近年來，在醫療曝露品質保證的提倡之下，英國國家放射防護委員會(National Radiological Protection Board, NRPB)的研究報告，指出應將受檢者接受X光檢查時所受之劑量，列為品質管制項目之ㄧ，以保障受檢者能夠在較低的輻射劑量下，獲得最佳的放射診斷影像。
基於此概念，本研究提出輻射劑量與影像品質最優化分析之方法。此分析方法以實際受檢者為對象，配合各家醫院之胸部後前向X光照像(chest PA view)標準程序，以入射表面劑量(entrance surface dose, ESD)及劑量面積乘積(dose-area product, DAP)為劑量指標，評估有效劑量(effective dose)。而影像品質指標方面，則以歐洲委員會(European Commission, EC)所公佈的胸部後前向X光照像之影像評分標準為依據，由放射專科醫師進行評分，並以此評分為依據，作為一主觀之量化標準。
經由本分析方法之實驗結果證明，在達成相同影像品質的條件之下，高管電壓與適當之照野面積，可使得受檢者得到較小之有效劑量。由本研究之分析結果可知，在採用高管電壓，並依受檢者之體型調整照野大小之下，配合對於光照野與自動曝露控制(automatic exposure control, AEC)裝置之校正與品質控制之加強，即可在較低之有效劑量下，獲得最佳之影像品質。若能廣泛的應用此最優化之X光照像方法至各醫院，則可大幅提升其放射診斷品質。

In a report of the British National Radiological Protection Board (NRPB), radiation monitoring has been recommended as an essential item for the quality assurance program in diagnostic radiology.
Our research objectives are to optimize the digital radiography by looking for the most suitable technical factors, obtaining the balance between image quality and radiation dose, and analyzing the optimization conditions. The entrance surface dose and dose-area product were used as dose indices to determine effective doses. Image quality was obtained subjectively. Three radiologists scored the images according to the image criteria recommended in the European guidelines, EUR 16260. The optimization analysis was then applied to determine the optimized technical factors for the chest PA radiography in a given hospital.
Our results indicate that using high tube potential and appropriate field size can significantly reduce the effective dose, yet achieving similar image quality in chest PA examination. Besides, to improve the quality of the diagnostic radiology, the calibration of light field and automatic exposure control device should be performed periodically.

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