Quantitative cerebral water content mapping in hepatic encephalopathy

Area of Science:

• Neurology
• Radiology
• Biochemistry

Background:

• Hepatic encephalopathy (HE) pathophysiology is linked to cerebral edema.
• Previous methods lacked in vivo confirmation of this hypothesis.
• Quantitative MRI offers a novel approach to assess brain water content in HE.

Purpose of the Study:

• To quantitatively measure localized water content in the brains of HE patients using MRI.
• To investigate the relationship between brain water content, HE grade, and cognitive function (critical flicker frequency).
• To provide direct in vivo evidence for low-grade cerebral edema in HE.

Main Methods:

• Magnetic Resonance Imaging (MRI) was used for quantitative measurement of localized water content.
• 38 patients with hepatic encephalopathy were included in the study.
• Regions of interest (ROIs) were defined in grey and white matter for detailed analysis.

Main Results:

• A significant global increase in white matter water content was observed.
• Grey matter water content was globally unaffected but showed significant spatial variations correlated with HE grade.
• Specific ROIs, including frontal/occipital white matter and basal ganglia, showed significant water content changes with HE grade.

Conclusions:

• This study provides the first direct, quantitative in vivo demonstration of low-grade cerebral edema in hepatic encephalopathy patients.
• Tissue water content changes were quantified across various brain regions, offering insights into HE pathophysiology.
• Findings highlight the utility of quantitative MRI in assessing brain edema in neurological conditions.