Evaluation of mannitol effect in patients with acute hepatic failure and acute-on-chronic liver failure using conventional MRI, diffusion tensor imaging and in-vivo proton MR spectroscopy

Figure 1 Conventional magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) were performed at three days after the onset of encephalopathy in a 29-year-old man with acute liver failure (ALF) before the mannitol administration. A: Axial T2-weighted imaging at the level of third ventricle does not show any visible abnormality; B: Localized proton spectrum from 2 cm × 2 cm × 2 cm voxel placed on right parietal region (A) shows the metabolite ratios with respect to Cr (NAA/Cr = 1.35, Cho/Cr = 0.34, Gln/Cr = 2.57, Glx/Cr = 4.12, mI/Cr = 0.45); C: Mean diffusivity (MD) map, [anterior limb of internal capsule (ALIC) = 0.68, posterior limb of internal capsule (PLIC) = 0.65, caudate nuclei (CN) = 0.67, putamen (P) = 0.60, thalamus (TH) = 0.66, frontal white matter (FWM) = 0.66, occipital white matter (OWM) = 0.67, corpus callosum (CC) = 0.60, cingulum = 0.70, frontal cortex = 0.63, parietal cortex = 0.70, occipital cortex = 0.63]; D: Fractional anisotropy (FA) map, (ALIC = 0.32, PLIC = 0.34, CN = 0.09, putamen = 0.08, thalamus = 0.11, FWM = 0.33, OWM = 0.38, CC = 0.53, cingulum = 0.45, frontal cortex = 0.16, parietal cortex = 0.10, occipital cortex = 0.12). The cut off value for the color-coded FA for display is kept at 0.2 (E) above which the color-coded regions reflect the white matter only [red (right-left), green (anterior-posterior), and blue (superior-inferior)]. Cho: Choline; Cr: Creatine; Gln: Glutamine; Glx: Glutamine/glutamate; mI: Myoinositol; NAA: N-acetylaspartate.