Bone Densitometry at the Royal Adelaide Hospital

The Dept of Nuclear Medicine & Bone Densitometry established bone densitometry in South Australia in 1982. Since then, we have upgraded & maintained state of the art bone densitometry equipment and achieved many firsts. These include the first total body bone densitometer in Australia, the first imaging bone densitometer, and the first X-ray based mobile bone densitometry service in Australia.

The department refurbishment has resulted in a dedicated bone densitometry suite. The suite operates with 3 X-ray based bone densitometers capable of scanning any site. We also operate our mobile service in rural regions all year, and an ultrasound absorptiometer which is primarily used for screening both at the RAH and at rural fairs.

The department is not associated with the equipment operated by the RAH Department of Medicine.

Our commitment to research ensures that the benefits of modern osteoporosis assessment & management are available to all South Australians - city or country.

We aim to increase community awareness of osteoporosis & its potential treatments by providing education and accurate, reproducible bone densitometry testing services to all South Australians.

A Mobile Bone Densitometry unit was begun as an initiative in 1994 as part of this aim. The unit offers spine & hip bone density testing to rural South Australia.


Normal and Osteoporotic bone (Courtesy Prof BEC Nordin)Osteoporosis results from the reduction of the mineralised material in the bone, and causes an overall weakening of the affected bones and increased risk of fracture. This occurs when bone is not being replaced at the same rate as it is lost (normally, bone is continually formed and removed in equal amounts), and occurs sooner if the amount of bone established when young is less than average.

Although some risk factors may suggest you might have osteoporosis, the only way to be certain is with a bone densitometry test.

Who is at risk ?

The female hormone, oestrogen, has an effect on the bone to maintain its density. Due to the loss of oestrogen at menopause post menopausal women are at the greatest risk - although not all post-menopausal women will develop osteoporosis.

Men can also develop osteoporosis, but not as commonly as women. The chart below lists some of the risk factors which may predispose you to developing osteoporosis. It is important to realise that even if you have no risk factors osteoporosis may still be present.

Risk Factors
  • EARLY MENOPAUSE ( ie under 45 years of age)
    eg Corticosteroids, Thyroxine. These medications are important so keep taking them.

Dispelling Osteoporosis Myths

Osteoporosis does not cause pain in joints. Back pain may be due to fractures in vertebrae which have resulted from osteoporosis.
Osteoarthritis is a different condition and is assessed by other techniques.

Who should have their bone density measured ?

Measuring your bone density provides information that helps you decide if you should alter your lifestyle, or commence treatment to reduce the risk of later fracture. Measurements are generally done around the time of the menopause, but it is never too late. It is even more important if you have one of the risk factors mentioned above.
Although osteoporosis occurs in men, it is less common and routine bone density is not recommended at present.

In South Australia, X-ray based bone densitometry currently requires a doctor's referral, and you should discuss with your doctor if measurement of your bone density is necessary.

In April 2007, the Australian Federal Government approved a funded DXA scan for people over the age of 70.

Having the bone density scan

The aims of bone densitometry are to identify those at risk of developing osteoporosis and to monitor change in bone density, particularly with therapy. The most useful techniques must therefore be accurate and reproducible.

Bone density can be assessed by a number of methods that rely on measurement of the amount of x-ray or sound passing through the bone of interest.

Available methods include :

DXA scans

Bone Densitometry scanningThe lower spine, upper femur (and sometimes the forearm) are usually measured as they are more sensitive to short term change. The lower spine scan requires you to lie on a bed on your back, with a pillow under your head and cushion under your knees. For the femur scan, the cushion under your knees is removed and your foot is strapped into a positioning brace.

The bone density test measures any dense object in the area being scanned, so any metal around your hips, waist or lower spine must be removed. If you wear a long line bra, you will be asked to remove it.
Depending on the equipment in use, appointments take up to 20 minutes, and it is important you arrive on time.

For the test, any metal or dense objects around your hips, spine or waist will need to be removed. Some bras (eg long-line bra) and fasteners on clothing may need to be removed - you will be also asked to remove it or given a change of clothing for the scan.

Where can a bone density test be obtained?

The RAH operates 4  DXA bone densitometers of the same brand and calibration, including the Mobile Bone Densitometry Unit in rural SA, but DXA bone densitometry tests are available at other major public hospitals and a number of private radiology & endocrine practices.
The cost of testing varies :

Why is DXA performed in Nuclear Medicine?

Many people ask why bone densitometry is performed in Nuclear Medicine as well as radiology and endocrinology departments.

Early bone densitometry used radioisotopes such as 153Gd and 125I as the photon source and radiology departments were not well equipped to handle these materials.

Additionally, bone densitometry is a functional rather than imaging modality, and early bone densitometry did not provide images. As it moved to imaging and X-ray based photon sources, Nuclear Medicine departments with their strong image processing skills and understanding of the statistics, remained important high quality providers of bone densitometry.

When are the results available?

Most practices send the results directly to your referring doctor unless a consultant physician is present to see you. If you are scanned by the RAH Bone Densitometry Service, results will usually be at the doctor's rooms within 5 working days, whether you are seen in Adelaide or the country.

Some doctors have access to the results electronically within 2-3 days normally.

What happens to the results ?

Your doctor will discuss your results with you. It may be necessary for you to have a follow up measurement after about 2 years after your first scan to determine the rate of bone loss.

As different bone densitometer manufacturers have differing calibration on their machines, it is important that any subsequent scans be done on the same machine (or at least the same brand) for results to be comparable.

To aid this in country areas, the Mobile Bone Density Unit will visit the same region annually, but the town may change.
The mobile service is equipped with the same brand of bone densitometer as our service at the RAH.

How often should a DXA test be performed?

Unlike other tests such as breast mammography or papilloma virus (PAP) smears, repeat DXA testing is related to how your strong your bones are.

Is more Calcium the answer?

Calcium, which circulates in the blood, plays an important role in the body's everyday function and aids in blood clotting, muscle contraction, and nerve & brain function, just to name a few. As calcium is one of the major constituents of bone, losses from the body exceeding intake (as often happens in aging women) results in loss of calcium from the bones and may lead to the development of osteoporosis. Although maintaining your calcium intake is important regardless of age, calcium alone will not prevent bone loss.

So what sort of treatments are given?

There are many treatment options for osteoporosis, and you should discuss these with your doctor. Treatments range from conservative therapies such as exercise, adequate sunshine and maintaining calcium in your diet to hormone therapies to therapies which act to reduce bone loss.

After the menopause, women require at least 1000mg of calcium a day. Vitamin D (derived from sunlight) and exercise have also been shown to be important in maintaining bone strength.

It is essential to consider the individual in establishing a therapy, as what is suitable for one person, may not work for another. You should consult your doctor to work out what is best for you.


The department operates 5 days a week at both the Royal Adelaide Hospital and in rural South Australia with the Mobile Bone Densitometry Service.
To make an appointment in the:

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