Title: Accelerated X-Ray Fluorescence Computed Tomography via Multi-Pencil-Beam Excitation Show Chinese title

Title: 通过多笔束激发的加速X射线荧光计算机断层扫描

Abstract: X-ray fluorescence computed tomography (XFCT), a form of X-ray molecular imaging, offers detailed quantitative imaging capabilities for high-Z metal nanoparticles (MNPs), which are widely studied for their applications in multifunctional theranostics. Due to its affordability and accessibility, the benchtop XFCT prototype typically employs a single-pixel detector (SPD) with single-pencil-beam (SPB) X-ray excitation. While this design (resembling the first-generation CT geometry) achieves reliable detection sensitivity, it is hindered by long imaging times. The use of simultaneous multiple-pencil-beam (MPB) excitation presents a promising solution to significantly reduce imaging times. In this study, we developed a repeatable workflow that combines Monte Carlo (MC) simulations and 3D printing to design Nbeam-MPB collimator, where Nbeam is the number of beams generated by the collimator. As an initial test, we fabricated a 2-MPB collimator and evaluated the performance of 2-MPB-based XFCT imaging on a physical phantom and small animals surgically implanted with agarose pellets containing gold chloride (H[AuCl4]). The results demonstrated a 2x acceleration in image acquisition without compromising the contrast-to-noise ratio (CNR). We further investigated the concept of Nbeam-MPB acceleration on the MC computational XFCT system, which confirmed the feasibility of achieving at least 4x acceleration with 4-MPB excitation. Combined with additional system optimization, such as X-ray beam flux optimization, XFCT imaging could be further accelerated, reducing acquisition time from hours to minutes and meeting the requirements for routine MNP imaging. Show Chinese abstract

Abstract: X射线荧光计算机断层扫描（XFCT），一种X射线分子成像形式，为高Z金属纳米颗粒（MNPs）提供了详细的定量成像能力，这些纳米颗粒因其在多功能诊疗中的应用而被广泛研究。 由于其成本低廉和易于获取，台式XFCT原型通常采用单像素探测器（SPD）和单笔形束（SPB）X射线激发。 虽然这种设计（类似于第一代CT几何结构）实现了可靠的检测灵敏度，但受到成像时间较长的限制。 同时使用多个笔形束（MPB）激发是一种有前景的解决方案，可以显著减少成像时间。 在本研究中，我们开发了一种可重复的工作流程，结合蒙特卡罗（MC）模拟和3D打印来设计Nbeam-MPB准直器，其中Nbeam是准直器产生的光束数量。 作为初步测试，我们制造了一个2-MPB准直器，并在物理幻影和手术植入含有氯金酸（H[AuCl4]）的琼脂糖珠的小动物上评估了基于2-MPB的XFCT成像性能。 结果表明，在不牺牲对比噪声比（CNR）的情况下，图像采集速度提高了2倍。 我们进一步在MC计算XFCT系统上研究了Nbeam-MPB加速的概念，这证实了使用4-MPB激发至少实现4倍加速的可行性。 结合其他系统优化，如X射线束通量优化，XFCT成像可以进一步加速，将采集时间从小时级缩短到分钟级，满足常规MNPs成像的要求。