Figure 3.

Box plot of the globus pallidus magnetisation transfer ratio (MTR) index normalised to white matter in the three study groups. Patients with stage I–II primary biliary cirrhosis (PBC) had a significantly reduced MTR index compared with healthy controls (*p = 0.03). The MTR index in stage III–IV patients was lower than that in stage I–II patients but this did not reach statistical significance. The boxes represent the interquartile range, which contain 50% of values, and the whiskers extend to the highest and lowest values. The median is represented by a line across the box. Differences were tested with the Kruskal-Wallis test (p = 0.01) and post hoc comparisons were made using the Mann-Whitney U test.