DICOM reader

Good morning everyone,

I am trying to use the itk GDCM reader in Python. This is what I wrote so far to read from a folder, as a ITK beginner:

reader = itk.ImageSeriesReader.New()
dicomIO = itk.GDCMImageIO.New()

name = dicomIO.GetPatientName('')
found, spacing2 = dicomIO.GetValueFromTag("0028|0030", "")

Now the thing is, I am sure the DICOM folder I am trying to read is valid. I am also sure that the patient name and the tag (“0028,0030”) I am trying to read (a spacing value) are present in the metadata. However, this code just gives me no result.

Am I supposed to write that another way around ?
In general it feels like most of the functions of this module have not really been written for Python. I could be missing some part of the documentation though…

Thanks for your help. Bests.

Hello @Edern_Haumont,

You need to call Update() on your reader to actually do the reading.

ITK Python is “just” a wrapping from the C++, explaining that it doesn’t look very pythonic. :wink:
You can look at SimpleITK which is more user-friendly and have python binaries. I know efforts have been made to enable a more pythonic logic and syntax in it. @blowekamp should be able to be more precise that me.



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I agree with Tim that a missing Update() is likely the cause of the problem. ITK has a pipeline architecture, that must be explicitly updated to be executed. This is a fundamental concept of ITK and is describe in the ITK Software Guide.

Regarding SimpleITK, it has been designed with an easier and more pythonic interface. We have a related example for printing meta-data (DICOM tags).

There is also a more complex example which reads a series copies select tags and writes a new series.

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Thank you @tim-evain and @blowekamp, that was exactly the problem !

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