What is a Body Composition Scan and How Does It Work?
A body composition scan using DXA (Dual Energy X-Ray Absorptiometry) provides precise and accurate data on bone and tissue composition, including bone mineral density (BMD), lean tissue mass, and fat tissue mass. It offers both total body and regional results (trunk, arms, legs, pelvis, and android/gynoid regions). The scan is fast, non-invasive, and uses a small amount of radiation.
Note: While a BMD measurement is generated during this scan, it is not accurate enough for a clinical diagnosis of Osteoporosis. Patients requiring a formal diagnosis should undergo a dedicated DEXA scan of the spine and hip.
Radiation Risk vs. Benefit
A body composition scan uses a small amount of ionizing radiation—equivalent to about two days of background radiation. Studies show that this low radiation dose carries minimal risk to patients, with the benefits (accurate measurement of body fat, lean mass, and bone composition) outweighing the potential risks.
Items to Remove Before the Scan
Please remove the following items to ensure accurate results:
- Purse, wallet, money clip, and any magnetic strip cards (e.g., credit cards)
- Electronic devices (mobile phones, pagers)
- Hearing aids
- Metal jewelry and watches
- Pens, paper clips, keys, coins
- Hair accessories containing metal (hair barrettes, hairpins)
- Any garment with metal zippers, buttons, snaps, hooks, underwire, or metal threads
- Shoes, belt buckles, safety pins
What Is the Purpose of This Test?
Body composition measurement with DXA can look beyond weight and the traditional Body Mass Index (BMI) to determine body fat distribution—an important risk factor in various serious diseases. This information can be valuable for monitoring and evaluating:
- Obesity
- Anorexia nervosa
- Cystic fibrosis
- Wasting syndrome (caused by HIV/AIDS)
- Chronic renal failure
Measuring body composition can help physicians monitor the effects of therapy, diet, or exercise and provide a thorough evaluation of a patient’s health status.
During the DXA Scan
The entire scan typically lasts about 20 minutes. You will lie on your back with your hands at your sides. The radiographer will then scan your body from head to feet, all in a single exposure.
How Do I Prepare for the Scan?
What to Wear: Wear loose, comfortable clothing without metal (zippers, buttons, buckles, etc.). Metal can interfere with the scan’s accuracy. You may be asked to remove clothing or change into a gown if your attire contains metal.
Food and Drink: There are no dietary restrictions before a body composition scan. You can eat normally on the day of your test. However, if you routinely take calcium supplements, stop for at least 24 hours before your appointment.
Other Considerations: Let the radiographer know if you have recently had a Barium enema or swallow, or if you received a contrast injection for a CT/MRI or radioisotope scan. They may also ask a few questions regarding your health and lifestyle before starting.
Contact Us
Diagnostic Healthcare Limited
The Royals, 353 Altrincham Road
Manchester, M22 4BJ
Tel: 0161 929 5679
Email: info@dhc.uk.com