World Osteoporosis Day – October 20

Prevent Osteoporosis and protect your Bones. Know your Bone Density by knowing about DEXA Scan.


Bone health has been defeated by our sedentary lifestyle and as a result, people’s aging process has accelerated. As a result of the existing bone breaking down quicker than new bone formation, bones of the skeletal system become fragile as a person grows older. These result in a decrease in calcium levels in the skeletal system – bones become lighter, soft (lacking density) and more delicate causing osteoporosis. Scientific literature estimates that approximately 80% of the urban Indian population is vitamin D deficient, which is indeed an add-on disadvantage.

Consequently, thicker bones take a longer time to get osteoporosis. Although osteoporosis can occur in men, it is most common in postmenopausal women as they can fall into a state of estrogen deficiency, causing changes in bone density. It is also important to note that hip fractures in old age and postmenopausal women occur about a decade earlier in India compared to western nations. Osteoporosis is hence a major concern for this aging population. It is up to us to realize the importance of measuring bone health for the geriatric in a hassle-free manner.

Dexa Scan:


DEXA is an acronym for Dual Energy X-ray Absorptiometry. As the name implies, two x-ray beams with different energy peaks are passed through the body, generating a 2D image. One beam gets absorbed by the soft tissues and the other by the bones. The key parameter to judge bone strength, the BMD is calculated by subtracting the soft tissue amount from the total area. These scores are compared with the normal ranges coordinated with chronological age. DEXA scan identifies brittle bones to predict the likelihood of a future fracture and helps to prescribe medication to slow down bone loss.

Taking A Dexa Scan:

Similar to a CT scan, the patient will lie on his/her back for about 10 minutes on a comfortable table whilst being scanned. The doctor (radiologist) is assisted by a computer software that will determine the body composition in terms of bone, lean muscle and fat tissues. The radiologist then compiles a report with the composition distribution of the whole body.

Why Dexa?

DEXA has the advantages of being a quick and non-invasive procedure with the further convenience of not requiring any form of anesthesia. It is also low cost, involves less radiation and short scan times, making it a very practical method. To make the layman understand the artistry of this simple scan, we can equate the amount of radiation exposure to just one dental x-ray.

Over the last decade, the DEXA scan has been used as the gold standard and is the most accurate scan for calculating the bone mineral density (BMD), bone mineral content (BMC) and fat-free mass (FFM) providing estimates of the percentage of body fat. It is also used for vertebral anomalies, for prescribing medications for bone loss and thyroid conditions and for the conditions of the hip and spine. DEXA can also effectively characterize lean and fat volume when compared to the CT or MRI to measure body composition.

This Brings Us To Dexa Scan for Fitness:

When we say body fat percentage, we mean measuring the fatty tissue alone without including any other type of tissue. A weight comparison between a sportsperson and an overweight person of the same height will reveal that the sportsperson will weigh more. This is because sportspersons have a higher muscle content. Thus, there is a need for DEXA to measure the exact body fat percentage. To state another example, a naturally slim model may have more fatty tissue than a model that has to work out more to maintain the required physique. The body composition when tracked with DEXA helps them achieve their goals faster and better as it is evidence based. An athlete’s or a fitness model’s low body fat can affect the healthy functions of the body, including a woman’s reproductive functions. Female professional body builders and fitness models have a body fat percentage that falls in the range of 15-17% while for males it falls in the range of 6-7%. These percentages are always risky as they top the essential fats percentage only by a very small value. Hence in such cases too DEXA scan helps by keeping track of body composition. DEXA is great for people getting fit, sportspersons, professional bodybuilders, models, fitness models and athletes. It allows them to see the progress they are making in their physical training, especially after an injury that elaborates on their need to maintain their fat percentage, muscle mass and sports performance to measure athletic development.

Dexa Scan For The Obese:

On the other hand, in the younger Indian population, obesity has reached epidemic proportions in 2020, with morbid obesity affecting 5% of the population. According to NFHS (National Family Health Survey) data, 19.8% of the men and 24.4% of the women in Tamil Nadu are obese. The traditional weigh-in or body mass index measurements are inaccurate. In a scientific study, traditional BMI had misclassified 34.7% of women and 35.2% of men into an incorrect category, majorly classifying many overweight and obese individuals as normal weight. The misclassification was age and gender-specific, with the largest discrepancy observed in women under 40 years of age. When obese patients are misclassified by traditional BMI as overweight, they are put under major health risks. The health risks of the morbidly obese are reduced life expectancy, diabetes, joint problems, high blood pressure, heart disease, gallbladder problems, certain types of cancer (breast, uterine, colon), digestive disorders, breathing difficulties (often sleep apnea, asthma), psychological problems such as depression, problems with fertility and pregnancy and urinary incontinence. DEXA scan works as a major motivation for these patients, as the exact body composition is achieved. Setting goals for fat loss along with a healthy lifestyle lets us celebrate when we reach milestones as DEXA is perceptive of our path towards success.

Start towards the new you! Enquire or make an appointment at the Department of Radiology at Kauvery Hospital.


Dr. Chris Joseph Chellaraj
Consultant Radiologist
Kauvery Hospital, Chennai