White Matter Diseases (please click on the first image to be enlarged).

Figure 14a.  Canavan disease in a 6-month-old boy with macrocephaly. (a) T2-weighted MR image shows extensive high-signal-intensity areas throughout the white matter, resulting in gyral expansion and cortical thinning. Striking demyelination of the subcortical U fibers is also noted. 

Figure 14 b: T1-weighted MR image shows demyelinated white matter with low signal intensity. 

Reference