DEXA
About DEXA
DEXA (Dual-Energy X-ray Absorptiometry), which is also known as a Bone Densitometry, is a form of x-ray that produces pictures of the inside of the body to measure for bone loss. Typically this is used to diagnose osteoporosis.
Also sometimes called DXA, DEXA is often time performed on the spine and hips however the whole body is sometimes scanned.
Preparing for Your DEXA Exam
DEXA Prep
No Calcium Supplements a minimum of 24 hours prior to examination.
No Nuclear Medicine Studies 1 week prior to the exam.
No IV or Fluid Contrast within 48 hours of the exam.
What to Expect During Your DEXA Exam
What does the equipment look like?
There are two types of DXA equipment: a central device and a peripheral device.
Most of the devices used for DXA (also known as Bone Densitometry) are central devices, which are used to measure bone density in the hip and spine. They are usually located in hospitals and medical offices. Central devices have a large, flat table and an “arm” suspended overhead.
Peripheral devices measure bone density in the wrist, heel or finger and are often available in drugstores and on mobile health vans in the community. The pDXA devices are smaller than the central DXA devices, weighing only about 60 pounds. They may have a portable box-like structure with a space for the foot or forearm to be placed for imaging. Other portable technologies such as specially designed ultrasound machines, are also sometimes used for screening. However, central DXA is the standard technique.
How does the procedure work?
The DXA machine sends a thin, invisible beam of low-dose x-rays with two distinct energy peaks through the bones being examined. One peak is absorbed mainly by soft tissue and the other by bone. The soft tissue amount can be subtracted from the total and what remains is a patient’s bone mineral density.
DXA machines feature special software that compute and display the bone density measurements on a computer monitor.
What will I experience during and after the procedure?
Bone density tests are a quick and painless procedure.
Routine evaluations every two years may be needed to see a significant change in bone mineral density, decrease or increase. Few patients, such as patients on high dose steroid medication, may need follow-up at six months.
Understand Your MRI/MRA Results
Who interprets the results and how do I get them?
An Abercrombie radiologist will analyze the images and send a signed report to your primary care or referring physician, who will discuss the results with you.
Follow-up examinations may be necessary. Your doctor will explain the exact reason why another exam is requested. Sometimes a follow-up exam is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. A follow-up examination may also be necessary so that any change in a known abnormality can be monitored over time. Follow-up examinations are sometimes the best way to see if treatment is working or if a finding is stable or changed over time.
