Osprey Basis set Siemens CMRR

I’ve been using both Siemens product sequences and the CMRR R&D sequence along with the inherent basis set(maybe the same one) from Osprey. However, I’ve encountered an issue with the diff1 spectrum produced by the CMRR R&D sequence, which looks unusual. You can see the results in the attached figure. Does anyone have insights into what might be causing this problem? I have a couple of hypotheses:

  1. It could be related to the basis set; perhaps CMRR requires its own specific basis set. I’m considering reaching out to experts in the field for guidance on this.

  2. There’s also the possibility of a coding issue on my end during data processing. I’m exploring this as well. Any advice or input would be greatly appreciated.


Hello Jiazhen,
I assume that something goes wrong when you subtract your spectra. In this case, you can get line shapes that look like dispersion curves. Also, you have peaks at the position of Cho and Cr. Normally, you should have a flat baseline there and only GABA, respectively.


Hello Heiner,
Thank you for your reply! It helped me a lot. The CMRR C2P sequence indeed suppresses the water signal quite effectively, to the point where it’s nearly absent. Since Osprey aligns with the water signal as a reference, this was causing an error.
To resolve the issue, I made a change to the default parameter settings in Osprey and used Choline as the reference instead. The results now appear normal. Thank you very much for your assistance!


1 Like