Abstract #2365

Magland J, Vasilic B, Wehrli F

An efficient MRI simulator is described for use with user-specified pulse sequences and high-resolution 3D virtual phantoms. The simulator models T1, T2, and T2* relaxation as well as arbitrary spectral composition. Phenomena predicted by the Bloch equation are accurately represented. For example, artifacts caused by chemical shift, approach to steady-state, off-resonance, or an imperfect B1 field, as well as the effects of finite sampling (e.g. Gibbs ringing), stimulated echo artifacts and partial volume are all handled automatically. The simulator solves the Bloch equation in k-space by storing in memory thousands of coherence pathways which evolve during the sequence. The program is coupled with software for importing arbitrary pulse sequences, so the virtual scanner can be used to compare and optimize novel sequences. Since the computation time depends only on the pulse sequence duration and complexity and not the size of the virtual phantom (besides loading into memory) the scanner can be used to