DTI Nifti data from the HCP import via DWI Convert Module

Support
1

Hello every one,

I’m using 3D Slicer 4.10.1. I’m currently trying to convert DTI Nifti data from the HCP import via DWI Convert Module (the data come from http://www.humanconnectomeproject.org/).
However I have this error message:

Diffusion-weighted DICOM Import (DWIConvert) standard error:
Error: ReadVolume: Unsupported source pixel type.
Input volume: float
Output volume: short
The only supported output type is . You may consider using allowLossyConversion option.
However, use this option with caution! Conversion from images of a different type may cause data loss due to rounding or truncation.

The bval. and .bvec files originally came in .txt format
Does someone have a clue ?

2

Hi,

Have you tried to use allowLossyConversion as suggested by DWIConvert.

For our processing of the HCP data, we use this option.

Regards,
Fan

3

Hi @zhangfanmark,
Yes I did, I even tried all possible combinations of options.
I noticed that every time I used the lossy option, the DWIconvert window pops up explaining that it crashed but I have no longer the message explaning the possible sources of error
“Diffusion-weighted DICOM Import (DWIConvert) standard error:
Error: ReadVolume: Unsupported source pixel type…”

4

Hi what version of Slicer are you using?

5

Hi @ljod,
I’m using Slicer 4.10.1 version

6

Hi I think Fan can get back to you about how he processed the data when his conference paper is submitted today.@zhangfanmark

7

Hi @ljod,
I have no explanation about why it worked this time… Few days ago, I registered to the other human connectome project (https://www.humanconnectome.org/) and I did the same manipulations, using the “allowLossyConversion” option as @zhangfanmark mentionned. Finally it worked this time…
I don’t know if initially the data was corrupted, but in case @ljod @zhangfanmark thank you for the advice!

8

Nicolas,

What exactly did you do to make this work?

HP

9

Hi! First, I also had this issue with DWIConvert, but it worked using allowLossyConversion. However, I cannot open the .nhdr file on Slicer. Do you know what could be wrong? Thanks!

Best,
Tamires

10

If you can provide an example .nhdr and corresponding .raw file then we can help investigating the issue.