Dicom reslice upside down problem

Support
1

Hi guys,

I import dicom data Using vtkDICOMImageReader(). The 3-plane result is upside-down, as follows:
image
image
image

But if I convert the DICOM files to .mha or .nii.gz, and using vtk to visualize them, there is no upside-down problem.

I have read many documents about this problem.The most related I found is the below one:
https://www.nitrc.org/plugins/mwiki/index.php/dcm2nii:MainPage#Spatial_Coordinates
According to this ,DICOM images are saved to disk in the order we read English: with the first line at the top of the screen and subsequent lines descending.
It seems the reason cause the problem.

But here is my question: Is there a standard inside way to deal with this using vtk? Or we must use transform to get the volume direction right ?

Ps: I know extend dicom support using vtk-dicom, but I’m using python. As far as I kown, the package don’t support python.

2

You can try setting the FileLowerLeft flag on the reader:

reader.FileLowerLeftOn()

This may change the slice ordering as a side-effect, however.

3

Thanks for your replay. But it seems that this does not work… Nothing changed compared to the old. Here is my code:

reader0 = vtk.vtkDICOMImageReader()
reader0.SetDirectoryName("D:\\project\\py\\slicer_-script\\lab\\Coordinate\\data\\patient1_Sorted")
reader0.Update()
reader0.FileLowerLeftOff()

Did I do anything wrong?

4

Like this:

reader0 = vtk.vtkDICOMImageReader()
reader0.SetDirectoryName("D:\\project\\py\\slicer_-script\\lab\\Coordinate\\data\\patient1_Sorted")
reader0.FileLowerLeftOn()
reader0.Update()