A DEXA scan (bone densitometry) is a noninvasive procedure used to determine the extent of bone loss. The results can help assess a patient's risk of osteoporosis by measuring bone mineral density.
A DEXA scan is a simple procedure with no major risks and no need for anesthesia. Only a very small amount of radiation is used during this procedure, which will not affect the patient over a series of exams. After the risk of osteoporosis and related fractures is determined, patients can take certain precautions to reduce their risk of fracture and keep bones as strong and healthy as possible.
Reasons for a DEXA Scan
A bone densitometry scan is most commonly performed on the lower spine and hips, allowing patients to take preventive measures against osteoporosis before they experience a broken bone. When used over time, a DEXA scan can detect even the smallest gain or loss in bone density to help detect or diagnose conditions.
The exam is recommended on a regular basis for women over the age of 65, or anyone over the age of 60 with an increased risk of osteoporosis, including those with the following criteria:
- Family history of the disease
- Slender in build
- Lead a sedentary life
- Take medications such as bone thinners or steroids
- Have certain illnesses
Bone densitometry is also recommended for patients at risk for bone fractures in general. Certain factors such as age, body weight, medical history, family history and lifestyle habits can greatly increase that risk.
These may include:
- Post-menopausal women who are not taking estrogen
- Post-menopausal women who are over 5'7" or under 125 pounds
- Patients with type 1 diabetes, liver disease, or kidney disease
- Patients who use medication that causes bone loss
- Patients with a thyroid or parathyroid condition
- Patients with a high bone turnover
- Patients who have had previous X-ray indications of fracture or osteoporosis
Bone densitometry is considered the most accurate diagnostic test for osteoporosis and can help determine a patient's risk of fracture.
The DEXA Scan Procedure
No special preparation is required for the bone densitometry procedure. Depending on the size of the targeted area, the procedure may last from 10 to 30 minutes. During the procedure, the patient lies on a padded table with an X-ray generator below and an imaging device above. The targeted area is positioned in order to achieve ideal results, before the imaging device is passed over the area to produce images that appear on a computer monitor. Using DEXA technology, the imaging device sends low-dose beams with two energy peaks that examine soft tissue and bone. The soft tissue results are then subtracted from the total to determine the patient's bone mineral density.
The results of a bone densitometry scan are visible after just a few minutes and can be discussed with the patient then or analyzed at a later date. There is no pain associated with this procedure, and patients are able to return home and resume their regular activities immediately. There are no major complications or side effects associated with the bone densitometry procedure.