Question

In a fast spin echo sequence, the readout gradient is turned on: (Select all that apply)

A)During frequency encoding.
B)During sampling of the resultant echo.
C)Between 90° and 180° pulses.
D)During initial 180° pulse.

Answer 1

In a fast spin echo sequence, the readout gradient is on during frequency encoding and sampling of the resultant echo to acquire spatially encoded data for imaging.

Step-by-step explanation:

In a fast spin echo sequence, the readout gradient is turned on during the following scenarios:

• During frequency encoding: The readout gradient helps in the spatial encoding of signals based on their frequency, which is essential for image formation.
• During sampling of the resultant echo: While the echo signals are being received, the readout gradient is active to acquire the spatially encoded data.

It is not typically active between the 90° and 180° pulses, or during the initial 180° pulse, as these pulses are primarily for creating the echo by refocusing spins.