Department of Radiology, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA, 19104, USA.
Department of Bioengineering, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA, 19104, USA.
Sci Rep. 2018 Aug 14;8(1):12119. doi: 10.1038/s41598-018-30570-y.
Spectral photon-counting computed tomography (SPCCT) is a rapidly emerging imaging modality that provides energy-dependent information on individual x-ray photons, leading to accurate material decomposition and simultaneous quantification of multiple contrast generating materials. Development of SPCCT-specific contrast agents is needed to overcome the issues with currently used iodinated contrast agents, such as difficulty in differentiation from calcified structures, and yield SPCCT's full promise. In this study, the contrast generation of different elements is investigated using a prototype SPCCT scanner based on a modified clinical CT system and suitable elements for novel contrast agent development for SPCCT imaging are identified. Furthermore, nanoparticles were synthesized from tantalum as a proof of concept spectral photon-counting CT agent and tested for their in vitro cytotoxicity and contrast generation to provide insight into the feasibility of nanoparticle contrast agent development from these elements. We found that gadolinium, ytterbium and tantalum generate high contrast in spectral photon-counting CT imaging and may be suitable elements for contrast agent development for this modality. Our proof of concept results with tantalum-based nanoparticles underscore this conclusion due to their detectability with spectral photon-counting CT, as well as their biocompatibility.
能谱光子计数计算机断层扫描（SPCCT）是一种新兴的成像方式，它提供了单个 X 射线光子的能量相关信息，从而实现了对多种对比生成材料的准确物质分解和同时定量。需要开发 SPCCT 专用对比剂来克服目前使用的碘对比剂存在的问题，例如难以与钙化结构区分，从而充分发挥 SPCCT 的潜力。在这项研究中，使用基于改进的临床 CT 系统的原型 SPCCT 扫描仪研究了不同元素的对比生成，并确定了用于 SPCCT 成像的新型对比剂开发的合适元素。此外，还合成了钽纳米粒子作为光谱光子计数 CT 造影剂的概念验证，并测试了它们的体外细胞毒性和对比生成能力，以深入了解从这些元素开发纳米粒子造影剂的可行性。我们发现，镝、镱和钽在能谱光子计数 CT 成像中产生高对比度，可能是这种方式的对比剂开发的合适元素。我们基于钽的纳米粒子的概念验证结果强调了这一结论，因为它们在光谱光子计数 CT 中具有可检测性，并且具有生物相容性。
