MR-IMAGING AND SPECTROSCOPY OF THE BASAL GANGLIA IN CHRONIC LIVER-DISEASE - CORRELATION OF T-1-WEIGHTED CONTRAST MEASUREMENTS WITH ABNORMALITIES IN PROTON AND P-31 MR SPECTRA

The purpose of this study was to correlate the hyperintensity in the g lobus pallidus seen on T-1-weighted magnetic resonance imaging (MRI) o f the brain in chronic liver disease with changes in metabolite ratios measured from both proton and phosphorus-31 magnetic resonance spectr oscopy (MRS) localised to the basal ganglia. T-1-weighted spin echo (T (1)WSE) images were obtained in 21 patients with biopsy-proven cirrhos is (nine Child's grade A, eight Child's grade B and four Child's grade C). Four subjects showed no evidence of neuropsychiatric impairment o n clinical, psychometric and electrophysiological testing, four showed evidence of subclinical hepatic encephalopathy and 13 had overt hepat ic encephalopathy. Signal intensities of the globus pallidus and adjac ent brain parenchyma were measured and contrast calculated, which corr elated with the severity of the underlying liver disease, when graded according to the Pugh's score (p<0.05). Proton MRS of the basal gangli a was performed in 12 patients and 14 healthy volunteers. Peak area ra tios of choline (Cho), glutamine and glutamate (Glx) and N-acetylaspar tate relative to creatine (Cr) were measured. Significant reductions i n mean Cho/Cr and elevations in mean Glx/Cr ratios were observed in th e patient population. Phosphorus-31 MRS of the basal ganglia was perfo rmed in the remaining nine patients and in 15 healthy volunteers. Peak area ratios of phosphomonoesters (PME), inorganic phosphate, phosphod iesters (PDE) and. phosphocreatine relative to beta ATP (ATP) were the n measured. Mean values of PME/ATP and PDE/ATP were significantly lowe r in the patient population. No correlation was found between the T(1) WSE MRI contrast measurements of the globus pallidus and the abnormali ties in the metabolite ratios measured from either proton or phosphoru s-31 MR spectra. Our results suggest that pallidal hyperintensity seen on T(1)WSE MR imaging of patients with chronic liver disease is not r elated to the functional abnormalities of the brain observed in hepati c encephalopathy.