Motion of Magnetization

Gradient Echo Sequences - One pulse

Gradient Echo Sequences - Two pulses

Gradient Echo Sequences - More pulses

GE Sequences - Approach to steady state

GE Sequences - The steady state

GE Sequences - RF-spoiled steady state

GE Sequences - Balanced sequences

CPMG - One refocusing pulse

CPMG - Mone refocusing pulses

CPMG - CPMG static pseudo steady state

Hyperechos - with CPMG sequences

Hyperechoes with gradient echo sequences

RF Pulses - Sinc pulse

A steady state for each single magnetization vector will be reached if 1) TR is constant, 2) dephasing within TR is constant, and 3) excitation pulses have constant flip angle and constant or linearly varying phase. A steady state only of the magnitude of the echo (sum over all magnetization vectors) can also be established for quadratically varying excitation pulse phases, as for RF-spoiled sequences. The evolution of the steady state magnetization between one excitation pulse and dephasing period is shown below. Flip angle was 50°, quadratic phase increase 50°, and T1 = 20TR, T2=10TR.

Same as before but with quadratic phase increase of 117°.

Last updated: Monday, 18.04.2011