title: Combining arterial-spin labeling with functional magnetic resonance imaging measurement for characterizing patients with minimal hepatic encephalopathy.
abstract: OBJECTIVE
  Our objective is to explore key changes in brain functions in relation to minimal hepatic encephalopathy (MHE). We incorporated both resting-state functional magnetic resonance imaging (fMRI) and arterial spin labeling (ASL) to enhance the detection of MHE.
  
  
  METHODS
  We undertook fMRI scanning for 56 MHE patients and 66 healthy controls. Region functional connectivity was carried out to assess the connectivity status between pairs of regions among 90 brain regions. Additionally, blood flow (BF) status was measured by ASL for all subjects. Spearman's correlation test was implemented to identify any correlation among z-values, results from number connection test type A, and digit symbol tests. Finally, the receiver operating characteristic curve was generated for assessing the accuracy of BF in MHE diagnosis.
  
  
  RESULTS
  The corresponding functional connectivity was significantly different between MHE and control groups in 15 regions. For MHE patients, BF showed an increasing pattern in regions of interest. Blood flood in the putamen was positively correlated with number connection test type A neuropsychological performance, whereas it was negatively correlated with the digit symbol test. Blood flood in the right putamen showed the highest value of area under the curve with a sensitivity of 85.7% and specificity of 89.4%.
  
  
  CONCLUSIONS
  Connectivity impairment resulting from ganglia-thalamo-cortical circuits may play important roles in mediating the development of MHE patients. An increase in the BF, particularly in the right putamen, may be considered as evidence for the presence of MHE.
authors.affiliation: Medical Imaging Department, The Second Hospital of Hebei Medical University, Shijiazhuang City, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.affiliation: Medical Imaging Department, The Second Hospital of Hebei Medical University, Shijiazhuang City, China.
authors.forename: Huaijun
authors.initials: H
authors.lastname: Liu
authors.affiliation: Medical Imaging Department, The Second Hospital of Hebei Medical University, Shijiazhuang City, China.
authors.forename: Jiping
authors.initials: J
authors.lastname: Yang
authors.affiliation: Medical Imaging Department, The Second Hospital of Hebei Medical University, Shijiazhuang City, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Tian
authors.affiliation: Medical Imaging Department, The Second Hospital of Hebei Medical University, Shijiazhuang City, China.
authors.forename: Haiqing
authors.initials: H
authors.lastname: Yang
authors.affiliation: Medical Imaging Department, The Second Hospital of Hebei Medical University, Shijiazhuang City, China.
authors.forename: Zuojun
authors.initials: Z
authors.lastname: Geng
keywords: arterial spin labeling; blood flow; functional connectivity; minimal hepatic encephalopathy; resting-state functional MRI