Phase Graph Tutorial

A collection of educational notebooks about Extended Phase Graphs (EPGs):

• phase_graphs.ipynb : plotting phase graphs
• epg_examples.ipynb : basic EPG examples
• plot_epg_states.ipynb : plot the EPG state evolution
• tse_signal_shaping.ipynb : variable flip-angles for TSE signal shaping
• epgOptimization_esmrmb25.ipynb : ESMRMB 2025 tutorial notebook

The notebooks imports functionality from epg_code.py, which should be in the same directory:

• pg_plot() - a function to plot phase graphs
• basic_epg() - a python class for basic EPG calculations

The latter is only used, if the pyepg class is not available. This is a python wrapper for a fast cpp implementation of EPGs, see here. Both classes have the same functionality, but pyepg is approximately 1000 times faster than basic_epg. With basic_epg some example may take several minutes.