Department of Hepato-Gastroenterology, Aarhus University Hospital, 8000 Aarhus, Denmark.
Arch Biochem Biophys. 2013 Aug 15;536(2):131-42. doi: 10.1016/j.abb.2013.05.006. Epub 2013 May 30.
We review PET- and MR studies on hepatic encephalopathy (HE) metabolism in human subjects from the point of views of methods, methodological assumptions and use in studies of cirrhotic patients with clinically overt HE, cirrhotic patients with minimal HE, cirrhotic patients with no history of HE and healthy subjects. Key results are: (1) Cerebral oxygen uptake and blood flow are reduced to 2/3 in cirrhotic patients with clinically overt HE but not in cirrhotic patients with minimal HE or no HE compared to healthy subjects. (2) Cerebral ammonia metabolism is enhanced due to increased blood ammonia in cirrhotic patients but the kinetics of cerebral ammonia uptake and metabolism is not affected by hyperammonemia. (3) Recent advantages in MR demonstrate low-grade cerebral oedema not only in astrocytes but also in the white matter in cirrhotic patients with HE.
我们从方法、方法假设以及在有临床显性肝性脑病的肝硬化患者、有轻微肝性脑病的肝硬化患者、无肝性脑病史的肝硬化患者和健康受试者的研究中的应用等方面，回顾了关于人类肝性脑病（HE）代谢的 PET 和 MR 研究。主要结果如下：（1）与健康受试者相比，有临床显性 HE 的肝硬化患者的脑氧摄取和血流减少至 2/3，但有轻微 HE 或无 HE 的肝硬化患者则没有。（2）由于血氨增加，肝硬化患者的脑氨代谢增强，但氨摄取和代谢的动力学不受高氨血症的影响。（3）MR 的最新优势显示，不仅在星形胶质细胞中，而且在有 HE 的肝硬化患者的白质中，都存在轻度脑水肿。
