Micro-SPECT 常應用於小動物模型以探討與人體相關疾病之致病機轉、進程及可能的治療藥物與方法研究。為提昇Micro-SPECT 之空間解析度，應用針孔(Pinhole)成像放大原理之Pinhole SPECT 其相關研究及技術被相繼探討與發展，而本研究計畫將以Pinhole SPECT 為主要研究課題。通常，核醫影像系統可由線性成像系統描述，其影像向量係由一物體向量經過一影像重建系統矩陣之映射(Mapping)產生，故影像重建系統矩陣將直接影響重建影像之影像品質，而取得一高精確性之影像重建系統矩陣對於高空間解析度的影像重建程序係相當重要的一環。本研究計畫中將研發一個融合二維格點(2D Grid)掃描量測實驗及高斯內插方法(Gaussian Interpolation)輔以幾何校正(Geometrical Calibration)與距離反比權重(Inverse Distance Weighting)之理論模擬，得以快速建立一高精確影像重建系統矩陣的方法，而此方法將應用於產生Single-pinhole SPECT、Multi-pinhole SPECT 以及Dual-isotope SPECT 之影像重建系統矩陣。由於 Dual-isotope SPECT 具備大幅減少個別使用不同核種進行造影之總影像擷取時間以及改善病人不舒適感的優點，其相關研究及技術亦蓬勃發展，而Dual-isotope SPECT 常因來自核種間彼此之串音汙染(Crosstalk Contamination)而使得各自的影像品質降低且產生錯誤之影像訊息，於本研究計畫將以三能窗法(Triple Energy Window)評估並消除康普吞散射光子，再以向下散射(Down Scattering)及鉛k X-ray 補償程序以減少串音汙染之影響，以獲得各自核種之正確的影像訊息及提昇其影像品質。Micro-SPECT along with small-animal models of human diseases is widely used in biomedical research to study disease mechanisms and investigate potential therapies. To improve the spatial resolution of SPECT systems, the researches and technologies based on pinhole imaging are discussed and developed successively. In this proposal, pinhole SPECT systems are the main imaging modality being considered. Generally, a nuclear medicine image system could be described as a linear digital-imaging system. The image vector is obtained by mapping the object function through the image reconstruction system matrix (IRSM). Therefore, the IRSM will influence the image quality directly, and the acquisition of IRSM with high precision and accuracy is essential for high-resolution image reconstructions. In this research, a method combined with experiments and simulations for fast generation of the IRSM with high preciseness is proposed. The IRSM will be generated with 2D-grid scanning experiments and Gaussian interpolations assisted with geometrical calibration and inverse distance weighting. This method will be applied to create the IRSM of single-pinhole SPECT, multi-pinhole SPECT and dual-isotope SPECT, respectively. As dual-isotope SPECT possesses the advantage of significantly shorter acquisition time than generating images with individual isotopes and better patient comfort, the related researches and techniques are of increasing growth. However, the crosstalk contaminations of dual isotopes affect the image quality of respective isotopes and induce incorrect image information. In this investigation, crosstalk contaminations of Compton scatters will be estimated and eliminated with triple energy window method, and the compensation process of down scattering and Pb X-ray will be utilized to decrease the crosstalk effect. Subsequently, the image quality of individual isotopes will be improved to ensure the correctness of image information. 研究期間：10008 ~ 10107
