Note the largest MS plaque (FLAIR left image) that shows typical peripheral enhancement (T1 C+ right image). You can also see other smaller plaques that do not enhance.
Now observe that this plaque, unlike other, has high signal on b1000 (left image), without restriction on ADC (right image). Other plaques do not show such high signal on b1000.
My point is that b1000 gives a clue to active plaques.