Imaging of Metabolic Bone Diseases: The Spine View, Part I

Metabolic bone diseases comprise a wide spectrum. Of them, osteoporosis is the most frequent and the most commonly found in the spine, with a high impact on health care systems and on morbidity due to vertebral fractures (VFs). This article discusses state-of-the-art techniques on the imaging of metabolic bone diseases in the spine, from the well-established methods to the latest improvements, recent developments, and future perspectives. We review the classical features of involvement of metabolic conditions involving the spine. Then we analyze the different imaging techniques for the diagnosis, characterization, and monitoring of metabolic bone disease: dual-energy X-ray absorptiometry (DXA) and DXA-based fracture risk assessment applications or indexes, such as the geometric parameters, Bone Strain Index, and Trabecular Bone Score; quantitative computed tomography; and magnetic resonance and ultrasonography-based techniques, such as radiofrequency echographic multi spectrometry. We also describe the current possibilities of imaging to guide the treatment of VFs secondary to metabolic bone disease.