Endocrine Abstracts

The clinical diagnostic examination of patients and the research-oriented investigation of the pathophysiology of skeletal disorders require imaging techniques that allow to visualize the skeleton at different scales: from the organ level to tissue, cellular, and subcellular levels, depicting morphology and function. Progress in the field of imaging technologies resulted in methods suited for clinical investigation of patients in vivo, non-invasive methods for preclinical animal studies and sophisticated functional and molecular imaging methods for both in vivo and ex vivo characterization of bone status have been introduced.

At the macroscopic scale the mechanical function of individual bones can now be assessed by 3-D volumetric spiral CT approaches. The image-data collected can be analyzed using Finite Element Models to calculate breaking strength under simulated impacting forces. This allows more accurate identification of subjects at risk for fracture and the monitoring of progress in fracture healing.

At the microscopic scale micro-CT has seen impressive advances with ever increasing image resolution – some devices are now suited for nano-CT imaging. This technology allows studies on the effects of bone turnover in normal and diseased tissue, including metabolic bone disorders such as osteoporosis but also of arthritis and skeletal tumours and metastases. Examinations of living animals enable the non-invasive longitudinal monitoring of skeletal effects of therapeutic interventions.

Finally, molecular imaging, i.e. the visualization of molecular, biochemical or cellular processes with radiological methods: to date this method is mostly restricted to animal studies. However, the achievements seen here are impressive: localized visualization of molecular and physiological information, e.g. imaging of labelled osteoblasts and their precursors, monitoring of the effects of hormones or gene therapy, or an earlier identification of skeletal metastases. Substantial research is still required to bring these advances to the clinic but the prospects for better individualized patient care based on combined molecular imaging and therapy are most exciting.