JEMRIS, the "Juelich Extensible MRI Simulator", provides an MRI sequence development and simulation environment for the MRI community.
JEMRIS supports the following features:
Utilising an optimised library for numerical solutions of differential equations (CVODE) provides accurate 3D MRI simulation results in cases where no analytical solution is available, e.g. to simulate complex nonlinear RF waveforms for selective excitation or adiabatic full passage pulses.
JEMRIS can deal with arbitrary RF and gradient waveforms, arbitrary multi-channel Tx-Rx coil geometries and configurations, as well as many important physical concepts, such as nonlinear gradients, chemical shift, reversible spin dephasing (T2*), susceptibility-induced off-resonance, temporal varying processes of the object (e.g. movement or flow), concomitant gradient fields, etc.
Symbolic mathematical calculations are supported by means of the GiNaC library. Thus, many extensions are readily available with no additional programming involved.
The core simulation routines take advantage of massive parallel processing (using the MPI standard) and are available on different hardware architectures. JEMRIS simulations scale on single-core hardware, small HPC clusters and also on massively parallel supercomputers.
A Matlab graphical user interface (GUI) is provided with which all simulation parameters are configured, including nearly arbitrary complex MRI sequences. The GUI stores these configurations in XML format which is parsed by the simulator using the Xerces library.