Add CSA header support

[dzemanov]

No description provided.

[marcelzwiers]

Mhhh, this comment from the main author doesn't sound good:

Different parts of dcmstack and dicom_parser (both abandoned)

nipy/nibabel#977 (comment)

[marcelzwiers]

FYI

[marcelzwiers]

There are two CSA headers, i.e.:

• (0029, 1010) - CSA Image Header Info
• (0029, 1020) - CSA Series Header Info

Now only CSASeriesHeaderInfo is used, but I don't know if it's worth it to also parse CSAImageHeaderInfo

[marcelzwiers]

Unfortunately the CSA header also supports indexing, e.g.:

asCoilSelectMeas[0].tNucleus             = ""1H""
asCoilSelectMeas[0].iUsedRFactor         = 3
asCoilSelectMeas[0].asList[0].sCoilElementID.tCoilID = ""HeadMatrix""
asCoilSelectMeas[0].asList[0].sCoilElementID.lCoilCopy = 1
asCoilSelectMeas[0].asList[0].sCoilElementID.tElement = ""H3P""
asCoilSelectMeas[0].asList[0].lElementSelected = 1
asCoilSelectMeas[0].asList[0].lRxChannelConnected = 1
asCoilSelectMeas[0].asList[1].sCoilElementID.tCoilID = ""HeadMatrix""
asCoilSelectMeas[0].asList[1].sCoilElementID.lCoilCopy = 1

[marcelzwiers]

Alternatively, instead of dicom-parser we can also use nibabel:
https://github.com/nipy/nibabel/blob/master/nibabel/nicom/csareader.py

I don't know what would be the best choice

[dzemanov]

There are two CSA headers, i.e.:

• (0029, 1010) - CSA Image Header Info
• (0029, 1020) - CSA Series Header Info

Now only CSASeriesHeaderInfo is used, but I don't know if it's worth it to also parse CSAImageHeaderInfo

I asked colleague about this and his response was that most of the "interesting" info is in CSA Series Header Info. He says he currently doesn't know about anything interesting in CSA Image Header Info. However, he says that if parsing is the same and it is easy to include both, then why not. For us, CSA Series Header Info includes all information we need.

[marcelzwiers]

I'm already parsing both now, and have also added support for nibabel. The test needs to be improved, currently dicom-parser and nibabel.csareader give different outputs

[dzemanov]

For the tags we need, dicom_parser gets them correctly and nibabel returns ''. I checked the parsed csa headers and it seems nibabel doesn't parse the part with interesting data:

   ### ASCCONV BEGIN
  ... 
   ### ASCCONV END

Differences:
nibabel includes values of "syngodt", "n_items" and "last3". The value is under key "items": [value]
dicom_parser has tag_no under "index" and value under key "value": whatever is needed to represent what is saved there, so can be string, array, dict.
I checked top level keys and those are the same for both. Afterwards nib needs "items" and dicom_parser "value".

From what I can tell, the values (under "items" or "value") are the same except for the ASCCONV part under MrPhoenixProtocol. Difference is also when there is no value: nibabel has empty [], dicom_parser has "value": None.

[dzemanov]

Mhhh, this comment from the main author doesn't sound good:

Different parts of dcmstack and dicom_parser (both abandoned)

nipy/nibabel#977 (comment)

Yes, that is unfortunate regarding not finished separate csa_header package :(. I tried it and it worked correctly, but author probably wants to do more testing.

[marcelzwiers]

So inside the CSA header, we have to deal with "raw" DICOM fields (with that clumsy index/items structure) as well as MrPhoenixProtocol fields (which have a more straightforward structure). I don't see an easy way to handle this

[dzemanov]

I probably don't understand. Dicom_parser works correctly even for MrPhoenixProtocol fields. The code you wrote works and we are able to read CSA header values under "items" or "value" thanks to it :). I tried it with our data and the code mapped items correctly, also using CSA header info. For nibabel, it reads everything correctly except for MrPhoenixProtocol.

[marcelzwiers]

Well, it's probably me who doesn't understand the CSA header very well. I get:

>>> get_dicomfield('MrPhoenixProtocol.tProtocolName', dcmfile)
CSASeriesHeaderInfo tag: MrPhoenixProtocol
CSASeriesHeaderInfo tag: tProtocolName
CSAImageHeaderInfo tag: MrPhoenixProtocol
''

But if I read it directly I get:

>>> value = Image(dcm_file_csa).header.get('CSASeriesHeaderInfo')
>>> value['MrPhoenixProtocol']['value']['tProtocolName']
'CBU+AF8-DTI+AF8-64D+AF8-1A'

I don't have time now to look into it, but it seems to me things are not working as intended

[dzemanov]

Well, it's probably me who doesn't understand the CSA header very well. I get:

>>> get_dicomfield('MrPhoenixProtocol.tProtocolName', dcmfile)
CSASeriesHeaderInfo tag: MrPhoenixProtocol
CSASeriesHeaderInfo tag: tProtocolName
CSAImageHeaderInfo tag: MrPhoenixProtocol
''

But if I read it directly I get:

>>> value = Image(dcm_file_csa).header.get('CSASeriesHeaderInfo')
>>> value['MrPhoenixProtocol']['value']['tProtocolName']
'CBU+AF8-DTI+AF8-64D+AF8-1A'

I don't have time now to look into it, but it seems to me things are not working as intended

For the first example, you need to use:
get_dicomfield('MrPhoenixProtocol.value.tProtocolName', dcmfile)

Does it return the same value?

[marcelzwiers]

Ok, couldn't help myself, I added better tests and had to make bugfixes. The code is still dodgy because I don't know how exactly the CSA header is structured

[dzemanov]

If you would like to see what is the structure loaded from dicom_parser or csareader, you can look in debugger when the whole csa header is in value. Or you can copy the content of value with whole csa header to file and autoformat it, so it is easy to look at.

[marcelzwiers]

Yes, I did that but I still find it fuzzy

…

_____________________ Sent from my phone Op zo 28 jan 2024 23:30 schreef DominikaZ ***@***.***>:

If you would like to see what is the structure loaded from dicom_parser or nibabel.csa_header, you can look in debugger when the whole csa header is in value. Or you can copy the content of value with whole csa header to file and autoformat it, so it is easy to look at. — Reply to this email directly, view it on GitHub <#220 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADTUGLZ5ZTEO3LDZWJJGQ2TYQ3GPVAVCNFSM6AAAAABCJRFQKSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTSMJTG42DEOBZGQ> . You are receiving this because you commented.Message ID: ***@***.***>

[dzemanov]

I understand. Maybe the code could try to catch exception if there would be any problem with that.

[marcelzwiers]

It seems to work so I'm merging it

[dzemanov]

Thank you very much! This will be a big help for us :).

[marcelzwiers]

Note that you should only use dicom-parser when you need data from the MrPhoenixProtocol, otherwise the nibabel csa parser will much faster (because of caching) and you will get the latest pydicom version (dicom-parser restricts pydicom to an older version)

…

_____________________ Sent from my phone Op ma 29 jan 2024 00:40 schreef DominikaZ ***@***.***>:

Thank you very much! This will be a big help for us :). — Reply to this email directly, view it on GitHub <#220 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADTUGL6KCBFSXAAXJKAUO4TYQ3OVPAVCNFSM6AAAAABCJRFQKSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTSMJTG43DCNZYGM> . You are receiving this because you modified the open/close state.Message ID: ***@***.***>