Dear all,

When I check the report of DTIPrep, I notice that it gives me some warning: "Image_information_checkingImage_origin_check FAILED", but the quality checking for the images is OK:

PASS: Gradient direction #is not less than 6!
PASS: Left Baseline images and the left b-value are ok!
PASS: Bad gradient directions #passed in the tolerance! 

Can you tell me what's the reason for the warning? Since for the QC result, everything is OK, is the warning important or not?

Thank you very much.

Best,
Jian

DTIPrep is based on your settings in the QC protocol. By default, image info and gradient info checks are set as "not failing overall QC" when these steps individually fail. You can interpret this behavior as a warning. In this specific case, the warning is that the image information is different from the one specified in the QC protocol, in particular the origin is different. This is actually expected, i.e. different scans should be expected to have different image origins, and thus you can safely disregard this warning. If the warning would be for differences in image size then you may be more worried (if you would assume that the images in your study should all have the same size). 

In any case, you can easily disable this QC step in the QC protocol  and thus you would not see this warning anymore.

Martin

Hi Martin,

Thanks for the reply. I used images of subject A to create the protocol A, with the default option of DTIPrep, and then using protocol A to check the quality of subject A. Since protocol A is from subject A, why I also got the warning?

Jian

Is this the same image or just the same subject A (but a different image of that subject) that you used for generating the default protocol.

Martin

The same subject, same image (used for generating the default protocol).

Jian

mmm, not sure what the problem is, likely this is a bug (Can you report this as a bug in the DTIPrep tracker?). Probably we should turn off the image-info-check by default in any case, as the value is rather limited (whereas the gradient info check is definitely useful to ensure the same diffusion gradient protocol was used for all DWIs in a given study).

Martin

Thanks. I will report this in the DTIPrep tracker.

Jian