Creighton University Medical Center. Day-to-day management will be provided by a team that has operated a MicroCT facility for the past eight years. The MicroXCT-200 will be used by six Major Users (seven NIH funded projects) and seven Minor/Other users from five major institutions within a 200- mile radius of Creighton University: Boys Town National Hospital (1 user), Creighton University (3 users), U of Missouri Kansas City (3 users), U of Nebraska Medical Center (1 user), and U of Nebraska-Lincoln (2 users). The MicroXCT-200 is a laboratory instrument that applies technology similar to that now offered by synchrotron radiation (SR) microscopy. The MicroXCT-200 improves upon SR-based imaging in not only being laboratory-based, but also often reaching higher resolutions than 3D images produced by SR microscopy. The MicroXCT-200 routinely reaches 0.5?m PR in 3D images of specimens measuring 3mm in diameter. It has been used for the past half decade for failure analysis in microchips and rock porosity analysis in core samples obtained during oil and gas exploration. Among the proposed projects are ones that address: bone quality in diabetic and other persons who suffer fragility fracture with non-osteoporotic bone mass;hair cells, inner ear epithelium, and otoconia in the cochlea;embryonic skeletal phenotyping, bone response to mechanical loading;tissue scaffold quality and bioresorbability;bone microcracks;bone implants;and protection from mild traumatic brain injury. By using MicroXCT-200, the Major Users propose to add significant new biologic endpoints to their research: #1 (Recker) osteocyte lacunar properties;#2 (Dallas) mouse embryo skeletal phenotyping;#3 (He) evaluation of cochlear hair cells;#4 and #5 (Johnson) lacunar-level finite element modeling;#6 (Weston) quantitative studies of inner ear epithelium;#7 (Lundberg) quantitation of otoconia. Minor users propose to add: #1- (Armas) lacunar properties, #2 (Subramanian) scaffolding matrix and surface evaluation;#3 (Turner) lacunar properties in skull bone with improved modeling of compression impact. Other users propose adding: #1 (Akhter) microcrack detection;#2 (Stern) lacunar- level finite element modeling with local bone mineral density assessment;#3- (Cullen) lacunar properties in loaded bone;and #4 (Wang) evaluation of bone apposed to the surface of orthopedic/dental implants.