Apologies if the answer to my query is obvious! I’m currently testing LCModel in place of jMRUI. I was wondering if it is possible to fit data using a lipid SPTYPE with individual phases for each resonance. I’m attempting to fit some inversion recovery data acquired in bone marrow at 3T, and I’m having issues when the spectra are partially inverted. Is there a flag in the CONTROL file I’m missing? Please see the following example.
Long story short: No, LCModel only has two (global) parameters for the zero- and first-order phase correction that are applied to the entire model. There are no resonance-specific phases.
(To be honest, in this particular dataset, I don’t see any resolved resonances other than water - what do the other spectra look like?)
This is a poor example as it’s from a highly sclerotic bone lesion, but there’s definitely an inverted superposition of methylene, methyl and beta-carboxyl at 1.3ppm. Here’s an example, same inversion time, but in normal-appearing vertebral marrow.
Hello @yazma,
Maybe you should read 11.7 in the LCModel. In your case, perhaps it’s possible to re-define the lipid signals with CHSIMU and choose a negative amplitude. However, I cannot say to what extent this is possible with the sptype.
