Import SEEG electrode positions with MNI coordinates in ICBM152 2023b

Discussions
1

Hello,

I'm trying to import my SEEG electrode MNI coordinates into an ICBM152 2023b model but it gives me this (see picture)? I do it from the EEG:ASCII XYZ_MNI,Name (,) because I only have a .txt or .csv file available... I don't understand what I'm doing wrong...
Thank you

MNI
MNI1280×720 242 KB

2

Hi Florian,

Do you happen to have more information regarding the electrode positions?

  • How were they acquired?
  • What coordinate system was used?
  • Where were they placed? (To verify the imported positions)

Best,
Raymundo

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3

Hi @Florian

Can you try another head template (one of the previous ICBM152)?

Do you have the names of the electrodes, and what will be the expected positions?

Best,

4

Hello @Raymundo and @tmedani
thank you for your help!! Some attempts of response. I am not in charge of analyzing the position of the electrodes. But I know that :

  • it was made with Freesurfer
  • in an MNI reference
  • the electrodes are scattered all over the brain as in the picture
  • the problem is the same with a other head template
    Have a good day
    Figure 1.3 TheBigOne
    Figure 1.3 TheBigOne673×627 270 KB
5

@Florian, can you share your channel file?
Or at least copy-paste one line from it here in the forum?

6

Hello Raymundo,
thank you for your answer. Here, my data.
F
XYZ.xlsx (52.5 KB)

7

Thank for sharing the file!

The data in it, indeed is in MNI space coordinates, and can be imported in Brainstorm.

However, some changes are needed:

  1. The file is saved as a native Excel file xlsx, it must be changed to either a comma-separated-value (csv) or tab-separated-values (tsv). This can be done from Excel. Both csv and tsv formats are text files that can be read with simple text editors such as notepad.

  2. Each row should have 4 columns, Name, X, Y and Z

Find attached the same channel file in csv format, with arbitrary names.
XYZ.csv (40.7 KB)

This is the imported result.

image
image1254×1036 207 KB

8

Thank you @Raymundo.Cassani
Sorry but from what import? Thank you

image
image1920×540 132 KB

F

9

You need to select EEG: ASCII: NAME,XYZ_MNI(*.*) as Files of Type (Type de fichier)
:bulb: Because it is a text file (ASCII), the columns are Name, X, Y and Z, and it is given in MNI space

10

Hello @Raymundo.Cassani
I had used this import but I still have the same problem as at the start... which I don't understand... Thank you

image
image1920×1080 180 KB

11

That is strange :thinking:
What steps are you performing?

These are the steps I am taking:

  1. Create a new Protocol

  2. In Anatomy View (iconSubjectDB), create a new Subject using Default anatomy (ICBM152 2023b)

  3. In Functional view (iconStudyDBSubj), right-click on Subject > Import channel file.
    Select file and EEG: ASCII: NAME,XYZ_MNI(*.*) type

  4. Right-click the channel file () > Edit channel file change the Type for all the electrodes to SEEG (Ctrl-A to select all, then right-click > Set channel Type)
    Close and save.

  5. Right-click the channel file > Display sensors > SEEG (Cortex)

    image
    image640×540 58.6 KB

1 Like
12

Hello @Raymundo.Cassani
Thanks, it works. I don't know where I was wrong, but it's a mistake I won't make again.
Have a good day
Florian

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