msl::readouts::Spiral Class Reference

Detailed Description

WHIRLED PEAS spiral readout.

The implementation follows "Exact, time-dependent analytical equations for spiral trajectories and matching gradient and density-correction waveforms", G. Krishnamoorthy and J. Pipe, Magnetic Resonance in Medicine 95(1), 2026.

Warning

There is a slight risk of slew rate overshoot "short" spirals, i.e. with a large number of interleaves.

#include <Spiral.h>

Public Types
enum	Direction { Out , In }
	Direction of the spiral. More...

Public Member Functions
	Spiral ()
	Create a default readout.
	Spiral (Spiral const &)=default
	Spiral (Spiral &&)=default
Spiral &	operator= (Spiral const &)=default
Spiral &	operator= (Spiral &&)=default
Direction const &	direction () const
Spiral	setDirection (Direction const &direction)
int32_t	interleaves () const
	Return the number of interleaves.
NLSStatus	prepare (MrProt &protocol, SeqLim &limits, SeqExpo &exports) override
	Prepare the real-time events.
NLSStatus	run (MrProt &protocol, SeqLim &limits, SeqExpo &exports) override
	Run the real-time events.
Spiral &	rotate (double angle)
	Rotate the original spiral.
Public Member Functions inherited from msl::Readout
	Readout (Readout const &)=default
	Readout (Readout &&)=default
Readout &	operator= (Readout const &)=default
Readout &	operator= (Readout &&)=default
double	phase () const
	Return the phase of the NCO during the readout.
Readout &	setPhase (double phase)
	Set the phase of the NCO during the readout.
long	contrast () const
	Return the contrast number.
Readout &	setContrast (long contrast)
	Set the contrast number.
long	timeOffset () const
	Return the time offset to get the effective echo time, accounting e.g. for the time of the excitation pulse peak.
Readout &	setTimeOffset (long timeOffset)
	Set the time offset to get the effective echo time, accounting e.g. for the time of the excitation pulse peak.
Vector3l const &	ncoOffset () const
	Return NCO k-space offset.
Readout &	setNCOOffset (Vector3l const &point)
	Set NCO k-space offset.
GradientSpecs const &	gradientSpecs () const
	Return the gradient specifications constraining the read-out duration.
Readout &	setGradientSpecs (GradientSpecs const &gradientSpecs)
	Set the gradient specifications constraining the read-out duration.
long	echoTime () const
	Return the effective echo time (requires preparation).
MrProtocolData::SeqExpoRFInfo	rfInfo () const override
	Return the RF information for SAR computation.
long	startTime () const override
	Return the start time of the events.
long	endTime () const override
	Return the end time of the events.
GradientPulse const &	gradient () const
	Return the read-out gradient.
long	adcStartTime () const
	Return the start time of the ADC.
long	adcEndTime () const
	Return the start time of the ADC.
Vector3d	areaBeforeADC () const
	Return the area of the read-out gradient before the start of the ADC.
Vector3d	areaBeforeEcho () const
	Return the area of the read-out gradient before the effective echo time.
Vector3d	areaAfterEcho () const
	Return the area of the read-out gradient after the effective echo time.
Vector3d	areaAfterADC () const
	Return the area of the read-out gradient after the end of the ADC.
sREADOUT const &	adc () const
	Return a reference to the ADC real-time object, e.g. for updating its meta-data.
sREADOUT &	adc ()
	Return a reference to the ADC real-time object, e.g. for updating its meta-data.
Public Member Functions inherited from msl::RealTimeEvents
	RealTimeEvents ()
	No-op constructor.
	RealTimeEvents (RealTimeEvents const &)=default
	RealTimeEvents (RealTimeEvents &&)=default
RealTimeEvents &	operator= (RealTimeEvents const &)=default
RealTimeEvents &	operator= (RealTimeEvents &&)=default
sSLICE_POS const &	slice () const
	Return the slice used in prepare and run.
virtual RealTimeEvents &	setSlice (sSLICE_POS const &slice)
	Set the slice used in prepare and run.

Additional Inherited Members
Protected Attributes inherited from msl::Readout
double	_phase
	Phase of the NCO during the readout.
long	_contrast
	Contrast number.
long	_timeOffset
	Time offset to get the effective echo time.
GradientSpecs	_gradientSpecs
	Gradient specifications constraining the read-out duration.
long	_echoTime
	Effective echo time.
GradientPulse	_gradient
	Read-out gradient.
NCOPair	_nco
	NCO before and after this gradient.
Vector3l	_ncoOffset
	NCO k-space offset.
sREADOUT	_adc
	Real-time readout object.
Protected Attributes inherited from msl::RealTimeEvents
sSLICE_POS	_slice
	Slice specifications attached to this real time object.

Member Enumeration Documentation

Direction

enum msl::readouts::Spiral::Direction

Direction of the spiral.

Enumerator
Out	From center to edge of k-space.
In	From edge to center of k-space.

Member Function Documentation

interleaves()

int32_t msl::readouts::Spiral::interleaves

(

)

const

Return the number of interleaves.

Warning

Requires a previous call to prepare

prepare()

NLSStatus msl::readouts::Spiral::prepare ( MrProt & protocol, SeqLim & limits, SeqExpo & exports )

overridevirtual

Prepare the real-time events.

Implements msl::RealTimeEvents.

run()

NLSStatus msl::readouts::Spiral::run ( MrProt & protocol, SeqLim & limits, SeqExpo & exports )

overridevirtual

Run the real-time events.

Implements msl::RealTimeEvents.

rotate()

Spiral & msl::readouts::Spiral::rotate

(

double

angle

)

Rotate the original spiral.

Parameters

angle

Angle of rotation [deg]

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The documentation for this class was generated from the following file:

• msl/readouts/Spiral.h