[Freesurfer] mri_convert : ERROR: cannot unpack mosiacs without ASCII header

Hi everyone,

I’m having some issues converting my DICOMs (DWI) into NIFTI using mri_convert. I looked for other topics with people having the same kind of problem but couldn’t find an answer.

Each time I run mri_convert on my DICOMs I get the following error : WARNING: file MR.1.3.12.2.1107.5.2.19.45306.2014091812330393354083931 does not contain a Siemens ASCII header has this file been anonymized? ERROR: cannot unpack mosiacs without ASCII header

Here are the following DICOMs informations : Identification NumarisVer syngo MR D13 ScannerModel Skyra PatientName xxxxx Date and time StudyDate 20140918 StudyTime 121037.203000 SeriesTime 123450.600000 AcqTime 123257.367500 Acquisition parameters PulseSeq ep_b0 Protocol AX DTI no angle MS NEX 4 2 PhEncDir COL EchoNo 1 FlipAngle 90 EchoTime 96 InversionTime -1 RepetitionTime 4700 PhEncFOV 0 ReadoutFOV 0 Image information RunNo 4 SeriesNo 5 ImageNo 1 NImageRows 990 NImageCols 990 NFrames 64 SliceArraylSize 0 IsMosaic 1 ImgPos 1075.1575 1069.8385 -48.6769 VolRes 2.1818 2.1818 2.0000 VolDim 0 0 0 Vc -1.0000 -0.0000 0.0000 Vr -0.0000 -1.0000 0.0000 Vs 0.0000 0.0000 0.0000 VolCenter 0.0000 0.0000 0.0000 TransferSyntaxUID 1.2.840.10008.1.2.1

Then I try using mri_convert -it dicom, it converts the files but not as it is expected, you could notice the difference when I run mri_info on my output : Volume information for output.nii.gz type: nii dimensions: 990 x 990 x 1 x 64 voxel sizes: 2.1818, 2.1818, 2.0000 type: SHORT (4) fov: 2160.000 dof: 0 xstart: -1080.0, xend: 1080.0 ystart: -1080.0, yend: 1080.0 zstart: -1.0, zend: 1.0 TR: 4700.00 msec, TE: 0.00 msec, TI: 0.00 msec, flip angle: 0.00 degrees nframes: 64 PhEncDir: UNKNOWN ras xform present xform info: x_r = -1.0000, y_r = -0.0000, z_r = -0.0000, c_r = -4.8425 : x_a = -0.0000, y_a = -1.0000, z_a = -0.0000, c_a = -10.1615 : x_s = 0.0000, y_s = 0.0000, z_s = 1.0000, c_s = -47.6769 Orientation : LPS Primary Slice Direction: axial

voxel to ras transform: -2.1818 -0.0000 -0.0000 1075.1575 -0.0000 -2.1818 -0.0000 1069.8385 0.0000 0.0000 2.0000 -48.6769 0.0000 0.0000 0.0000 1.0000

voxel-to-ras determinant 9.52066

ras to voxel transform: -0.4583 0.0000 0.0000 492.7805 0.0000 -0.4583 0.0000 490.3426 -0.0000 -0.0000 0.5000 24.3384 0.0000 0.0000 0.0000 1.0000

I would really appreciate your help, thank you.

Best,

Ismail