基于能谱CT与碘分布对门静脉高压血流动力学演变规律的研究

Portal hypertension is the main complication of cirrhosis. But the developing regulation of portal hypertension between blood perfusion and collateral circulation remains unknown. The iodine concentration in vivo follows the pharmacokinetics law when performing contrast enhanced CT. Thus the mathematic model of iodine distribution time-density curve of normal liver, spleen and portal vein has already been established according to the relevant physiological parameters in our previous study. Dual-energy CT could obtain monochromatic energy, measure the iodine content within the scanning material quantitatively and obtain the time-density curve of iodine contrast media in vivo. On account of the two above, we hypothesized that the hemodynamic mathematic model of portal venous system of cirrhotic patients could be set up with spectral CT and the developing law could be studied by that. Firstly, we plan to validate the normal homodynamic model of portal venous system by spectral CT, then measure the iodine content of different phases and get TDC of cirrhotic patients who underwent enhanced spectral CT scanning. By contrast to the normal modeling, the corresponding homodynamic model could be obtained and classified. Combined to the circumstances of portal-systemic collateral circulation, we could explore the developing regularity and pathophysiological mechanism of the hemodynamics of portal venous system and provide the theoretical basis for treatment of portal hypertension patients.

肝硬化失代偿期可引起门静脉高压，但是门静脉高压时肝脏血流灌注与门-体侧枝循环之间相互关系的演变规律尚未阐明。CT增强扫描时含碘对比剂在体内遵循药代动力学规律，我们已据此根据相关生理参数建立了正常肝脏、脾脏及门静脉碘分布的"时间-密度曲线"模型；能谱CT能够获得单能量图像，并可以定量测定被扫描体的碘含量，获取碘对比剂在体内分布的时间-密度曲线，基于上述两点，我们提出依据能谱CT对碘分布的测量可以建立门静脉系统血流动力学模型并对其演变规律进行研究的假设。本研究拟首先应用能谱CT对门静脉系统正常血流动力学模型进行验证后，对行能谱CT增强扫描的肝硬化门静脉高压患者，通过测定不同时相的碘含量获得其时间-密度曲线，与正常模型进行比较、拟合出其相应的血流动力学模型并进行分类后，结合门-体侧支循环的情况，探索门静脉高压患者门静脉系统血流动力学的变化规律，为门静脉高压的治疗提供理论基础。

肝硬化门静脉高压的血流动力学改变，包括肝脏血流灌注的改变、内脏血流的重新分配及门、体侧支循环的形成，是互相关联，互相影响的，对肝硬化门静脉高压治疗方式的选择需对其进行综合考虑、全面分析。. CT增强扫描可反映肝硬化门静脉高压患者肝灌注及门静脉分、属支、门-体侧支循环形成的状况。能谱增强CT可以定量测定组织内的碘含量，从而定量反映碘对比剂在肝、脾及门静脉内的时间-密度（浓度）曲线(TDC)，模拟相应器官的血流动力学改变状况。. 本项目分别获得了正常人依据生理参数获得的碘对比剂的理论TDC及行能谱CT增强扫描的肝功能正常者的实际TDC，对两者进行拟合，得到了正常人体内碘对比剂的能谱CT扫描的TDC；由此推算出肝硬化患者的理论TDC，通过与能谱CT扫描获得的实际TDC拟合，得到了肝硬化患者的能谱CT的TDC；结合其肝、脾体积及门-体侧支循环状况，得到了肝硬化门静脉高压患者的不同血流动力学模型。从而可以从整体上综合评估肝硬化患者的肝脏、脾脏及门静脉系统的血流动力学状况，为肝硬化门静脉高压患者的个体化治疗方案的选择提供重要信息。