A bone density scan is an x-ray image that is created by using dual energy x-ray absorptiometry or DEXA. This technique can examine the whole body or specific sites such as hip, spine and forearm. DEXA is extremely safe and painless. The radiation dose for hip, spine or forearm is about 10% of a standard chest x-ray.
A bone density scan is an image taken of the bones of the body by a machine that sends out rays of radiation energy. When these rays pass through skin and muscle they are blocked by the bones, creating shadow effects. These shadows are captured and displayed on a computer screen. The computer then calculates the density of your bones.
The different parts of your body have different body tissues, which vary in their absorption of the x-rays. This means bones, soft tissues and other internal features can be seen on the screen in varying shades of grey.
Bone density examinations do not require any preparation. Articles of clothing may have to be removed if they contain metal or plastic that may show up on the x–ray. You may be asked to change into a gown.
Bone density examinations require you to stay still for between 30 seconds and 5 minutes, depending on which particular scans are being performed.
You will be asked to complete a questionnaire before the examination.
You will be required to lie on the Bone Density table and lay still whilst the scans are being acquired. The camera will slowly move above you but will not touch you.
If you are being seen in a clinic or are on a ward the images are seen by the referring doctor and a Radiologist. If you have been sent here by the doctor the Radiologist sends a report back to the doctor.