- 期刊
電腦斷層影像重組技術：疊代運算法與濾波反投影法之輻射劑量比較
Image Reconstruction Technique of Computed Tomography: Compared Iterative Reconstruction Method with Filtered Back Projection Method
摘要
由於電腦斷層掃描（computed tomography，CT）軟硬體設備的發展突飛猛進，CT檢查的臨床運用也更為廣泛，近年來其檢查量持續快速地成長，造成患者所接受之輻射劑量與全國人口的輻射曝露大幅增加而被世界各國所重視並加以規範。疊代運算法（iterative reconstruction，IR）為CT最新的影像重組技術，其作用為減少影像的雜訊，在不影響影像品質下降低病人的輻射劑量，或是維持相同的輻射劑量下藉由增加影像的訊雜比而提高影像品質。本研究使用熱發光劑量計（thermoluminescent dosimeters, TLD）與標準的擬人化假體來測量輻射劑量，以兩種不同的影像重組技術進行CT檢查，比較濾波反投影法（filtered back projection，FBP）與疊代運算法（IR; iDOSE-3與iDOSE-5）對於器官輻射劑量的差異。研究結果顯示iDOSE-3及iDOSE-5分別比FBP的輻射劑量降低了12.24 %～38.35 %及21.10 %～44.36 %，尤其在卵巢、膀胱與睪丸的輻射劑量有明顯的下降。因此，CT使用疊代運算法可大幅降低病患的輻射劑量而仍維持影像品質。
並列摘要
Because of great advances in software and hardware of computed tomography (CT), the clinical CT examination has become more widely used. With rapid growth in the amount of CT examinations in the recent years, the radiation dose received by patients with radiation exposure of the population increased significantly, and thus was emphasized and regulated worldwide. Iterative reconstruction (IR) is an up-to-date technique of CT image reconstruction to decrease patient's radiation dose for same image quality, or to increase the image quality for the same radiation dose by increased signal to noise ratio (SNR) of the images. In this study, thermoluminescent dosimeters (TLD) with standard anthropomorphic phantom were used to measure the radiation dose. Two different CT image reconstruction techniques were performed to compare the differences of organ radiation dose between filtered back projection (FBP) and IR methods(iDOSE-3 and iDOSE-5). The results show that the radiation dose for iDOSE-3 method reduced by 12.24 %~38.35 % compared with that for FBP method. And the radiation dose for iDOSE-5 method reduced by 21.10 %~44.36 % compared with that for FBP method. In particular, radiation dose significantly reduced in the ovaries, bladder and testes. Therefore, CT examination using IR technique can significantly reduce patient radiation dose with maintenance of the image quality.
延伸閱讀
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