Table 3:

MR imaging features in patients with cirrhosis with or without overt HE

	T1WI Sequence	¹H-MR spectroscopy	MTR	T2/FLAIR Sequence	DWI
MR imaging abnormalities	Bilateral, symmetric high signal intensity of the globus pallidus and substantia nigra	Increase in glutamine/glutamate signal; depletion of myo-inositol signal; decrease in choline signal; normal NAA signal	Mild (10%) and diffuse decrease in normal-appearing white matter	Diffuse white matter high signal intensities involving predominantly the hemispheric corticospinal tract; focal high-signal T2 lesions in subcortical hemispheric white matter	Increase mean diffusivity in hemispheric white matter; normal fractional anisotropy
Pathogenesis	Increased brain tissue concentration of manganese	Osmolar adaptation of intra-astrocytic accumulation of glutamine	Mild and diffuse brain edema	Mild and diffuse brain edema	Interstitial brain edema
Functional consequences	Parkinsonism (particularly if substantia nigra is involved)	Overt hepatic encephalopathy (particularly with increase in glutamine/glutamate)	Functional abnormalities of the corticospinal tract on TMS	Functional abnormalities of the corticospinal tract on TMS; cognitive impairment	Cognitive impairment

Note:—T1WI Indicates T1-weighted imaging; NAA, N-acetylaspartate; TMS, transcranial magnetic stimulation; FLAIR, fluid-attenuated inversion recovery; DWI, diffusion-weighted imaging; MTR, magnetization transfer ratio.