Magnetic Resonance Selective Signal Suppresion

 

Outline and Learning Guide


INTRODUCTION AND OVERVIEW

T1-BASED FAT AND FLUID SUPPRESSION

STIR Fat Suppression

Fluid Suppression

SPIR FAT SUPPRESSION

MAGNETIZATION TRANSFER CONTRAST (MTC)

Free Proton Pool

Bound Proton Pool

Magnetization Transfer

Selective Saturation

REGIONAL SATURATION

MIND and MAP SUMMARY

 

 

Learning Objectives

 
  • Discuss two reasons why it is sometimes desirable to suppress the RFsignals from specific tissues or anatomical regions in MR imaging.
     
  • Identify the tissue characteristic that makes it possible to selectively suppress the signals from fat and fluids without suppressing the signals from other tissues.
     
  • Give the full names of the two fat suppression methods that are known by the acronyms STIR and SPIR.
     
  • Explain the process by which the STIR method suppresses signals from fat.
     
  • Explain why the STIR method cannot be used to selectively suppress other tissues such as brain white matter.
     
  • Identify the protocol factor that must be properly adjusted when using the STIR method to produce optimum fat suppression.
     
  • Explain how an inversion recovery method can be used to suppress the RF signals from body fluids.
     
  • Describe the general appearance of a T2 weighted image in which fluid suppression has been applied.
     
  • Explain why acquisition time is of special concern when using fluid suppression and what can be done to produce practical imaging.
     
  • Describe  the concept of the SPIR fat suppression method.
     
  • Describe the characteristic of fat that makes it possible to suppress it's signals with the SPIR method.

  • Describe the general condition that is required for optimum performanceof the SPIR fat suppression process.

  • Describe an advantage of using SPIR rather than STIR for fat suppression.

  • Describe the general process of using magnetization transfer to selectively suppress signals from certain tissues.

  • Briefly describe the difference between the "bound" and "free" proton pools in tissue.
     
  • Describe the general significance of the free protons in MR imaging.
     
  • Explain how it is possible to apply an RF pulse selectively
    to the bound proton pool.

  • Briefly describe the possible application of the magnetization transfer contrast (MTC) in clinical imaging.

  • Explain the process that can be used to selectively apply saturation pulses to one anatomical region without affecting other regions.

  • Explain the general purpose and application of selective regional saturation in MR imaging.
 

 

Text Reference

Chapter 8

Magnetic Resonance Imaging: Principles, Methods, and Techniques
Medical Physics Publishing,  http://www.medicalphysics.org

 

 

Mind Map