# Failure to convert DICOM files to Nrrd for Diffusion MRI Analysis

**URL:** <https://discourse.slicer.org/t/failure-to-convert-dicom-files-to-nrrd-for-diffusion-mri-analysis/6072>\
**Category:** Support\
**Tags:** diffusion, dicom\
**Created:** [March 8, 2019, 12:11pm UTC](https://discourse.slicer.org/t/failure-to-convert-dicom-files-to-nrrd-for-diffusion-mri-analysis/6072 "2019-03-08T12:11:21Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![Bebo](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/bebo/32/3614_2.png) [@Bebo](https://discourse.slicer.org/u/Bebo)\
**Post date:** [March 8, 2019, 12:11pm UTC](https://discourse.slicer.org/t/failure-to-convert-dicom-files-to-nrrd-for-diffusion-mri-analysis/6072/1 "2019-03-08T12:11:21Z")

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Hello every one,  
I’m a new 3D slicer user (4.10.1 version), I intend to convert DCM files to Nrrd for the purpose of diffusion MRI analysis (the public data come from the Visual Human Project).  
However I have this error message:  
Diffusion-weighted DICOM Import (DWIConvert) standard error:  
**Error: no DICOMfiles found in inputDirectory: D:/Modélisation\_tête/GRANDIN\_TETE\_HUMAINE/2 - Datas/4 - 3D Slicer/Intput\_directory/st000/se000**  
**Unable to create converter!**  
I tried to use the lastest build version (4.11) but no DWI volume set was created and that version doesn’t have DWI converter extension yet…  
I also tried to use the “patch” option or to copy/paste the data into another folder as I could read in previous posts but it didn’t work neither  
Can someone help me please ??

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**Author:** ![cpinter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cpinter/32/7995_2.png) [@cpinter](https://discourse.slicer.org/u/cpinter)\
**Post date:** [March 8, 2019, 2:28pm UTC](https://discourse.slicer.org/t/failure-to-convert-dicom-files-to-nrrd-for-diffusion-mri-analysis/6072/2 "2019-03-08T14:28:33Z")

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The DICOM importer and database are known to have problems with special characters in the paths. Please try to move the data to a path that only has ascii characters, and make sure your databsae is in such a folder as well.

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**Author:** ![jaygummers](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jaygummers/32/3215_2.png) [@jaygummers](https://discourse.slicer.org/u/jaygummers)\
**Post date:** [March 8, 2019, 3:18pm UTC](https://discourse.slicer.org/t/failure-to-convert-dicom-files-to-nrrd-for-diffusion-mri-analysis/6072/3 "2019-03-08T15:18:55Z")

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Yes, I have also faced the similar issue with special characters in the database. However, I couldn’t fix it even after moving the DB into the same folder. 😕

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**Author:** ![cpinter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cpinter/32/7995_2.png) [@cpinter](https://discourse.slicer.org/u/cpinter)\
**Post date:** [March 8, 2019, 3:46pm UTC](https://discourse.slicer.org/t/failure-to-convert-dicom-files-to-nrrd-for-diffusion-mri-analysis/6072/4 "2019-03-08T15:46:04Z")

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Have you reported this problem?  
It’s possible that not just the database but the files were also in folders with paths containing spaces and/or non-ascii characters.

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**Author:** ![Bebo](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/bebo/32/3614_2.png) [@Bebo](https://discourse.slicer.org/u/Bebo)\
**Post date:** [March 12, 2019, 9:00am UTC](https://discourse.slicer.org/t/failure-to-convert-dicom-files-to-nrrd-for-diffusion-mri-analysis/6072/5 "2019-03-12T09:00:31Z")

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@cpinter I did as you said I changed the path with only ascii characters path but now I have another error message:

**Diffusion-weighted DICOM Import (DWIConvert) standard error:**

**Exception extracting gradient vectors**  
**itk::ExceptionObject (00000000002FB410)**  
**Location: "unknown"**  
**File: D:\D\S\Slicer-4101-build\ITK\Modules\IO\DCMTK\src\itkDCMTKFileReader.cxx**  
**Line: 577**  
**Description: itk::ERROR: Cant find tag 18 9089**  
I googled the message error but wasn’t conclusive…

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**Author:** ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)\
**Post date:** [March 12, 2019, 11:11am UTC](https://discourse.slicer.org/t/failure-to-convert-dicom-files-to-nrrd-for-diffusion-mri-analysis/6072/6 "2019-03-12T11:11:32Z")

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Have a look at this dicussion of dcm2niix as an alternative:

> [@Convert single files into one .nii](https://discourse.slicer.org/t/convert-single-files-into-one-nii/5407):
>
> Hi, I have multiple single .ima files. These contain single slices info. What I want to achieve is to merge all these into one .nii file. What is the best way to do that? Thanks

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**Author:** ![Bebo](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/bebo/32/3614_2.png) [@Bebo](https://discourse.slicer.org/u/Bebo)\
**Post date:** [March 20, 2019, 1:44pm UTC](https://discourse.slicer.org/t/failure-to-convert-dicom-files-to-nrrd-for-diffusion-mri-analysis/6072/7 "2019-03-20T13:44:10Z")

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Hi @pieper thank you for your answer,  
However even if did manage to reconstruct the geometry and the convertion, I did not have the b-vector and b-value files critical for the diffusion MRI analysis is that normal ?

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**Author:** ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)\
**Post date:** [March 20, 2019, 8:26pm UTC](https://discourse.slicer.org/t/failure-to-convert-dicom-files-to-nrrd-for-diffusion-mri-analysis/6072/8 "2019-03-20T20:26:35Z")

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@bebo looking back, it seems you are trying to work with the visible human data, but I don’t believe there is any DWI acquisition, so no, you wouldn’t be able do diffusion analysis.

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**Author:** ![Bebo](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/bebo/32/3614_2.png) [@Bebo](https://discourse.slicer.org/u/Bebo)\
**Post date:** [March 21, 2019, 7:48am UTC](https://discourse.slicer.org/t/failure-to-convert-dicom-files-to-nrrd-for-diffusion-mri-analysis/6072/9 "2019-03-21T07:48:31Z")

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@pieper thank you for answer.  
Indeed, I googled it and it seems that there’s no DWI acquisition… which explains all my troubles… Any way Thank you !!