3. Consider two materials, A and B with relaxation constants (T1A, T2A) and (TIB, T2B) respectively. Assume a 90 degree flip angle and at A, B have the same proton density. (a-b: 5 pts each; c: 10 pts) a. Determine the TE that maximizes ||M. (t)|-|M, (1)|| for TR = 0. xy,A xy,B b. Determine the TR that maximizes |M2,4(t) Mz,B(t) with a TE = 0. c. Assuming these materials are white matter and gray matter at 3 T, determine the TR that maximizes T1 signal differences with a TE = 0 and determine the TE that maximized T2 signal differences for TR = co. Use T1 and T2 values from p. 32 of MRI Notes #1 and assume p=1 for both.