Hi,

I have been trying to mathematically derive the formula to find FRACTIONAL ANISOTROPY

(Fractional anisotropy is a method that is used to emphasize and evaluate white matter fiber tracts)

The formula that is given in many textbooks and published paper is

I understand the purpose of Lambda but unable to understand the need for SQUAREROOT (3/2)

Please do kindly explain the reason behind having SQUAREROOT(3/2) for the Fractional Anisotropy formula

The paper from which I found this formula is http://ac.els-cdn.com/S109078071100334X/1-s2.0-S109078071100334X-main.pdf?_tid=1a51f47e-3ca7-11e6-b075-00000aab0f26&acdnat=1467060088_0e9b31e7bbd5af7c0353a9eb06eae939

-Rahul Manay