Herz, KaiMueller, SebastianPerlman, OrZaitsev, MaximKnutsson, LindaSun, Phillip ZheZhou, Jinyuanvan Zijl, PeterHeinecke, KerstinSchuenke, PatrickFarrar, ChristianSchmidt, ManuelDörfler, ArndScheffler, KlausZaiss, Moritz2021-07-122021-05-07Herz, Kai, Sebastian Mueller, Or Perlman, Maxim Zaitsev, Linda Knutsson, Phillip Zhe Sun, Jinyuan Zhou et al. "Pulseq‐CEST: Towards multi‐site multi‐vendor compatibility and reproducibility of CEST experiments using an open‐source sequence standard." Magnetic Resonance in Medicine 2021, no. 00 (2021): 1-14. DOI: 10.1002/mrm.288250740-31941522-2594https://nrs.harvard.edu/URN-3:HUL.INSTREPOS:37368147Creative Commons Attribution License: https://creativecommons.org/licenses/by/4.0/ Funding information: Max Planck Society, German Research Foundation (ZA 814/5-­1, SCHU 3468/1-­1, SFB 1340 project C03, and Reinhart Koselleck project DFG SCHE 658/12); National Institutes of Health (P41 EB015909, RO1EB019934, RO1 EB015032, R01 CA203873, and P41 EB024495); Swedish Research Council (2015-­04170 and 2019-­03637); Swedish Cancer Society (CAN 2015/251 and 2018/550); this project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No 836752 (OncoViroMRI). This paper reflects only the author’s view and the Research Executive Agency of the European Commission is not responsible for any use that may be made of the information it contains.Purpose: As the field of CEST grows, various novel preparation periods using different parameters are being introduced. At the same time, large, multisite clinical studies require clearly defined protocols, especially across different vendors. Here, we propose a CEST definition standard using the open Pulseq format for a shareable, simple, and exact definition of CEST protocols. Methods: We present the benefits of such a standard in three ways: (1) an open database on GitHub, where fully defined, human-­readable CEST protocols can be shared; (2) an open-­source Bloch-­McConnell simulation to test and optimize CEST preparation periods in silico; and (3) a hybrid MR sequence that plays out the CEST preparation period and can be combined with any existing readout module. Results: The exact definition of the CEST preparation period, in combination with the flexible simulation, leads to a good match between simulations and measurements. The standard allowed finding consensus on three amide proton transfer–­weighted protocols that could be compared in healthy subjects and a tumor patient. In addition, we could show coherent multisite results for a sophisticated CEST method, highlighting the benefits regarding protocol sharing and reproducibility. Conclusion: With Pulseq-­ CEST, we provide a straightforward approach to standardize, share, simulate, and measure different CEST preparation schemes, which are inherently completely defined.en-USRadiology Nuclear Medicine and imagingCESTopen-sourcePulseqstandardizationJournal Article2021-07-1210.1002/mrm.28825Herz K, Mueller S, Perlman O, et al. Pulseq-­CEST: Towards multi-­site multi-­vendor compatibility and reproducibility of CEST experiments using an open-­source sequence standard. Magn Reson Med. 2021;00:1–­14. https://doi.org/10.1002/mrm.28825