Sequence description parameters

Sequence block parameters

Parameters required for the nested sequence blocks of the RF array in the above table. These parameters describe one block of the sequence RF (with or without gradient), rephasing, delay.

Field	Value type	Req?	Description	Example value
time	float	Y	Total pulse time. In seconds.	0.003
frequencyOffset	float	N	Offset of pulse central frequency from receiver centre. In Hz.	-246
phaseOffset	float	N	Phase offset applied to whole pulse. In radians. Default = 0.	0.0
amp	List of floats	Y	List of amplitudes in units specified by RFUnits. Must contain >=1 points.	[0 1.0 … 1.0 0.0]
phase	List of floats	Y	List of pulse phase points. Must match the size of amp. In radians.	[0 0.0 … 0.0 0.0]
grad	Float (1x3)	Y	Slice selection gradient amplitude (in GradUnits/m) for each of the three spatial axes.	[3.5 0 0]
ampScale	Float	N	Optional scaling of the pulse amplitude. Default = 1.0.	2.0
delays	Float (1x Nblocks)	Y	Free evolution time after RF in each RF block. In seconds. Measured from end of RF to start of next RF.	[0.005 0.001 0.005]
rephaseAreas	Float (Nblocksx3)	Y	Area of gradients (in seconds.GradUnits/m) on each spatial axis during the delay time. Can be applied on more than one axis per block.	[[-5.1e-3 0 0] [ 0 -5.1e-3 0] [ 0 0 -5.1e-3]]