Editing Osteoporosis (section)

===Dual-energy X-ray===
[[Dual-energy X-ray absorptiometry]] (DEXA scan) is considered the [[gold standard (test)|gold standard]] for the diagnosis of osteoporosis. Osteoporosis is diagnosed when the [[bone density|bone mineral density]] is less than or equal to 2.5 standard deviations below that of a young (30–40-year-old<ref name="WHOcriteria"/><sup>:58</sup>), healthy adult women reference population. This is translated as a [[Bone density#T-score|T-score]]. But because bone density decreases with age, more people become osteoporotic with increasing age.<ref name="WHOcriteria"/><sup>:58</sup> The World Health Organization has established the following diagnostic guidelines:<ref name="WHOcriteria"/><ref name=WHO1994/>

{| class="wikitable"
! Category !! [[Bone density#T-score|T-score]] range !! % young women
|-
| Normal || [[Bone density#T-score|T-score]] ≥ −1.0 || 85%
|-
| [[Osteopenia]] || −2.5 < T-score < −1.0 || 14%
|-
| Osteoporosis || T-score ≤ −2.5 || 0.6%
|-
| Severe osteoporosis || T-score ≤ −2.5 with fragility fracture<ref name=WHO1994/> ||
|}

The International Society for Clinical Densitometry takes the position that a diagnosis of osteoporosis in men under 50 years of age should not be made on the basis of densitometric criteria alone. It also states, for premenopausal women, Z-scores (comparison with age group rather than peak bone mass) rather than T-scores should be used, and the diagnosis of osteoporosis in such women also should not be made on the basis of densitometric criteria alone.<ref name="pmid14742881">{{cite journal |vauthors=Leib ES, Lewiecki EM, Binkley N, Hamdy RC |title=Official positions of the International Society for Clinical Densitometry |journal=J Clin Densitom |volume=7 |issue=1 | year=2004 |pmid=14742881 | doi=10.1385/JCD:7:1:1 |pages=1–5|s2cid=32856123 }} quoted in: [http://www.guideline.gov/summary/summary.aspx?ss=15&doc_id=6567&nbr=4129 "Diagnosis of osteoporosis in men, premenopausal women, and children"] {{webarchive|url=https://web.archive.org/web/20080224001118/http://www.guideline.gov/summary/summary.aspx?ss=15&doc_id=6567&nbr=4129 |date=24 February 2008 }}</ref>