mtrk – A flexible open-source framework for developing MRI pulse sequences based on common web standards

Motivation: Pulse-sequence development has been challenging due to high software complexity and limited documentation. Moreover, proprietary licenses make sharing developments difficult. Goal(s): To provide an open-source solution based on modern software engineering principles that simplifies the design, implementation, and dissemination of sequences. Approach: Our vendor-agnostic “mtrk” framework is based on a compact, human-readable descriptive language (SDL) in JSON format. SDL files can be generated with any programming language and can be played on MRI scanners or tested with simulators. Results: Python libraries for SDL generation and tools for interactive sequence design and visualization are presented. mtrk sequences were equivalent to vendor sequences in experiments. Impact: mtrk will lower the burden for students and researchers to develop and disseminate sequences. It will aid reproducible research, as developments can be publicly shared. Moreover, it will allow exploring innovative concepts such as remote calculation and cloud-driven “sequence-as-a-service” models.