What is a Bone Density Scan (DXA)?
Bone density scanning, also called Dual-Energy X-ray Absorptiometry (DXA or DEXA) or bone densitometry, is an enhanced form of X-ray technology that is used to measure bone loss. DXA is today’s most widely used and most thoroughly studied bone density measurement technology.
DXA is most often used to diagnose osteoporosis, a condition that often affects women after menopause but may also be found in men. Osteoporosis involves a gradual loss of calcium, as well as structural changes, causing the bones to become thinner, more fragile and more likely to break. DXA is also effective in tracking the effects of treatment for osteoporosis and other conditions that may contribute to bone loss.
What are some common indications for DXA?
The DXA test can also assess an individual's risk for developing fractures. The risk of fracture is affected by many factors, some of which may be: age, body weight, cigarette smoking, excessive alcohol consumption, prior fractures, and family history of osteoporotic fractures. A patient’s comprehensive medical history revealing these factors is taken into consideration before deciding which course of treatment would be most beneficial and appropriate.
Bone density testing is strongly recommended for post-menopausal woman. Criteria such as: relative tallness (5 feet, 7 inches or above), low body weight (less than 125 pounds), whether one takes estrogen replacement hormones, hip fracture histories, and whether one smokes all contribute to the need to be tested. Bone density testing is also highly advised for individuals diagnosed with any of the following conditions: type 1 diabetes, thyroid, parathyroid, liver and/or kidney disorders. Those taking medications known to cause bone loss or anyone with a history of high bone turnover (a condition revealed by excessive collagen in urine samples) should also be tested.
Preparing for your DXA exam?
On the day of the exam, patients should eat a normal diet and avoid taking calcium supplements for a minimum of 24 hours before the exam. Patients should wear loose, comfortable clothing and avoid garments with metal zippers, belts, or buttons. Most often, a gown will be issued and patients may be asked to remove some or all of their clothing, jewelry, dentures, eyeglasses, or anything made of metal that may interfere with the x-ray process.
What does the DXA machine look like?
Our DXA machine consists of a large, flat table with a suspended "arm" mounted overhead. The patient lies on the padded table and the arm moves back and forth over their body scanning as it goes along. Once the patient is situated on the table, the procedure generally takes no more than 15 minutes to complete.