Contrast-enhanced Perfusion MR Imaging In The Patients With Subclinical Hepatic Encephalopathy

Purpose: To investigate the perfusion pattern of the brain in patients with subclinical hepatic encephalopathy by using MRI perfusion technique, and to reveal its mechanism.Materials and Methods: 12 patients ( 9 men, 3 women; their age from 28 to 64 years, mean age 50 years, mean education time 11.7 ±2.4 years ) with subclinical hepatic encephalopathy (SHE) diagnosed by neuropsychologic tests and 10 age and education-matched healthy volunteers accepted examinations on 1.5T GE MR scanner. The scanning protocol included head plain scan and dynamic susceptibility contrast enhanced perfusion MR imaging. The patients were diagnosed SHE by number connection test or symbol digit test. 10 patients were accompanied with Parkinsonian signs evaluated by Unified Parkinson's Disease Rating Scale (UPDRS). GE-EPI sequence (1500/75ms: [TR/TE]) was used in perfusion imaging. The slice thickness was 6mm with 0.5mm inter-slice gap. The matrix was 128*128. The contrast was injected from cubital vein at the speed of 4ml/s. The injection dose was 0.1mmol/kg. Scanning range was from basal ganglion section to frontal-parietal lobe. Perfusion data were transferred to the SUN workstation. Using the MGH perfusion software, the parameter maps of CBF, CBV and MTT were created. Bilateral head of caudate nucleus, globus pallidus, putamen, thalamus were selected as region of interest (ROI). Ipsilateral white matter of frontal lobe was used as reference, the ratios of ROI were calculated and compared with those in the control group.Results: Bilateral symmetrical high signal intensity could be detected in globus pallidus in all patients. Compared with control group, for CBF, the values of left globus pallidus reached statistical increase. The CBF values in left putamen and thalamus were close to statistical increase (p=0.05). For MTT, the values of...