Detector-trigger-based cardiac multiphase micro-CT imaging for small animals

Article type: Research Article

Authors: Shi, Yu^{a; b; c} | Li, Juntao^{a; b; c} | Li, Ke^d | Zhang, Xuexue^{a; b; c} | Chang, Peng^{a; b} | Huang, Zujian^{a; b; c} | Liu, Yanyun^{a; b; c} | Wang, Yihan^{a; b; c} | Zhan, Yonghua^{a; b} | Cao, Xu^{a; b; c} | Zhu, Shouping^{a; b; c; *}

Affiliations: [a] School of Life Science and Technology, Xidian University & Engineering Research Center of Molecular and Neuro Imaging, Ministry of Education, Xi’an, Shaanxi, China | [b] Xi’an Key Laboratory of Intelligent Sensing and Regulation of trans-Scale Life Information & International Joint Research Center for Advanced Medical Imaging and Intelligent Diagnosis and Treatment, School of Life Science and Technology, Xidian University, Xi’an, Shaanxi, China | [c] Innovation Center for Advanced Medical Imaging and Intelligent Medicine, Guangzhou Institute of Technology, Xidian University, Guangzhou, Guangdong, China | [d] Xi’an Key Laboratory for Prevention and Treatment of Common Aging Diseases, Translational and Research Centre for Prevention and Therapy of Chronic Disease, Institute of Basic and Translational Medicine, Xi’an Medical University, Xi’an, China

Correspondence: [*] Corresponding authors: Shouping Zhu, School of Life Science and Technology, Xidian University, Xi’an, Shaanxi 710126, China. Tel.: +86 029 81891070; E-mail: spzhu@xidian.edu.cn.

Abstract: BACKGROUND:Micro-computed tomography is important in cardiac imaging for preclinical small animal models, but motion artifacts may appear due to the rapid heart rates. To avoid influence of motion artifacts, the prospective ECG gating schemes based on an X-ray source trigger have been investigated. However, due to the lack of pulsed X-ray exposure modes, high-resolution micro-focus X-ray sources do not support source triggering in most cases. OBJECTIVE:To develop a fast-cardiac multiphase acquisition strategy using prospective ECG gating for micro-focus X-ray tubes with a continuous emission mode. METHODS:The proposed detector-trigger-based prospective ECG gating acquisition scheme (DTB-PG) triggers the X-ray detector at the R peak of ECG, and then collects multiple phase projections of the heart in one ECG cycle by sequence acquisition. Cardiac multiphase images are reconstructed after performing the same acquisition in all views. The feasibility of this strategy was verified in multiphase imaging experiments of a phantom with 150 ms motion period and a mouse heart on a micro-focus micro-CT system with continuous emission mode. RESULTS:Using a high frame-rate CMOS detector, DTB-PG discriminates the positions of the motion phantom well in 10 different phases and enables to distinguish the changes in the cardiac volume of the mouse in different phases. The acquisition rate of DTB-PG is much faster than other prospective gating schemes as demonstrated by theoretical analysis. CONCLUSIONS:DTB-PG combines the advantages of prospective ECG gating strategies and X-ray detector-trigger mode to suppress motion artifacts, achieve ultra-fast acquisition rates, and relax hardware limitations.

Keywords: 4D micro-CT, multiple cardiac phases, ECG gating, detector trigger, sequence acquisition

DOI: 10.3233/XST-230034

Journal: Journal of X-Ray Science and Technology, vol. 31, no. 5, pp. 1047-1066, 2023