DEXA?

DEXA? How to understand the scan

DXA, often written DEXA, is the standard bone-density test used to diagnose osteoporosis, estimate fracture risk, and monitor treatment. The scan is valuable, but the report is only as good as the acquisition, positioning, analysis, and interpretation 1, 2, 3.

Topic summary

A DXA report usually lists bone mineral density and T-scores for the lumbar spine, total hip, femoral neck, and sometimes the forearm. It can also support fracture-risk tools and treatment monitoring 1, 3.

Quality matters. Technical problems can make a report look better or worse than the biology. Consensus guidance emphasizes the need to distinguish real change from scan quality or analysis problems 4.

From scan to plan

PrepareCheck prior scans, hardware, fractures, medications.
ScanHip and spine first; forearm in selected cases.
Quality checkPositioning, artifacts, vertebrae included or excluded.
InterpretT-score plus fracture risk and clinical context.

Important facts in the report

Lowest site matters

The femoral neck, total hip, spine, and forearm can tell different stories. Ask which site is driving the conclusion.

Spine can be tricky

Arthritis, compression fractures, aortic calcification, and hardware may make lumbar spine BMD misleading.

Change has a threshold

Small differences between scans may be noise. A good report should know the facility’s precision and least significant change.

Questions to ask

  • Were any vertebrae excluded from the spine analysis, and why?
  • Which site has the lowest T-score?
  • Can this scan be compared with my prior scan?
  • Does my FRAX estimate include femoral neck BMD?
  • Would vertebral fracture assessment, forearm DXA, or trabecular bone score change the discussion?

References

  1. El Maghraoui A, Roux C. DXA scanning in clinical practice. QJM. 2008. PMID: 18334497. DOI: 10.1093/qjmed/hcn022.
  2. Watts NB. Fundamentals and pitfalls of bone densitometry using dual-energy X-ray absorptiometry (DXA). Osteoporosis International. 2004. PMID: 15322740. DOI: 10.1007/s00198-004-1681-7.
  3. Morgan SL, Prater GL. Quality in dual-energy X-ray absorptiometry scans. Bone. 2017. PMID: 28159711. DOI: 10.1016/j.bone.2017.01.033.
  4. Licata AA, Binkley N, Petak SM, Camacho PM. Consensus statement on the quality of DXA scans and reports. Endocrine Practice. 2018. PMID: 29466058. DOI: 10.4158/CS-2017-0081.
  5. Morin SN, Leslie WD, Schousboe JT. Osteoporosis: A Review. JAMA. 2025. PMID: 40587168. DOI: 10.1001/jama.2025.6003.

Educational content only. This page summarizes published evidence and is not personal medical advice, diagnosis, treatment, or a substitute for care from your own clinician.