الفهرس 
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Abstract
Multiple sclerosis (MS) is a chronic inflammatory autoimmune demyelinating disease of the central nervous system. Its onset is usually during young adulthood. MS attacks the myelinated axons in the CNS, destroying the myelin and the axons to varying degrees. There are four clinical forms of MS, of which relapsing remitting type is the most common. As the etiology of MS is unknown, finding a cure will remain challenging.
Adding MRI to diagnosis and monitoring of MS was a great advance. It helped to appreciate the realistic record of the disease and to detect DIT and DIS even before they are evident clinically.
Diffusion MRI is very sensitive to alterations of the Brownian movements of water molecules providing a unique information about the tissue and cellular microstructure in the human brain So, Diffusion MRI has been shown to be sensitive to evaluation of MS damage over time and to provide in vivo correlates of MS clinical severity. Moreover, DWI does not need contrast media and takes very short time.
All MS lesions that appeared hyperintense (bright) signals in DWI-b0 were in match with hyperintensity of lesions in T2WI, So DWI B0 can precisely detect all confluent and separate MS plaques like T2 WI, yet with much lesions noticeability in DWI than T2 WI
Differentiation of MS disease activity from older lesions beyond the active stage; this could be achieved by:
1. The use of CE T1WI that shows enhancement of the active lesions which happens due to the increase in the blood brain barrier permeability.
2. The use of DWI-b1000 that shows the active lesions as hyper-intense (bright) signals; the contrast provided by DWI-b1000 depends on the molecular movement of water.
But many false positive lesions on DWI were not enhanced on CE T1WI due to residual T2 shine-through and residual vasogenic edema that may disappear in the next follow up MRI examinations.
DWI-B1000 can be used for screening of MS plaques activity especially in conditions requiring rapid examinations or in cases where Gadolinium MRI contrast is contraindicated.
In another cases with non-conclusive pattern of MS lesions seen in CE T1WI and T2WI, the use of DWI sequence with its two components (DWI-b1000 and DWI-b0 images) can also be used to support the diagnosis of MS lesions seen in both CE T1WI and T2WI.