Figure 6.
Comparison of myelin imaging biomarkers as defined by DBSI, DTI and MTR. MTR (A) and FLAIR (B) images were used to guide the selection of 42 regions of interest with a wide range of MTR contrast in three multiple sclerosis patients. One region of interest adjacent to the posterior lateral ventricle (MTR = 0.04) and one region of interest are noted by white arrow heads in the normal-appearing corpus callosum (MTR ≈ 0.4). Reduced MTR correlated with increased DBSI radial diffusivity (B, E and H) and DTI radial diffusivity (C, F and I), in accordance with the idea that each of these three imaging biomarkers represents myelin integrity. MTR also correlated with DBSI non-restricted isotropic fraction (D, G and J), suggesting that MTR is also sensitive to increased water content, likely oedema and/or tissue loss. The red circle, yellow triangle, and blue squares indicated the data from Patients 1, 2 and 3, respectively.