What's wrong with my DWI? Failed to convert from DWI to tensors

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1

Hi all,

I’ve been working to do some tractography using slicerDMRI, but seems to encounter the same problem with all DWI files that i have as i failed to convert it to tensors. Here, I attached the .nrrd file of our DWI.

Can anyone point out whats wrong with my DWI?

Really appreciate your help.

Regards,
Peter

2

If you look at the header you can see that there’s only one volume (a baseline, with gradient 0,0,0). For tractography you typically need dozens of gradients at different angles.

# Complete NRRD file format specification at:
# http://teem.sourceforge.net/nrrd/format.html
type: short
dimension: 3
space: right-anterior-superior
sizes: 160 160 25
space directions: (-1.3536703538588315,-0.23908993262719125,0.032211445171427509) (0.24112542786612504,-1.3467566568679989,0.13685771888390255) (0.029318512241917394,0.53090466025518757,5.1727440171111505)
kinds: domain domain domain
endian: little
encoding: gzip
space origin: (99.988388696114995,105.71384036457,-55.297402783850025)
measurement frame: (-1,0,0) (0,-1,0) (0,0,1)
DICOM_0008_0060_Modality:=MR
DICOM_0008_0070_Manufacturer:=SIEMENS
DICOM_0008_1090_ManufacturerModelName:=Skyra
DICOM_0018_0022_ScanOptions:=FS
DICOM_0018_0023_MRAcquisitionType:=2D
DICOM_0018_0080_RepetitionTime:=5500
DICOM_0018_0081_EchoTime:=64
DICOM_0018_0083_NumberOfAverages:=1
DICOM_0018_0087_MagneticFieldStrength:=3
DICOM_0018_1020_SoftwareVersions:=syngo MR E11
DICOM_0018_1314_FlipAngle:=180
DWMRI_b-value:=0
DWMRI_gradient_0000:=0   0   0
modality:=DWMRI
3

Thank you for the reply. Do you have any suggestion on what to change in the process of doing the MRI?

4

Acquiring diffusion MRI in a form compatible with tractography is a complex process, and the detail vary a lot by scanner type. Generally speaking you would want dozens of gradient directions and usually there will be a standard sequence from the scanner vendor the provides good results.