The research is intended to evaluate the short-term reproducibility of the XtremeCT device for measurements of peripheral bone density and bone structure in population-based volunteers from different age groups and to compare the XtremeCT with current peripheral quantitative computed tomography (pQCT) technology. The investigators will also assess the correlation between XtremeCT measurements of bone structure with hormones and biochemical markers of bone turnover.

The investigators plan to perform high resolution-peripheral quantitative computer tomography (HR-pQCT) using the XtremeCT device in future research studies to investigate the structural changes that occur during adolescence and young adulthood to attain peak bone mass (peak bone strength) and to evaluate the structural effects of anabolic treatments for osteoporosis. This preliminary study will establish the short term precision of the device in the populations that the investigators are likely to study and whether the new device is superior to their current pQCT device. It will also provide information on how measurements from the new device relate to bone turnover markers, which are one of their standard assessments of bone metabolism. They will also determine whether hormones that influence bone metabolism have specific effect on different components of bone structure. By providing data on the size and variability of differences in bone structure by gender and at important stages of skeletal development (end of longitudinal growth, peak bone mass and aging) this study will also form the basis of power calculations for future longitudinal studies.

Inclusion Criteria:

• Healthy subjects
• Willing to participate
• Aged 16-18, 30-32 or ≥ 70 years

Exclusion Criteria:

• Unable to give informed consent

• Prior fracture of both wrists or both tibiae

• Confirmed fracture of three or more vertebrae between the levels of L1 and L4, or degenerative bone disease preventing three or more vertebrae from being evaluated

• Diagnosis of any disease or condition known to affect bone metabolism

• Use of any medication known to affect bone metabolism

• Pregnancy

  • 16-18 and 30-32 year old women will undergo a urine-based pregnancy test at the study site prior to undergoing any study procedures to avoid unnecessary exposure of a foetus to ionizing radiation.

Volunteers