[Insight-users] GDCM Sets Invalid Pregnancy Status in DICOM Tags In Addition to Other Errors

[Constantine Zakkaroff]

Hello Insight Users,

I'm experiencing strange things with writing DICOM headers with ITK 4.4.1.

In my code I follow the example DicomSeriesReadSeriesWrite.cxx, 
remembering to use 
seriesWriter->SetMetaDataDictionaryArray(seriesReader->GetMetaDataDictionaryArray());

In the output DICOM files I notice a few strange things. For example, 
pregnancy status gets an invalid value.

Input header: (0010,21C0) Pregnancy Status VR: US Length: 2 Value: 4
Output header: (0010,21C0) Pregnancy Status VR: US Length: 2 Value: 52

According to DICOM specification only values 1-4 are allowed. What is 
52? Pregnant with alien species? :)

Furthermore, there are worse things, where spacing between slices is 
overwritten with an incorrect value:

Input header: (0018,0088) Spacing Between Slices VR: DS Length: 2 Value: 16
Output header: (0018,0088) Spacing Between Slices VR: DS Length: 2 Value: 1

Similarly, double oblique image orientation is overwritten with axial 
orientation:

(0020,0037) Image Orientation (Patient) VR: DS Length: 86 Value: 
0.65752613544464\0.63155889511108\-0.4108439087867\-0.5298969745635\0\-0.8480620384216
(0020,0037) Image Orientation (Patient) VR: DS Length: 12 Value: 1\0\0\0\1\0

Can anyone suggest whether it's a bug or a feature?

In addition, I have been struggling for years with outputting private 
DICOM tags as they are read from disk. I use SetLoadPrivateTags(true) on 
the GDCMImageIO and GDCMSeriesFileNames objects but the output headers 
don't show private tags from original files. Is there something I'm 
doing wrong?

Many thanks,
Constantine