現今的盛行的小動物正子斷層掃瞄儀(PET)，為了提高計數率，通常會使用全三維的方式去收取資料。但是全三維的影像資料龐大，所以若要直接進行三維的影像重建，會耗費很多的計算時間，所以文獻中提出了重新分裝法，能把三維的正弦圖重新分裝成二維的正弦圖，然後在利用二維的重建法得到影像，如此就可以減少運算時間。之後又有文獻提出利用重新分裝法的概念反向思考，就可以從二維的正弦圖資料推測出三維正弦圖資料，並運用到三維疊代式影像重建法中；本論文就是利用修正過後的逆向式傅立葉分裝法與傅立葉分裝法的概念，來模擬三維疊代式影像重建法最花時間的正向與反向投影這兩部份，以減少三維疊代式影像重建法的時間，並達到與三維重建法一樣的效果。本研究中使用了林口長庚醫院分子影像中心的Inveon-PET的NEMA假體、線射源、點射源以及小動物影像來進行驗證，並與傳統重建方法的比較。由結果可看出在本論文使用的方法，在時間上的確比3DRP來的快速，並且在解析度的表現上也是相近的。

Animal PET system has become a powerful tool in preclinical imaging applications. In order to improve sensitivity and the counting rate, animal PET systems usually acquire data in fully three dimension mode. Due to the huge amount of 3D data, the computation for 3D reconstruction takes longer. Although rebinning algorithms could reduce the computation time by converting 3D data into 2D, it is believed that fully 3D can preserve the information, and lead to better image quality. In this study, we modified an inverse rebinning (FORE) algorithm to simulate the 3D forward and backward projections that are required in the fully 3D reconstructions. To evaluate the performance of the proposed method, data from animal PET from NEMA phantom, line source, point source and mouse were acquired and reconstructed using the proposed method, and compared to those from conventional 3D reconstruction (3DRP) and rebinning methods with 2D reconstruction. The results demonstrated that our proposed method generated similar performance in resolution with that of 3DRP reconstruction but with much less computation time. Future work will include more Monte Carlo data verification as well as comparison to full 3D reconstruction.

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