ABOUT BONE DENSITOMETRY

What is DEXA scan or bone mineral densitometry (BMD) ?

A dual energy X-ray absorptiometry (DEXA) scan, also called a bone density scan, is a common technique used to measure bone density. This completely painless procedure is easily performed and exposes the patient to minimal radiation.

By measuring BMD, it is possible to predict fracture risk, but not the type of fracture. It is specially recommended in women of post menopausal status and in older people.

What does a DEXA scan measure ?

The World Health Organization has developed definitions for low bone mass (osteopenia) and osteoporosis. These definitions are based on a T-score. The T-score is a measure of how dense a patient’s bone is compared to a normal, healthy 30-year-old adult.

Normal: T-score between 0 and -1 is considered a normal result.
Low bone mass (medically termed osteopenia): T-score between -1 and -2.5. This signifies an increased fracture risk.
Osteoporosis: T score less than or equal to -2.5) defines osteoporosis.

What is osteoporosis ?

Osteoporosis is a metabolic disease that is characterized by low bone mass and deterioration of bone tissue. This further leads to increased bone fragility and risk of fracture. Most commonly it affects the hip, spine, wrist and shoulder. It affects both men and women equally.

Signs and symptoms –

There typically are no symptoms in the early stages of bone loss. You may have signs and symptoms that include:

  • Back pain, caused by a fractured or collapsed vertebra

  • Loss of height over time

  • A stooped posture

  • A bone fracture that occurs much more easily than expected

What are the risk factors –

  • Women are much more likely to develop osteoporosis than are men

  • Family history

  • Post menopausal status

  • Thyroid problems

  • Low calcium intake

  • Eating disorders

  • Gastrointestinal surgery

  • Steroids and other medications

  • Seizures

  • Gastric reflux

  • Medical conditions – eg – Celiac disease, Inflammatory bowel disease, kidney or liver disease, Lupus, Multiple myeloma, Rheumatoid arthritis

  • Sedentary lifestyle

  • Excessive alcohol consumption

  • Tobacco use