MT Pulse Type

Use MT Pulse Type to have flexibility in the choice of the MTRF pulse.

• A larger frequency offset is preferred for the 8 ms MT pulse type, since its frequency spectrum is wider than the 16 ms pulse, leaving the free water signal unaffected.
• The use of the Fermi pulse results in higher flip angles with lower amplitudes, ensuring the effectiveness of the MT pulse with shorter scan times.

• The MT RF pulse for 2D Spin Echo and 3D TOF GRE/SPGR is fixed to Fermi type. If the MT Pulse Type is changed, the default value of the pulse duration and flip angle changes as follow:

  Table 1. Pulse duration and flip angle

  PSD	MT pulse duration	MT offset	MT flip	MT pulse type
  2D GRE/SPGR	16 msec	1200 Hz	900	Sinc
  2D GRE/SPGR	8 msec	1200 Hz	670	Fermi
  3D GRE/SPGR	8 msec	1200 Hz	670	Fermi
  3D GRE/SPGR	14 msec	1200 Hz for T/R coils or 2400 Hz for other coils	950	Sinc