The evolution of CT imaging in metabolic bone disease assessment

Computed tomography (CT) is becoming increasingly important in the field of osteoporosis, both in terms of dedicated applications and for opportunistic screening. The latter is a hot topic likely to change osteoporosis risk stratification and management to an unprecedented degree; it is also arguably one of the key areas for the use of Artificial Intelligence (AI) in medicine. Quantitative CT (QCT) is currently undergoing a revival, with technological improvements allowing reduced radiation exposure and offering significant advantages over traditional techniques like Dual-energy X-ray Absorptiometry (DXA). Moreover, innovative modalities such as high-resolution peripheral QCT (HR-pQCT) and, to a lesser extent, cone beam CT (CBCT) are emerging and becoming more available in clinical practice for osteoporosis imaging, especially in specific scenarios. Furthermore, Dual-Energy CT (DECT) and Photon-Counting CT (PCCT) are becoming more popular in radiology departments and represent promising options for the detection of osteoporosis. This brief narrative review explores the world of CT applied to metabolic bone diseases, focusing in particular on its use for opportunistic diagnosis and screening, an attractive application that has been emerging in recent years. KEY WORDS: Opportunistic screening, bone frailty assessment, osteoporosis, quantitative computed tomography (QCT), artificial intelligence (AI).