Angle between the net magnetization vector before and after a RF excitation pulse. Small tip angles allow a decrease in TR, which is used to decrease scan time in Field Echo pulse sequences. See Flip Angle.

(T/R) Also called transceiver coil. An RF coil that acts as a transmitter (T) producing the B1 excitation field and as a receiver (R) of the MRI signal. Such a coil requires a T/R switching circuit to switch between the two modes. A body coil is typically a T/R coil, but smaller volume T/R coils (head/extremities) are often used at high field as a possibility of reducing RF power absorption (SAR).

The coil of the RF transmitter, inside the MR imager is used in excitation of the spins. Also called transmit-only coil it is used to create the B1 field. As a radio frequency generator send this coil bursts of RF pulses. These pulses serve to disturb the spins in the patient.

A saturation pulse, which moves from one spatial location to another for each RF pulse excitation or each MR slice acquired.

(TSE TF) The turbo factor is the number of echoes acquired after each excitation. This is a measure of the scan time acceleration, e.g. at turbo factor 3 the scan time is 3 times faster as a SE sequence with comparable parameters. In combination with profile order and effective echo time the TSE turbo factor controls the echo spacing.

See also Scan Time and Echo Spacing.