Bone density test

Special x-rays are used to determine how many grams of bone mineral content (calcium and other bone minerals) is filled into a section of the bone. Bones with high mineral content indicate very dense bones thus indicating the bones are strong and have fewer chances of breakage. Bone density tests are recommended by doctors to check for osteoporosis. Bone density tests are done either by central or peripheral devices. Central devices are huge machines on which the patient can lie down. Such devices are mainly used to check the lumbar vertebrae (lower region of the spine), the narrow neck of the femur bone adjoining the hip and the bones of the wrist and the forearm.

Dual energy X-ray absorptiometry (DXA): This test produces exact results and is the most preferred choice to diagnose osteoporosis. The patient will be asked to lie down on a padded platform as an imager (an apparatus like a mechanical arm) passes above the body. The required information is captured by the device and the test is completed within 20 minutes. The amount of radiation exposure in this test is equal to one-tenth of a chest x-ray radiation. DXA scan can detect even a 1% change in the bone, that which can not be achieved through an ordinary x-ray.

Quantitative CT scan: The bone density (especially spine) is measured with the help of a computerized tomography (CT) scanner along with computer software. The scan produces a three-dimensional picture which also relates to the aging consequences of the bone and diseases other than osteoporosis. The patient is made to lie down on a movable table that is directed into a big tube-like area where images are pictured. The test is completed within 20 minutes and the radiation exposure is slightly more when compared to the DXA scan.

Peripheral devices are moveable machines that measure the bone density on the periphery of the skeleton. e.g. finger, wrist or heel. They are smaller machines when compared to the central devices and can be found in pharmacies and have their own restrictions. These machines are used to check for the bone density in the heel, or wrist or fingers.

Osteoporosis

Literally meaning 'porous bones', osteoporosis is a medical condition that is characterized by fragile skeletal structure. Osteoporosis threatens nearly 34 million women in the US alone and many more worldwide. Osteoporosis is commonly noticed in post-menopausal women. But actual loss of bone mass happens in the 30s. This occurs due to loss of lose an excessive amount of their protein and mineral content, particularly calcium from the bones. Over time it leads to reduced bone mass and decreased bone strength. Normal bone marrow has small holes within it, but a bone with osteoporosis will have much larger holes. Osteoporosis can be classified into two categories - primary and secondary. Primary osteoporosis is associated with bone loss, which is prevalent in older persons and post menopause women. Secondary osteoporosis results from chronic conditions that contribute significantly to accelerated bone loss.

Most often osteoporosis is caused by a combination of lifestyle, genetic and hormonal factors. Slender, small-framed women are particularly at risk. Typical symptoms of osteoporosis are severe back pain, curvature of the spine and loss of height. A woman suffering from osteoporosis suffers from joint aches and muscle aches. There is an increased tendency to fractures on account of brittle and thin bones. Osteoporosis can be hereditary. Women with very thin body frames can be at increased risk of osteoporosis on account of lesser bone mass. Prolonged use of corticosteroids can put a woman at increased risk of osteoporosis since drugs such as prednisone, cortisone, prednisolone and dexamethasone damage bone mass. Other medications that can lead to bone loss are diuretics, anti-seizure drugs and anticoagulants. Hyperthyroidism is another contributory factor to developing osteoporosis. Chronic conditions such as renal failure, malnutrition and connective tissue diseases contribute towards development of osteoporosis.

Diagnosis of osteoporosis may include a series of tests such as bone densitometry (a bone density scan) performed by your physician. There are three types of bone density scans: dual-energy x-ray absorptiometry (DEXA), single photon absorptiometry (SPA), and quantitative computed tomography (QCT). The most common bone density scan is the DEXA - a test that measures bone density based on how bone absorbs two sets of photons (atomic particles with no electrical charge) generated by an x-ray tube. A bone density test is recommended by physicians to post menopausal women, especially those with a higher risk factor.

It is essential to build on your bone mass during the ages of 25 - 35 so as to keep osteoporosis at bay. This can be done by maintaining a balanced diet, with plenty of calcium and following a regular exercise regimen. Weight-bearing exercises are of special importance in strengthening the bones. Running, skipping, aerobics, tennis and weight training are ideal osteoporosis exercises that can be undertaken thrice a week for at least 30 minutes. Apart from bone density, these exercises also increase the strength, co-ordination and balance, thereby reducing the risk of falls. A sedentary lifestyle can put you at increased risk of developing osteoporosis in latter years.

• Consuming a balanced diet, rich in calcium
  
• Eating green leafy vegetables, citrus fruits, dairy products, nuts and shellfish
  
• Calcium supplements
  
• Avoid smoking and excess alcohol intake