周围型双能X线骨密度仪(pDXA)检测技术

The measurement technique of pDXA

测量椎骨和股骨骨密度(BMD)的中央型双能X线骨密度仪(DXA)受到广泛的认可,然而DXA扫描并不适合所有可能获益的患者。周围型双能X线骨密度仪(pDXA)是以测量前臂为主的双能X线骨密度仪,准确性和精确性均较好,非优势前臂桡骨33%(1/3)处的骨密度可以用于临床骨质疏松诊断;由于前臂骨折较常见,以及有些影响髋部和脊柱骨密度测定的疾病如脊柱内固定术后、脊柱侧弯、严重退行性变,多节段椎体骨折,双侧髋关节置换术后或肥胖等,pDXA测定骨密度可以有效的避免这些影响;pDXA还具有仪器体积小,设备费用低,辐射剂量低,便于携带和搬运等优点。因此pDXA测量骨密度对临床诊断骨质疏松症是有帮助的。

The use of central type DXA for the measurement of bone mineral density （BMD） of the vertebra and femur has been widely accepted. However, DXA scan is not appropriate for all patients to benefit from it. Peripheral dual-energy X-ray absorptiometry （pDXA） is a BMD monitor that mainly measures the forearms, with good accuracy and validity. BMD of the 33% （1/3） site of disadvantaged forearm radius can be used in clinical diagnosis of osteoporosis. Because forearm fracture is common, and because some factors may influence BMD measuring, such as internal fixation in the spine, scoliosis, severe retrogression, multiple segment vertebral fractures, bilateral hip arthroplasty, obesity, etc. , pDXA could effectually avoid the above influence, pDXA has other merits including small in size, less in cost, low dose of radiation, and easy to carry. Therefore, pDXA for BMD measurement is helpful in clinical diagnosis of osteoporosis.