DESCRIPTION: The investigators propose to test the feasibility of developing a three-dimensional method for quantitative X-ray computed tomographic measurement of osteoporosis and its long term progression under treatment, as further described by their abstract: "The large and increasing number of women being treated for osteoporosis underscores the benefit of rapid determination of therapy efficacy. To address this need, we will develop a precise 3D quantitative computed tomography (QCT) technique to quantify the density of the highly-responsive trabecular bone in the spine and hip. We will accomplish this by (i) by developing automated techniques to delineate trabecular and cortical regions of interest based on anatomic landmarks in the 3D images and (ii) by addressing a key source of error associated with variations in coupling between the calibration reference phantom and patient. In Phase I, we will perform two tasks. First, we will implement and evaluate for commercial feasibility three algorithms for analysis of volumetric QCT images, comparing them to each other and to the standard 2D technique. Second, we will measure in vitro the magnitude of the precision error associated with clinically-observed variations in phantom-patient coupling. We will determine whether improving the coupling reduces precision errors. In Phase II, we will commercially develop the algorithm shown to have best performance. If the results of the coupling measurements show a measurable effect on precision error, we will build and evaluate a phantom designed to improve patient phantom coupling." PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE