質子照影(Proton Range Radiography 以下簡稱PRR)在質子治療中是一個影像品質控制工具。病人開始質子治療之前，PRR的即時影像可以使用與質子治療相同的質子束產生。比較PRR的影像與電腦斷層的影像，醫生可以知道腫瘤的變化來評估治療是否有效。PRR是由兩片氣體電子倍增器(Gas Electron Multiplier)以及三十片塑膠閃爍體(Plastic Scintillator)所組成。氣體電子倍增器為記錄粒子軌跡而塑膠閃爍體則是紀錄粒子在閃爍體的能量損失或是粒子距離。本論文主要利用上述兩個條件來重建影像，由這些影像來分析PRR的影像解析度以及找尋最低劑量並保有清晰影像的劑量值。Proton Range Radiography (PRR) is an image quality control tool in proton therapy. Before a patient begins proton irradiation, a real-time imaging can be generated by the same proton beam. By comparing with the computer tomography image; the doctor can know any changes of tumor to evaluate the validity of the treatment. The PRR detector includes a pair of gas electron multiplier and a range telescope made with a stack of 30 scintillators. The gas electron multiplier is to record the trajectory of the particle and the scintillator is to record the energy loss of particle passing through scintillator. In this thesis, we used these two conditions to reconstruct the image and analysis image resolution from these images. In order to find the minimum dosage require for clean picture, we through a simple algorithm to search the minimum dosage.
