Dual Energy X-ray Absorptiometry (DEXA)

Indications

Dual-energy x-ray absorptiometry (DEXA) is indicated in patients suspected to have osteoporosis. Repeat DEXA scans are indicated to monitor the response to osteoporosis treatment and to monitor loss of bone patients with osteopenia. The most reliable site for monitoring changes in BMD in older individuals (>65) is the total hip.

Initial DEXA in those aged >50 years

The main indications for an initial DEXA are shown below.

• Low trauma fracture at any site (except skull, fingers and toes) age >50.
• Suspected vertebral fracture (kyphosis, height loss >2.5cm).
• Primary hyperparathyroidism, to decide on the need for parathyroidectomy.
• Clinical risk factors for osteoporosis in those >50 with a 10-year fracture risk of >10% calculated by QFracture or FRAX.  Clinical risk factors, taken from SIGN142. are summarised in Table 1.

Initial DEXA in those aged <50 years

Exceptionally, DEXA may be considered in people younger than 50 with very strong clinical risk factors for osteoporosis or major low trauma osteoporotic fractures as summarised below:

•         Low trauma hip or vertebral fracture

•         Commitment to oral prednisolone >7.5mg/ day for 3months or annual dose >630mg.

•         Primary hyperparathyroidism, to decide on the need for parathyroidectomy.

•         A 10-year fracture risk of >= 10% and a major risk factor, defined as:

• Untreated early menopause (age<45)
• Excess alcohol intake (>3.5 units/day)
• Low BMI (<20 kg/m2)
• Chronic inflammatory disease (RA, SLE, AxSPA, PsA, IBD)
• Malabsorption
• Coeliac Disease
• Neurological diseases (Alzheimer’s, Parkinson’s disease, Multiple sclerosis)
• Endocrine diseases
• Chronic liver disease
• Moderate to severe kidney disease (eGFR < 60ml/min/1.73m2)

M.A & S.R/H.B. 25-01-24