Osteoporosis is often called a ‘silent disease,’ because it progresses, without symptoms, until a fracture occurs most commonly in your hips, spine and wrists.  However, a bone density scan can alert doctors to the disease before a patient has experienced any symptoms.

Radiology imaging techniques play a crucial role in the early diagnosis, management and monitoring of low bone density. The rapid evolution of high-quality imaging techniques, using reduced radiation doses, has positioned radiology ideally for this role. 

What is osteoporosis?

A healthy bone viewed under a microscope, looks like honeycomb. Osteoporosis, put simply, is when the ‘holes and spaces’ in the honeycomb increase in size, causing the bones to lose density or mass and develop abnormal tissue structure. This is caused by the body losing too much bone or making too little bone because of a lack of calcium, vitamin D and not doing any weight-bearing exercises or both. This can lead to a decrease in bone strength which, in turn, can increase the risk of broken or fractured bones. 

There are degrees of bone density loss which are determined by radiologists doing a DEXA scan. 

‘The standard method of determining your bone density,’ says Dr Hein Els, director at SCP Radiology, ‘is a DEXA scan (dual-energy X-ray absorptiometry). This involves using two X-ray beams, at different energy levels. to measure the bone mineral density. It has a high accuracy for overall bone density and is commonly found in clinics and hospitals.’  

The scan uses a low radiation exposure making it safer for routine screening and follow-up.

‘The amount of radiation is minimal,’ says Dr Els, ‘it’s equivalent to 1 or 2 days of background radiation at sea level.’  

Osteoporosis vs Osteopenia

Osteoporosis and osteopenia are both conditions measured on a DEXA scan and characterised by decreased bone density. While they are related, they differ in severity and implications for bone health. 

The fracture risk is higher in osteoporosis due to more significant bone fragility.

Understanding and managing both conditions are crucial for maintaining bone health and preventing fractures. 

Measuring bone density

‘We measure your bone mass density by comparing it to that of a healthy, young adult. The result will tell us how much lower (or higher) your bone mass score,’ explains Dr Els. ‘Software is also used to calculate a predicted 10-year fracture risk for a major osteoporotic fracture and a hip fracture. The result is a T-score which you will be given by your doctor.’

Who is at greater risk

The vast majority of patients referred for a DEXA scan are women.  However, men over the age of 50 are also at risk, though not to the same degree as women.  The aim is to prevent fractures later in life by maintaining healthy bone mineral density, which means it is beneficial to know your bone mineral density. Fractures in the elderly population are a significant cause of morbidity and mortality.

Apart from diagnosing osteoporosis and osteopenia and assessing fracture risk, DEXA scans are helpful in the following ways:

• Monitoring bone density changes over time: For individuals diagnosed with osteoporosis or those undergoing treatment for bone loss, DEXA scans are used to monitor changes in bone density. This helps in evaluating the effectiveness of treatment
• Postmenopausal women: Are at a higher risk of developing osteoporosis due to decreased oestrogen levels. DEXA scans are recommended for postmenopausal women, especially those with additional risk factors
• Men over 50 can also be at risk of osteoporosis
• A family history of osteoporosis or fractures can increase an individual’s risk. DEXA scans can help assess bone density in those with a genetic predisposition
• Individuals with a low body mass index (BMI) are at a higher risk for osteoporosis and may benefit from bone density testing
• Smokers and heavy alcohol users are risk factors for osteoporosis
• Patients with fragility fractures: Individuals who have experienced fractures from minor falls or injuries may undergo DEXA scans to determine if osteoporosis is the underlying cause

How do you treat low bone mass density?

This can be done through medication such as bisphosphonates, hormone-related therapy and other bone-building medications or through lifestyle changes. This includes an adequate intake of calcium and vitamin D, regular weight-bearing exercise, quitting smoking and limiting alcohol.

The DEXA scan is the safest, most reliable method of determining your bone loss and whether your bones are normal or if you are osteopenic or osteoporotic – the precursor to osteoporosis or full-blown osteoporosis. Regular medical check-ups and proactive lifestyle changes can significantly mitigate the risks associated with these conditions.

‘There is no need to be harbouring this silent disease,’ says Dr Els, ‘when radiography is available to test for these and can put you on a path to wellness.’