Good Ingredients Make a Good Dish: Open-Source Sequence Programming
Rita G. Nunes1
1Institute for Systems and Robotics - Lisboa and Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Portugal

Synopsis

Keywords: Image acquisition: Sequences

In this presentation, I will introduce the open-source pulse sequence programming tool Pulseq. I will start by describing how it interacts with the scanner and how to install it. I will then go through simple sequence examples (gradient and spin echo sequences), describing how to add RF pulses, gradients and acquisition objects to the sequence. Finally, I will provide examples of a few more advanced applications focusing on quantitative MRI, namely diffusion, T1 and T2 mapping

Description

The goal of this presentation is to provide basic notions of pulse sequence programming and to introduce the open-source pulse sequence programming tool Pulseq [1].
I will start by describing how Pulseq interacts with the scanner, namely explaining how ".seq" files describe the pulse sequences and what is required to use this tool.
I will then go through simple pulse sequence examples (gradient and spin echo sequences), describing how to add basic objects to a pulse sequence, namely: RF pulses, gradients and acquisition objects. I will show both the original Matlab implementation and the Python equivalent, made possible through the use of PyPulseq [2].
Finally, to showcase more advanced uses of these tools, I will provide examples of a few more advanced applications focusing on quantitative MRI, namely brain diffusion [3] and myocardial T1 mapping [4,5].

Objectives

At the end of this presentation, the audience should:
  • Understand how the open-source tool Pulseq interacts with the vendor environment;
  • Understand how to add basic blocks to a simple pulse sequence using Matlab/Python;
  • Understand the potentialities and limitations of this tool.

Acknowledgements

Funding from La Caixa Foundation and FCT under the project LCF/PR/HP22/52320018; FCT through projects LA/P/0083/2020 and UID/EEA/50009/2020.

References

[1] Layton KJ, Kroboth S, Jia F, Littin S, Yu H, Leupold J, Nielsen JF, Stöcker T, Zaitsev M. Pulseq: A rapid and hardware-independent pulse sequence prototyping framework (2017). Magn Reson Med. 77(4):1544-1552

[2] Ravi K, Geethanath S, Vaughan Jr JT. (2019) PyPulseq: A Python Package for MRI Pulse Sequence Design. Journal of Open Source Software 4.42: 1725

[3] Nunes RG, Ravi KS, Geethanath S, Vaughan Jr JT (2020) Implementation of a Diffusion-Weighted Echo Planar Imaging sequence using the Open Source Hardware-Independent PyPulseq Tool, ISMRM

[4] Gaspar AS, Silva NA, Nunes RG. (2021) ProMyoT1: Open-source inversion recovery myocardial T1-mapping sequence for fast prototyping, ISMRM

[5] Gaspar AS, Silva NA, Price AN, Ferreira AM, Nunes RG (2023) Open-Source Myocardial T1 mapping with Simultaneous Multi-slice acceleration: combining an auto-calibrated blipped-bSSFP readout with VERSE-MB pulses. Magn Reson Med. In Press, doi:10.1002/mrm.29661

Proc. Intl. Soc. Mag. Reson. Med. 31 (2023)