Automated Accurate Calculation of b-Matrix for Diffusion MRI Pulse Sequences

A toolkit for b-matrix calculation has been implemented in Matlab and it contains the program scripts as well as the demo examples of GE, SE, RARE, and SPEN sequences.

Functional description

1. The toolkit provides two approaches for calculating the b matrix:

   • The approach based on the divide-and-conquer approach
   • The approach based on numerical integration

2. It allows the calculation of b-matrices for various types of sequences：

   • GE, SE, and EPI sequences
   • The case of a single coherence pathway involving multiple 180º refocusing pulses
     • Double spin-echo
     • The family of RARE-like diffusion-weighting sequences
   • SPEN sequences

How to use the toolkit?

1. Download the "calculate_b_matrix" toolkit

2. Set the path in matlab

   • HOME-> Set Path -> Add with Subfolders: select the "calculate_b_matrix" folder.

3. In main function script, modify the data source and approach flag
   For instance, in the demo script "main_calc_b_matrix_demo.m",

   • line 23: select an excel file (templates were provided in the "demos" folder)
   • line 24: select one of the b-matrix calculation approaches by changing "Flag_use_symbolic"

   NOTE: demo03_RARE_template.xlsx is not a real TSE data, it just shows how to enter multiple antiphase instants manually.