fMRI: OpenfMRI.org data, FSL, ANTS, c3daffine

A growing number of datasets are available on OpenfMRI. This script demonstrates how to use nipype to analyze a data set:

python fmri_ants_openfmri.py --datasetdir ds107
from __future__ import division, unicode_literals
from builtins import open, range, str, bytes

from glob import glob
import os

from nipype import config
from nipype import LooseVersion
from nipype import Workflow, Node, MapNode
from nipype.utils.filemanip import filename_to_list
import nipype.pipeline.engine as pe
import nipype.algorithms.modelgen as model
import nipype.algorithms.rapidart as ra
from nipype.algorithms.misc import TSNR
from nipype.interfaces.c3 import C3dAffineTool
from nipype.interfaces import fsl, Function, ants, freesurfer as fs
import nipype.interfaces.io as nio
from nipype.interfaces.io import FreeSurferSource
import nipype.interfaces.utility as niu
from nipype.interfaces.utility import Merge, IdentityInterface
from nipype.workflows.fmri.fsl import (create_featreg_preproc,
                                       create_modelfit_workflow,
                                       create_fixed_effects_flow)
from nipype.utils import NUMPY_MMAP


config.enable_provenance()
version = 0
if (fsl.Info.version() and LooseVersion(fsl.Info.version()) > LooseVersion('5.0.6')):
    version = 507

fsl.FSLCommand.set_default_output_type('NIFTI_GZ')

imports = [
    'import os',
    'import nibabel as nb',
    'import numpy as np',
    'import scipy as sp',
    'from nipype.utils.filemanip import filename_to_list, list_to_filename, split_filename',
    'from scipy.special import legendre'
]

def median(in_files):
    """Computes an average of the median of each realigned timeseries

    Parameters
    ----------

    in_files: one or more realigned Nifti 4D time series

    Returns
    -------

    out_file: a 3D Nifti file
    """
    average = None
    for idx, filename in enumerate(filename_to_list(in_files)):
        img = nb.load(filename, mmap=NUMPY_MMAP)
        data = np.median(img.get_data(), axis=3)
        if average is None:
            average = data
        else:
            average = average + data
    median_img = nb.Nifti1Image(average / float(idx + 1), img.affine,
                                img.header)
    filename = os.path.join(os.getcwd(), 'median.nii.gz')
    median_img.to_filename(filename)
    return filename


def create_reg_workflow(name='registration'):
    """Create a FEAT preprocessing workflow together with freesurfer

    Parameters
    ----------
        name : name of workflow (default: 'registration')

    Inputs:

        inputspec.source_files : files (filename or list of filenames to register)
        inputspec.mean_image : reference image to use
        inputspec.anatomical_image : anatomical image to coregister to
        inputspec.target_image : registration target

    Outputs:

        outputspec.func2anat_transform : FLIRT transform
        outputspec.anat2target_transform : FLIRT+FNIRT transform
        outputspec.transformed_files : transformed files in target space
        outputspec.transformed_mean : mean image in target space
    """

    register = pe.Workflow(name=name)

    inputnode = pe.Node(interface=niu.IdentityInterface(fields=['source_files',
                                                                'mean_image',
                                                                'anatomical_image',
                                                                'target_image',
                                                                'target_image_brain',
                                                                'config_file']),
                        name='inputspec')
    outputnode = pe.Node(interface=niu.IdentityInterface(fields=['func2anat_transform',
                                                                 'anat2target_transform',
                                                                 'transformed_files',
                                                                 'transformed_mean',
                                                                 'anat2target',
                                                                 'mean2anat_mask'
                                                                 ]),
                         name='outputspec')

Estimate the tissue classes from the anatomical image. But use spm’s segment as FSL appears to be breaking.

stripper = pe.Node(fsl.BET(), name='stripper')
register.connect(inputnode, 'anatomical_image', stripper, 'in_file')
fast = pe.Node(fsl.FAST(), name='fast')
register.connect(stripper, 'out_file', fast, 'in_files')

Binarize the segmentation

binarize = pe.Node(fsl.ImageMaths(op_string='-nan -thr 0.5 -bin'),
                   name='binarize')
pickindex = lambda x, i: x[i]
register.connect(fast, ('partial_volume_files', pickindex, 2),
                 binarize, 'in_file')

Calculate rigid transform from mean image to anatomical image

mean2anat = pe.Node(fsl.FLIRT(), name='mean2anat')
mean2anat.inputs.dof = 6
register.connect(inputnode, 'mean_image', mean2anat, 'in_file')
register.connect(stripper, 'out_file', mean2anat, 'reference')

Now use bbr cost function to improve the transform

mean2anatbbr = pe.Node(fsl.FLIRT(), name='mean2anatbbr')
mean2anatbbr.inputs.dof = 6
mean2anatbbr.inputs.cost = 'bbr'
mean2anatbbr.inputs.schedule = os.path.join(os.getenv('FSLDIR'),
                                            'etc/flirtsch/bbr.sch')
register.connect(inputnode, 'mean_image', mean2anatbbr, 'in_file')
register.connect(binarize, 'out_file', mean2anatbbr, 'wm_seg')
register.connect(inputnode, 'anatomical_image', mean2anatbbr, 'reference')
register.connect(mean2anat, 'out_matrix_file',
                 mean2anatbbr, 'in_matrix_file')

Create a mask of the median image coregistered to the anatomical image

mean2anat_mask = Node(fsl.BET(mask=True), name='mean2anat_mask')
register.connect(mean2anatbbr, 'out_file', mean2anat_mask, 'in_file')

Convert the BBRegister transformation to ANTS ITK format

convert2itk = pe.Node(C3dAffineTool(),
                      name='convert2itk')
convert2itk.inputs.fsl2ras = True
convert2itk.inputs.itk_transform = True
register.connect(mean2anatbbr, 'out_matrix_file', convert2itk, 'transform_file')
register.connect(inputnode, 'mean_image', convert2itk, 'source_file')
register.connect(stripper, 'out_file', convert2itk, 'reference_file')

Compute registration between the subject’s structural and MNI template This is currently set to perform a very quick registration. However, the registration can be made significantly more accurate for cortical structures by increasing the number of iterations All parameters are set using the example from: #https://github.com/stnava/ANTs/blob/master/Scripts/newAntsExample.sh

reg = pe.Node(ants.Registration(), name='antsRegister')
reg.inputs.output_transform_prefix = "output_"
reg.inputs.transforms = ['Rigid', 'Affine', 'SyN']
reg.inputs.transform_parameters = [(0.1,), (0.1,), (0.2, 3.0, 0.0)]
reg.inputs.number_of_iterations = [[10000, 11110, 11110]] * 2 + [[100, 30, 20]]
reg.inputs.dimension = 3
reg.inputs.write_composite_transform = True
reg.inputs.collapse_output_transforms = True
reg.inputs.initial_moving_transform_com = True
reg.inputs.metric = ['Mattes'] * 2 + [['Mattes', 'CC']]
reg.inputs.metric_weight = [1] * 2 + [[0.5, 0.5]]
reg.inputs.radius_or_number_of_bins = [32] * 2 + [[32, 4]]
reg.inputs.sampling_strategy = ['Regular'] * 2 + [[None, None]]
reg.inputs.sampling_percentage = [0.3] * 2 + [[None, None]]
reg.inputs.convergence_threshold = [1.e-8] * 2 + [-0.01]
reg.inputs.convergence_window_size = [20] * 2 + [5]
reg.inputs.smoothing_sigmas = [[4, 2, 1]] * 2 + [[1, 0.5, 0]]
reg.inputs.sigma_units = ['vox'] * 3
reg.inputs.shrink_factors = [[3, 2, 1]] * 2 + [[4, 2, 1]]
reg.inputs.use_estimate_learning_rate_once = [True] * 3
reg.inputs.use_histogram_matching = [False] * 2 + [True]
reg.inputs.winsorize_lower_quantile = 0.005
reg.inputs.winsorize_upper_quantile = 0.995
reg.inputs.args = '--float'
reg.inputs.output_warped_image = 'output_warped_image.nii.gz'
reg.inputs.num_threads = 4
reg.plugin_args = {'qsub_args': '-pe orte 4',
                   'sbatch_args': '--mem=6G -c 4'}
register.connect(stripper, 'out_file', reg, 'moving_image')
register.connect(inputnode, 'target_image_brain', reg, 'fixed_image')

Concatenate the affine and ants transforms into a list

pickfirst = lambda x: x[0]

merge = pe.Node(niu.Merge(2), iterfield=['in2'], name='mergexfm')
register.connect(convert2itk, 'itk_transform', merge, 'in2')
register.connect(reg, 'composite_transform', merge, 'in1')

Transform the mean image. First to anatomical and then to target

warpmean = pe.Node(ants.ApplyTransforms(),
                   name='warpmean')
warpmean.inputs.input_image_type = 0
warpmean.inputs.interpolation = 'Linear'
warpmean.inputs.invert_transform_flags = [False, False]
warpmean.inputs.terminal_output = 'file'

register.connect(inputnode, 'target_image_brain', warpmean, 'reference_image')
register.connect(inputnode, 'mean_image', warpmean, 'input_image')
register.connect(merge, 'out', warpmean, 'transforms')

Transform the remaining images. First to anatomical and then to target

warpall = pe.MapNode(ants.ApplyTransforms(),
                     iterfield=['input_image'],
                     name='warpall')
warpall.inputs.input_image_type = 0
warpall.inputs.interpolation = 'Linear'
warpall.inputs.invert_transform_flags = [False, False]
warpall.inputs.terminal_output = 'file'

register.connect(inputnode, 'target_image_brain', warpall, 'reference_image')
register.connect(inputnode, 'source_files', warpall, 'input_image')
register.connect(merge, 'out', warpall, 'transforms')

Assign all the output files

    register.connect(reg, 'warped_image', outputnode, 'anat2target')
    register.connect(warpmean, 'output_image', outputnode, 'transformed_mean')
    register.connect(warpall, 'output_image', outputnode, 'transformed_files')
    register.connect(mean2anatbbr, 'out_matrix_file',
                     outputnode, 'func2anat_transform')
    register.connect(mean2anat_mask, 'mask_file',
                     outputnode, 'mean2anat_mask')
    register.connect(reg, 'composite_transform',
                     outputnode, 'anat2target_transform')

    return register


def get_aparc_aseg(files):
    """Return the aparc+aseg.mgz file"""
    for name in files:
        if 'aparc+aseg.mgz' in name:
            return name
    raise ValueError('aparc+aseg.mgz not found')


def create_fs_reg_workflow(name='registration'):
    """Create a FEAT preprocessing workflow together with freesurfer

    Parameters
    ----------

        name : name of workflow (default: 'registration')

    Inputs::

        inputspec.source_files : files (filename or list of filenames to register)
        inputspec.mean_image : reference image to use
        inputspec.target_image : registration target

    Outputs::

        outputspec.func2anat_transform : FLIRT transform
        outputspec.anat2target_transform : FLIRT+FNIRT transform
        outputspec.transformed_files : transformed files in target space
        outputspec.transformed_mean : mean image in target space
    """

    register = Workflow(name=name)

    inputnode = Node(interface=IdentityInterface(fields=['source_files',
                                                         'mean_image',
                                                         'subject_id',
                                                         'subjects_dir',
                                                         'target_image']),
                     name='inputspec')

    outputnode = Node(interface=IdentityInterface(fields=['func2anat_transform',
                                                          'out_reg_file',
                                                          'anat2target_transform',
                                                          'transforms',
                                                          'transformed_mean',
                                                          'transformed_files',
                                                          'min_cost_file',
                                                          'anat2target',
                                                          'aparc',
                                                          'mean2anat_mask'
                                                          ]),
                      name='outputspec')

    # Get the subject's freesurfer source directory
    fssource = Node(FreeSurferSource(),
                    name='fssource')
    fssource.run_without_submitting = True
    register.connect(inputnode, 'subject_id', fssource, 'subject_id')
    register.connect(inputnode, 'subjects_dir', fssource, 'subjects_dir')

    convert = Node(freesurfer.MRIConvert(out_type='nii'),
                   name="convert")
    register.connect(fssource, 'T1', convert, 'in_file')

    # Coregister the median to the surface
    bbregister = Node(freesurfer.BBRegister(registered_file=True),
                      name='bbregister')
    bbregister.inputs.init = 'fsl'
    bbregister.inputs.contrast_type = 't2'
    bbregister.inputs.out_fsl_file = True
    bbregister.inputs.epi_mask = True
    register.connect(inputnode, 'subject_id', bbregister, 'subject_id')
    register.connect(inputnode, 'mean_image', bbregister, 'source_file')
    register.connect(inputnode, 'subjects_dir', bbregister, 'subjects_dir')

    # Create a mask of the median coregistered to the anatomical image
    mean2anat_mask = Node(fsl.BET(mask=True), name='mean2anat_mask')
    register.connect(bbregister, 'registered_file', mean2anat_mask, 'in_file')

use aparc+aseg’s brain mask

binarize = Node(fs.Binarize(min=0.5, out_type="nii.gz", dilate=1), name="binarize_aparc")
register.connect(fssource, ("aparc_aseg", get_aparc_aseg), binarize, "in_file")

stripper = Node(fsl.ApplyMask(), name='stripper')
register.connect(binarize, "binary_file", stripper, "mask_file")
register.connect(convert, 'out_file', stripper, 'in_file')

Apply inverse transform to aparc file

aparcxfm = Node(freesurfer.ApplyVolTransform(inverse=True,
                                             interp='nearest'),
                name='aparc_inverse_transform')
register.connect(inputnode, 'subjects_dir', aparcxfm, 'subjects_dir')
register.connect(bbregister, 'out_reg_file', aparcxfm, 'reg_file')
register.connect(fssource, ('aparc_aseg', get_aparc_aseg),
                 aparcxfm, 'target_file')
register.connect(inputnode, 'mean_image', aparcxfm, 'source_file')

Convert the BBRegister transformation to ANTS ITK format

convert2itk = Node(C3dAffineTool(), name='convert2itk')
convert2itk.inputs.fsl2ras = True
convert2itk.inputs.itk_transform = True
register.connect(bbregister, 'out_fsl_file', convert2itk, 'transform_file')
register.connect(inputnode, 'mean_image', convert2itk, 'source_file')
register.connect(stripper, 'out_file', convert2itk, 'reference_file')

Compute registration between the subject’s structural and MNI template This is currently set to perform a very quick registration. However, the registration can be made significantly more accurate for cortical structures by increasing the number of iterations All parameters are set using the example from: #https://github.com/stnava/ANTs/blob/master/Scripts/newAntsExample.sh

reg = Node(ants.Registration(), name='antsRegister')
reg.inputs.output_transform_prefix = "output_"
reg.inputs.transforms = ['Rigid', 'Affine', 'SyN']
reg.inputs.transform_parameters = [(0.1,), (0.1,), (0.2, 3.0, 0.0)]
reg.inputs.number_of_iterations = [[10000, 11110, 11110]] * 2 + [[100, 30, 20]]
reg.inputs.dimension = 3
reg.inputs.write_composite_transform = True
reg.inputs.collapse_output_transforms = True
reg.inputs.initial_moving_transform_com = True
reg.inputs.metric = ['Mattes'] * 2 + [['Mattes', 'CC']]
reg.inputs.metric_weight = [1] * 2 + [[0.5, 0.5]]
reg.inputs.radius_or_number_of_bins = [32] * 2 + [[32, 4]]
reg.inputs.sampling_strategy = ['Regular'] * 2 + [[None, None]]
reg.inputs.sampling_percentage = [0.3] * 2 + [[None, None]]
reg.inputs.convergence_threshold = [1.e-8] * 2 + [-0.01]
reg.inputs.convergence_window_size = [20] * 2 + [5]
reg.inputs.smoothing_sigmas = [[4, 2, 1]] * 2 + [[1, 0.5, 0]]
reg.inputs.sigma_units = ['vox'] * 3
reg.inputs.shrink_factors = [[3, 2, 1]] * 2 + [[4, 2, 1]]
reg.inputs.use_estimate_learning_rate_once = [True] * 3
reg.inputs.use_histogram_matching = [False] * 2 + [True]
reg.inputs.winsorize_lower_quantile = 0.005
reg.inputs.winsorize_upper_quantile = 0.995
reg.inputs.float = True
reg.inputs.output_warped_image = 'output_warped_image.nii.gz'
reg.inputs.num_threads = 4
reg.plugin_args = {'qsub_args': '-pe orte 4',
                   'sbatch_args': '--mem=6G -c 4'}
register.connect(stripper, 'out_file', reg, 'moving_image')
register.connect(inputnode, 'target_image', reg, 'fixed_image')

Concatenate the affine and ants transforms into a list

pickfirst = lambda x: x[0]

merge = Node(Merge(2), iterfield=['in2'], name='mergexfm')
register.connect(convert2itk, 'itk_transform', merge, 'in2')
register.connect(reg, 'composite_transform', merge, 'in1')

Transform the mean image. First to anatomical and then to target

warpmean = Node(ants.ApplyTransforms(), name='warpmean')
warpmean.inputs.input_image_type = 0
warpmean.inputs.interpolation = 'Linear'
warpmean.inputs.invert_transform_flags = [False, False]
warpmean.inputs.terminal_output = 'file'
warpmean.inputs.args = '--float'
# warpmean.inputs.num_threads = 4
# warpmean.plugin_args = {'sbatch_args': '--mem=4G -c 4'}

Transform the remaining images. First to anatomical and then to target

warpall = pe.MapNode(ants.ApplyTransforms(),
                     iterfield=['input_image'],
                     name='warpall')
warpall.inputs.input_image_type = 0
warpall.inputs.interpolation = 'Linear'
warpall.inputs.invert_transform_flags = [False, False]
warpall.inputs.terminal_output = 'file'
warpall.inputs.args = '--float'
warpall.inputs.num_threads = 2
warpall.plugin_args = {'sbatch_args': '--mem=6G -c 2'}

Assign all the output files

register.connect(warpmean, 'output_image', outputnode, 'transformed_mean')
register.connect(warpall, 'output_image', outputnode, 'transformed_files')

register.connect(inputnode, 'target_image', warpmean, 'reference_image')
register.connect(inputnode, 'mean_image', warpmean, 'input_image')
register.connect(merge, 'out', warpmean, 'transforms')
register.connect(inputnode, 'target_image', warpall, 'reference_image')
register.connect(inputnode, 'source_files', warpall, 'input_image')
register.connect(merge, 'out', warpall, 'transforms')

Assign all the output files

register.connect(reg, 'warped_image', outputnode, 'anat2target')
register.connect(aparcxfm, 'transformed_file',
                 outputnode, 'aparc')
register.connect(bbregister, 'out_fsl_file',
                 outputnode, 'func2anat_transform')
register.connect(bbregister, 'out_reg_file',
                 outputnode, 'out_reg_file')
register.connect(bbregister, 'min_cost_file',
                 outputnode, 'min_cost_file')
register.connect(mean2anat_mask, 'mask_file',
                 outputnode, 'mean2anat_mask')
register.connect(reg, 'composite_transform',
                 outputnode, 'anat2target_transform')
register.connect(merge, 'out', outputnode, 'transforms')

return register

Get info for a given subject

def get_subjectinfo(subject_id, base_dir, task_id, model_id):
    """Get info for a given subject

    Parameters
    ----------
    subject_id : string
        Subject identifier (e.g., sub001)
    base_dir : string
        Path to base directory of the dataset
    task_id : int
        Which task to process
    model_id : int
        Which model to process

    Returns
    -------
    run_ids : list of ints
        Run numbers
    conds : list of str
        Condition names
    TR : float
        Repetition time
    """
    from glob import glob
    import os
    import numpy as np
    condition_info = []
    cond_file = os.path.join(base_dir, 'models', 'model%03d' % model_id,
                             'condition_key.txt')
    with open(cond_file, 'rt') as fp:
        for line in fp:
            info = line.strip().split()
            condition_info.append([info[0], info[1], ' '.join(info[2:])])
    if len(condition_info) == 0:
        raise ValueError('No condition info found in %s' % cond_file)
    taskinfo = np.array(condition_info)
    n_tasks = len(np.unique(taskinfo[:, 0]))
    conds = []
    run_ids = []
    if task_id > n_tasks:
        raise ValueError('Task id %d does not exist' % task_id)
    for idx in range(n_tasks):
        taskidx = np.where(taskinfo[:, 0] == 'task%03d' % (idx + 1))
        conds.append([condition.replace(' ', '_') for condition
                      in taskinfo[taskidx[0], 2]])  # if 'junk' not in condition])
        files = sorted(glob(os.path.join(base_dir,
                                         subject_id,
                                         'BOLD',
                                         'task%03d_run*' % (idx + 1))))
        runs = [int(val[-3:]) for val in files]
        run_ids.insert(idx, runs)
    json_info = os.path.join(base_dir, subject_id, 'BOLD',
                             'task%03d_run%03d' % (task_id, run_ids[task_id - 1][0]),
                             'bold_scaninfo.json')
    if os.path.exists(json_info):
        import json
        with open(json_info, 'rt') as fp:
            data = json.load(fp)
            TR = data['global']['const']['RepetitionTime'] / 1000.
    else:
        task_scan_key = os.path.join(base_dir, subject_id, 'BOLD',
                                     'task%03d_run%03d' % (task_id, run_ids[task_id - 1][0]),
                                     'scan_key.txt')
        if os.path.exists(task_scan_key):
            TR = np.genfromtxt(task_scan_key)[1]
        else:
            TR = np.genfromtxt(os.path.join(base_dir, 'scan_key.txt'))[1]
    return run_ids[task_id - 1], conds[task_id - 1], TR

Analyzes an open fmri dataset

def analyze_openfmri_dataset(data_dir, subject=None, model_id=None,
                             task_id=None, output_dir=None, subj_prefix='*',
                             hpcutoff=120., use_derivatives=True,
                             fwhm=6.0, subjects_dir=None, target=None):
    """Analyzes an open fmri dataset

    Parameters
    ----------

    data_dir : str
        Path to the base data directory

    work_dir : str
        Nipype working directory (defaults to cwd)
    """

Load nipype workflows

preproc = create_featreg_preproc(whichvol='first')
modelfit = create_modelfit_workflow()
fixed_fx = create_fixed_effects_flow()
if subjects_dir:
    registration = create_fs_reg_workflow()
else:
    registration = create_reg_workflow()

Remove the plotting connection so that plot iterables don’t propagate to the model stage

preproc.disconnect(preproc.get_node('plot_motion'), 'out_file',
                   preproc.get_node('outputspec'), 'motion_plots')

Set up openfmri data specific components

subjects = sorted([path.split(os.path.sep)[-1] for path in
                   glob(os.path.join(data_dir, subj_prefix))])

infosource = pe.Node(niu.IdentityInterface(fields=['subject_id',
                                                   'model_id',
                                                   'task_id']),
                     name='infosource')
if len(subject) == 0:
    infosource.iterables = [('subject_id', subjects),
                            ('model_id', [model_id]),
                            ('task_id', task_id)]
else:
    infosource.iterables = [('subject_id',
                             [subjects[subjects.index(subj)] for subj in subject]),
                            ('model_id', [model_id]),
                            ('task_id', task_id)]

subjinfo = pe.Node(niu.Function(input_names=['subject_id', 'base_dir',
                                             'task_id', 'model_id'],
                                output_names=['run_id', 'conds', 'TR'],
                                function=get_subjectinfo),
                   name='subjectinfo')
subjinfo.inputs.base_dir = data_dir

Return data components as anat, bold and behav

contrast_file = os.path.join(data_dir, 'models', 'model%03d' % model_id,
                             'task_contrasts.txt')
has_contrast = os.path.exists(contrast_file)
if has_contrast:
    datasource = pe.Node(nio.DataGrabber(infields=['subject_id', 'run_id',
                                                   'task_id', 'model_id'],
                                         outfields=['anat', 'bold', 'behav',
                                                    'contrasts']),
                         name='datasource')
else:
    datasource = pe.Node(nio.DataGrabber(infields=['subject_id', 'run_id',
                                                   'task_id', 'model_id'],
                                         outfields=['anat', 'bold', 'behav']),
                         name='datasource')
datasource.inputs.base_directory = data_dir
datasource.inputs.template = '*'

if has_contrast:
    datasource.inputs.field_template = {'anat': '%s/anatomy/T1_001.nii.gz',
                                        'bold': '%s/BOLD/task%03d_r*/bold.nii.gz',
                                        'behav': ('%s/model/model%03d/onsets/task%03d_'
                                                  'run%03d/cond*.txt'),
                                        'contrasts': ('models/model%03d/'
                                                      'task_contrasts.txt')}
    datasource.inputs.template_args = {'anat': [['subject_id']],
                                       'bold': [['subject_id', 'task_id']],
                                       'behav': [['subject_id', 'model_id',
                                                  'task_id', 'run_id']],
                                       'contrasts': [['model_id']]}
else:
    datasource.inputs.field_template = {'anat': '%s/anatomy/T1_001.nii.gz',
                                        'bold': '%s/BOLD/task%03d_r*/bold.nii.gz',
                                        'behav': ('%s/model/model%03d/onsets/task%03d_'
                                                  'run%03d/cond*.txt')}
    datasource.inputs.template_args = {'anat': [['subject_id']],
                                       'bold': [['subject_id', 'task_id']],
                                       'behav': [['subject_id', 'model_id',
                                                  'task_id', 'run_id']]}

datasource.inputs.sort_filelist = True

Create meta workflow

wf = pe.Workflow(name='openfmri')
wf.connect(infosource, 'subject_id', subjinfo, 'subject_id')
wf.connect(infosource, 'model_id', subjinfo, 'model_id')
wf.connect(infosource, 'task_id', subjinfo, 'task_id')
wf.connect(infosource, 'subject_id', datasource, 'subject_id')
wf.connect(infosource, 'model_id', datasource, 'model_id')
wf.connect(infosource, 'task_id', datasource, 'task_id')
wf.connect(subjinfo, 'run_id', datasource, 'run_id')
wf.connect([(datasource, preproc, [('bold', 'inputspec.func')]),
            ])

def get_highpass(TR, hpcutoff):
    return hpcutoff / (2. * TR)
gethighpass = pe.Node(niu.Function(input_names=['TR', 'hpcutoff'],
                                   output_names=['highpass'],
                                   function=get_highpass),
                      name='gethighpass')
wf.connect(subjinfo, 'TR', gethighpass, 'TR')
wf.connect(gethighpass, 'highpass', preproc, 'inputspec.highpass')

Setup a basic set of contrasts, a t-test per condition

def get_contrasts(contrast_file, task_id, conds):
    import numpy as np
    import os
    contrast_def = []
    if os.path.exists(contrast_file):
        with open(contrast_file, 'rt') as fp:
            contrast_def.extend([np.array(row.split()) for row in fp.readlines() if row.strip()])
    contrasts = []
    for row in contrast_def:
        if row[0] != 'task%03d' % task_id:
            continue
        con = [row[1], 'T', ['cond%03d' % (i + 1) for i in range(len(conds))],
               row[2:].astype(float).tolist()]
        contrasts.append(con)
    # add auto contrasts for each column
    for i, cond in enumerate(conds):
        con = [cond, 'T', ['cond%03d' % (i + 1)], [1]]
        contrasts.append(con)
    return contrasts

contrastgen = pe.Node(niu.Function(input_names=['contrast_file',
                                                'task_id', 'conds'],
                                   output_names=['contrasts'],
                                   function=get_contrasts),
                      name='contrastgen')

art = pe.MapNode(interface=ra.ArtifactDetect(use_differences=[True, False],
                                             use_norm=True,
                                             norm_threshold=1,
                                             zintensity_threshold=3,
                                             parameter_source='FSL',
                                             mask_type='file'),
                 iterfield=['realigned_files', 'realignment_parameters',
                            'mask_file'],
                 name="art")

modelspec = pe.Node(interface=model.SpecifyModel(),
                    name="modelspec")
modelspec.inputs.input_units = 'secs'

def check_behav_list(behav, run_id, conds):
    import numpy as np
    num_conds = len(conds)
    if isinstance(behav, (str, bytes)):
        behav = [behav]
    behav_array = np.array(behav).flatten()
    num_elements = behav_array.shape[0]
    return behav_array.reshape(int(num_elements / num_conds),
                               num_conds).tolist()

reshape_behav = pe.Node(niu.Function(input_names=['behav', 'run_id', 'conds'],
                                     output_names=['behav'],
                                     function=check_behav_list),
                        name='reshape_behav')

wf.connect(subjinfo, 'TR', modelspec, 'time_repetition')
wf.connect(datasource, 'behav', reshape_behav, 'behav')
wf.connect(subjinfo, 'run_id', reshape_behav, 'run_id')
wf.connect(subjinfo, 'conds', reshape_behav, 'conds')
wf.connect(reshape_behav, 'behav', modelspec, 'event_files')

wf.connect(subjinfo, 'TR', modelfit, 'inputspec.interscan_interval')
wf.connect(subjinfo, 'conds', contrastgen, 'conds')
if has_contrast:
    wf.connect(datasource, 'contrasts', contrastgen, 'contrast_file')
else:
    contrastgen.inputs.contrast_file = ''
wf.connect(infosource, 'task_id', contrastgen, 'task_id')
wf.connect(contrastgen, 'contrasts', modelfit, 'inputspec.contrasts')

wf.connect([(preproc, art, [('outputspec.motion_parameters',
                             'realignment_parameters'),
                            ('outputspec.realigned_files',
                             'realigned_files'),
                            ('outputspec.mask', 'mask_file')]),
            (preproc, modelspec, [('outputspec.highpassed_files',
                                   'functional_runs'),
                                  ('outputspec.motion_parameters',
                                   'realignment_parameters')]),
            (art, modelspec, [('outlier_files', 'outlier_files')]),
            (modelspec, modelfit, [('session_info',
                                    'inputspec.session_info')]),
            (preproc, modelfit, [('outputspec.highpassed_files',
                                  'inputspec.functional_data')])
            ])

# Comute TSNR on realigned data regressing polynomials upto order 2
tsnr = MapNode(TSNR(regress_poly=2), iterfield=['in_file'], name='tsnr')
wf.connect(preproc, "outputspec.realigned_files", tsnr, "in_file")

# Compute the median image across runs
calc_median = Node(Function(input_names=['in_files'],
                            output_names=['median_file'],
                            function=median,
                            imports=imports),
                   name='median')
wf.connect(tsnr, 'detrended_file', calc_median, 'in_files')

Reorder the copes so that now it combines across runs

def sort_copes(copes, varcopes, contrasts):
    import numpy as np
    if not isinstance(copes, list):
        copes = [copes]
        varcopes = [varcopes]
    num_copes = len(contrasts)
    n_runs = len(copes)
    all_copes = np.array(copes).flatten()
    all_varcopes = np.array(varcopes).flatten()
    outcopes = all_copes.reshape(int(len(all_copes) / num_copes),
                                 num_copes).T.tolist()
    outvarcopes = all_varcopes.reshape(int(len(all_varcopes) / num_copes),
                                       num_copes).T.tolist()
    return outcopes, outvarcopes, n_runs

cope_sorter = pe.Node(niu.Function(input_names=['copes', 'varcopes',
                                                'contrasts'],
                                   output_names=['copes', 'varcopes',
                                                 'n_runs'],
                                   function=sort_copes),
                      name='cope_sorter')

pickfirst = lambda x: x[0]

wf.connect(contrastgen, 'contrasts', cope_sorter, 'contrasts')
wf.connect([(preproc, fixed_fx, [(('outputspec.mask', pickfirst),
                                  'flameo.mask_file')]),
            (modelfit, cope_sorter, [('outputspec.copes', 'copes')]),
            (modelfit, cope_sorter, [('outputspec.varcopes', 'varcopes')]),
            (cope_sorter, fixed_fx, [('copes', 'inputspec.copes'),
                                     ('varcopes', 'inputspec.varcopes'),
                                     ('n_runs', 'l2model.num_copes')]),
            (modelfit, fixed_fx, [('outputspec.dof_file',
                                   'inputspec.dof_files'),
                                  ])
            ])

wf.connect(calc_median, 'median_file', registration, 'inputspec.mean_image')
if subjects_dir:
    wf.connect(infosource, 'subject_id', registration, 'inputspec.subject_id')
    registration.inputs.inputspec.subjects_dir = subjects_dir
    registration.inputs.inputspec.target_image = fsl.Info.standard_image('MNI152_T1_2mm_brain.nii.gz')
    if target:
        registration.inputs.inputspec.target_image = target
else:
    wf.connect(datasource, 'anat', registration, 'inputspec.anatomical_image')
    registration.inputs.inputspec.target_image = fsl.Info.standard_image('MNI152_T1_2mm.nii.gz')
    registration.inputs.inputspec.target_image_brain = fsl.Info.standard_image('MNI152_T1_2mm_brain.nii.gz')
    registration.inputs.inputspec.config_file = 'T1_2_MNI152_2mm'

def merge_files(copes, varcopes, zstats):
    out_files = []
    splits = []
    out_files.extend(copes)
    splits.append(len(copes))
    out_files.extend(varcopes)
    splits.append(len(varcopes))
    out_files.extend(zstats)
    splits.append(len(zstats))
    return out_files, splits

mergefunc = pe.Node(niu.Function(input_names=['copes', 'varcopes',
                                              'zstats'],
                                 output_names=['out_files', 'splits'],
                                 function=merge_files),
                    name='merge_files')
wf.connect([(fixed_fx.get_node('outputspec'), mergefunc,
             [('copes', 'copes'),
              ('varcopes', 'varcopes'),
              ('zstats', 'zstats'),
              ])])
wf.connect(mergefunc, 'out_files', registration, 'inputspec.source_files')

def split_files(in_files, splits):
    copes = in_files[:splits[0]]
    varcopes = in_files[splits[0]:(splits[0] + splits[1])]
    zstats = in_files[(splits[0] + splits[1]):]
    return copes, varcopes, zstats

splitfunc = pe.Node(niu.Function(input_names=['in_files', 'splits'],
                                 output_names=['copes', 'varcopes',
                                               'zstats'],
                                 function=split_files),
                    name='split_files')
wf.connect(mergefunc, 'splits', splitfunc, 'splits')
wf.connect(registration, 'outputspec.transformed_files',
           splitfunc, 'in_files')

if subjects_dir:
    get_roi_mean = pe.MapNode(fs.SegStats(default_color_table=True),
                              iterfield=['in_file'], name='get_aparc_means')
    get_roi_mean.inputs.avgwf_txt_file = True
    wf.connect(fixed_fx.get_node('outputspec'), 'copes', get_roi_mean, 'in_file')
    wf.connect(registration, 'outputspec.aparc', get_roi_mean, 'segmentation_file')

    get_roi_tsnr = pe.MapNode(fs.SegStats(default_color_table=True),
                              iterfield=['in_file'], name='get_aparc_tsnr')
    get_roi_tsnr.inputs.avgwf_txt_file = True
    wf.connect(tsnr, 'tsnr_file', get_roi_tsnr, 'in_file')
    wf.connect(registration, 'outputspec.aparc', get_roi_tsnr, 'segmentation_file')

Connect to a datasink

def get_subs(subject_id, conds, run_id, model_id, task_id):
    subs = [('_subject_id_%s_' % subject_id, '')]
    subs.append(('_model_id_%d' % model_id, 'model%03d' % model_id))
    subs.append(('task_id_%d/' % task_id, '/task%03d_' % task_id))
    subs.append(('bold_dtype_mcf_mask_smooth_mask_gms_tempfilt_mean_warp',
                 'mean'))
    subs.append(('bold_dtype_mcf_mask_smooth_mask_gms_tempfilt_mean_flirt',
                 'affine'))

    for i in range(len(conds)):
        subs.append(('_flameo%d/cope1.' % i, 'cope%02d.' % (i + 1)))
        subs.append(('_flameo%d/varcope1.' % i, 'varcope%02d.' % (i + 1)))
        subs.append(('_flameo%d/zstat1.' % i, 'zstat%02d.' % (i + 1)))
        subs.append(('_flameo%d/tstat1.' % i, 'tstat%02d.' % (i + 1)))
        subs.append(('_flameo%d/res4d.' % i, 'res4d%02d.' % (i + 1)))
        subs.append(('_warpall%d/cope1_warp.' % i,
                     'cope%02d.' % (i + 1)))
        subs.append(('_warpall%d/varcope1_warp.' % (len(conds) + i),
                     'varcope%02d.' % (i + 1)))
        subs.append(('_warpall%d/zstat1_warp.' % (2 * len(conds) + i),
                     'zstat%02d.' % (i + 1)))
        subs.append(('_warpall%d/cope1_trans.' % i,
                     'cope%02d.' % (i + 1)))
        subs.append(('_warpall%d/varcope1_trans.' % (len(conds) + i),
                     'varcope%02d.' % (i + 1)))
        subs.append(('_warpall%d/zstat1_trans.' % (2 * len(conds) + i),
                     'zstat%02d.' % (i + 1)))
        subs.append(('__get_aparc_means%d/' % i, '/cope%02d_' % (i + 1)))

    for i, run_num in enumerate(run_id):
        subs.append(('__get_aparc_tsnr%d/' % i, '/run%02d_' % run_num))
        subs.append(('__art%d/' % i, '/run%02d_' % run_num))
        subs.append(('__dilatemask%d/' % i, '/run%02d_' % run_num))
        subs.append(('__realign%d/' % i, '/run%02d_' % run_num))
        subs.append(('__modelgen%d/' % i, '/run%02d_' % run_num))
    subs.append(('/model%03d/task%03d/' % (model_id, task_id), '/'))
    subs.append(('/model%03d/task%03d_' % (model_id, task_id), '/'))
    subs.append(('_bold_dtype_mcf_bet_thresh_dil', '_mask'))
    subs.append(('_output_warped_image', '_anat2target'))
    subs.append(('median_flirt_brain_mask', 'median_brain_mask'))
    subs.append(('median_bbreg_brain_mask', 'median_brain_mask'))
    return subs

subsgen = pe.Node(niu.Function(input_names=['subject_id', 'conds', 'run_id',
                                            'model_id', 'task_id'],
                               output_names=['substitutions'],
                               function=get_subs),
                  name='subsgen')
wf.connect(subjinfo, 'run_id', subsgen, 'run_id')

datasink = pe.Node(interface=nio.DataSink(),
                   name="datasink")
wf.connect(infosource, 'subject_id', datasink, 'container')
wf.connect(infosource, 'subject_id', subsgen, 'subject_id')
wf.connect(infosource, 'model_id', subsgen, 'model_id')
wf.connect(infosource, 'task_id', subsgen, 'task_id')
wf.connect(contrastgen, 'contrasts', subsgen, 'conds')
wf.connect(subsgen, 'substitutions', datasink, 'substitutions')
wf.connect([(fixed_fx.get_node('outputspec'), datasink,
             [('res4d', 'res4d'),
              ('copes', 'copes'),
              ('varcopes', 'varcopes'),
              ('zstats', 'zstats'),
              ('tstats', 'tstats')])
            ])
wf.connect([(modelfit.get_node('modelgen'), datasink,
             [('design_cov', 'qa.model'),
              ('design_image', 'qa.model.@matrix_image'),
              ('design_file', 'qa.model.@matrix'),
              ])])
wf.connect([(preproc, datasink, [('outputspec.motion_parameters',
                                  'qa.motion'),
                                 ('outputspec.motion_plots',
                                  'qa.motion.plots'),
                                 ('outputspec.mask', 'qa.mask')])])
wf.connect(registration, 'outputspec.mean2anat_mask', datasink, 'qa.mask.mean2anat')
wf.connect(art, 'norm_files', datasink, 'qa.art.@norm')
wf.connect(art, 'intensity_files', datasink, 'qa.art.@intensity')
wf.connect(art, 'outlier_files', datasink, 'qa.art.@outlier_files')
wf.connect(registration, 'outputspec.anat2target', datasink, 'qa.anat2target')
wf.connect(tsnr, 'tsnr_file', datasink, 'qa.tsnr.@map')
if subjects_dir:
    wf.connect(registration, 'outputspec.min_cost_file', datasink, 'qa.mincost')
    wf.connect([(get_roi_tsnr, datasink, [('avgwf_txt_file', 'qa.tsnr'),
                                          ('summary_file', 'qa.tsnr.@summary')])])
    wf.connect([(get_roi_mean, datasink, [('avgwf_txt_file', 'copes.roi'),
                                          ('summary_file', 'copes.roi.@summary')])])
wf.connect([(splitfunc, datasink,
             [('copes', 'copes.mni'),
              ('varcopes', 'varcopes.mni'),
              ('zstats', 'zstats.mni'),
              ])])
wf.connect(calc_median, 'median_file', datasink, 'mean')
wf.connect(registration, 'outputspec.transformed_mean', datasink, 'mean.mni')
wf.connect(registration, 'outputspec.func2anat_transform', datasink, 'xfm.mean2anat')
wf.connect(registration, 'outputspec.anat2target_transform', datasink, 'xfm.anat2target')

Set processing parameters

preproc.inputs.inputspec.fwhm = fwhm
gethighpass.inputs.hpcutoff = hpcutoff
modelspec.inputs.high_pass_filter_cutoff = hpcutoff
modelfit.inputs.inputspec.bases = {'dgamma': {'derivs': use_derivatives}}
modelfit.inputs.inputspec.model_serial_correlations = True
modelfit.inputs.inputspec.film_threshold = 1000

datasink.inputs.base_directory = output_dir
return wf

The following functions run the whole workflow.

if __name__ == '__main__':
    import argparse
    defstr = ' (default %(default)s)'
    parser = argparse.ArgumentParser(prog='fmri_openfmri.py',
                                     description=__doc__)
    parser.add_argument('-d', '--datasetdir', required=True)
    parser.add_argument('-s', '--subject', default=[],
                        nargs='+', type=str,
                        help="Subject name (e.g. 'sub001')")
    parser.add_argument('-m', '--model', default=1,
                        help="Model index" + defstr)
    parser.add_argument('-x', '--subjectprefix', default='sub*',
                        help="Subject prefix" + defstr)
    parser.add_argument('-t', '--task', default=1,  # nargs='+',
                        type=int, help="Task index" + defstr)
    parser.add_argument('--hpfilter', default=120.,
                        type=float, help="High pass filter cutoff (in secs)" + defstr)
    parser.add_argument('--fwhm', default=6.,
                        type=float, help="Spatial FWHM" + defstr)
    parser.add_argument('--derivatives', action="store_true",
                        help="Use derivatives" + defstr)
    parser.add_argument("-o", "--output_dir", dest="outdir",
                        help="Output directory base")
    parser.add_argument("-w", "--work_dir", dest="work_dir",
                        help="Output directory base")
    parser.add_argument("-p", "--plugin", dest="plugin",
                        default='Linear',
                        help="Plugin to use")
    parser.add_argument("--plugin_args", dest="plugin_args",
                        help="Plugin arguments")
    parser.add_argument("--sd", dest="subjects_dir",
                        help="FreeSurfer subjects directory (if available)")
    parser.add_argument("--target", dest="target_file",
                        help=("Target in MNI space. Best to use the MindBoggle "
                              "template - only used with FreeSurfer"
                              "OASIS-30_Atropos_template_in_MNI152_2mm.nii.gz"))
    args = parser.parse_args()
    outdir = args.outdir
    work_dir = os.getcwd()
    if args.work_dir:
        work_dir = os.path.abspath(args.work_dir)
    if outdir:
        outdir = os.path.abspath(outdir)
    else:
        outdir = os.path.join(work_dir, 'output')
    outdir = os.path.join(outdir, 'model%02d' % int(args.model),
                          'task%03d' % int(args.task))
    derivatives = args.derivatives
    if derivatives is None:
        derivatives = False
    wf = analyze_openfmri_dataset(data_dir=os.path.abspath(args.datasetdir),
                                  subject=args.subject,
                                  model_id=int(args.model),
                                  task_id=[int(args.task)],
                                  subj_prefix=args.subjectprefix,
                                  output_dir=outdir,
                                  hpcutoff=args.hpfilter,
                                  use_derivatives=derivatives,
                                  fwhm=args.fwhm,
                                  subjects_dir=args.subjects_dir,
                                  target=args.target_file)
    # wf.config['execution']['remove_unnecessary_outputs'] = False

    wf.base_dir = work_dir
    if args.plugin_args:
        wf.run(args.plugin, plugin_args=eval(args.plugin_args))
    else:
        wf.run(args.plugin)

Example source code

You can download the full source code of this example. This same script is also included in the Nipype source distribution under the examples directory.