ISSN 1004-4140
    CN 11-3017/P

    一种使用栅控X射线管的双能口腔锥形束CT系统

    A Dual-Energy Dental Cone-beam CT System Using Grid-Controlled X-Ray Tube

    • 摘要: 目的:本研究拟提出一种使用栅控X射线管的新型双能口腔锥形束CT(CBCT)系统设计,研制原型样机并验证其成像性能,期望该系统能在扫描时间和辐射剂量不显著增加的情况下实现较好的基本成像性能和金属伪影抑制能力。方法:本研究采用快速kV切换、投影阈基材料分解作为双能扫描和重建的技术路线,使用栅控X射线管缩短高低能辐射脉冲的建立和关断时间、增加有限时间内的高低能投影数量进而提升成像性能。结论:本研究提出的双能口腔CBCT可在约15s的扫描时间内交替获得900幅大面阵高能、低能投影数据,该获取速率显著快于文献中已报道的其他kV切换式双能口腔CBCT。在DAP低于欧盟建议值的条件下,该系统双能扫描所得虚拟单能图像的空间分辨率、低对比度分辨率、均匀性等基本成像性能优于或符合相关标准要求,而金属伪影则显著弱于同等DAP的单能扫描图像。

       

      Abstract: Objective: This study aims to design a novel dual-energy dental cone-beam CT (CBCT) system using a grid-controlled X-ray tube, construct a prototype, and evaluate its performance. The system aims to deliver strong basic imaging performance and effective metal artifact suppression capabilities without significantly increasing scan time or radiation dose. Methods: Rapid kilovolt (kV)-switching and basis-material decomposition in the projection domain are performed for dual-energy scanning and reconstruction. A grid-controlled X-ray tube is utilized to reduce the rise and fall times of radiation pulse and increase the number of high- and low-energy projections acquired within a limited scanning time, thus improving imaging performance. Conclusion: The proposed dual-energy CBCT system can alternatively acquire 900 high- and low-energy large FOV projection data within 15 s. This acquiring rate is significantly higher than those of other kV-switching dental CBCT systems reported in the literature. The basic performance (such as spatial resolution, low-contrast resolution, and uniformity) of the VMI image obtained via the dual-energy scanning mode of this novel system satisfies the requirements of relative standards with a DAP value lower than that suggested by the European Commission. Additionally, the metal artifact is significantly lower than those under single-energy scanning modes with similar DAPs.

       

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