利用原廠假體在不同DXA系統中測量之差異研究

Discuss of the Original Phantom by Different DXA Systems

10.6717/JTMRT.201609_4(2).0006

陳家慶(Chia-Ching Chen)；蔡裕豐(Yuh-Feng Tsai)；盧大年(Ta-nein Lu)；林清熹(Ching-His Lin)；吳金珠(Chin-Chu Wu)；陳儒廷(Ju-Ting Chen)

雙能量X 射線吸收儀 ； 骨質密度 ； 假體 ； dual-energy x-ray absorptiometry ； bone mineral density ； phantom

臺灣醫事放射期刊

4卷2期（2016 / 09 / 01）

41 - 46

繁體中文

利用GE 及Hologic 校正假體測量雙能量X 射線吸收儀(dual- X-ray absorptionmetry, DXA)準確度之差異性研究，而準確度關係著檢驗報告的可信度。校正假體於GE、Hologic及Norland 之DXA 腰椎模式下掃描十次，每次掃描完畢後取下並重新定位，測量結果依準確度百分誤差、ANOVA 進行分析，以費雪LSD 法驗證。GE 假體實際BMD 為1.271±0.038g/cm^2，以GE 最為接近假體數值(-0.002g/cm^2: 0.16%)；Norland 次之(-0.146 g/cm^2:11.57%)；Hologic 再次之(-0.194g/cm^2: 15.26%)，三者檢測數值有顯著性之差異，事後驗證發現，GE DXA 數值與假體數值並無顯著性差異。Hologic 假體實際BMD 為1.016±0.004g/cm^2，以Hologic 最為接近假體數值(-0.009g/cm^2: 0.89%)；Norland 次之(-0.029g/cm^2: 2.85%)；GE 再次之(-0.146g/cm^2: 14.37%)，三者檢測數值有顯著性之差異，事後驗證發現，三者與假體數值皆有顯著性差異。DXA 附帶之標準假體檢測儀器的準確度是方便而基本的方法，但儀器附帶之標準假體皆為自家公司所出產，或許讓使用單位覺得此種品質控制方式是否準確？是否應由第三方之假體認證DXA 之準確度，或由公式將測量之數值相互轉換，以提高檢測數值之可信度。儀器之準確度高低影響著病患檢測數值正確性，須確保儀器準確度方能提供準確之檢測報告。

The use of GE and Hologic calibration phantom to measure the accuracy of dual- energy x-ray absorptionmetry, accuracy related to the reliability of examination. The phantom for lumbar spine scanning in different brand DXAs (GE, Hologic and Norland), for 10 times repeatedly, when each scan has done, removed and repositioned, the results was according to the mean percent difference by LSD verification with ANOVA analysis.GE phantom BMD measured was 1.271±0.038g/cm^2 and closest to the calibration phantom value (-0.002g/cm^2: 0.16%), then Norland (-0.146 g/cm^2: 11.57%) and the last Hologic (-0.194g/cm^2: 15.26%), there were significant differences between them, so as the verification with the same results. Accordingly DXA additional standardized measurement phantom is the fundamental useful model for the accuracy of instrument, but the individual phantom is produced by the manufacturer, may doubt by the user regarding its quality and accuracy? Whether should it by the third phantom to verify the vary devices for accuracy, or apply a conversional formula to make sure the correction and reliability, and ensure the confidence among different machines in use. The accuracy of device will affect the measurement value of the results of patient, ensure the devices’ accuracy standardized, and then the outcomes are valuable.