Graphical representation of values for right and left side R2c/R2 ratios (upper graphs) and mean R2 area (µV x s; lower graphs) in healthy subjects and patients with multiple sclerosis.

<p>The individual values for right (R) and left (L) sides are tied by a line to highlight the degree of between-sides asymmetry. Horizontal dashed lines indicate the normal upper cut-off values for both response size parameters. Note that healthy subjects show relatively more symmetrically distributed values with respect to patients for both the R2c/R2 ratio and the mean R2 area. A unilateral R2c/R2 ratio value above 1 was observed in 9 patients (lines reaching above 1 in panel <b>B</b>). Only 2 AbLat patients had a single value above 1 in the R2c/R2 ratio (marked with asterisks in <b>B</b>). Although no differences on the distribution of the mean R2 area values were apparent between both groups (lower graphs), 8 patients had a significant increase in the inter-side difference which was coincident with a unilateral enhancement on the R2c/R2 ratio (AbEx patients). These 8 subjects are identified in panel <b>D</b> because of their steeper slope in the inter-side.