XA60 MEGA-PRESS poor quality compared to E11

Data Acquisition Edited 1H-MRS
1

Hello-
We have started to acquire MEGA-PRESS (Richard Edden’s sequence) on our recently upgraded Siemens PRISM (E11c to XA60) and the spectral quality has taken a dive. We’ve not made any adjustments to the parameters. Any thoughts?

E11_XA60_comparison
E11_XA60_comparison1280×720 265 KB

2

Hi Brenda,

  1. We’ve seen a similar dataset from another XA60 user (we don’t have XA60 here ourselves yet) and suspect that this relates to the number of FID points acquired before the top of the echo being stored in a different header field location than in previous software versions. We should be able to get on top of this relatively quickly.
  2. I’m noticing that even your VE11 dataset does not seem to have the co-edited MM30 terms in it. Are you using a custom basis set or otherwise doing something substantially different to the example MEGA-PRESS job files?

Cheers,
Georg

3

Hi Georg,

Thanks for the quick reply! I am happy to here it could be a relatively simple fix. Siemens sure has made the upgrade to XA60 bumpy.

We aren’t using a custom basis set, just the default basis set with the Osprey fitting algorithm. Let me know if there’s any value to sending you the job files.

Best,
Brenda

4

Hi-
Any chance you folks have had a chance to take a look at a fix? Below is a link to some
XA 60 data. Looking forward to your thoughts.

Best,
Brenda

megapress_acquiredXA60.zip

5

Hi Brenda,

Gizeaddis has fixed a few things in the sequence that should get rid of the problem (it is not just a processing thing), I believe he’ll send new binaries to you.

Cheers,
Georg

6

Thanks Georg and Gizeaddis!

I’ll keep an eye our for the binaries.

Best,
Brenda

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