Figure 3.

Mean raw T2-weighted 3D FLAIR images cropped to contain only the lateral ventricles and centred on the choroid plexus. Shown are the centre slice of the mean cropped MRI for: (A) high disease activity patients, (B) low disease activity patients, and (C) the subtracted mean image (low subtracted from high disease activity). Mean lesion masks in the same cropped regions were created for (D) high disease activity and (E) low disease activity patients, and (F) the subtracted mean image (low subtracted from high disease activity). This mean difference in lesion masks visually indicates similar mean lesion load and lesion locations between the two groups. However, it can be seen in (C) that it seems there may be a higher incidence of T2-hyperintense lesions in the splenium of the corpus callosum, along with higher intensities in the choroid plexus and lateral ventricular CSF, in patients with high disease activity. Colour bars indicate intensity measures in first row of mean raw cropped-FLAIR images (A-C) and indicate an average incidence of lesions in specific voxels in the second row of mean lesion masks (D-F).

CP: corpus callosum; CSF: cerebrospinal fluid.