Incoherent or Spolied Gradient-Echo - Video Lesson

Hey, everybody. Welcome to today's lesson on pulse sequences. This lesson focuses on incoherent or spoiled gradient echo sequences, including the mechanisms behind how they work, their advantages and disadvantages, and their suggested parameters. Let's get started. Remember, a gradient echo pulse sequence uses gradient magnetic fields to reface the spins after the application of the RF excitation pulse as opposed to the one hundred eighty degree RF refacing pulses used in spin echo pulse sequences. The use of gradients allows for shorter scan times because we don't have to wait to apply the one hundred eighty degree refacing pulse. Incoherent gradient echo sequences use the steady state as the basis of the pulse sequence. The short repetition times and flip angles of thirty to forty five degrees used in the steady state results in residual transverse magnetization. In other words, the transverse magnetization builds up over time because it does not have long enough to decay