2-D projection imaging (i.e., polar scanning) was an early MR imaging technique that is enjoying a comeback because it is very fast. Consider the pulse sequence shown in Figure P13.8 and let
Figure P13.8
(a) Find an expression for the signal given θ.
(b) If the cross section being imaged is f(x, y) = Aδ(x − 1, y) + Bδ(x, y + 1), sketch the recorded signal for θ = 0, and θ = 90◦.
(c) How can one obtain an image of the cross section using this pulse sequence?