Have you ever been referred for a scan or medical imaging procedure not knowing what the words on the referral note mean, or what to expect from the scan? We are here to help and to explain some of the tricky terms of radiology. First up, bone densitometry or dual-energy X-ray absorptiometry (DEXA).

What does it mean?

Bone densitometry, simply known as a bone density scan, is a medical imaging technique used to assess bone mineral density.

What happens?

It involves exposing a patient to low levels of X-rays, usually targeting the hip and spine. The data is processed on a computer and the bone density measurements are displayed on the monitor. It is non-invasive, quick and involves minimal radiation exposure and is absolutely painless.

Why do you have it

You may need a bone density scan if you are over 50 with a risk of developing osteoporosis or, under 50 with risk fractures such as smoking or a previous broken bone. A bone density scan measures how dense your bones are and how likely you are to suffer a fracture.  It is the preferred procedure for identifying osteopenia or osteoporosis.

Osteopenia is a condition where people have a lower bone mass or bone mineral density than is usual for a person’s age.

Osteoporosis, on the other hand, is a bone disease where the body loses bone mass or density. The bones become weaker and are more likely to fracture.

What to remember

1. You need to make an appointment
2. If you have any previous bone density results take them with you
3. Tell the radiographer:
   • If there is any possibility you may be pregnant
   • Of any recent intravenous administration of a contrast or barium study
   • Prior lumbar spine or hip surgery or some bone disorders may influence the results
4. Provide the radiographer with a detailed medical history

What to expect

• Any garments with metal zippers, belts or buttons and jewellery may interfere with X-ray images. You will therefore be required to wear the gown provided
• During the examination you will lie on a flat, padded examination table while a mechanical arm-like device will pass over your body, emitting low-dose radiation. This procedure is painless
• You will have to remain as still as possible throughout the short examination
• Regions that will receive specific attention include the lumbar (lower back) vertebrae, the femoral neck (upper part of your thighbone which connects to the hip), the wrists and forearms
• You may wait for the results or they may be sent to you

This article is part of a series. Visit our news section for more.