Magnetization Transfer Effects in Single Slice Spoiled Gradient Echo Imaging
Gore J, Gochberg D, Ou X
We investigated magnetization transfer (MT) effects on the steady state MR signal for a sample subjected to a series of identical on resonance rf pulses, such as would be experienced while imaging a single slice using a spoiled gradient echo sequence. The MT coupling terms for a two-pool system were added to the Bloch Equations, and we derived the resulting steady state signal equation and compared this result to the conventional signal equation without MT effects. We found that the steady state signal is increased by a small amount because of MT. Consequences of this MT effect include 1) inaccuracies in T1 values determined via steady state gradient echo methods and 2) the ability to quantify the MT parameters by fitting the gradient echo steady state signal to the signal equation appropriately modified to include MT effects.