title: Dynamic susceptibility contrast-enhanced first-pass perfusion MR imaging in patients with subclinical hepatic encephalopathy.
abstract: OBJECTIVE
  Subclinical hepatic encephalopathy (SHE) is frequently reported on single-photon emission computed tomography (SPECT), but is rarely described with magnetic resonance (MR) techniques. This study aimed to investigate hemodynamic changes in brain basal ganglia in patients with SHE using dynamic susceptibility contrast (DSC)-enhanced MR perfusion imaging.
  
  
  METHODS
  Twelve patients with SHE and ten age- and education-matched volunteers agreed to undergo MR examination. The scanning protocol included conventional anatomical images and DSC-enhanced perfusion MR imaging. Using MGH perfusion software, parameter maps of cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were created. The bilateral caudate nucleus head, globus pallidus, putamen and thalamus were selected as regions of interest (ROI), with ipsilateral white matter of the frontal lobe used as reference. Ratios (ROI versus ipsilateral white matter in frontal lobe) for CBF, CBV and MTT in the patient group were compared with those in the control group.
  
  
  RESULTS
  The CBF ratios for every ROI were higher in SHE patients versus the controls. Statistically, significant increases were detected in the left globus pallidus, putamen and thalamus (P<0.05). For MTT, the reduction in values reached statistical significance in the right head of the caudate nucleus and bilateral thalamus (P<0.05). CBV values were not significantly different compared with those of the control group (P>0.05).
  
  
  CONCLUSIONS
  Increased CBF and decreased MTT values in the basal ganglia and thalamus were identified in patients with SHE. The CBF increase was compatible with the idea that the CBF is redistributed from cortical areas to the basal ganglia structures.
authors: Department of Radiology, The General Hospital of Chinese People's Armed Police Forces, No 69, Yongding Road, 100039 Beijing, China.
authors: Tao
authors: T
authors: Li
authors: Xin
authors: X
authors: Li
authors: Weihua
authors: W
authors: Zhou
authors: Xiaoming
authors: X
authors: Cui
authors: Lin
authors: L
authors: Ma
mesh_terms: D000328:Adult; D000465:Algorithms; D003287:Contrast Media; D019786:Gadolinium DTPA; D006501:Hepatic Encephalopathy / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA