DEXA is now called DXA which stands for Dual – emission X- ray absorptiometry. It is used to study bone mineral density and is used extensively in the medical field.
Procedure: Two X-ray beams are directed at the patient’s bones. Usually the distal radius and ulna, vertebral column and proximal femur are subjected to DEXA. Once the soft tissue absorption is subtracted out, depending on the absorption of every beam by the bone, the BMD can be calculated. The radiation dose you are exposed to is nearly 1/10th of that used for a standard chest x-ray.
Uses of DEXA scan: It is used to detect osteoporosis. It is relatively cheap, easily accessible, easy to use and an accurate method to calculate the bone mineral density in adults. It is also used to regularly monitor the response to treatment in patients suffering from osteoporosis. It can similarly be used to measure the whole body composition & the fat content in your body. The fat mass can be indirectly calculated subtracting it from the Lean Soft Tissue (LST) & or Body Cell mass (BCM), which the DEXA measures accurately.
The normal bone T- score is greater than -1. Osteopenia T-score is between -1 and -2.5. Osteoporosis T- score is less than -2.5. A T-score of less than -2.5 suggests osteoporosis and that your bones are extremely liable to fractures from the slightest injury. In fact in most women who have suffered from fractures following osteoporosis did not even report injuries; they sustained the fracture during some daily activity, which suggests the intensity of proneness to develop fractures with a T-score of less than -2.5.
Use of DEXA scan in the Pediatric age group: It is not accurate to use T-scores to assess the Bone Mineral Density in children. Also the WHO classification of osteoporosis and osteopenia used in adults cannot be used in the case of children, but one can use the Z –scores to aid diagnosis. Children suffering from Rickets, Turner’s syndrome etc. can be subjected to the DEXA scan to calculate their Bone Mineral Density. However its use in pediatrics is still in its nascent stages. And further research and evaluation is necessary before it can be used regularly in the pediatric age group.
It is advisable that women over the age of 65 years should get a DEXA scan. Attaining menopause itself is a risk factor for developing fragile bones and post menopausal women should undergo a DEXA scan. Women who are at a higher risk should get a scan done over the age of 60 years itself. You may be at a higher risk if you are suffering from fragile bones, have sustained frequent fractures following trivial injuries, you consume excess of alcohol, or are a heavy smoker, if you have used steroids – glucocorticoids for a long period of time, long term use of phenobarbitone or phenytoin, a family history of early fractures in parents, if you are suffering from rheumatoid arthritis, or chronic liver or respiratory illnesses etc.
- Bone Density Scan – When, Why And How To Get One
- Running may be Superior For Strong Bones
- Acetubular Fractures Treatment
- National Osteoporosis Foundation – About it
- Bone Scan Is Not A Big Deal…!
- Bone Cancer: The Symptoms and Treatments
- Green Tea could Naturally Prevent and Treat Osteoporosis, Scientists Say
- Acetubulum Problems