I can't access to Transfer Syntax UID and some other tags

[miguelyanez18]

Hello, I'm using Python to work with Dicom files using the pydicom package. I'm having trouble accessing some tags like Transfer Syntax UID. I'm attaching a picture of tags I can't get, and another picture of the error in the terminal when I tried to access Transfer Syntax UID value

Thank you in advance

[mrbean-bremen]

These tags (e.g. tags in group 2) do not belong to the dataset itself, but are meta data tags, which you can access via file_meta. file_mata is a separate dataset, which can be accessed like the main dataset. Note that under some circumstances no meta data may be present, so it is sensible to check for its existence:

ds = dcmread('myfile.dcm')
if hasattr(ds, 'file_meta'):
    for meta_tag in ds.file_meta:
        print(meta_tag)
    print(ds.file_meta.TransferSyntaxUID)

[miguelyanez18]

Thank you very much @mrbean-bremen . Your answer is what I was looking for. If I understand well, the second line checks if we have tags that don't belong to the dataset itself, and the third line is a cycle to find those tags with that characteristic. If I do this with a separate ds.dir(), Could I have all file tags in a list?

[mrbean-bremen]

Not sure I understand you correctly, but you can of course concatenate two lists or 2 dictionaries. ds.file_meta is of type Dataset similar to ds.

[miguelyanez18]

I made it. Thank you very much for your help. I appreciated that. What I finally did is construct a dictionary with those tags that don't belong to the dataset itself + those tags that belong to the dataset using ds.dir(), which shows all public metadata.

Best regards @mrbean-bremen