Rheumatology Book

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Dual Energy XRAY Absorptiometry

Aka: Dual Energy XRAY Absorptiometry, DEXA Scan, DEXA
  1. See Also
    1. Osteoporosis
    2. Bone Mineral Density
  2. Indications: Osteoporosis Evaluation
    1. See Bone Mineral Density
    2. Gold standard Osteoporosis Screening and monitoring
  3. Sites for measuring bone mass
    1. Lumbar Vertebrae
      1. Assess risk of Vertebral Compression Fractures
      2. Screening younger patients without Osteoarthritis
    2. Femoral Neck
      1. Assess risk of Hip Fractures
      2. Screening older patients with Osteoarthritis
    3. Other locations
      1. Wrist
      2. Calcaneus
    4. References
      1. Cummings (1993) Lancet 341:72
      2. Marshall (1996) BMJ 312:1254
  4. Advantages
    1. Negligible radiation
    2. Accurate, reproducible predictor osteoporotic Fracture
    3. Excellent measure of treatment response
  5. Disadvantages
    1. Moderate cost
    2. Osteoarthritis interferes with Spine DEXA Scan reading
      1. False elevated BMD on PA Spine views in elderly
      2. In elderly, use hip or lateral spine views
  6. Scoring
    1. See Bone Mineral Density (T-Score and Z-Score)
  7. Monitoring: Osteoporosis
    1. Recheck DEXA Scan every 2 years or less often
    2. Monitoring for change
      1. Use absolute value in grams per cm^2 from now and prior DEXA Scan (not the T-Score)
      2. Use Least Significant Change defined for the particular scanner used
        1. Calculate the difference in absolute values (g/cm^2) between now and prior DEXA Scan
        2. Significant difference if change in absolute value exceeds Least Significant Change
  8. References
    1. Blake (1998) Endocrinol Metab Clin North Am 27:267-88
    2. Bracker (1998) Postgrad Med 104(4):77-86
    3. Genant (1998) Radiographics 18:913-8

Dual-Energy X-Ray Absorptiometry (C1510486)

Definition (NCI) A technique for scanning bone and measuring bone mineral density (BMD). A DXA scanner produces 2 X-ray beams, each with different energy levels. One beam is high energy while the other is low energy. The amount of x-rays that pass through the bone is measured for each beam. This will vary depending on the thickness of the bone. Based on the difference between the 2 beams, the bone density can be measured. (MedicineNet.com)
Definition (NCI) An imaging test that measures bone density (the amount of bone mineral contained in a certain volume of bone) by passing x-rays with two different energy levels through the bone. It is used to diagnose osteoporosis (decrease in bone mass and density).
Concepts Diagnostic Procedure (T060)
MSH D015502, D003721
English Dual-Energy X-Ray Absorptiometry, dual-energy x-ray absorptiometry, Dual Energy X Ray Absorptiometry, X-Ray Absorptiometry, Dual-Energy, X Ray Absorptiometry, Dual Energy, DPX Absorptiometry, Absorptiometry, Dual X-Ray, Dual X-Ray Absorptiometry, Dual X Ray Absorptiometry, X-Ray Absorptiometry, Dual, Absorptiometry, Dual X Ray, Absorptiometries, DPX, Absorptiometry, DPX, Absorptiometry, Dual-Energy X-Ray, Absorptiometry, Dual Energy X Ray, dual-energy x-ray absorptiometry (DXA) scan, dual energy x-ray absorptiometry, dxa, DXA, dual energy x-ray absorptiometric scan, dual x-ray absorptiometry, Dual X-ray Absorptiometry, Dual Energy X-ray Absorptiometry, BMD scan, DEXA, bone mineral density scan, Dual energy x-ray absorptiometry, DEXA scan
Dutch dubbele energie röntgenfoto absorptiometrie, DEXA-scan, Röntgenabsorptiemetrie, Dual-energy
French Absorptiométrie double énergie à rayons X, Examen par absorptiométrie à rayons X (DEXA), Absorptiométrie à rayons X en double énergie, Absorptiométrie à rayons X à double énergie, Absorptiométrie DEXA
German DEXA-Scan, Dual-Energie Roentgen-Absorptiometrie, DEXA, DXA, Absorptiometrie, Dual-Röntgen-, Dual-Röntgenabsorptiometrie, Röntgenabsorptiometrie, Dual-Energie-, Absorptiometrie, Dual-Energie-Röntgen-, Absorptiometrie, Doppel-Röntgen-, Doppel-Röntgenabsorptiometrie
Italian Mineralometria ossea a raggi X a doppia energia, Scansione DEXA
Portuguese Scan da avaliação de absorção com Raio X de energia dupla, Avaliação de absorção com Raio X de energia dupla
Spanish Absorciometría de rayos X de doble energía, Absorciometría por rayos X de doble energía
Japanese 二重エネルギーＸ線吸収法, ＤＥＸＡスキャン, DEXAｽｷｬﾝ, ﾆｼﾞｭｳｴﾈﾙｷﾞｰXｾﾝｷｭｳｼｭｳﾎｳ
Czech DEXA snímek, Rentgenová denzitometrie, rentgenová absorpční fotometrie s duální energií
Hungarian DEXA vizsgálat, Kettős energiájú röntgen absorptiometria
Sources
Derived from the NIH UMLS (Unified Medical Language System)


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