BrainWeb.relaxation

BrainWeb.relaxation()

Return the T1, T2 and T2’, in s, of each tissue class at field_t T.

T1 is BrainWeb’s, at 1.5 T, times (field_t / 1.5)**b with the class’s exponent in T1_EXPONENTS, or BrainWeb’s without one; T2 is BrainWeb’s. T2’ is the one BrainWeb’s T2 and T2* leave at 1.5 T, 1 / (1/T2* - 1/T2), times 1.5 / field_t, as the static dephasing regime makes R2’ proportional to the field (Yablonskiy and Haacke, Magn Reson Med 32:749, 1994), or the one t2_prime gives the class; infinite for a class without T2 or T2*.

Raises:

ValueError – If field_t is not above zero.