open-discussion > DTIPrep is not recognizing B0 Images
Jun 9, 2020  07:06 PM | Steven Meisler - Harvard University / MIT
DTIPrep is not recognizing B0 Images
Hello DTIPrep team,

I am working with DWI data that have multiple b-vals (0, 1000, 1500, 3000). However, for whatever reason (I did not collect the data), each entry in the bval text file is slightly off from the standard number. For example, at some of the entries where 3000 should be, 3010 is there instead. This was also true for the baseline scans, where there were 5s instead of 0s. As one may expect, when I ran these data under DTIPrep (1.2.4, Linux, also tested 1.2.9) with the default protocol, I received an error: FAIL:Single b-value DWI without a b0/baseline. I presume this is because there were 5s in place of 0s in the bvals. In addition, I also receive the following error: DWI data error. Not all the gradient directions have same repetition. GradientNumber= XX 1 != 7. Something else peculiar with the output, however, is that every QCed b-value for any slice that survived correction was 3010, regardless of the slice's original bvalue. 

I made a script to change every 5 to a 0 in the bvals, but even then, I see that DTIPrep still chooses to ignore these b0 images, and the problems listed above persist. Hopefully these problems are related. Please let me know if you would need any additional information to help diagnose the problem.

Thanks,
Steven

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TitleAuthorDate
DTIPrep is not recognizing B0 Images
Steven Meisler Jun 9, 2020
Martin Styner Jun 11, 2020
Steven Meisler Jun 15, 2020
Martin Styner Jun 16, 2020
Steven Meisler Jun 25, 2020
Martin Styner Jun 25, 2020
Steven Meisler Jun 26, 2020
Martin Styner Jun 26, 2020
Steven Meisler Jun 29, 2020
Steven Meisler Jul 1, 2020
Martin Styner Jul 1, 2020