AI 中文总结
研究用于核医学的康普顿成像中像素大小对空间分辨率的影响，采用两种算法评估，经蒙特卡罗模拟，发现100μm左右像素尺寸可实现几十微米量级空间分辨率。
AI 中文摘要
我们正在开发一种用于核医学的康普顿成像新实现方式，使用大量堆叠的单片硅传感器。在这项工作中，我们研究像素大小如何影响空间分辨率，像素大小是传感器设计的重要输入参数。一般来说，较大像素的CMOS设计挑战性较小，可为模拟和数字电子设备留出更多空间。空间分辨率是影响康普顿成像系统性能的关键参数之一。还需考虑康普顿或光电相互作用中产生的反冲电子的范围，这会影响相互作用点的估计精度。用两种相互作用位置重建算法评估了可实现的分辨率：一种基于检测电荷的高斯拟合，另一种基于沿电子轨迹的特征能量沉积，前者在较低能量下表现更好。对嵌入水模体中的140keV和511keV源进行了蒙特卡罗模拟，像素间距从25μm到250μm。随着像素尺寸增加，能量平均平面内分辨率从8μm降至94μm。平面外分辨率在低能量时为216μm，受传感器厚度限制，在高能量时提高到155μm。结果表明，100μm左右的像素尺寸可实现几十微米量级的空间分辨率。
英文摘要
We are developing a new implementation of Compton imaging for nuclear medicine using a large volume of stacked monolithic silicon sensors. In this work we investigate how the spatial resolution is impacted by the pixel size, an important input to the design of the sensors. In general CMOS design is less challenging with larger pixels leaving more space for analog and digital electronics. On the other hand, spatial resolution is one of the key parameters that will impact the performance of the Compton imaging system. It is also important to consider the range of the recoil electron produced in Compton or photoelectric interactions, which impacts how accurately the interaction point can be estimated. The achievable resolution was evaluated with two interaction position reconstruction algorithms: one based on a Gaussian fit of the detected charge and a second based on the characteristic energy deposition along the electron track, with the former performing better at lower energies. Monte Carlo simulations were performed for 140 keV and 511 keV sources embedded in a water phantom, with pixel pitches ranging from 25 $μm$ to 250 $μm$. Energy-averaged in-plane resolution degraded from 8 $μm$ to 94 $μm$ as pixel size increased. The out-of-plane resolution was 216 $μm$ at low energies, limited by sensor thickness, and improved to 155 $μm$ at higher energies. The results suggest that pixel sizes in the order of 100 $μm$ can achieve spatial resolutions on the order of tens of micrometers.
Comments14 pages, 8 figures
