# What attributes to write from CompositeTransform Object to which DICOM tags?
**URL:** https://discourse.itk.org/t/what-attributes-to-write-from-compositetransform-object-to-which-dicom-tags/4376
**Category:** Beginner Questions
**Created:** [August 28, 2021, 6:22am UTC](https://discourse.itk.org/t/what-attributes-to-write-from-compositetransform-object-to-which-dicom-tags/4376 "2021-08-28T06:22:31Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@wafflesaregreat](https://discourse.itk.org/u/wafflesaregreat)
#### Post date: [August 28, 2021, 6:22am UTC](https://discourse.itk.org/t/what-attributes-to-write-from-compositetransform-object-to-which-dicom-tags/4376/1 "2021-08-28T06:22:31Z")
Hi everyone, I’m just wondering what kind of information should be written to DICOM meta tags. Ideally, everything regarding the translation and rotation matrices should be written for Image Fusion/Registration purposes but I’m a little lost as to which tags are relevant to which information.
```auto
itk::simple::CompositeTransform
CompositeTransform (0000018CF08DE930)
RTTI typeinfo: class itk::CompositeTransform
Reference Count: 1
Modified Time: 92272
Debug: Off
Object Name:
Observers:
none
Transforms in queue, from begin to end:
>>>>>>>>>
Euler3DTransform (0000018CF0A24B80)
RTTI typeinfo: class itk::Euler3DTransform
Reference Count: 1
Modified Time: 92259
Debug: Off
Object Name:
Observers:
none
Matrix:
1 0 0
0 1 0
0 0 1
Offset: [-6.24571, 0.00429469, -52.5]
Center: [6.25701, 0.00700536, 1733.5]
Translation: [-6.24571, 0.00429469, -52.5]
Inverse:
1 0 0
0 1 0
0 0 1
Singular: 0
Euler's angles: AngleX=0 AngleY=0 AngleZ=0
m_ComputeZYX = 0
>>>>>>>>>
VersorRigid3DTransform (0000018CF0A23B00)
RTTI typeinfo: class itk::VersorRigid3DTransform
Reference Count: 1
Modified Time: 92268
Debug: Off
Object Name:
Observers:
none
Matrix:
0.99841 -0.0163883 -0.0539281
0.017555 0.99962 0.0212323
0.0535596 -0.0221453 0.998319
Offset: [92.0196, -21.8661, 11.5732]
Center: [6.25701, 0.00700536, 1733.5]
Translation: [-1.47477, 15.0499, 8.99422]
Inverse:
0.99841 0.017555 0.0535596
-0.0163883 0.99962 -0.0221453
-0.0539281 0.0212323 0.998319
Singular: 0
Versor: [-0.0108493, -0.0268842, 0.00848972, 0.999544]
End of MultiTransform.
<<<<<<<<<<
TransformsToOptimizeFlags, begin() to end():
0 1
TransformsToOptimize in queue, from begin to end:
End of TransformsToOptimizeQueue.
<<<<<<<<<<
End of CompositeTransform.
<<<<<<<<<<
```
Looking at the dicom website [C.20.2 Spatial Registration Module](http://dicom.nema.org/medical/Dicom/2016b/output/chtml/part03/sect_C.20.2.html)
I suspect that the Transformation Matrix(3006,00C6) and Type(0070,030C) are important but I’m unsure of the terminology of DICOM tags.
---
### Author:  [@zivy](https://discourse.itk.org/u/zivy)
#### Post date: [August 29, 2021, 6:40pm UTC](https://discourse.itk.org/t/what-attributes-to-write-from-compositetransform-object-to-which-dicom-tags/4376/2 "2021-08-29T18:40:03Z")
Hello @wafflesaregreat,
This is likely more of a question for a DICOM forum. From the transformation information you provided you have two rigid transformations, possibly combine into one (manually) to set the minimal amount of information in the DICOM header, but I believe a sequence of matrices is also supported by the standard.
The only SimpleITK/ITK specific information you need is the structure of the transformation, as described in the [fundamental concepts](https://simpleitk.readthedocs.io/en/master/fundamentalConcepts.html#transforms), all components are accessible via `Get*` methods.