Osteoporosis is a disease that primarily affects the elderly and usually with crippling effects. Although osteoporosis is preventable and its effects somewhat reversible, early diagnosis is essential in order to make effective treatment decisions. Covered in this issue are imaging with plain film, ultrasound, and CT. Separate reviews of vertebral fractures and morphometry as well as well as percutaneous vertebroplasty are included. Articles on densitometry in children and quality assurance round out the issue.