Simulators#

The sequences that ship with TorchSim. A constructor takes the keywords simulate() takes and fixes them, so a sequence and the tissue it is being asked about are written down together and what is left to give at the call is whatever is actually varying.

Closed form#

Signals that have an analytic expression, evaluated in one pass.

torchsim.simulators.bSSFPSimulator

The balanced SSFP steady state, read at the echo time.

torchsim.simulators.SPGRSimulator

The spoiled gradient-echo steady state, read at the echo time.

torchsim.simulators.MP2RAGESimulator

Two gradient-echo blocks read at two inversion times, in closed form.

torchsim.simulators.InversionRecoverySimulator

Longitudinal recovery from an inversion, read at a series of delays.

torchsim.simulators.MultiEchoSimulator

Transverse decay, read at a series of echo times.

torchsim.simulators.DoubleAngleSimulator

Excitation at a series of flip angles, scaled by the transmit field.

torchsim.simulators.SpinEchoSimulator

A spin echo repeated every TR, optionally behind an inversion.

torchsim.simulators.LookLockerSimulator

Recovery from an inversion under a spoiled train of small flip angles.

torchsim.simulators.MOLLISimulator

Look-Locker readout blocks separated by free recovery, after one inversion.

torchsim.simulators.IRbSSFPSimulator

Recovery from an inversion under a balanced SSFP train.

torchsim.simulators.HSFPSimulator

A balanced train whose flip angle varies slowly, in the hybrid state.

torchsim.simulators.MultiGradientEchoSimulator

Water and fat, dephasing and decaying across a gradient-echo train.

torchsim.simulators.IRMultiGradientEchoSimulator

A multi-gradient-echo train read at a series of inversion times.

torchsim.simulators.DiffusionSimulator

Attenuation by Gaussian diffusion, at a series of b-values.

torchsim.simulators.LorentzianSimulator

A Z-spectrum as equilibrium minus one Lorentzian line per pool.

torchsim.simulators.ASLSimulator

The label-control difference of arterial spin labelling, over time.

State machine#

Trains that have to be played out, run on the extended phase graph engine.

torchsim.simulators.FSESimulator

A refocused echo train, sampled at every echo.

torchsim.simulators.HyperechoSimulator

A refocused train mirrored about a central refocusing pulse.

torchsim.simulators.StimulatedEchoSimulator

Three pulses, sampled at the spin echo of the first two and at the stimulated echo.

torchsim.simulators.MPRAGESimulator

An inversion followed by a spoiled train, sampled at the k-space centre.

torchsim.simulators.MPnRAGESimulator

An inversion followed by a spoiled gradient-echo train, every shot read.

torchsim.simulators.MRFSimulator

An inversion, then a variable flip-angle train whose readouts wind on.

torchsim.simulators.FLASHSimulator

A spoiled gradient-echo train from equilibrium, optionally inverted first.

torchsim.simulators.TrueFISPSimulator

A balanced SSFP train from equilibrium, optionally inverted first.

torchsim.simulators.fmSSFPSimulator

A balanced SSFP train whose RF frequency is swept through one passband per sweep.

torchsim.simulators.CESTSimulator

A Z-spectrum simulated through a train of saturation pulses, pool by pool.

Functional wrappers#

One call, protocol and tissue together, for a signal and optionally its derivative. What the classes above do, without holding one.

Analytical#

torchsim.bssfp_sim

SPoiled Gradient Recalled echo simulator wrapper.

torchsim.spgr_sim

SPoiled Gradient Recalled echo simulator wrapper.

Iterative#

torchsim.fse_sim

Fast Spin Echo simulator wrapper.

torchsim.mprage_sim

MPRAGE simulator wrapper.

torchsim.mp2rage_sim

MP2RAGE simulator wrapper.

torchsim.mpnrage_sim

MPnRAGE simulator wrapper.

torchsim.mrf_sim

SSFP MR Fingerprinting simulator wrapper.