Magnetic Resonance Spin Echo Imaging

Outline

Mind Map

Learning Objectives

Teaching Visuals

Online Module
(Requires Enrollment)

Text Reference

 

Outline and Learning Guide


INTRODUCTION AND OVERVIEW

THE SPIN ECHO PROCESS

RF Pulse Sequence

THE SPIN ECHO METHOD

Proton Density (PD) Contrast

T1 Contrast

T2 Contrast

Multiple Spin Echo

INVERSION RECOVERY

T1 Contrast

MIND MAP and SUMMARY

 

 

Learning Objectives

 
  •  Describe the free induction decay (FID) process and explain what happens to the transverse magnetization during this time.
     
  • Describe the general magnetic field condition that produces the initial de-phasing of protons following an excitation pulse..
     
  • Explain the concept of T2* and describe its general relationship to T2..
     
  •  Describe and illustrate how a 180 degree RF pulse produces re-phasing of protons.
     
  • Describe the common characteristic or feature of all spin-echo imaging methods.
     
  • Sketch a diagram showing the RF pulses used in a basic spin-echo cycle and show the time intervals, TR and TE.
     
  • Describe the relationship between TE and the RF pulse time intervals in spin echo.
     
  • Explain why the spin echo imaging method can be used for producing T2 images.
     
  • Explain how changing the value of TE from 15 msec to 150 msec affects image contrast.
     
  •  Select typical values of TR and TE to be used with the spin echo method to produce:
    T1 weighted images
    T2 weighted images
    Proton density weighted images
     
  • Explain the concept of multiple echo imaging and why it is useful.
     
  • Describe the inversion recovery imaging method.
     
  • Illustrate and explain how inversion recovery can produce images with more T1 contrast than the spin echo method.
     
  • Describe the relationship between TI and the RF pulse time intervals in inversion recovery.
     
  • Explain the general effect of changing TI on image contrast with inversion recovery.
     
  • Sketch a diagram showing the RF pulses and time intervals, TR, TI, and TE used in inversion recovery.
     
  • Explain the general effect of changing TR from a value of 100 msec to 500 msec on the signal intensity and relative brightness of a spin-echo image.
     
  • Explain the general effect of changing TE on the signal intensity and relative brightness of a spin-echo image.
     
  • State typical protocol factor values used to produce a T1 weighted image with the inversion recovery method.
     
  • Compare and describe the general difference between T1 images produced with the spin-echo and inversion methods.
 

 

Text Reference

Chapter 6

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

 

 

Mind Map