Topic: MRI physics

Order Description

Consider the excitation of a slice of thickness Δz = 4 mm by a band-limited rf pulse on for a time duration τRF = 4 ms. Assume that the flip angles of the spins are dominated by the exact (time) center of the rf pulse. If the applied gradient strength is given as 10 mT/m:
a) find the difference in accumulated phase between two spins on opposite sides of the slice (i.e., at z = z0 ± Δz/2) at the end of the rf pulse.
b) How long must the rephasing gradient be applied, for complete refocusing, if Grephase = -GSS and the two gradients are boxcar pulses? What is the duration of the total slice select process, including the time that both GSS and Grephase are applied?