Error in dwipreproc eddy

Hi,

I am getting an error in the eddy command of the dwipreprocessing. I am using FSL 5.0.9 with eddy patch. I am using the SGE Cluster.

The command I use is as follows:

dwipreproc -pe_dir AP DWI_denois.mif DWI_denois_preproc.mif -rpe_none $quiet -nthreads ${NSLOTS} $force -eddy_options "--data_is_shelled "

The force and quiet are flags for overwriting warning.

The error message is as follows:

dwipreproc: e[00;31m[WARNING] Total readout time not provided at command-line; assuming sane default of 0.1e[0m
e[03;36mCommand:e[0m  mrinfo dwi.mif -export_grad_mrtrix grad.b
e[03;36mCommand:e[0m  dwi2mask dwi.mif - | maskfilter - dilate - | mrconvert - mask.nii -datatype float32 -stride -1,+2,+3
dwipreproc: e[03;32me[0m
dwipreproc: e[01;31m[ERROR] Command failed: dwi2mask dwi.mif - | maskfilter - dilate - | mrconvert - mask.nii -datatype float32 -stride -1,+2,+3e[0me[03;34m (dwipreproc:457)e[0m
dwipreproc: e[03;32mOutput of failed command:e[0m
dwi2mask: [ERROR] DWI volumes could not be classified into b-value shells; gradient encoding may not represent a HARDI sequence

The dwi2mask command fails.
Could you please advise what could be the issue?
Thank you.
Apoorva

Seems like you have an exotic DW encoding… What does this report:

mrinfo DWI_denois.mif -shells -shellcount

I’d expect that would probably give rise to the same DWI volumes could not be classified into b-value shells error… Assuming it does, you can drill into the specific of your encoding with:

mrinfo DWI_denois.mif -dwgrad

which will give you the DW encoding as MRtrix3 interprets it (you can get the original unmodified encoding by adding the -raw_dwgrad option to the above - this skips the unit normalisation and scaling by gradient vector norm - see here for details).

Hi,

The ‘mrinfo DWI_denois.mif -shells -shellcount command’ indeed gives the error you specified.

mrinfo DWI_denois.mif -shells -shellcount
mrinfo: [ERROR] DWI volumes could not be classified into b-value shells; gradient encoding may not represent a HARDI sequence

The $ mrinfo DWI_denois.mif -dwgrad command gives the following output:

 -0.57735     0.57735     0.57735           5
   -0.57735     0.57735     0.57735           5
   0.999682   0.0201575  -0.0151623         200
 0.00032054    0.602889    0.797825        4985
-0.00507475  -0.0102284    0.999935         200
-0.00011974   -0.802913   -0.596096        4985
  -0.710691  -0.0108116    0.703422         395
    4.8e-07   -0.999997 -0.00239615        5010
   0.701825   -0.712272  -0.0104731         405
   0.600888  0.00298427    0.799328        4965
  5.895e-05   -0.718672    -0.69535         400
  -0.598494   -0.801124 -0.00243904        5005
   0.577008    0.585676    0.569249     599.999
   0.800963  0.00306244    0.598706        4970
   0.577008   -0.585676    0.569249     599.999
  -0.798487   -0.602007 -0.00228192        5000
   7.64e-06   -0.999981 -0.00618013         810
   0.407565   -0.818365    0.405178        4795
   0.891448    0.453086  -0.0058056        1005
   0.408289   -0.411625    0.814779        4775
   0.896478  0.00723177     0.44303     995.001
   0.408289    0.411625    0.814779        4775
  -0.444725   -0.895649 -0.00576262        1010
  -0.407874   -0.818903   -0.403777        4790
   0.448482   0.0063503    0.893769     989.999
   0.816234   -0.411277    0.405725        4785
-0.00043871   -0.897969    0.440059        1005
   0.816234    0.411277    0.405725        4785
 -0.0004406   -0.453876    0.891065         995
   0.426028   -0.642492    0.636949        4390
  -0.816017   -0.414494    0.402878        1200
   0.426028    0.642492    0.636949        4390
    0.81714   -0.414907   -0.400169        1195
   0.638897    -0.64225    0.423469        4395
   -0.40711   -0.820321    0.401666        1205
   0.639582   -0.429733    0.637388        4385
  -0.408588   -0.414752    0.813041        1195
   0.639582    0.429733    0.637388        4385
   0.409509   -0.415708    -0.81209        1190
   0.638897     0.64225    0.423469        4395
   0.407721    -0.82156   -0.398501        1205
   0.217856   -0.874644    0.433056        4200
  -0.704232   -0.709956 -0.00440404        1610
   0.218178   -0.440011    0.871085        4180
   0.708885  0.00536232    0.705303        1585
   0.218178    0.440011    0.871085        4180
-0.00044024   -0.711749    0.702434        1600
  -0.218003    -0.87534   -0.431573        4195
   0.999977  0.00558527 -0.00391128        1795
   0.435372   -0.874172    0.215114        4205
   0.665193    0.670564    0.328425        1805
   0.436821   -0.221681    0.871806        4175
   0.667175    0.338713    0.663439        1795
   0.436821    0.221681    0.871806        4175
   0.667175   -0.338713    0.663439        1795
  -0.435564   -0.874506   -0.213362        4200
   0.665193   -0.670564    0.328425        1805
   0.872053    -0.43944    0.215446        4190
   0.333041    0.671278     0.66217        1800
    0.87319   -0.221654     0.43406        4180
   0.333041   -0.671278     0.66217        1800
    0.87319    0.221654     0.43406        4180
-0.00112104 -0.00449361    0.999989        1785
   0.872053     0.43944    0.215446        4190
   0.950523  0.00510864   -0.310613        1985
 0.00044888    0.450809     0.89262        3980
   0.947113   -0.320878 -0.00380253        2000
-0.00011084   -0.896881   -0.442273        3995
  -0.316659 -0.00447619    0.948529        1980
   0.445827   -0.895115 -0.00279058        4010
   0.315046   -0.949069 -0.00377631        2010
  -0.447889 -0.00327192    0.894083        3970
-0.00015447   -0.951028   -0.309104        2005
   0.893009   -0.450032 -0.00257576        3995
 0.00079282    0.320958    0.947093        1990
   0.896108  0.00349674   -0.443823        3970
   0.904181     0.30621    0.297812        2195
   0.229176   -0.691219    0.685343        3790
   0.904181    -0.30621    0.297812        2195
  -0.229482   -0.692145   -0.684305        3780
  -0.300922   -0.907001   -0.294612        2205
    0.68695   -0.690576    0.226283        3800
   0.301662    0.306217    0.902902        2185
   0.688755    -0.23309    0.686503        3780
   0.301662   -0.306217    0.902902        2185
   0.688755     0.23309    0.686503        3780
   0.300738   -0.906314    0.296904        2205
  -0.687243   -0.690872   -0.224482        3795
    0.57694    0.581527    0.573556        2395
-0.00019651    -0.71105   -0.703141        3585
    0.57694   -0.581527    0.573556        2395
   0.235135   -0.943805    0.232256        3605
   0.834427  0.00431612   -0.551102        2575
   0.235827   -0.239389    0.941849        3575
   0.829939   -0.557844 -0.00330685        2605
   0.235827    0.239389    0.941849        3575
  -0.555716 -0.00409388    0.831362        2580
  -0.235231   -0.944256   -0.230318        3605
   0.552757   -0.833336 -0.00329815        2610
   0.705237   -0.708967 -0.00274865        3605
-0.00021195   -0.835789   -0.549051        2595
  -0.708192 -0.00356633    0.706011        3575
 0.00064112    0.558753    0.829334        2590
   0.942595   -0.239331    0.232886        3590
   0.800598    0.538068    0.263676        2800
   0.942595    0.239331    0.232886        3590
   0.802172    0.271552     0.53177        2790
 0.00050161    0.246239    0.969209        3380
   0.802172   -0.271552     0.53177        2790
  -6.97e-05   -0.971499   -0.237043        3405
   0.800598   -0.538068    0.263676        2800
   0.241798   -0.970322 -0.00305879        3410
  -0.533543   -0.804374   -0.261372        2800
  -0.242789 -0.00345739    0.970073        3370
   0.534972    0.271524     0.80005        2785
   0.484416   -0.730375    0.481554        3395
   0.534972   -0.271524     0.80005        2785
   0.485022   -0.488821    0.725126        3385
   0.533223   -0.803935    0.263366        2805
   0.485022    0.488821    0.725126        3385
  -0.267129   -0.805497   -0.528977        2795
  -0.484891   -0.731024   -0.480089        3390
   0.267171    0.538561    0.799107        2790
    0.72722   -0.488681    0.482018        3390
   0.267171   -0.538561    0.799107        2790
    0.72722    0.488681    0.482018        3390
   0.266884   -0.804567    0.530513        2800
   0.969227   -0.246152  -0.0027906        3395
    9.7e-07   -0.999995 -0.00311522        3215
   0.971274  0.00388091   -0.237931        3380
   0.969227    0.246152  -0.0027906        3395
-0.00063001 -0.00347089    0.999994        3175
   0.970786  0.00387629    0.239914        3385
   0.999988  0.00408237 -0.00282692        3190
   -0.72722   -0.488681    0.482018        3390
   0.267129   -0.805497   -0.528977        2795
   0.727865   -0.489165   -0.480552        3385
   0.267541   -0.539603   -0.798279        2780
  -0.484416   -0.730375    0.481554        3395
  -0.267171   -0.538561    0.799107        2790
  -0.485022   -0.488821    0.725126        3385
  -0.266884   -0.804567    0.530513        2800
   0.485742   -0.489552    -0.72415        3380
   0.533543   -0.804374   -0.261372        2800
   0.484891   -0.731024   -0.480089        3390
  -0.534972    0.271524     0.80005        2785
  -0.241798   -0.970322 -0.00305879        3410
  -0.534972   -0.271524     0.80005        2785
   0.242789  0.00345739    0.970073        3370
  -0.533223   -0.803935    0.263366        2805
 -7.021e-05   -0.971016    0.239013        3410
   0.801114   -0.538356   -0.261512        2795
-0.00050161   -0.246239    0.969209        3380
   0.803103   -0.271809   -0.530231        2780
   0.943048    0.239432   -0.230939        3585
  -0.802172   -0.271552     0.53177        2790
   0.943048   -0.239432   -0.230939        3585
  -0.800598   -0.538068    0.263676        2800
  -0.705237   -0.708967 -0.00274865        3605
-0.00064112   -0.558753    0.829334        2590
   0.708192  0.00356633    0.706011        3575
-0.00021202   -0.834785    0.550576        2600
  -0.235135   -0.943805    0.232256        3605
   0.555716  0.00409388    0.831362        2580
  -0.235827   -0.239389    0.941849        3575
  -0.552757   -0.833336 -0.00329815        2610
  -0.235827    0.239389    0.941849        3575
   0.833415   0.0043044     0.55263        2585
   0.235231   -0.944256   -0.230318        3605
  -0.829939   -0.557844 -0.00330685        2605
-0.00039238   -0.710056    0.704145        3595
    0.57766   -0.582258   -0.572088        2390
   -0.68695   -0.690576    0.226283        3800
   -0.57694   -0.581527    0.573556        2395
  -0.688755    -0.23309    0.686503        3780
   0.300922   -0.907001   -0.294612        2205
   0.689687    -0.23335   -0.685478        3770
  -0.301662    0.306217    0.902902        2185
   0.687243   -0.690872   -0.224482        3795
  -0.301662   -0.306217    0.902902        2185
  -0.229176   -0.691219    0.685343        3790
  -0.300738   -0.906314    0.296904        2205
   0.229482   -0.692145   -0.684305        3780
   0.904871   -0.306404   -0.295508        2190
   0.893009    0.450032 -0.00257576        3995
   0.904871    0.306404   -0.295508        2190
   0.895433    0.003491    0.445182        3975
-0.00079282   -0.320958    0.947093        1990
  -0.445827   -0.895115 -0.00279058        4010
-0.00015538   -0.950265    0.311442        2010
   0.447889  0.00327192    0.894083        3970
   0.316659  0.00447619    0.948529        1980
-0.00011103   -0.896144    0.443763        4000
  -0.315046   -0.949069 -0.00377631        2010
-0.00044888   -0.450809     0.89262        3980
    0.94975  0.00509873    0.312969        1990
  -0.872053    -0.43944    0.215446        4190
   0.947113    0.320878 -0.00380253        2000
   -0.87319   -0.221654     0.43406        4180
   2.14e-06   -0.999993 -0.00386732        1815
   0.873834   -0.221769   -0.432703        4175
   0.333453   -0.672487   -0.660735        1790
   0.872425   -0.439604   -0.213594     4190.01
  -0.333041   -0.671278     0.66217        1800
  -0.435372   -0.874172    0.215114        4205
   0.665899   -0.671099    -0.32589        1800
  -0.436821   -0.221681    0.871806        4175
   0.668377   -0.339147   -0.662006        1785
  -0.436821    0.221681    0.871806        4175
  -0.667175   -0.338713    0.663439        1795
   0.435564   -0.874506   -0.213362        4200
  -0.665193   -0.670564    0.328425        1805
  -0.217856   -0.874644    0.433056        4200
-0.00044103   -0.713092   -0.701071        1595
  -0.218178   -0.440011    0.871085        4180
   0.704232   -0.709956 -0.00440404        1610
  -0.218178    0.440011    0.871085        4180
  -0.708885 -0.00536232    0.705303        1585
   0.218003    -0.87534   -0.431573        4195
    0.40711   -0.820321    0.401666        1205
  -0.638897    -0.64225    0.423469        4395
   0.408588   -0.414752    0.813041        1195
  -0.639582   -0.429733    0.637388        4385
   0.408588    0.414752    0.813041        1195
   0.640285   -0.430257   -0.636328        4375
  -0.407721    -0.82156   -0.398501        1205
   0.639362   -0.642719   -0.422054        4385
   0.816017   -0.414494    0.402878        1200
  -0.426028   -0.642492    0.636949        4390
   0.816017    0.414494    0.402878        1200
   0.426623   -0.643175   -0.635861        4380
  0.0004406    0.453876    0.891065         995
  -0.816234   -0.411277    0.405725        4785
-0.00043707   -0.899567   -0.436783        1005
   0.816743   -0.411536   -0.404437        4780
   0.444725   -0.895649 -0.00576262        1010
  -0.407565   -0.818365    0.405178        4795
  -0.448482  -0.0063503    0.893769     989.999
  -0.408289   -0.411625    0.814779        4775
   0.891448   -0.453086  -0.0058056        1005
   0.408917   -0.412091   -0.814228        4765
   0.897827  0.00725749   -0.440289         990
   0.407874   -0.818903   -0.403777        4790
-0.00126091 -0.00634322    0.999979         790
   0.999992  0.00321519 -0.00241168        4980
   0.999941  0.00880033 -0.00629136     800.001
   0.801781  0.00306921    -0.59761        4960
   0.578607   -0.587327   -0.565916         600
   0.798487   -0.602007 -0.00228192        5000
  -0.577008   -0.585676    0.569249     599.999
  -0.600888 -0.00298427    0.799328        4965
  4.451e-05   -0.715932     0.69817         405
   0.598494   -0.801124 -0.00243904        5005
   0.710691   0.0108116    0.703422         395
-0.00023942   -0.802098    0.597193        4995
  -0.701825   -0.712272  -0.0104731         405
-0.00032054   -0.602889    0.797825        4985
 0.00494776    -0.99988   -0.014653         210

I interpret the columns to be in the [ x y z b ] format.

The unmodified encoding command $ mrinfo DWI_denois.mif -raw_dwgrad gives the following result:

Image:               "DWI_denois.mif"
************************************************
  Dimensions:        144 x 144 x 87 x 258
  Voxel size:        1.79861 x 1.79861 x 1.8 x 4.3
  Data strides:      [ -2 3 4 1 ]
  Format:            MRtrix
  Data type:         32 bit float (little endian)
  Intensity scaling: offset = 0, multiplier = 1
  Transform:             1           0          -0      -124.1
                                0           1          -0      -114.3
                               -0           0           1      -78.69
 comments:          TE=1e+02;Time=114950.477;phase=1;dwell=0.330
  dw_scheme:      -0.57735,0.57735,0.57735,5
  [258 entries]       -0.57735,0.57735,0.57735,5
                             ...
                            -0.00032054,-0.602889,0.797825,4985
                            0.00494776,-0.99988,-0.014653,210
  mrtrix_version:    3.0_RC1-83-gc16a3d0e

After reading the documentation, should I import the DW table in the FSL format?
Could you advise how to interpret the information in the mrinfo?

Thank you.
Apoorva

Well, the error message was spot on: your acquisition looks like it’s using a Diffusion Spectrum Imaging scheme, not a HARDI scheme - it’s acquired on a regular grid in q-space, it’s not multi-shell. Here’s what it looks like plotted in Matlab:

Unfortunately, we don’t offer any means of processing these types of data currently - other than the standard DTI pipeline. There’s not a lot we can do about this in the near future unfortunately…

Hi,

Could you please point me out to the standard DTI pipeline used by MRtrix?
I think I will have to process the DSI data through that pipeline.

Thank you so much for all your help on this!
Best,
Apoorva

Well, we don’t really have a standard pipeline for DTI analysis - MRtrix3 is almost entirely geared towards higher-order analyses. While you can do some analysis of the data, it’ll be limited essentially to dwi2tensor and tensor2metric. Preprocessing-wise, dwidenoise and mrdegibbs should work fine, but dwipreproc relies on the data being multi-shell, so you won’t be able to perform correction for motion, eddy-current distortion, and eddy-current distortions.

For these reasons, I’d recommend using other packages if you have to process these data, I’m sure there must a few good ones out there designed to handle DSI data - maybe other users on this forum can provide helpful suggestions…?

Thank you so much for all your help on this! I will use another software to perform motion correction and eddy current distortion correction before using MRtrix again for the steps ahead.

Apoorva