SequenceTable

class pulserver.proxy.SequenceTable

Bases: object

The readouts of a sequence chain as MRD describes them, in play order.

k-space is not tabulated: readout_k() integrates a readout’s when asked, through the ReadoutTable of its chain file.

Attributes:

• counters (dict of str to ndarray) – Every label of MRD_COUNTERS some file of the chain writes, one int32 value per readout, 0 in a file that never writes it. A counter no file writes is absent, and 0 on every readout.

• flags (ndarray) – uint64 ISMRMRD flag masks: the non-boundary flags the sequence sets, first/last flags of every counter the sequence writes, and LAST_IN_MEASUREMENT on the final readout of the chain. A boundary is read within its encoding space and the other image-selecting counters, so a slice closes once per echo.

• center_sample, num_samples (ndarray) – As ReadoutTable states them, over the chain.

• trajectory_dimensions (ndarray) – int8 axes of k a readout carries as its trajectory: every axis its encoding space varies along, up to the last, including those constant across the readout; 0 for a readout whose k does not move and for every readout of a Cartesian space not TableSpace.ramp_sampled.

• sample_time_us (ndarray) – float32 dwell, in µs.

• encoding_space (ndarray) – int32 index into spaces.

• spaces (tuple of TableSpace) – Numbered in chain order: each subsequence’s primary space, then its navigator space when it has NAV readouts.

• sequence_parameters (dict of str to list of float) – Over the chain’s SequenceDefinitions: the TR and TI minima and every distinct TE in ascending order, in ms, and every distinct FlipAngle in ascending order, in degrees. Keys no file defines or measures are absent.

• fov_offset_m (tuple of float) – The field-of-view shift the scanner plays the chain at, in m, along the axes the design’s blocks are rotated onto, as pulserver.ir.prescribe() takes it.

Methods

read	Tabulate the NextSequence chain starting at a sequence file.
readout_k	Return the k-space position of each sample of one readout, in 1/m.
readout_phase_modulation	Return the phase one readout's samples are corrected by, in rad, or None.

Attributes

fov_offset_m
counters
flags
center_sample
trajectory_dimensions
sample_time_us
encoding_space
num_samples
spaces
sequence_parameters