Thank you very much Humberto! Your response resolved my issue! I made the following settings in the Osprey job.m file, limiting the registration frequency range to [2.93 3.02], and tried different methods for sub-spectra alignment. Here are my results. I think the L1Norm method yielded the best outcome.
opts.SpecReg='RestrSpecReg';
opts.SpecRegRange=[2.93 3.02];
opts.SubSpecAlignment.mets='L2Norm';
opts.SubSpecAlignment.mets='L1Norm';
opts.SubSpecAlignment.mets='none';
Oh, I noticed the low SNR and high FWHM in the L1Norm results, perhaps it’s not so good. However, the GABA peak in the L2Norm results looks a bit strange; it appears as a peak with two valleys on both sides, rather than a doublet. TE is 74ms, and the editing pulses are set at 1.9/7.5ppm.
Hello Yushan,
I’m glad that you made some progress based on my suggestions. I realized that I forgot to mention that there is another option for unstable water that might also help:
opts.UnstableWater = 1; % write in the job file
You have an unusual echo time of 74 ms. Is there a specific reason for this? Usually, the GABA edited experiment is run at 68 or 80 ms. I can’t say for certain that might causing issues, but could be worth looking into.
Did you also try no alignment at all? opts.SpecReg=‘None’; You can see in the pre-alignment display that the Cr and Cho peaks align well, but are shifted after the restricted spectral alignment so you are getting subtraction artifacts. I would stick to L2Norm for the sub spectra alignment.
Hope this helps!
Humberto
