Not working "DWI Component"


(Екатерина Николаевская) #1

Operating system: MacOS High Sierra 10.13.6
Slicer version: 4.81
Expected behavior: I was hoping everything would be easy:-)
Actual behavior:
Good day!
Please help in my situation:
I have DWI images in DICOM. In the converter (diffusion - import and export - diffusion weighted DICOM import (DWI convert) transformed the images into “nrrd”. Trying to build “Diffusion Tensor Imaging”. I can not change the “DWI Component” parameter (module Volumes, field Scalar Display). Program does not allow me to do this. The value of “DWI Component” is 0. How can I make 10?
On the example of the pictures downloaded from the page - Documentation - Slicer Training - everything works out for me.
Just ask for help in the following.
After creating the “Diffusion Tensor Imaging” how to find the values ​​of the “anisotropy fraction”? I heard that they should be unloaded into a separate file. Could you tell us more about how to do this?

(Isaiah Norton) #2

Hi @Ekaterina, here are some suggestions to get started from raw DICOM files.

  1. please see this tutorial for loading DWI data from DICOM:

    If that works correctly then you should be able to change the DWI Component in the resulting file.

  2. Next, please see this tutorial (from around page 57) for how to calculate a diffusion tensor volume from a DWI image, and then measure Fractional Anistropy.

It sounds like you may have tried step 1 already, and there was a problem. If that is true, then please run the conversion again and send a log file. Also please provide more information about the dataset (scanner model, etc. – if you are able to privately share data then that would be most helpful).

(Isaiah Norton) #3

Also, see below to download a set of DWI DICOM data which is known to work with Slicer/DWIConvert. I would suggest following both tutorials first, using one of these datasets, and then if successful try with your own data.

Segmentation fault: 11 with DWIConvert
(Екатерина Николаевская) #4

Good day! Thanks for your reply!

I am using the “RadiAnt” program. In it, the patient’s pictures look right.

When loading the same images in “3D sliser”, the images are displayed incorrectly (as in the screenshot).

The error occurs with snapshots of DWI (several gradients!), the rest of the images load well.

Please tell me how to solve the problem.

(Isaiah Norton) #5

Please be careful not to publicly post images/data that contain personal identifying information (I removed the original image and replaced with identifiers blotted out).

Based on the series/file names in your screenshot, for example 801: DTI_medium_iso:

  • I believe you may be trying to load pre-computed tensor maps – tensors computed on the scanner. Slicer does not support these, Slicer only loads original/raw DWI images (gradient volumes).
  • If the files are indeed DWI, please make sure to use the “Diffusion-weighted DICOM Import (DWIConvert)” module. I mentioned this because usually the output from DWIConvert would not include the series number in the output like your screenshot shows (801:).


  • See the tutorial linked above for instructions to use DWIConvert.