Women’s Digital Imaging of Ridgewood (WDI) in New Jersey has begun using Dual Energy X-ray Absorptiometry (DXA), to measure body fat in patients who want a more accurate method of establishing goals and measuring results for weight management and fitness programs. Dual-energy X-ray absorptiometry (DEXA) is the latest, most accurate, and most expensive means of determining body composition, and it is generally considered the current gold standard for this purpose. The information you can derive from a full-body scan is invaluable, including bone density; body fat percentage; lean body mass; fat mass; and the distribution of fat and lean tissue in the arms, trunk, and legs. DEXA output even provides the differences in lean mass and fat mass between the left and right sides. This information can be particularly important for athletes who wish to develop symmetrical bodies or who, because of the nature of the sport, need to produce the same muscular power in each leg or in each arm.
“Knowing your ratio of fat to lean body mass helps you determine how to reshape your body correctly,” says Dr. Lisa Weinstock, Director of Women’s Digital Imaging. “With DXA analysis, you can show patients where they have to make changes and measure how successful they are in making them.” The results provided by DXA imaging can help health care professionals treat conditions such as obesity, anorexia nervosa, cystic fibrosis, and chronic renal failure. It can also help athletes develop training programs to achieve optimal performance.
Fat analysis before and after gastric bypass surgery and at the beginning and midway through diet and exercise programs to accurately gauge results. Personal trainers are using Total Body Fat analysis to assess their clients’ success and make changes in their training regimen when necessary. DXA Total Body Fat analysis is helping nutritionists guide anorexic patients safely back to developing a healthy body and self-image.
A DEXA scan is painless and the volunteer is not enclosed by the equipment at any stage during the scanning process. The scanner itself consists of a large, flat table which the volunteer lies on during the scan. Beneath the table is an x-ray generator. The DEXA machine sends a thin, invisible beam of very low-dose x-rays through the body. Some of these x-rays are absorbed by the tissues in the body such as fat and bone. An arm is suspended above the table and passes over the volunteer’s body during the scanning process. This arm contains an x-ray detector that measures the amount of x-rays that have passed through the volunteer’s body. The information collected by the arm is then used to generate an image of the body.During the scanning procedure the volunteer must hold very still. This ensures that the image taken is not blurred. A full body DEXA scan usually takes five minutes.The amount of radiation energy that is used with DEXA is extremely small. You would need to have approximately 800 full-body DEXA scans before being exposed to the same amount of radiation received from one standard chest X ray. In fact, the level of radiation is so low that DEXA is approved by the FDA as a screening device to predict body composition. Usually, X-ray devices are reserved as diagnostic instruments because of the amount of radiation they impart, but not so for DEXA.