dual energy X-ray absorptiometry (DEXA)

From Aaushi
Jump to navigation Jump to search

Indications

* see screening for osteoporosis

Procedure

Absolute measurement routinely made:

* significant loss of height is >4 cm (>1.5 inches)[3]

* postmenopausal women with diabetes mellitus have higher bone mineral density but lower trabecular bone scores than women without diabetes mellitus[3]

Interpretation

Results are compared to both:

  • young, normal controls 'T score'
  • age & sex-matched controls 'Z score'

By World Health Organization Standards a 'T score'

Each standard deviation below peak bone mass indicates a 2-3 fold increase risk of fracture.

* diagnoses of osteoporosis in premenopausal women & men < 50 years can be made with 'Z score' < -2.0[1]

* reviewing DEXA scans for accuracy is a key part of BMD interpretation

More general terms

More specific terms

Additional terms

References

  1. 1.0 1.1 Medical Knowledge Self Assessment Program (MKSAP) 11, 14, 19 American College of Physicians, Philadelphia 1998, 2006, 2022
    Medical Knowledge Self Assessment Program (MKSAP) 19 Board Basics. An Enhancement to MKSAP19. American College of Physicians, Philadelphia 2022
  2. Greendale GA, UCLA Intensive Course in Geriatric Medicine & Board Review, Marina Del Ray, CA, Sept 12-15, 2001
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 Geriatric Review Syllabus, 10th edition (GRS10) Harper GM, Lyons WL, Potter JF (eds) American Geriatrics Society, 2019
    Geriatric Review Syllabus, 10th edition (GRS11) Harper GM, Lyons WL, Potter JF (eds) American Geriatrics Society, 2022
  4. Krueger D, Shives E, Siglinsky E, et al. DXA errors are common and reduced by use of a reporting template. J Clin Densitom. 2019;22(1):115-124 PMID: https://www.ncbi.nlm.nih.gov/pubmed/30327243 https://www.sciencedirect.com/science/article/abs/pii/S1094695018301586
  5. Martineau P, Morgan SL, Leslie WD. Bone mineral densitometry reporting: pearls and pitfalls. Can Assoc Radiol J. 2021 Aug;72(3):490-504 PMID: https://www.ncbi.nlm.nih.gov/pubmed/32309998 https://journals.sagepub.com/doi/10.1177/0846537120919627
  6. Morgan SL, Prater GL. Quality in dual-energy X-ray absorptiometry scans. Bone. 2017;104:13-38 PMID: https://www.ncbi.nlm.nih.gov/pubmed/28159711 https://www.sciencedirect.com/science/article/abs/pii/S8756328217300339
  7. Roux C, Briot K. Current role for bone absorptiometry. Joint Bone Spine. 2017;84(1):35-37 PMID: https://www.ncbi.nlm.nih.gov/pubmed/27282091 https://www.sciencedirect.com/science/article/abs/pii/S1297319X16300677
  8. Ginther JP, Ginther AW, Brodersen LD. Adding VFA to DXA identifies fracture risk in a way not duplicated by other measures. Endocr Pract. 2017;23(12):1375-1378 PMID: https://www.ncbi.nlm.nih.gov/pubmed/29019717 https://www.endocrinepractice.org/article/S1530-891X(20)35163-6/abstract