Question

Any two RF pulses produce an echo that is called a Hahn Echo if RF flip angle = ? or Stimulated Echo if RF flip angle = ?

A) 45; stimulated
B) 90; stimulated
C) 180; stimulated
D) 90; spontaneous

Answer 1

The correct answer is option B) 90; stimulated. A Hahn Echo is produced when two RF pulses have a flip angle of 180 degrees, while a Stimulated Echo is produced when two RF pulses have a flip angle of 90 degrees.

Step-by-step explanation:

The correct answer is option B) 90; stimulated. A Hahn Echo is produced when two RF pulses have a flip angle of 180 degrees. This means that the magnetic field is rotated by 180 degrees during each RF pulse. On the other hand, a Stimulated Echo is produced when two RF pulses have a flip angle of 90 degrees. This means that the magnetic field is rotated by 90 degrees during each RF pulse.