Reconstructing DTI, missing bvec and bval

[giacomo.pg]

Hello everyone,

I am reconstructing a DTI image from a dataset of 71 DWI NIfTI images. I successfully concatenated the images using mrcat and imported the resulting file into dsi_studio. However, dsi_studio reported back that bvec and bval files were missing. bvec and bval files are not present in the dataset.

Is there an issue with how I am generating the concatenated file, or are the files actually separate (and so I need to find them)? If they are separate, is it possible to reconstruct the DTI image if any are missing (I suppose no)?

Thank you for your assistance!

[smeisler]

Hi @giacomo.pg and welcome to the mrtrix community!

@giacomo.pg

I am reconstructing a DTI image from a dataset of 71 DWI NIfTI images.

What are the source of these 71 images? This seems unconventional. Is each image a single volume in the overall DWI dataset?

@giacomo.pg

However, dsi_studio reported back that bvec and bval files were missing. bvec and bval files are not present in the dataset.

Is there an issue with how I am generating the concatenated file, or are the files actually separate (and so I need to find them)?

Yes, you will need bvec / bval files to be able to do pretty much anything with DWI processing. If you have the raw DICOMS or scanner protocol you might be able to get some of that information.

Best,
Steven

[giacomo.pg]

Thank you!

@smeisler

What are the source of these 71 images? This seems unconventional. Is each image a single volume in the overall DWI dataset?

Yes, each image is a single volume.

It is a dataset from another institution (with no DICOMs or scanner protocol) and at this point I suspect it is incomplete.

Thank you very much for your help!
Giacomo