Opportunistic Screening for Osteoporosis Using Body CT Scans Obtained for Other Indications: the UW Experience

Low bone mineral density (osteoporosis and osteopenia) leading to fragility fractures is associated with significant morbidity and mortality in our aging population. This condition is grossly underdiagnosed due to both insufficient screening and its silent nature prior to complicating fragility fractures. Body CT scans are commonly obtained among older adults for a wide variety of indications and contain rich data regarding bone health that are often ignored. At the University of Wisconsin, we have sought to harness this CT information for “opportunistic” osteoporosis screening. In this article, we review the various CT-based approaches we have taken to date, including routine assessment of the spine for both vertebral fractures and trabecular density, as well as assessment of the hip, deriving femoral neck T-scores that are essentially equivalent to dual-energy x-ray absorptiometry (DXA). Future directions of research and clinical implementation are also discussed.