Analytical description of GMAX-induced magnetization.
The Gradient-Modulated Adiabatic Excitation (GMAX) method is characterized by the use of adiabatic pulses with main applications on volume localization in spectroscopy and slice selection in MRI. Its use derives from the interesting nodal point magnetization profile induced throughout the sample. Nevertheless, the interpretation on such behavior for the magnetization has been of qualitative purpose only, using the adiabatic condition as a starting point. Here, we present discrete spatial analytic solutions, starting from the solution in terms of the hypergeometric functions for sech and tanh pulses. From these discrete solutions, it is possible to infer analytically the characteristic behavior of transverse magnetization, on the purpose to obtain greater control of the magnetization from parameters of the sequence that carry physical interpretation.
Teles
João
J
Departamento de Física e Informática (FFI - IFSC), Universidade de São Paulo São Carlos, SP 13560-970, Brazil. jteles@if.sc.usp.br
Tannús
Alberto
A
D003198:Computer Simulation; D004574:Electromagnetic Fields; D019544:Equipment Failure Analysis / Q000379:methods; D007089:Image Enhancement / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D008962:Models, Theoretical; D011846:Radio Waves