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| * [[Osteoporosis]] in these bones, especially [[metacarpals]] and [[metatarsals]], appeared as loss of [[Cortical bone|cortical thickness]]. However, [[Cortical bone|cortical thickness]] of less than 25% of entire [[bone]] demonstrate [[osteoporosis]].<ref name="urlOsteoporosis | Radiology Reference Article | Radiopaedia.org" /> | | * [[Osteoporosis]] in these bones, especially [[metacarpals]] and [[metatarsals]], appeared as loss of [[Cortical bone|cortical thickness]]. However, [[Cortical bone|cortical thickness]] of less than 25% of entire [[bone]] demonstrate [[osteoporosis]].<ref name="urlOsteoporosis | Radiology Reference Article | Radiopaedia.org" /> |
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| === Dual energy X-ray absorptiometery (DEXA, DXA) ===
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| * The most important [[modality]] for measuring [[Bone mineral density|bone mineral density (BMD)]], that every [[osteoporosis]] diagnostic and [[therapeutic]] decision are based on, is [[Dual energy X-ray absorptiometry|dual energy X-ray absorptiometry (DEXA)]].<ref name="pmid27048946">{{cite journal |vauthors=Messina C, Monaco CG, Ulivieri FM, Sardanelli F, Sconfienza LM |title=Dual-energy X-ray absorptiometry body composition in patients with secondary osteoporosis |journal=Eur J Radiol |volume=85 |issue=8 |pages=1493–8 |year=2016 |pmid=27048946 |doi=10.1016/j.ejrad.2016.03.018 |url=}}</ref> [[Dual energy X-ray absorptiometry|DEXA]] is a 2-dimensional image of a 3-demensional subject, mainly depends on size of the [[bone]] which is studied; therefore, it would explain the variety of [[Bone mineral density|BMD]] upon sex, [[body weight]], and also [[Ethnicity and health|ethnicity]].<ref name="pmid9589631">{{cite journal |vauthors=Seeman E |title=Growth in bone mass and size--are racial and gender differences in bone mineral density more apparent than real? |journal=J. Clin. Endocrinol. Metab. |volume=83 |issue=5 |pages=1414–9 |year=1998 |pmid=9589631 |doi=10.1210/jcem.83.5.4844 |url=}}</ref>
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| * Considering the effect of [[bone]] size on 2-dimensional image of [[Dual energy X-ray absorptiometry|DEXA]], the measured [[Bone mineral density|BMD]] is not reflecting the exact [[Bone mineral density|BMD]]; however, the [[Dual energy X-ray absorptiometry|DEXA]] [[fracture]] prediction would be better than 3-dimansional images, because small [[bones]] [[Fracture|fractured]] easily than large [[bones]].<ref name="pmid18348697">{{cite journal |vauthors=Black DM, Bouxsein ML, Marshall LM, Cummings SR, Lang TF, Cauley JA, Ensrud KE, Nielson CM, Orwoll ES |title=Proximal femoral structure and the prediction of hip fracture in men: a large prospective study using QCT |journal=J. Bone Miner. Res. |volume=23 |issue=8 |pages=1326–33 |year=2008 |pmid=18348697 |pmc=2680175 |doi=10.1359/jbmr.080316 |url=}}</ref>
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| * [[Dual energy X-ray absorptiometry|DEXA]] is the choice [[modality]] because of the following factors:
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| *# Short duration of procedure
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| *# High [[validity]] in [[Bone mineral density|BMD]] measurement (accuracy)
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| *# High [[reliability]] in [[Bone mineral density|BMD]] measurement (reproducible)
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| *# High range of application (different [[bone]] sites)<ref name="pmid12377088">{{cite journal |vauthors=Cummings SR, Bates D, Black DM |title=Clinical use of bone densitometry: scientific review |journal=JAMA |volume=288 |issue=15 |pages=1889–97 |year=2002 |pmid=12377088 |doi= |url=}}</ref>
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| * There are many factors influencing the [[osteoporosis]] diagnosis, such as [[trabecular bone]] architecture; however, [[Dual energy X-ray absorptiometry|DEXA]] is the best predictor of [[osteoporosis]] and osteoporotic [[fractures]] by means of central [[Bone mineral density|BMD]] surveys.<ref name="pmid21427343">{{cite journal |vauthors=Lorente-Ramos R, Azpeitia-Armán J, Muñoz-Hernández A, García-Gómez JM, Díez-Martínez P, Grande-Bárez M |title=Dual-energy x-ray absorptiometry in the diagnosis of osteoporosis: a practical guide |journal=AJR Am J Roentgenol |volume=196 |issue=4 |pages=897–904 |year=2011 |pmid=21427343 |doi=10.2214/AJR.10.5416 |url=}}</ref>
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| * For adults, it has to be always two sites of [[Bone mineral density|BMD]] measurement, [[lumbar spine]] and [[Femur neck|femoral neck]]; in case each of them is impossible to evaluate, [[forearm]] will be substituted.<ref name="pmid18442754">{{cite journal |vauthors=Baim S, Binkley N, Bilezikian JP, Kendler DL, Hans DB, Lewiecki EM, Silverman S |title=Official Positions of the International Society for Clinical Densitometry and executive summary of the 2007 ISCD Position Development Conference |journal=J Clin Densitom |volume=11 |issue=1 |pages=75–91 |year=2008 |pmid=18442754 |doi=10.1016/j.jocd.2007.12.007 |url=}}</ref>
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| * For children (less than 20 years old), [[femoral]] [[Maturity (psychological)|maturity]] level may be different among population, leading to lack of unique reference measure; thus, just one site of measurement (i.e., [[lumbar spine]]) is considered.<ref name="pmid18442749">{{cite journal |vauthors=Baim S, Leonard MB, Bianchi ML, Hans DB, Kalkwarf HJ, Langman CB, Rauch F |title=Official Positions of the International Society for Clinical Densitometry and executive summary of the 2007 ISCD Pediatric Position Development Conference |journal=J Clin Densitom |volume=11 |issue=1 |pages=6–21 |year=2008 |pmid=18442749 |doi=10.1016/j.jocd.2007.12.002 |url=}}</ref>
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| * Upon the [[World Health Organization|world health organization (WHO)]] report in 1994, using T-score ([[Standard deviation|standard deviations (SD)]] below or above the average of young Caucasian women), [[Bone mineral density|BMD]] measures are divided into three groups, include:
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| *# T-score greater than -1.0 [[Standard deviation|SD]] assumed as normal [[Bone mineral density|BMD]]
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| *# T-score between -1.0 and -2.5 [[Standard deviation|SD]] assumed as [[osteopenia]]
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| *# T-score less than -2.5 [[Standard deviation|SD]] assumed as [[osteoporosis]]<ref name="urlWHO IRIS: Assessment of fracture risk and its application to screening for postmenopausal osteoporosis : report of a WHO study group [meeting held in Rome from 22 to 25 June 1992]">{{cite web |url=http://apps.who.int/iris/handle/10665/39142 |title=WHO IRIS: Assessment of fracture risk and its application to screening for postmenopausal osteoporosis : report of a WHO study group [meeting held in Rome from 22 to 25 June 1992] |format= |work= |accessdate=}}</ref>
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| * [[Z-score]] is same as the T-score, but the target population is matched for [[age]], sex, [[race]], and also in some studies, [[weight]].
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| * Using [[Dual energy X-ray absorptiometry|DEXA]] in men, almost always show higher [[Bone mineral density|BMD]] levels. But regarding the effect of [[bone]] size on [[Dual energy X-ray absorptiometry|DEXA]] measured [[Bone mineral density|BMD]] levels, it seems that higher [[Bone mineral density|BMD]] levels may be due to larger [[bones]] in men. Surprisingly, after matching the [[Bone mineral density|BMD]] levels, it is concluded that volumetric [[Bone mineral density|BMD]] is even lower in men. However, their [[fracture]] risk is same as women's risk; thus, the women's reference range of [[Bone mineral density|BMD]] is assumed for men, too.<ref name="pmid22057550">{{cite journal |vauthors=Srinivasan B, Kopperdahl DL, Amin S, Atkinson EJ, Camp J, Robb RA, Riggs BL, Orwoll ES, Melton LJ, Keaveny TM, Khosla S |title=Relationship of femoral neck areal bone mineral density to volumetric bone mineral density, bone size, and femoral strength in men and women |journal=Osteoporos Int |volume=23 |issue=1 |pages=155–62 |year=2012 |pmid=22057550 |pmc=3640410 |doi=10.1007/s00198-011-1822-8 |url=}}</ref>
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| * Regarding the vast advantages of [[Dual energy X-ray absorptiometry|DEXA]] (low [[radiation exposure]], high availability, and tremendous information related to [[fracture]] risk), it seems that [[Dual energy X-ray absorptiometry|DEXA]] will remain the masterpiece of [[fracture]] risk assessment and also [[osteoporosis]] diagnosis.<ref name="pmid28716497">{{cite journal |vauthors=Jain RK, Vokes T |title=Dual-energy X-ray Absorptiometry |journal=J Clin Densitom |volume= |issue= |pages= |year=2017 |pmid=28716497 |doi=10.1016/j.jocd.2017.06.014 |url=}}</ref>
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| {| align="center"
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| | [[image:Case courtesy of Dr Henry Knipe, Radiopaedia.org, rID 45995.jpg|thumb|350px|Osteopenia - Case courtesy of Dr Henry Knipe, Radiopaedia.org, rID 45995]]
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| | [[image:Case courtesy of Dr Henry Knipe, Radiopaedia.org, rID 45996.jpg|thumb|300px|Osteopenia with forearm measurement - Case courtesy of Dr Henry Knipe, Radiopaedia.org, rID 45996]]
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| | [[image:Case courtesy of Dr Henry Knipe, Radiopaedia.org, rID 45997.jpg|thumb|350px|Osteoporosis - Case courtesy of Dr Henry Knipe, Radiopaedia.org, rID 45997]]
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| |}
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| ==References== | | ==References== |
| {{Reflist|2}} | | {{Reflist|2}} |
