What are the recommendations for Dual-Energy X-ray Absorptiometry (DEXA) scans?

DEXA Scan Recommendations

All women aged 65 years and older and all men aged 70 years and older should undergo routine DEXA screening regardless of risk factors. 1, 2, 3

Standard Screening by Age and Sex

• Women ≥65 years: Perform DEXA screening at the lumbar spine, total hip, and femoral neck 1, 2
• Men ≥70 years: Perform DEXA screening at the same sites 1, 2, 3
• Postmenopausal women <65 years: Screen if they have elevated fracture risk based on clinical assessment or FRAX calculation showing ≥9.3% 10-year major osteoporotic fracture risk 1, 2, 3
• Men <70 years: Screen only if specific risk factors are present 2, 3

The most recent 2025 European guidelines emphasize that routine screening should not occur in younger individuals without risk factors 1, 3.

High-Risk Populations Requiring Earlier Screening

Screen immediately (regardless of age) if any of the following are present:

• Previous fragility fracture at any site (hip, spine, forearm, humerus, pelvis) 1, 2
• Long-term glucocorticoid therapy (≥5 mg prednisone daily for ≥3 months) 1, 2, 3
• Medical conditions causing bone loss: hyperparathyroidism, hypogonadism, chronic inflammatory diseases 2, 3
• Medications associated with bone loss (aromatase inhibitors, androgen deprivation therapy) 1, 2, 3
• Body weight <127 lb (58 kg) 1
• Parental history of hip fracture 1
• Premature menopause or oophorectomy before natural menopause 4
• Spinal cord injury (screen as soon as medically stable) 2, 3

Specific High-Risk Scenarios

Breast Cancer Survivors

• Postmenopausal women: Obtain baseline DEXA at diagnosis 1
• Repeat every 2 years if taking aromatase inhibitors, premenopausal women on tamoxifen plus GnRH agonists, or those with chemotherapy-induced premature menopause 1

Early Menopause/Oophorectomy

• Obtain baseline DEXA immediately after menopause onset 4
• Follow-up scans every 1-2 years 4
• Use T-scores (not Z-scores) for interpretation in all postmenopausal women regardless of age 4

Anatomic Sites to Scan

Standard sites (measure all three): 1

• Lumbar spine (L1-L4)
• Total hip
• Femoral neck

Additional site when indicated:

• One-third radius (distal forearm) if spine or hip cannot be measured due to artifacts, hardware, or severe degenerative changes 1

The 2025 guidelines specify that the lowest T-score at any measured site should be used for diagnosis 1.

Vertebral Fracture Assessment (VFA)

Perform VFA or standard radiography if: 1, 2

• T-score <-1.0 AND any of the following:
  • Women ≥70 years or men ≥80 years
  • Historical height loss >4 cm
  • Self-reported but undocumented vertebral fracture
  • Glucocorticoid therapy ≥5 mg prednisone daily for ≥3 months

Follow-Up Scanning Intervals

Normal Bone Density or Mild Osteopenia

• Repeat in 2-3 years for routine monitoring 1, 2
• Women with normal BMD at age 65: Can extend interval to 4-8 years as repeat testing does not improve fracture prediction 2
• Never repeat scans <2 years apart in stable patients, as precision limitations prevent reliable measurement of change 2

Osteoporosis or On Treatment

• Repeat in 1-2 years to monitor treatment effectiveness 1, 2, 3
• Each facility must calculate its own least significant change (LSC) to determine if BMD changes are real versus measurement error 1

Accelerated Bone Loss Risk

• Repeat in 1-2 years for patients on glucocorticoids, aromatase inhibitors, or with spinal cord injury 1, 2, 3

Diagnostic Criteria

Osteoporosis diagnosis: T-score ≤-2.5 at lumbar spine, femoral neck, total hip, or one-third radius 1

Alternative diagnosis: Some societies presume osteoporosis diagnosis with low-trauma major fracture even if BMD is normal 1

Use young adult Caucasian female reference database for T-score calculation in both women and men 1

Quality Assurance Requirements

• Perform scans at facilities with skilled technologists who have completed precision assessment 1
• Each facility must determine its own precision error and calculate LSC when new equipment is installed 1
• Follow-up scans should use the same DXA system, same positioning, and same analysis protocols 1
• Maximum acceptable LSC: 5.0% for total hip, 5.3% for lumbar spine 1

Common Pitfalls to Avoid

• Do not use Z-scores in postmenopausal women—T-scores are appropriate regardless of age 4
• Do not repeat scans <2 years apart in stable patients without high-risk features, as this provides no clinical benefit and wastes resources 2
• Inspect images carefully for degenerative changes, which can falsely elevate spine BMD; rely on hip measurements when spine is affected 4
• Do not wait until age 65 to screen women with significant risk factors like early menopause, prior fracture, or chronic glucocorticoid use 1, 4
• Assess for new risk factors at each clinical encounter, including height loss >4 cm, new medications affecting bone metabolism, or development of secondary causes 2