Magnetization Transfer

Use the Magnetization Transfer Imaging Option to improve contrast between blood flow and surrounding tissue in 3D TOF images, to augment post-contrast T1-weighted brain images, and to increase myelographic effect for improved disc and cord lesion visualization. This is achieved by saturating tissues containing significant amounts of protein (e.g., gray/white brain matter, skeletal muscle). This is achieved by applying a large saturation pulse that is 1200 Hz off the center frequency.

Table 1. Image legend

Number	Description
1	MT pulse
2	CSF
3	pulse offset

Spin Echo with a Magnetization Transfer preparation technique can be used to augment post-contrast T1-weighted brain images. Similar to the MRA application, the Magnetization Transfer preparation is used to suppress brain parenchyma signal relative to contrast-laden blood.

Magnetization Transfer can also be used with 2D Multi-planar GRE or 3D GRE to increase myelographic effect for improved disc and cord lesion visualization.

• The minimum TR is a function of the gradient strength.
• The off-resonance saturation pulse applies peak SAR. The minimum TR may need to be increased if a FC or spatial saturation pulse is used.
• Magnetization Transfer with 3D TOF GRE/SPGR and 3D GRE/SPGR increases the minimum TR.
• Approximate signal saturation to be expected when using Magnetization Transfer:
  • Skeletal muscle: 60%
  • White brain matter: 40%
  • Gray brain matter: 30%
  • Blood: 15%