Chapter 80 - Macroimaging

Abstract

This chapter reviews in vivo imaging techniques used in the field of osteoporosis for diagnosis of osteoporosis, fracture prediction, or monitoring of therapeutic interventions and age-related changes. Standard techniques include radiography to diagnose fractures, quantitative computed tomography (QCT) to determine bone mineral density (BMD) and cortical geometry, and finite element analysis to measure bone strength. New developments include advanced dual-energy X-ray absorptiometry (DXA) analysis to obtain the trabecular bone score for assessing vertebral bone texture and the possibility of generating CT-like volumetric data from DXA scans[VK1] . High-resolution peripheral QCT can be used to measure trabecular structure and cortical porosity at the distal forearm and tibia. Magnetic resonance imaging (MRI) offers the unique possibility of determining cortical water to characterize collagen content and cortical porosity. Another application of MRI is the measurement of bone marrow fat content and composition, marrow perfusion, and marrow molecular diffusion. Most recent applications of CT include opportunistic screening, the reuse of existing CT images obtained for routine clinical purposes such as tumor diagnosis, to identify patients at high risk for osteoporotic fracture. Another emerging field is the combination of muscle parameters determined either by MRI or by CT with standard BMD and geometry parameters to improve fracture risk prediction by potentially addressing the components of a fall, which are related to muscle characteristics