High-Resolution Peripheral Quantitative Computed Tomography (HR-pQCT) Scanner

Vanderbilt University Medical Center, Nashville TN

Investigators

Abstract

Project Summary/Abstract This application seeks funding to purchase a high-resolution, peripheral quantitative computed tomography (HR- pQCT) scanner for studies with diverse goals such as improving musculoskeletal health, understanding the signals in brain imaging, preventing post-traumatic osteoarthritis or the osteoarthritis that follows reconstructive surgery of the anterior cruciate ligament, and identifying patients at risk of an osteoporotic fracture due to hypertension or a pathological fracture due to bone metastasis. The scanner will be installed at the Vanderbilt University Institute of Imaging Science and be managed by a shared resource or core called the Center for Human Imaging. This core provides investigators at Vanderbilt University Medical Center (VUMC), Vanderbilt University, and the local Veterans Affairs Medical Center access to multiple magnetic resonance imaging scanners and a dual-energy X-ray absorptiometry scanner for research purposes, but without the non-invasive HR-pQCT scanner, it lacks the ability to provide investigators the means to obtain high quality, volumetric images of bone in humans. Because the radiation exposure is low and isolated to small regions, the scanner can be used in longitudinal studies requiring serial scans. These images are comparable to the images that investigators get scanning bones of small animals like mice. Moreover, the analysis software is the same between the human scanner and the animal scanner making the transition from preclinical to clinical research seamless. By having the HR-pQCT scanner available to multiple investigators, the impact of ongoing federally funded projects will be enhanced because the instrument facilitates a direct translational pathway. For example, it provides measurements of trabecular morphology such as bone volume fraction and trabecular number. It also provides measurements of cortical structure and microstructure such as cross-sectional cortical area, cortical thickness, and cortical porosity. Because the scanner is calibrated to a mineral phantom, all scans can be evaluated to obtain measurements of volumetric bone mineral density. Moreover, the resolution of the scanner and the accompanying software allows users to separate measurements of trabecular bone from cortical bone or to combine measurements as a total. The software is also capable of converting the scans to computational models that can estimate a subject’s bone strength. Such capabilities are state-of-the-art going beyond projection measurements like areal bone mineral density, which cannot distinguish the contribution of cortical bone from the contribution of trabecular bone to fracture risk. Being incorporated into an existing core that has strong institutional support, a working plan is in place to provide financial and technical support of the new scanner as well as a scheduling system that investigators can easily access to reserved time on the instrument. The HR- pQCT scanner will support the ongoing investment of VUMC into advanced biomedical imaging techniques and help scientist achieve their research goals.