Having trouble running QSIPrep

gavkhar_a · August 15, 2025, 3:56pm

Summary of what happened:

If you have an insight of what might be going wrong, i’d appreciate it. Please and thank you!
Gavkhar

Command used (and if a helper script was used, a link to the helper script or the command generated):

sbatch RunQSIprep_FACT.sh sub-FACT130

Version:

I used qsiprep-0.23.0.sif

Environment:

Apptainer

Data

formatted according to a BIDS validation.

PASTE VALIDATOR OUTPUT HERE

Tree output


My BIDs folder tree looks like this: 
fact/
└── sub-FACT130/
    ├── ses-post/
    └── ses-pre/
        ├── anat/
        ├── dwi/
            |----sub-FACT130_ses-pre_dwi.bval 
            |----sub-FACT130_ses-pre_dwi.bvec
            |----sub-FACT130_ses-pre_dwi.json 
            |----sub-FACT130_ses-pre_dwi.nii.gz
            |----sub-FACT130_ses-pre_task-topupdwi_run-01_bold.json
            |---sub-FACT130_ses-pre_task-topupdwi_run-01_bold.nii.gz
        └── sub-FACT130_ses-pre_scans.tsv

Relevant log outputs (up to 20 lines):

Process Process-2:
Traceback (most recent call last):
  File "/opt/conda/envs/qsiprep/lib/python3.10/multiprocessing/process.py", line 314, in _bootstrap
    self.run()
  File "/opt/conda/envs/qsiprep/lib/python3.10/multiprocessing/process.py", line 108, in run
    self._target(*self._args, **self._kwargs)
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/qsiprep/cli/workflow.py", line 50, in build_workflow
    from ..workflows.base import init_qsiprep_wf
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/qsiprep/workflows/base.py", line 46, in <module>
    from ..interfaces import (
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/qsiprep/interfaces/__init__.py", line 10, in <module>
    from .confounds import DMRISummary, GatherConfounds
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/qsiprep/interfaces/confounds.py", line 29, in <module>
    from .gradients import concatenate_bvals, concatenate_bvecs
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/qsiprep/interfaces/gradients.py", line 10, in <module>
    from dipy.reconst.dti import decompose_tensor
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/dipy/reconst/dti.py", line 13, in <module>
    from dipy.data import get_sphere
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/dipy/data/__init__.py", line 11, in <module>
    from dipy.core.gradients import GradientTable, gradient_table
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/dipy/core/gradients.py", line 10, in <module>
    from dipy.core.sphere import disperse_charges, HemiSphere
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/dipy/core/sphere.py", line 8, in <module>
    from dipy.reconst.recspeed import remove_similar_vertices
  File "recspeed.pyx", line 1, in init dipy.reconst.recspeed
ValueError: numpy.dtype size changed, may indicate binary incompatibility. Expected 96 from C header, got 88 from PyObject

Screenshots / relevant information:

Steven · August 15, 2025, 4:01pm

Hi @gavkhar_a, and welcome to neurostars!

In the future, please use the Software Support post category and template to organize your post. As it stands there is not enough information for us to support you. I have edited the template in your post, you can add this information by editing your post.

I would also recommend updating QSIPrep (1.0.1 most recent at this point), and providing a more complete tree output that shows files.

Best,
Steven

gavkhar_a · August 15, 2025, 4:33pm

Hi Steven,

Thank you! Apologies re formatting. I just fixed. I will also make sure to run the QSIPrep version you recommended – hopefully it fixes these errors!(?)

Steven · August 15, 2025, 4:38pm

Hi @gavkhar_a,

This does not provide enough information. It would help to see the contents of that script, or at least the QSIPrep command.

Best,
Steven

gavkhar_a · August 16, 2025, 1:31am

Thank you Steven!

Here is the content of the script. Thank you again for help!

#!/bin/bash
#SBATCH --job-name=qsiprep
#SBATCH --nodes=1
#SBATCH --ntasks-per-node=6
#SBATCH --time=50:00:00
#SBATCH --mem=24000
#SBATCH --mail-user=ga2541@umd.edu
#SBATCH --mail-type=ALL
#
Sub=$1
participant=${Sub#sub-}
bids_dir=/scratch/zt1/project/romeo-prj/shared/fact
output_dir=/scratch/zt1/project/romeo-prj/shared/fact_qsiprep_output
work_dir=/scratch/zt1/project/romeo-prj/shared/fact_qsiprep_work
module load apptainer

echo "------------------------------------------------------------------"
echo "started QSIprep"
echo ${Sub}
date
echo "------------------------------------------------------------------"

cd /home/${USER}

apptainer run --cleanenv \
    --bind ${bids_dir}:/data:ro \
    --bind ${output_dir}:/out \
    --bind ${work_dir}:/work \
    qsiprep-0.23.0.sif \
    /data /out participant \
    --participant_label ${participant} \
    --bids-filter-file /work/bids_filter.json \
    --fs_license_file /home/${USER}license.txt \
    --separate_all_dwis \
    --output_resolution 1.25 \
    --skip_bids_validation \
    -w /work

echo "------------------------------------------------------------------"
echo "Ended QSIprep"
echo ${Sub}
date
echo "------------------------------------------------------------------"

Steven · August 16, 2025, 2:02am

It looks like you mistakenly have some BOLD files in the DWI folder?

gavkhar_a · August 16, 2025, 2:06am

Oh no – those are DTI fieldmaps!

Steven · August 16, 2025, 2:23am

Those should be placed in the fmap folder with proper bids naming convention. See rules here: Magnetic Resonance Imaging - Brain Imaging Data Structure 1.10.0

gavkhar_a · August 16, 2025, 10:25pm

Thanks!
So I pulled the version you recommended (1.0.1) but for some reason it pulls the 1.0.2 development version of QSIprep).

scratch$ apptainer pull qsiprep_1.0.1.sif docker://pennlinc/qsiprep:1.0.1
INFO:    Converting OCI blobs to SIF format
INFO:    Starting build...
Copying blob 0f0ed9680ff1 done   | 
Copying blob a404e5416296 done   | 
Copying blob e2250e4b9e64 done   |
.........

2025/08/16 18:14:45  info unpack layer: sha256:4f4fb700ef54461cfa02571ae0db9a0dc1e0cdb5577484a6d75e68dc38e8acc1
INFO:    Creating SIF file...

^so above you see it pulls it but when I try to check which version, it gives me this:

**login-2:**scratch$ apptainer exec qsiprep_1.0.1.sif qsiprep --version
QSIPrep v1.0.2.dev0+gfc89945.d20250405

Would you recommend downgrading it to the latest stable version (0.24.0)?
Thank you,
Gavkhar

Steven · August 16, 2025, 10:50pm

Hi @gavkhar_a,

In the future, please format your terminal outputs and code as special text. This can be done using the </> button in the text editor, or surrounding your text with tick marks (`). You can see I edited it for you this time.

This is just a bug in how the version is reported. Your command is correct and so the container should be correct as well. I do not recommend downgrading.

Best,
Steven

gavkhar_a · August 16, 2025, 11:21pm

Got it – thank you!
So I tried running this reformatted script:

#!/bin/bash
#SBATCH --job-name=qsiprep
#SBATCH --nodes=1
#SBATCH --ntasks-per-node=6
#SBATCH --time=50:00:00
#SBATCH --mem=24000
#SBATCH --mail-user=ga2541@umd.edu
#SBATCH --mail-type=ALL
#
Sub=$1
participant=${Sub#sub-}
bids_dir=/scratch/zt1/project/romeo-prj/shared/fact
output_dir=/scratch/zt1/project/romeo-prj/shared/fact_qsiprep_output
work_dir=/scratch/zt1/project/romeo-prj/shared/fact_qsiprep_work
module load apptainer

echo "------------------------------------------------------------------"
echo "started QSIprep"
echo ${Sub}
date
echo "------------------------------------------------------------------"

cd /home/${USER}/scratch

apptainer exec --cleanenv \
    --bind ${bids_dir}:/data:ro \
    --bind ${output_dir}:/out \
    --bind ${work_dir}:/work \
    qsiprep_1.0.1.sif \
    qsiprep /data /out participant \
    --participant-label ${participant} \
    --fs-license-file /home/${USER}/license.txt \
    --separate-all-dwis \
    --output-resolution 1.25 \
    --skip-bids-validation \
    -w /work

And i am getting this message:

scratch$ sbatch RunQSIprep_FACT.sh sub-FACT130
------------------------------------------------------------------
started QSIprep
sub-FACT130
Sat Aug 16 19:11:31 EDT 2025
------------------------------------------------------------------
Process Process-2:
Traceback (most recent call last):
  File "/opt/conda/envs/qsiprep/lib/python3.10/multiprocessing/process.py", line 314, in _bootstrap
    self.run()
  File "/opt/conda/envs/qsiprep/lib/python3.10/multiprocessing/process.py", line 108, in run
    self._target(*self._args, **self._kwargs)
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/qsiprep/cli/workflow.py", line 51, in build_workflow
    from ..workflows.base import init_qsiprep_wf
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/qsiprep/workflows/base.py", line 45, in <module>
    from ..interfaces import (
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/qsiprep/interfaces/__init__.py", line 4, in <module>
    from .confounds import DMRISummary, GatherConfounds
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/qsiprep/interfaces/confounds.py", line 29, in <module>
    from .gradients import concatenate_bvals, concatenate_bvecs
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/qsiprep/interfaces/gradients.py", line 10, in <module>
    from dipy.reconst.dti import decompose_tensor
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/dipy/reconst/dti.py", line 13, in <module>
    from dipy.data import get_sphere
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/dipy/data/__init__.py", line 11, in <module>
    from dipy.core.gradients import GradientTable, gradient_table
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/dipy/core/gradients.py", line 10, in <module>
    from dipy.core.sphere import disperse_charges, HemiSphere
  File "/opt/conda/envs/qsiprep/lib/python3.10/site-packages/dipy/core/sphere.py", line 8, in <module>
    from dipy.reconst.recspeed import remove_similar_vertices
  File "recspeed.pyx", line 1, in init dipy.reconst.recspeed
ValueError: numpy.dtype size changed, may indicate binary incompatibility. Expected 96 from C header, got 88 from PyObject
------------------------------------------------------------------
Ended QSIprep

Here is my BIDS tree for the subject i am trying to run:

The fmap folder contains the PA fieldmap for dwi scans. The /scratch/zt1/project/romeo-prj/shared/fact folder contains BIDs formatted folders for each subject and within those, I am trying to run QSIprep only for ses-pre scans.
I’m not sure what I am doing wrong. Very much looking forward to your reply! Thanks so much.

Best,
Gavkhar

Steven · August 17, 2025, 1:33am

Hi @gavkhar_a,

It looks like both your DWI and fmaps have the PA phase encoding direction, in which case they cannot be used to correct each other. Can you confirm the phase encoding directiosn by looking at the associated jsons? Also your bval and bvecs have a different name (missing the dir-<> label).

When fixing those errors please run the BIDS validator on the dataset to find potential other errors with data/metadata organization.

Best,
Steven

gavkhar_a · August 17, 2025, 1:59am

Thanks so much Steven!
Yes, since the fmaps were named as “topup” runs, I renamed them earlier as PAs after confirming/looking into their jsons (they say ““PhaseEncodingDirection”: “j-”,”).

Sorry for not catching the BIDS compliance-error earlier. I just now renamed the bval abd bvec files to comply with BIDS. and this is how the dwi directory looks like now:

Am i right in thinking that qsiprep will not run correctly because of this you said: “It looks like both your DWI and fmaps have the PA phase encoding direction, in which case they cannot be used to correct each other”?

I just tried again and it did give me the same error message as above.

Thank you again so much for your help!

Steven · August 17, 2025, 2:12am

Hi @gavkhar_a,

Sounds like fmap should be dir-AP then. Did you link the fieldmap to the DWI with the IntendedFor field? Did you confirm the DWI has a reverse phase encoding direction (i.e., j)?

The error doesn’t seem like it is about susceptibility distortion correction.

May you please show the BIDS validation report?

Best,
Steven

gavkhar_a · August 17, 2025, 2:38am

Thanks Steven! I could not find the IntendedFor characteristic in the json file – I may have missed it?

login-1:fmap$ cat sub-FACT130_ses-pre_dir-PA_epi.json
{
  "AcquisitionMatrixPE": 128,
  "AcquisitionNumber": 1,
  "AcquisitionTime": "12:21:16.752500",
  "BandwidthPerPixelPhaseEncode": 19.531,
  "BaseResolution": 128,
  "ConversionSoftware": "dcm2niix",
  "ConversionSoftwareVersion": "v1.0.20180622 GCC6.3.0",
  "DerivedVendorReportedEchoSpacing": 0.00080001,
  "DeviceSerialNumber": "35469",
  "DwellTime": 2.8e-06,
  "EchoTime": 0.057,
  "EffectiveEchoSpacing": 0.000400005,
  "FlipAngle": 90,
  "ImageOrientationPatientDICOM": [0.996543, 0.0807755, -0.0194357, -0.0824693, 0.990091, -0.113657],
  "ImageType": [
    "ORIGINAL",
    "PRIMARY",
    "M",
    "ND",
    "MOSAIC"
],
  "InPlanePhaseEncodingDirectionDICOM": "COL",
  "InstitutionAddress": "Vassar_43_Cambridge_MA_US_02139",
  "InstitutionName": "McGovern_Brain_Institute",
  "InstitutionalDepartmentName": "Department",
  "MRAcquisitionType": "2D",
  "MagneticFieldStrength": 3,
  "Manufacturer": "Siemens",
  "ManufacturersModelName": "TrioTim",
  "Modality": "MR",
  "ParallelReductionFactorInPlane": 2,
  "PartialFourier": 0.75,
  "PatientPosition": "HFS",
  "PercentPhaseFOV": 100,
  "PhaseEncodingDirection": "j-",
  "PhaseEncodingSteps": 96,
  "PhaseResolution": 1,
  "PixelBandwidth": 1395,
  "ProcedureStepDescription": "INVESTIGATORS_Gabrieli",
  "ProtocolName": "TopUp_Distortion_Map_A-P-A_Diffusion",
  "PulseSequenceDetails": "%CustomerSeq%_Andre_ep2d_se_dist_nav_map",
  "ReceiveCoilName": "32Ch_Head",
  "ReconMatrixPE": 128,
  "RepetitionTime": 7.24,
  "SAR": 0.212809,
  "ScanOptions": "PFP_FS",
  "ScanningSequence": "EP",
  "SequenceName": "epse2d1_128",
  "SequenceVariant": "SK_SP",
  "SeriesDescription": "TopUp_Distortion_Map_A-P-A_Diffusion",
  "SeriesNumber": 17,
  "ShimSetting": [6351, -28080, -24530, 440, -193, 187, 88, 113],
  "SliceThickness": 2,
  "SliceTiming": [3.635, 0, 3.7325, 0.0975, 3.83, 0.1975, 3.93, 0.295, 4.0275, 0.3925, 4.125, 0.49, 4.2225, 0.59, 4.3225, 0.6875, 4.42, 0.785, 4.5175, 0.885, 4.6175, 0.9825, 4.715, 1.08, 4.8125, 1.1775, 4.91, 1.2775, 5.01, 1.375, 5.1075, 1.4725, 5.205, 1.5725, 5.305, 1.67, 5.4025, 1.7675, 5.5, 1.865, 5.5975, 1.965, 5.6975, 2.0625, 5.795, 2.16, 5.8925, 2.26, 5.9925, 2.3575, 6.09, 2.455, 6.1875, 2.555, 6.285, 2.6525, 6.385, 2.75, 6.4825, 2.8475, 6.58, 2.9475, 6.68, 3.045, 6.7775, 3.1425, 6.875, 3.2425, 6.975, 3.34, 7.0725, 3.4375, 7.17, 3.535],
  "SoftwareVersions": "syngo_MR_B17",
  "SpacingBetweenSlices": 2,
  "StationName": "MRC35469",
  "TaskName": "topupdwi",
  "TotalReadoutTime": 0.0508007,
  "TxRefAmp": 346.603}

And here is the bids-validator output. I may be wrong but this suggests it’s all compliant for this subject?

Thank you so much!
Gavkhar

Steven · August 17, 2025, 2:46am

Hi @gavkhar_a,

You have to manually add it to the fmap json. The entry should list the path to the DWI to correct relative to the subject folder (so the path beginning with ses-<>.

Please use the command line version tool instead.

Have you done this?

Best,
Steven

gavkhar_a · August 17, 2025, 2:53am

Hi Steven,

The dwi has “j-” direction so wouldn’t it be PA encoding? I was basing it off of this post of yours but please let me know if this varies depending on dwi and functional runs.

the bids validation output:

login-1:bids_validator$ python -m bids_validator /scratch/zt1/project/romeo-prj/shared/fact/sub-FACT130
login-1:bids_validator$ echo $?
0
login-1:bids_validator$ 

If you have any examples of how I would like the IntendedFor to fmap json, I'd appreciate it! thanks so much! 

Best,
Gavkhar

Steven · August 17, 2025, 2:58am

Hi @gavkhar_a

If both your DWI and fmap are j- phase encoding direction they cannot be used for SDC.

“IntendedFor”: “ses-x/dwi/sub-y_ses-x_dwi.nii.gz”

I am not sure what python bids validator you are using. Please use the command line version: GitHub - bids-standard/bids-validator: Validator for the Brain Imaging Data Structure

Best,
Steven

Steven · August 17, 2025, 3:04am

Also can you clarify what those fmaps are? Were they created by TOPUP? That seems odd because that’s not something a scanner would produce (it requires off the scanner processing)

gavkhar_a · August 17, 2025, 3:09am

Thank you for the tip re bids-validator. I just ran it and here is the report (sorry it is long):

bids-validator-deno /scratch/zt1/project/romeo-prj/shared/fact/sub-FACT130
	[WARNING] TSV_ADDITIONAL_COLUMNS_UNDEFINED A TSV file has extra columns which are not defined in its associated JSON sidecar
		operator
		/ses-pre/sub-FACT130_ses-pre_scans.tsv
		/ses-post/sub-FACT130_ses-post_scans.tsv

		randstr
		/ses-pre/sub-FACT130_ses-pre_scans.tsv
		/ses-post/sub-FACT130_ses-post_scans.tsv

		TODO -- fill in rows and add more tab-separated columns if desired
		/ses-post/dwi/sub-FACT130_ses-post_task-topupdwi_run-01_events.tsv

	Please visit https://neurostars.org/search?q=TSV_ADDITIONAL_COLUMNS_UNDEFINED for existing conversations about this issue.

	[WARNING] GZIP_HEADER_MTIME The gzip header contains a non-zero timestamp.
This may leak sensitive information or indicate a non-reproducible conversion process.

		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz
		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz

		4 more files with the same issue

	Please visit https://neurostars.org/search?q=GZIP_HEADER_MTIME for existing conversations about this issue.

	[WARNING] SIDECAR_KEY_RECOMMENDED A data file's JSON sidecar is missing a key listed as recommended.
		ReceiveCoilActiveElements
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: Information describing the active/selected elements of the receiver coil.
This does not correspond to a tag in the DICOM ontology.
The vendor-defined terminology for active coil elements can go in this field.

		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: Information describing the active/selected elements of the receiver coil.
This does not correspond to a tag in the DICOM ontology.
The vendor-defined terminology for active coil elements can go in this field.


		4 more files with the same issue

		GradientSetType
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: It should be possible to infer the gradient coil from the scanner model.
If not, for example because of a custom upgrade or use of a gradient
insert set, then the specifications of the actual gradient coil should be
reported independently.

		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: It should be possible to infer the gradient coil from the scanner model.
If not, for example because of a custom upgrade or use of a gradient
insert set, then the specifications of the actual gradient coil should be
reported independently.


		4 more files with the same issue

		MRTransmitCoilSequence
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: This is a relevant field if a non-standard transmit coil is used.
Corresponds to DICOM Tag 0018, 9049 `MR Transmit Coil Sequence`.

		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: This is a relevant field if a non-standard transmit coil is used.
Corresponds to DICOM Tag 0018, 9049 `MR Transmit Coil Sequence`.


		4 more files with the same issue

		MatrixCoilMode
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: (If used)
A method for reducing the number of independent channels by combining in
analog the signals from multiple coil elements.
There are typically different default modes when using un-accelerated or
accelerated (for example, `"GRAPPA"`, `"SENSE"`) imaging.

		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: (If used)
A method for reducing the number of independent channels by combining in
analog the signals from multiple coil elements.
There are typically different default modes when using un-accelerated or
accelerated (for example, `"GRAPPA"`, `"SENSE"`) imaging.


		4 more files with the same issue

		CoilCombinationMethod
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: Almost all fMRI studies using phased-array coils use root-sum-of-squares
(rSOS) combination, but other methods exist.
The image reconstruction is changed by the coil combination method
(as for the matrix coil mode above),
so anything non-standard should be reported.

		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: Almost all fMRI studies using phased-array coils use root-sum-of-squares
(rSOS) combination, but other methods exist.
The image reconstruction is changed by the coil combination method
(as for the matrix coil mode above),
so anything non-standard should be reported.


		4 more files with the same issue

		PulseSequenceType
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: A general description of the pulse sequence used for the scan.

		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: A general description of the pulse sequence used for the scan.


		4 more files with the same issue

		MTState
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: Boolean stating whether the magnetization transfer pulse is applied.
Corresponds to DICOM Tag 0018, 9020 `Magnetization Transfer`.

		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: Boolean stating whether the magnetization transfer pulse is applied.
Corresponds to DICOM Tag 0018, 9020 `Magnetization Transfer`.


		4 more files with the same issue

		SpoilingState
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: Boolean stating whether the pulse sequence uses any type of spoiling
strategy to suppress residual transverse magnetization.

		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: Boolean stating whether the pulse sequence uses any type of spoiling
strategy to suppress residual transverse magnetization.


		4 more files with the same issue

		NumberShots
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: The number of RF excitations needed to reconstruct a slice or volume
(may be referred to as partition).
Please mind that this is not the same as Echo Train Length which denotes the
number of k-space lines collected after excitation in a multi-echo readout.
The data type array is applicable for specifying this parameter before and
after the k-space center is sampled.
Please see
[`"NumberShots"` metadata field]\
(SPEC_ROOT/appendices/qmri.md#numbershots-metadata-field)
in the qMRI appendix for corresponding calculations.

		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: The number of RF excitations needed to reconstruct a slice or volume
(may be referred to as partition).
Please mind that this is not the same as Echo Train Length which denotes the
number of k-space lines collected after excitation in a multi-echo readout.
The data type array is applicable for specifying this parameter before and
after the k-space center is sampled.
Please see
[`"NumberShots"` metadata field]\
(SPEC_ROOT/appendices/qmri.md#numbershots-metadata-field)
in the qMRI appendix for corresponding calculations.


		4 more files with the same issue

		ParallelReductionFactorOutOfPlane
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: The parallel imaging (for instance, GRAPPA) factor in the second phase encoding dimension of 3D sequences.
Use the denominator of the fraction of k-space encoded in the second phase encoding dimension.
For example, 2 means half of k-space is encoded.
Will typically be 1 for 2D sequences, as each slice in a 2D acquisition is usually fully encoded.
`ParallelReductionFactorOutOfPlane` should not be confused with `MultibandAccelerationFactor`,
as they imply different methods of accelerating the acquisition.
Corresponds to DICOM Tag 0018, 9155 `Parallel Reduction Factor out-of-plane`.

		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: The parallel imaging (for instance, GRAPPA) factor in the second phase encoding dimension of 3D sequences.
Use the denominator of the fraction of k-space encoded in the second phase encoding dimension.
For example, 2 means half of k-space is encoded.
Will typically be 1 for 2D sequences, as each slice in a 2D acquisition is usually fully encoded.
`ParallelReductionFactorOutOfPlane` should not be confused with `MultibandAccelerationFactor`,
as they imply different methods of accelerating the acquisition.
Corresponds to DICOM Tag 0018, 9155 `Parallel Reduction Factor out-of-plane`.


		4 more files with the same issue

		ParallelAcquisitionTechnique
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: The type of parallel imaging used (for example `"GRAPPA"`, `"SENSE"`).
Corresponds to DICOM Tag 0018, 9078 `Parallel Acquisition Technique`.

		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: The type of parallel imaging used (for example `"GRAPPA"`, `"SENSE"`).
Corresponds to DICOM Tag 0018, 9078 `Parallel Acquisition Technique`.


		4 more files with the same issue

		PartialFourierDirection
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: The direction where only partial Fourier information was collected.
Corresponds to DICOM Tag 0018, 9036 `Partial Fourier Direction`.

		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: The direction where only partial Fourier information was collected.
Corresponds to DICOM Tag 0018, 9036 `Partial Fourier Direction`.


		4 more files with the same issue

		MixingTime
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: In the context of a stimulated- and spin-echo 3D EPI sequence for B1+ mapping
or a stimulated-echo MRS sequence,
corresponds to the interval between spin- and stimulated-echo pulses.
In the context of a diffusion-weighted double spin-echo sequence,
corresponds to the interval between two successive diffusion sensitizing
gradients, specified in seconds.

		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: In the context of a stimulated- and spin-echo 3D EPI sequence for B1+ mapping
or a stimulated-echo MRS sequence,
corresponds to the interval between spin- and stimulated-echo pulses.
In the context of a diffusion-weighted double spin-echo sequence,
corresponds to the interval between two successive diffusion sensitizing
gradients, specified in seconds.


		4 more files with the same issue

		InversionTime
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: The inversion time (TI) for the acquisition, specified in seconds.
Inversion time is the time after the middle of inverting RF pulse to middle
of excitation pulse to detect the amount of longitudinal magnetization.
Corresponds to DICOM Tag 0018, 0082 `Inversion Time`
(please note that the DICOM term is in milliseconds not seconds).

		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: The inversion time (TI) for the acquisition, specified in seconds.
Inversion time is the time after the middle of inverting RF pulse to middle
of excitation pulse to detect the amount of longitudinal magnetization.
Corresponds to DICOM Tag 0018, 0082 `Inversion Time`
(please note that the DICOM term is in milliseconds not seconds).


		4 more files with the same issue

		SliceEncodingDirection
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: The axis of the NIfTI data along which slices were acquired,
and the direction in which `"SliceTiming"` is defined with respect to.
`i`, `j`, `k` identifiers correspond to the first, second and third axis of
the data in the NIfTI file.
A `-` sign indicates that the contents of `"SliceTiming"` are defined in
reverse order - that is, the first entry corresponds to the slice with the
largest index, and the final entry corresponds to slice index zero.
When present, the axis defined by `"SliceEncodingDirection"` needs to be
consistent with the `slice_dim` field in the NIfTI header.
When absent, the entries in `"SliceTiming"` must be in the order of increasing
slice index as defined by the NIfTI header.

		/ses-pre/fmap/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: The axis of the NIfTI data along which slices were acquired,
and the direction in which `"SliceTiming"` is defined with respect to.
`i`, `j`, `k` identifiers correspond to the first, second and third axis of
the data in the NIfTI file.
A `-` sign indicates that the contents of `"SliceTiming"` are defined in
reverse order - that is, the first entry corresponds to the slice with the
largest index, and the final entry corresponds to slice index zero.
When present, the axis defined by `"SliceEncodingDirection"` needs to be
consistent with the `slice_dim` field in the NIfTI header.
When absent, the entries in `"SliceTiming"` must be in the order of increasing
slice index as defined by the NIfTI header.


		2 more files with the same issue

		MultibandAccelerationFactor
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: The multiband factor, for multiband acquisitions.

		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: The multiband factor, for multiband acquisitions.


		4 more files with the same issue

		EffectiveEchoSpacing
		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: The "effective" sampling interval, specified in seconds,
between lines in the phase-encoding direction,
defined based on the size of the reconstructed image in the phase direction.
It is frequently, but incorrectly, referred to as "dwell time"
(see the `"DwellTime"` parameter for actual dwell time).
It is required for unwarping distortions using field maps.
Note that beyond just in-plane acceleration,
a variety of other manipulations to the phase encoding need to be accounted
for properly, including partial fourier, phase oversampling,
phase resolution, phase field-of-view and interpolation.

		/ses-post/anat/sub-FACT130_ses-post_T1w.nii.gz - Field description: The "effective" sampling interval, specified in seconds,
between lines in the phase-encoding direction,
defined based on the size of the reconstructed image in the phase direction.
It is frequently, but incorrectly, referred to as "dwell time"
(see the `"DwellTime"` parameter for actual dwell time).
It is required for unwarping distortions using field maps.
Note that beyond just in-plane acceleration,
a variety of other manipulations to the phase encoding need to be accounted
for properly, including partial fourier, phase oversampling,
phase resolution, phase field-of-view and interpolation.


		PhaseEncodingDirection
		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: The letters `i`, `j`, `k` correspond to the first, second and third axis of
the data in the NIFTI file.
The polarity of the phase encoding is assumed to go from zero index to
maximum index unless `-` sign is present
(then the order is reversed - starting from the highest index instead of
zero).
`PhaseEncodingDirection` is defined as the direction along which phase is was
modulated which may result in visible distortions.
Note that this is not the same as the DICOM term
`InPlanePhaseEncodingDirection` which can have `ROW` or `COL` values.

		/ses-post/anat/sub-FACT130_ses-post_T1w.nii.gz - Field description: The letters `i`, `j`, `k` correspond to the first, second and third axis of
the data in the NIFTI file.
The polarity of the phase encoding is assumed to go from zero index to
maximum index unless `-` sign is present
(then the order is reversed - starting from the highest index instead of
zero).
`PhaseEncodingDirection` is defined as the direction along which phase is was
modulated which may result in visible distortions.
Note that this is not the same as the DICOM term
`InPlanePhaseEncodingDirection` which can have `ROW` or `COL` values.


		TotalReadoutTime
		/ses-pre/anat/sub-FACT130_ses-pre_T1w.nii.gz - Field description: This is actually the "effective" total readout time,
defined as the readout duration, specified in seconds,
that would have generated data with the given level of distortion.
It is NOT the actual, physical duration of the readout train.
If `"EffectiveEchoSpacing"` has been properly computed,
it is just `EffectiveEchoSpacing * (ReconMatrixPE - 1)`.

		/ses-post/anat/sub-FACT130_ses-post_T1w.nii.gz - Field description: This is actually the "effective" total readout time,
defined as the readout duration, specified in seconds,
that would have generated data with the given level of distortion.
It is NOT the actual, physical duration of the readout train.
If `"EffectiveEchoSpacing"` has been properly computed,
it is just `EffectiveEchoSpacing * (ReconMatrixPE - 1)`.


		B0FieldIdentifier
		/ses-pre/fmap/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: The presence of this key states that this particular 3D or 4D image MAY be
used for fieldmap estimation purposes.
Each `"B0FieldIdentifier"` MUST be a unique string within one participant's tree,
shared only by the images meant to be used as inputs for the estimation of a
particular instance of the *B<sub>0</sub> field* estimation.
It is RECOMMENDED to derive this identifier from DICOM Tags, for example,
DICOM tag 0018, 1030 `Protocol Name`, or DICOM tag 0018, 0024 `Sequence Name`
when the former is not defined (for example, in GE devices.)

		/ses-pre/fmap/sub-FACT130_ses-pre_dir-PA_epi.nii.gz - Field description: The presence of this key states that this particular 3D or 4D image MAY be
used for fieldmap estimation purposes.
Each `"B0FieldIdentifier"` MUST be a unique string within one participant's tree,
shared only by the images meant to be used as inputs for the estimation of a
particular instance of the *B<sub>0</sub> field* estimation.
It is RECOMMENDED to derive this identifier from DICOM Tags, for example,
DICOM tag 0018, 1030 `Protocol Name`, or DICOM tag 0018, 0024 `Sequence Name`
when the former is not defined (for example, in GE devices.)


		StimulusPresentation
		/ses-post/dwi/sub-FACT130_ses-post_task-topupdwi_run-01_events.tsv - Field description: Object containing key-value pairs related to the software used to present
the stimuli during the experiment.


	Please visit https://neurostars.org/search?q=SIDECAR_KEY_RECOMMENDED for existing conversations about this issue.

	[WARNING] EVENTS_TSV_MISSING Task scans should have a corresponding 'events.tsv' file.
If this is a resting state scan you can ignore this warning or rename the task to include the word "rest".

		/ses-post/dwi/sub-FACT130_ses-post_task-topupdwi_run-01_bold.nii.gz

	Please visit https://neurostars.org/search?q=EVENTS_TSV_MISSING for existing conversations about this issue.

	[ERROR] MISSING_DATASET_DESCRIPTION A dataset_description.json file is required in the root of the dataset
		

	Please visit https://neurostars.org/search?q=MISSING_DATASET_DESCRIPTION for existing conversations about this issue.

	[ERROR] INVALID_LOCATION The file has a valid name, but is located in an invalid directory.
		/ses-pre/sub-FACT130_ses-pre_scans.tsv - Expected location: /sub-FACT130/ses-pre/
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.bvec - Expected location: /sub-FACT130/ses-pre/

		16 more files with the same issue

	Please visit https://neurostars.org/search?q=INVALID_LOCATION for existing conversations about this issue.

	[ERROR] SCANS_FILENAME_NOT_MATCH_DATASET Filenames in scans.tsv file do not match what is present in the BIDS dataset.

		/ses-pre/sub-FACT130_ses-pre_scans.tsv
		/ses-post/sub-FACT130_ses-post_scans.tsv

	Please visit https://neurostars.org/search?q=SCANS_FILENAME_NOT_MATCH_DATASET for existing conversations about this issue.

	[ERROR] DATATYPE_MISMATCH The datatype directory does not match datatype of found suffix and extension
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.bvec - Datatype rule being applied: rules.files.raw.fmap.pepolar
		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.bval - Datatype rule being applied: rules.files.raw.fmap.pepolar

		4 more files with the same issue

	Please visit https://neurostars.org/search?q=DATATYPE_MISMATCH for existing conversations about this issue.

	[ERROR] VOLUME_COUNT_MISMATCH The number of volumes in this scan does not match the number of volumes in the
associated '.bvec' and '.bval' files.

		/ses-pre/dwi/sub-FACT130_ses-pre_dir-PA_epi.nii.gz

	Please visit https://neurostars.org/search?q=VOLUME_COUNT_MISMATCH for existing conversations about this issue.

	[ERROR] ALL_FILENAME_RULES_HAVE_ISSUES Multiple filename rules were found as potential matches. All of them had at least one issue during filename validation.
		/ses-post/dwi/sub-FACT130_ses-post_task-topupdwi_run-01_events.tsv - Rules that matched with issues: rules.files.raw.task.events, rules.files.raw.task.events__mri, rules.files.raw.task.events__motion, rules.files.raw.task.events__pet, rules.files.raw.task.events__mrs

	Please visit https://neurostars.org/search?q=ALL_FILENAME_RULES_HAVE_ISSUES for existing conversations about this issue.


          Summary:                         Available Tasks:        Available Modalities:
          19 Files, 58.8 MB                topupdwi                MRI                  
          1 - Subjects 2 - Sessions                                                     

	If you have any questions, please post on https://neurostars.org/tags/bids.

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