A standardized open-source MESE sequence implemented in PyPulseq for reproducible water T2 quantification in skeletal muscle

Motivation: A promising tool in the assessment of muscular dystrophies is the measurement of water T2 (wT2) within the muscle. However, quantitative measurements, in general, lack reproducibility and comparability. One important step towards reproducible quantitative research is the exact transferability of the sequence design from scanner to scanner. Goal(s): To develop an open-source, vendor-independent multi-echo spin echo (MESE) sequence for the acquisition of wT2 in muscle. Approach: A MESE sequence was programmed in PyPulseq, tested on healthy volunteers and compared to a product MESE sequence. Results: The sequences produced similar images, but the obtained wT2 values differed slightly, probably due to hidden vendor-specific parameters. Impact: The developed vendor-independent MESE sequence offers the advantage of better transferability between different scanners. This is an important step towards better reproducibility of muscle wT2 values in patients with muscle dystrophies.