FORECAST is a fast alternative to Bloch simulation for simulating off-resonance effects in steady-state MRI. FORECAST accelerates simulation of steady-state pulse sequences by using multiple Fast Fourier Transforms to evaluate the signal equation, which can currently include proton density, T2, and off-resonance effects. Currently the simulation is limited to Cartesian pulse sequences, but we plan to add support for non-Cartesian pulse sequences.
Included examples:
- Simulation of susceptibility artifacts around air and metal.
- Simulation of water-fat shift (i.e. chemical shift).
- Simulation of a brainweb dataset, including T1, T2, susceptibility, and water-fat shift (Matlab R2015A or later required to automatically download the dataset)

If you use FORECAST in your research, please include a reference to our MRM paper and a link to the most recent code:
F. Zijlstra, J.G. Bouwman, I. Braskute, M.A. Viergever, and P.R. Seevinck, "Fast Fourier-based simulation of off-resonance artifacts in steady-state gradient echo MRI applied to metal object localization", Magn. Reson. Med., 2016