A DEXA scan (Dual Energy X-ray Absorptiometry) uses X-rays to measure what the body is composed of. The same technology answers 2 different clinical questions: how dense your bones are, and how much fat and lean mass you carry. Your referral will name which of the 2 your doctor has asked for. Both are performed at selected Jones Radiology clinics, and both can be booked online.
What a DEXA scan is
DEXA stands for Dual Energy X-ray Absorptiometry. The scanner passes 2 X-ray beams of different energy levels through the body. Bone, fat and lean tissue absorb those beams differently, and the difference between them is what lets the scanner measure each tissue separately.
That 1 measurement principle is why the same machine answers 2 unrelated questions. Aimed at the skeleton, it measures bone mineral density. Aimed at the whole body, it measures fat and lean mass and where they sit.
A DEXA scan is quick, open and non-invasive. There is no tunnel to enter and no injection.
The 2 types of DEXA scan
Both scans are performed on the same equipment, but they answer different questions, are usually requested by different clinicians and are reported differently. The 2 summaries below cover the same 5 points, in the same order, so you can read them side by side.
Bone density DEXA scan
A bone density scan measures the strength of your skeleton.
- What it measures: bone mineral density, which is how much mineral content is stored within your bone.
- Why it is done: to assess bone health, to look for osteoporosis or osteopenia, and to help estimate your risk of fracture.
- Which part of you is scanned: the lower back and a hip, and possibly a forearm if that is needed because of your medical history or your lower back and hip results.
- Who usually asks for it: a GP, or a specialist such as an endocrinologist or rheumatologist.
- Also called: bone densitometry, BMD, bone density test.
Read more about the bone density scan.
Body composition DEXA scan
A body composition scan measures what your body is made of. It is not an assessment of bone health.
- What it measures: fat mass, lean muscle mass and how they are distributed across your body.
- Why it is done: to establish a baseline and to track change over time, for example alongside a training, nutrition or metabolic program.
- Which part of you is scanned: the whole body.
- Who usually asks for it: a GP, a sports physician or an allied health practitioner.
- Also called: body composition analysis, DEXA body scan, body fat scan.
Read more about the body composition scan.
Which scan has your doctor asked for
Check your referral before you book. It will name either a bone density scan (sometimes written as bone densitometry or BMD) or a body composition scan.
The 2 scans are booked differently, take different amounts of time and are reported differently, so booking the wrong one means booking again. If your referral is not clear, confirm with the doctor who wrote it before you book.
Bone density and body composition are 2 different scans on the same machine. Your referral names the one your doctor has asked for.
What happens during a DEXA scan
A DEXA scan is performed with you lying on an open table. You are not enclosed at any point, and nothing is injected.
You need to stay still while the scan is running.
The table is padded, and the scanning arm passes above you without touching you. You may be asked to hold a still position, or to rest your legs on a support.
How long a DEXA scan takes
A bone density scan usually takes 15 to 20 minutes. We suggest allowing 30 minutes at the clinic.
A body composition scan takes about 10 minutes, and we suggest allowing 20 minutes.
How to prepare
- If you take calcium supplements, withhold them for 24 hours before your scan.
- Wear thin clothing with no metal or dense components on it. We can supply an imaging gown if you would prefer.
- Remove jewellery before your scan, or preferably leave it at home.
- Bring any previous DEXA scans, if they were not performed at a Jones Radiology clinic.
Precautions
If you are pregnant, or think you might be, it is important we are aware before your appointment.
A bone density or body composition scan is not an urgent examination, so we would not recommend either during pregnancy.
Our X-ray dose information page explains how Jones Radiology handles imaging during pregnancy in full.
Some tests need to be completed before a DEXA scan can give an accurate result, because injected or ingested media interferes with the measurement. Please tell us at the time of booking if you have recently had any of the following.
- A barium study. Allow 1 week before a DEXA scan.
- A contrast study, such as an X-ray, CT or MRI using dye. Allow 48 hours.
- A nuclear medicine injection. Allow 48 hours, although some nuclear medicine injections need 1 to 2 weeks.
Our scanners have a weight limit of 227kg.
Radiation and safety
A DEXA scan uses very low dose X-rays. Nothing is injected, and nothing remains in the body afterwards.
The maximum X-ray dose you receive is the equivalent of 1 day of natural background exposure.
Where to have a DEXA scan in South Australia
Not every clinic offers both scans, so it is worth checking the list before you book. Every address, opening hours and parking detail is on our clinic locations page.
Clinics offering bone density scans
Bone density scans are performed at Alice Springs, Burnside, Gawler, Morphett Vale, Mount Barker, Port Augusta, Prospect, and 337 South Terrace in Adelaide.
Clinics offering body composition scans
Body composition scans are performed at Burnside, Gawler, Morphett Vale, Mount Barker, Port Augusta, Prospect, and 337 South Terrace in Adelaide.
Booking a DEXA scan online
You can book both scans online, in 3 steps.
- Choose your scan and your clinic.
- Pick a time that suits you.
- Upload your referral. A clear photo taken on your phone or a PDF both work.
Online booking does not cover every appointment. Please call 1800 375 663 instead if your appointment is at our Alice Springs clinic, or if you are a patient of another healthcare facility such as a nursing home, aged care residence or external hospital. Those appointments are arranged directly with the facility.
If you have already booked and only need to send your paperwork, use Upload a Referral.
Referrals and fees
Imaging is performed on referral from your doctor, specialist or other eligible health practitioner. A referral is required for both scans.
Fees depend on the examination, your referral and your eligibility for a Medicare rebate. Current information is set out on our Payment and Fees page.
Your results
Your images are reported by a Jones Radiology subspecialist radiologist, so your scan is read by a radiologist working in the relevant area of imaging. The report goes to the doctor who referred you, who will discuss the findings with you.
You can also view your own reports through the Patient portal.
Why patients choose Jones Radiology
Jones Radiology is 100% South Australian doctor owned and operated. Every study is reported by a subspecialist radiologist rather than a generalist. We have clinics across metropolitan Adelaide, regional South Australia and Alice Springs.
DEXA scan questions
Is a DEXA scan the same as a bone density scan?
A bone density scan is a DEXA scan, but not every DEXA scan is a bone density scan. DEXA is the technology. Bone density and body composition are the 2 studies performed with it.
Does a DEXA scan hurt?
No. Nothing enters the body and nothing presses on you. You lie still on an open table while the scanning arm passes above you.
Do I need a referral for a DEXA scan?
Yes. Both a bone density scan and a body composition scan need a referral.
How often should I have a bone density scan?
That is a decision for the doctor who referred you, and it depends on your results and your circumstances.
Can I have both scans at the same visit?
Yes. Both scans need to be clearly requested, either on 1 referral or on 2 separate referrals.
What is the difference between a DEXA scan and a nuclear medicine bone scan?
A DEXA scan measures how dense your bones are. A nuclear medicine bone scan looks for areas of abnormal activity in bone, and is a different examination to answer a different medical question.
Can I have a DEXA scan if I have had a hip or knee replacement?
Joint replacements, spinal hardware after surgery, or a recent fracture can affect the result. For a bone density scan we simply scan other available sites. For a body composition scan the affected region will read differently, but every other area remains accurate.
Our scanners are cross-calibrated, so a follow-up scan can be performed accurately at any of our clinics.
Are you ready to make your Bone Density Scan appointment?
Our online booking platform allows you to quickly and easily make an appointment online.
