Bone Densitometry

This service is available at Cashmere Radiology and St George's Radiology.

Bone densitometry is used to categorise patients as normal, osteopenic, or osteoporotic following the World Health Organisation (WHO) classifications.

What is Osteoporosis ?

Osteoporosis is a silent, progressive disease characterised by decreased bone density and increased bone fragility, with a consequent susceptibility to fracture.

One third of Caucasian women over the age of 50 have osteoporosis, yet nearly 80% remain undiagnosed. After menopause, a woman's risk of suffering an osteoporotic spine or femur fracture is 30% or three times that of a man's.

Osteoporosis is a complex disease that may progress silently for decades - there may be no symptoms until fractures occur. Bone loss is the major risk factor that can be modified in mid-life to reduce fracture risk. Bone loss can be reduced by treatment, but it is difficult to restore the microarchitecture of the skeleton once bone has been lost. Early detection and intervention are crucial.

Osteoporosis used to be considered an inevitable consequence of aging. Today, with new techniques for early detection and ever-increasing treatment options, osteoporosis management is a reality.

Diagnosis of Osteoporsis

Doctors use bone densitometry to categorise patients as normal, osteopenic, or osteoporotic following the World Health Organisation (WHO) classifications. The patient's T-score (comparison to the young adult reference) is the critical variable in diagnosis. Typically, the femurs and the spine are assessed, with the diagnosis made using the lowest T-score.

Fracture Risk Assessment

Bone mineral density (BMD) is the strongest tool to predict fracture risk, which increases exponentially as BMD decreases. Femur BMD is recognised as the strongest predictor of femur fracture risk, which has the highest morbidity, mortality and cost of all osteoporotic fractures. A decrease of 1 standard deviation (SD) in femur BMD corresponds to approximately a 3X increase in femur fracture risk. In comparison, a 1 SD decrease in spine BMD corresponds to a 2X increase in spine fracture risk.