Imaging of diabetic bone structure

Abstract

Epidemiological studies have found that patients with type 2 diabetes mellitus (T2DM) have a higher incidence of fragility fractures despite normal or elevated bone mineral density (BMD) measured with DXA. Studies have shown that bone structure and composition independent of BMD may explain the increased risk of fragility fractures in T2DM. High-resolution quantitative computed tomography (HR-pQCT) is a new technology to investigate bone quality analyzing cortical and trabecular bone structure. Using HR-pQCT differences in cortical porosity at the distal radius and tibia between T2DM patients with and without fragility fractures have been found. It has been suggested that cortical porosity may serve as a new imaging biomarker for increased fragility in T2DM. In addition, abnormalities of bone marrow fat using MR spectroscopy of the spine were demonstrated in T2DM patients: vertebral bone marrow fat content correlated significantly with HbA1c and visceral adipose tissue in T2DM patients and decreased unsaturated bone marrow lipids were found to be associated with T2DM and fragility fractures. Other imaging technologies that have been used to assess bone structure and texture in diabetic bone disease are high-resolution MRI, quantitative ultrasound, and trabecular bone score derived from DXA images. This chapter will summarize results from recent studies analyzing bone structure and quality in patients with diabetic bone disease and increased fracture risk.