EPSI sequence analysis

1

Hi everyone,

I’m fairly new to MRSI and have run into a wall with a Siemens 3-D ¹H EPSI dataset. All I have are the original .IMA (DICOM) files—no accompanying TWIX .dat, RDA, or separate water-reference scan. My goal is to get the data into FSL-MRS, but first I need to reconstruct the spectroscopic volume. I tried converting the series with “spec2nii” but then “ValueError: cannot reshape array of size 3800000 into shape (32,38,100,1000)”. From digging through the headers, this is what I saw:
(0008,0016) UI [1.3.12.2.1107.5.9.1] # 20, 1 SOPClassUID
(0008,0008) CS [ORIGINAL\PRIMARY] # 16, 2 ImageType
I don’t have MIDAS installed, and downloading MIDAS no longer seems to be an option. I don’t know what the next steps would be…

Has anyone successfully reconstructed Siemens EPSI data in this situation—or patched spec2nii to handle it? Any guidance, code snippets, or alternative tools would be hugely appreciated.

Thanks in advance,
Ilyas

2

For spec2nii, @wclarke should be able to guide.

@bsoher is currently probably the best person to talk to get some sort of continued support for MIDAS.

3

@Ilyas I think I’ve come across this before. See FSL-MRS Spec2Nii reshape issue

Are you sure that this is the MIDAS package EPSI? Or is there another EPSI floating around somewhere? Can you find out the source of the sequence?