BONE DENSITY TESTING – DEXA
Bone density testing is used to assess the strength of the bones and the probability of fracture in persons at risk for osteoporosis. The test, referred to as bone densitometry or bone mineral density scan (BMD), is a simple, noninvasive procedure that takes just minutes.
Unlike a bone scan, bone densitometry testing does not involve the administration of radioactive contrast material into the bloodstream. The most commonly used test is known as a dual energy x-ray absorptiometry (DEXA) scan, and it can be performed with devices that measure bone density in the hip and spine, or smaller peripheral devices to measure bone density in the wrist, heel, or finger. The central bone density device is used in hospitals and medical offices, while the smaller peripheral device is available in some drugstores and in screening sites in the community. The DEXA scan involves a much smaller radiation exposure than a standard chest x-ray.
In premenopausal women, estrogen produced in the body maintains bone density. Following the onset of menopause, bone loss increases each year and can result in a total loss of 25%-30% of bone density in the first five to ten years after menopause. Your doctor can help you decide when and if you need a bone density test. In general, this testing is recommended for women 65 and older along with younger postmenopausal women who have further risk factors for osteoporosis, including:
- A history of bone fractures as an adult or having a close relative with a history of bone fractures
- Vitamin D deficiency, which can occur as a result of certain medical conditions
- Excessive alcohol or caffeine consumption
- Weight loss or low body weight; small-boned body frame
- Early menopause or late onset of menstrual periods
- Physicial inactivity
- Taking a medication [such as prednisone or phenytoin, (Dilantin)] known to cause bone loss
- Low estrogen levels
Your bone density measurement will be compared to the average peak bone density of young adults of the same sex and race. The results are usually reported as a "T score" and a "Z score." The T score compares your bone density with that of healthy young women, while the Z score is acomparison of your bone density with that of other people of the same age, gender and race.
In either the T or Z score, a negative number means you have thinner bones than the standard. The more negative the number, the greater the degree of bone loss.
Osteoporosis is defined as the beginning of bone loss and corresponds to a T score of -1 to -2.5. A T score lower than -2.5 is indicative of osteoporosis.
Osteoporosis Risk Factors:
- Female gender, Caucasian or Asian race, thin and small body frames, and a family history of osteoporosis (Having a mother with an osteoporotic hip fracture doubles your risk of hip fracture)
- Cigarette smoking, excessive alcohol and caffeine consumption, lack of exercise, and a diet low in calcium
- Poor nutrition and poor general health
- Low estrogen levels such as occur in menopause or with early surgical removal of both ovaries. Another cause of low estrogen level is chemotherapy, such as for breast cancer. Chemotherapy can cause early menopause due to its toxic effects on the ovaries.
- Amenorrhea (loss of the menstrual period) in young women also causes low estrogen and osteoporosis. Amenirrhea can occur in women who undergo extremely vigorous training and in women with very low body fat (example: anorexia nervosa).
- Chronic diseases such as rheumatoid arthritis and chronic hepatitis C, an infection of the liver.
- Immobility, such as after a stroke, or from any condition that interferes with walking.
- Hyperthyroidism, a disease wherein there is excessive parathyroid hormone production by the parathyroid gland (a small gland located near the thyroid gland.) Normally, the parathyroid hormone maintains blood calcium levels by, in part, removing calcium from the bone. In untreated hyperparathyroidism, excessive parathyroid hormone causes too much calcium to be removed from the bone, which can lead to osteoporosis.
- Vitamin D deficiency. Vitamin D helps the body absorb calcium. When vitamin D is lacking, the body cannot absorb adequate amounts of calcium to prevent osteoporosis. Vitamin D deficiency can result from lack of intestinal absorption of the vitamin such as occurs in celiac sprue and primary biliary cirrhosis.
Using reflected sound echoes to study and characterize internal structures and tissues, ultrasound technology is used regularly with heart patients, as a follow-up to a mammogram, and with pregnant women.
The benefit of the technology for heart patients is the original diagnosis and follow-up of heart valve abnormalities. In follow-up to mammograms, the equipment proves valuable in determining if suspicious lumps are benign cysts or cancerous growths. The technology continues to provide new ways to diagnosis problems in the gallbladder, musculoskeletal system, and prostate gland. However, it may be most well known for it use in obstetrics.
A new addition to the ultrasound department is helping expectant parents to have a better look at their upcoming new addition. A 3-D state-of-the-art ultrasound provides parents with a view of the fetus in the womb. While doctors are using the exam to determine the developmental age and overall health of the fetus, parents are being provided with an incredible view of the baby.