用于脑卒中早期检测鉴别的新型脑部电阻抗增强造影灌注成像基础研究

Early detection and timely treatment of stroke are important to save the patient’s life and improve their prognosis. However, due to the technical shortcomings of existing imaging equipment and other non-technical reasons, early diagnosis and treatment of stroke is still very low. Thus, the research and development of new methods for stroke primary diagnosis are of great significance. In previous clinical trials, it has been found that the infusion of the treatment fluid can change the brain impedance distribution, which inspired us to use contrast-enhanced agent to improve electrical impedance tomography capability. In this project, a new method, so-called contrast-enhanced electrical impedance tomography (CEIT), is proposed. The blood perfusion of the brain can be achieved with dynamic electrical impedance tomography by injecting electrical properties agent into the body, and then, it would be used for stroke primary diagnosis. The following researches are planned to be conducted. First, the electrical properties of several existing agent materials are measured to select an appropriate contrast agent. Then, different injection methods and parameters are compared to establish the implementation route and standard of CEIT. At the same time, image reconstruction algorithms and analysis methods are researched to improve the image quality and detection accuracy of contrast-enhanced imaging. Finally, through experiments, a comparative study with the existing perfusion imaging methods and the proposed CEIT is carried out and the feasibility of stroke primary diagnosis of CEIT is studied. We hope CEIT method could be eventually tested in clinical trials in the future through this research.

脑卒中早期检测对于及时救治患者的生命和改善预后具有重要的意义。但由于现有影像设备不足等原因，脑卒中早期诊治率仍然很低，因此探索脑卒中新的检测鉴别方法具有重要意义。我们在前期的临床实验中发现，治疗液体的输注能够明显改变脑部阻抗分布，由此本项目提出了全新的脑部电阻抗增强造影灌注成像方法，该方法通过向体内注入电特性增强造影剂进行电阻抗动态成像，实现脑部灌注成像,进而以期达到脑卒中早期检测鉴别目的。为此本项目首先通过造影剂材料及其注入方法的研究，优选出合适造影剂，构建电阻抗增强造影灌注成像完整实施途径，并确定最优造影参数，建立实施规范；通过图像重构算法和图像分析研究，提高增强造影成像的图像质量和检测准确性；最后通过实验，开展与现有灌注成像手段的对照研究，并完成用于脑卒中早期检测鉴别的新型脑部电阻抗增强造影灌注成像的有效性评估。以期最终将该技术推向临床应用研究。

脑卒中早期检测对于及时救治患者的生命和改善预后具有重要的意义。但由于现有影像设备不足等原因，脑卒中早期诊治率仍然很低，因此探索脑卒中新的检测鉴别方法具有重要意义。我们在前期的临床实验中发现，治疗液体的输注能够明显改变脑部阻抗分布，由此本项目提出了全新的脑部电阻抗增强造影灌注成像方法，该方法通过向体内注入电特性增强造影剂进行电阻抗动态成像，实现脑部灌注成像,进而以期达到脑卒中早期检测鉴别目的。主要完成内容包括：（1）完成了造影剂优选，碘佛醇、碘克沙醇、碘比醇、碘海醇这几种含碘造影剂和5%葡萄糖溶液的电导率显著低于血液电导率，生理盐水与六氟化硫微泡造影剂的电导率相近且都高于血液电导率，碘佛醇、葡萄糖可以作为新型脑部电阻抗增强造影灌注成像的造影剂；（2）提出了一种适合电阻抗增强造影灌注成像的目标自适应差分迭代算法，该算法无需最优正则化参数，在保持快速成像的同时，能有效提高图像重构质量。（3）通过实验验证了可以通过动脉注射、静脉注射方式进行电阻抗增强造影成像，并且可以检测局部缺血性脑损伤。