Review Article
DTI Measurements in Multiple Sclerosis: Evaluation of Brain Damage and Clinical Implications
Table 1
Schematic description of the main DTI parameters.
| ā | Unit of measure | Formula | Object measured |
|
FA | Scalar value ranging between 0-1 | | Fibers directionality/axonal loss | MD | mm2/sec | | Amount of water diffusion/myelin loss | AD | mm2/sec | | Diffusivity parallel to the fibers/myelin and axonal content | RD | mm2/sec | | Diffusivity perpendicular to the fibers/myelin content |
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FA: fractional anisotropy; MD: mean diffusivity; AD: axial diffusivity; RD: radial diffusivity; mm: millimeters; sec: second.
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