Brain glutamine and glutamate levels in patients with liver cirrhosis: assessed by 3.0-T MRS.

Abstract

Background/Objectives: Magnetic resonance spectroscopic (MRS) studies have revealed abnormal metabolism in the brain of patients with liver cirrhosis, including an increase in total brain glutamine (Gln) and glutamate (Glu) levels (Glx). However, with conventional MRS techniques, it was difficult to separate the Glx signals. Using a high-magnetic field MR equipment and a newly developed data processing method, we attempted to separate the Glx signals on an MRS. Subjects and Methods: Twenty-three patients with liver cirrhosis and 11 healthy adults were enrolled in this study. After designating a region of interest in the occipital lobe gray matter of each subject, [Formula: see text] (proton)-MRS was performed using 3.0-T MR equipment. Results: MRS conducted using the 3.0-T MR equipment allowed Gln signals in the brain to be distinguished from the Glx signals. The brain signal intensity of Gln was found to be significantly higher in the liver cirrhosis group (0.658 +/- 0.23) than in the control group (0.473 +/- 0.08) (P < 0.05). Neither the Glu nor the Gln signal intensity showed any correlation with the blood ammonia level. Conclusion: High-magnetic field MRS allowed us to separate the Glx signals in the brain and revealed that the increase in the total brain Glu and Gln levels in patients is solely attributable to an increase in the level of Gln.