def afni_unifize(in_file,
write_dir=None,
out_file=None,
caching=False,
terminal_output='allatonce',
verbose=True,
environ=None,
copy_geometry=False,
**unifize_kwargs):
if write_dir is None:
write_dir = os.path.dirname(in_file)
if environ is None:
environ = {'AFNI_DECONFLICT': 'OVERWRITE'}
if caching:
memory = Memory(write_dir)
copy_geom = memory.cache(fsl.CopyGeom)
unifize = memory.cache(afni.Unifize)
copy = memory.cache(afni.Copy)
unifize.interface().set_default_terminal_output(terminal_output)
copy.interface().set_default_terminal_output(terminal_output)
else:
copy_geom = fsl.CopyGeom(terminal_output=terminal_output).run
unifize = afni.Unifize(terminal_output=terminal_output).run
copy = afni.Copy(terminal_output=terminal_output).run
if out_file is None:
out_file = fname_presuffix(in_file,
suffix='_unifized',
newpath=write_dir)
if copy_geometry:
unifized_file = fname_presuffix(in_file,
suffix='_unifized_rough_geom',
newpath=write_dir)
else:
unifized_file = out_file
out_unifize = unifize(in_file=in_file,
out_file=unifized_file,
environ=environ,
quiet=not (verbose),
**unifize_kwargs)
if copy_geometry:
out_copy = copy(in_file=out_unifize.outputs.out_file,
out_file=out_file,
environ=environ)
out_copy_geom = copy_geom(dest_file=out_copy.outputs.out_file,
in_file=in_file)
return out_file
def init_enhance_and_skullstrip_epi_wf(name='enhance_and_skullstrip_epi_wf'):
workflow = pe.Workflow(name=name)
inputnode = pe.Node(niu.IdentityInterface(fields=['in_file']),
name='inputnode')
outputnode = pe.Node(niu.IdentityInterface(fields=[
'mask_file', 'skull_stripped_file', 'bias_corrected_file', 'out_report'
]),
name='outputnode')
n4_correct = pe.Node(ants.N4BiasFieldCorrection(dimension=3,
copy_header=True),
name='n4_correct')
skullstrip_first_pass = pe.Node(fsl.BET(frac=0.2, mask=True),
name='skullstrip_first_pass')
unifize = pe.Node(afni.Unifize(t2=True,
outputtype='NIFTI_GZ',
args='-clfrac 0.4',
out_file="uni.nii.gz"),
name='unifize')
skullstrip_second_pass = pe.Node(afni.Automask(dilate=1,
outputtype='NIFTI_GZ'),
name='skullstrip_second_pass')
combine_masks = pe.Node(fsl.BinaryMaths(operation='mul'),
name='combine_masks')
apply_mask = pe.Node(fsl.ApplyMask(), name='apply_mask')
mask_reportlet = pe.Node(SimpleShowMaskRPT(), name='mask_reportlet')
workflow.connect([
(inputnode, n4_correct, [('in_file', 'input_image')]),
(n4_correct, skullstrip_first_pass, [('output_image', 'in_file')]),
(skullstrip_first_pass, unifize, [('out_file', 'in_file')]),
(unifize, skullstrip_second_pass, [('out_file', 'in_file')]),
(skullstrip_first_pass, combine_masks, [('mask_file', 'in_file')]),
(skullstrip_second_pass, combine_masks, [('out_file', 'operand_file')
]),
(unifize, apply_mask, [('out_file', 'in_file')]),
(combine_masks, apply_mask, [('out_file', 'mask_file')]),
(n4_correct, mask_reportlet, [('output_image', 'background_file')]),
(combine_masks, mask_reportlet, [('out_file', 'mask_file')]),
(combine_masks, outputnode, [('out_file', 'mask_file')]),
(mask_reportlet, outputnode, [('out_report', 'out_report')]),
(apply_mask, outputnode, [('out_file', 'skull_stripped_file')]),
(n4_correct, outputnode, [('output_image', 'bias_corrected_file')]),
])
return workflow
def init_unifize_and_skullstrip_wf(name='unifize_and_skullstrip_wf'):
wf = pe.Workflow(name=name)
# inputnode/outputnode can be thought of as the parameters and return values of a function
inputnode = pe.Node(niu.IdentityInterface(['in_file', 'out_file']), name='inputnode')
outputnode = pe.Node(niu.IdentityInterface(['out_file']), name='outputnode')
#
# The rest of the workflow should be defined here.
#
bet = pe.Node(fsl.BET(), name='bet')
unifize = pe.Node(afni.Unifize(outputtype='NIFTI'), name='unifize')
wf.connect([
(inputnode, unifize, [('in_file', 'in_file')]),
(unifize, bet, [('out_file', 'in_file')]),
(inputnode, bet, [('out_file', 'out_file')]),
(bet, outputnode, [('out_file', 'out_file')]),
])
return wf
def init_enhance_and_skullstrip_bold_wf(name='enhance_and_skullstrip_bold_wf',
pre_mask=False,
omp_nthreads=1):
"""
This workflow takes in a :abbr:`BOLD (blood-oxygen level-dependant)`
:abbr:`fMRI (functional MRI)` average/summary (e.g., a reference image
averaging non-steady-state timepoints), and sharpens the histogram
with the application of the N4 algorithm for removing the
:abbr:`INU (intensity non-uniformity)` bias field and calculates a signal
mask.
Steps of this workflow are:
1. Calculate a tentative mask by registering (9-parameters) to *fMRIPrep*'s
:abbr:`EPI (echo-planar imaging)` -*boldref* template, which
is in MNI space.
The tentative mask is obtained by resampling the MNI template's
brainmask into *boldref*-space.
2. Binary dilation of the tentative mask with a sphere of 3mm diameter.
3. Run ANTs' ``N4BiasFieldCorrection`` on the input
:abbr:`BOLD (blood-oxygen level-dependant)` average, using the
mask generated in 1) instead of the internal Otsu thresholding.
4. Calculate a loose mask using FSL's ``bet``, with one mathematical morphology
dilation of one iteration and a sphere of 6mm as structuring element.
5. Mask the :abbr:`INU (intensity non-uniformity)`-corrected image
with the latest mask calculated in 3), then use AFNI's ``3dUnifize``
to *standardize* the T2* contrast distribution.
6. Calculate a mask using AFNI's ``3dAutomask`` after the contrast
enhancement of 4).
7. Calculate a final mask as the intersection of 4) and 6).
8. Apply final mask on the enhanced reference.
Step 1 can be skipped if the ``pre_mask`` argument is set to ``True`` and
a tentative mask is passed in to the workflow throught the ``pre_mask``
Nipype input.
.. workflow ::
:graph2use: orig
:simple_form: yes
from niworkflows.func.util import init_enhance_and_skullstrip_bold_wf
wf = init_enhance_and_skullstrip_bold_wf(omp_nthreads=1)
**Parameters**
name : str
Name of workflow (default: ``enhance_and_skullstrip_bold_wf``)
pre_mask : bool
Indicates whether the ``pre_mask`` input will be set (and thus, step 1
should be skipped).
omp_nthreads : int
number of threads available to parallel nodes
**Inputs**
in_file
BOLD image (single volume)
pre_mask : bool
A tentative brain mask to initialize the workflow (requires ``pre_mask``
parameter set ``True``).
**Outputs**
bias_corrected_file
the ``in_file`` after `N4BiasFieldCorrection`_
skull_stripped_file
the ``bias_corrected_file`` after skull-stripping
mask_file
mask of the skull-stripped input file
out_report
reportlet for the skull-stripping
.. _N4BiasFieldCorrection: https://hdl.handle.net/10380/3053
"""
workflow = Workflow(name=name)
inputnode = pe.Node(niu.IdentityInterface(fields=['in_file', 'pre_mask']),
name='inputnode')
outputnode = pe.Node(niu.IdentityInterface(
fields=['mask_file', 'skull_stripped_file', 'bias_corrected_file']),
name='outputnode')
# Dilate pre_mask
pre_dilate = pe.Node(fsl.DilateImage(operation='max',
kernel_shape='sphere',
kernel_size=3.0,
internal_datatype='char'),
name='pre_mask_dilate')
# Ensure mask's header matches reference's
check_hdr = pe.Node(MatchHeader(),
name='check_hdr',
run_without_submitting=True)
# Run N4 normally, force num_threads=1 for stability (images are small, no need for >1)
n4_correct = pe.Node(ants.N4BiasFieldCorrection(
dimension=3, copy_header=True, bspline_fitting_distance=200),
name='n4_correct',
n_procs=1)
# Create a generous BET mask out of the bias-corrected EPI
skullstrip_first_pass = pe.Node(fsl.BET(frac=0.2, mask=True),
name='skullstrip_first_pass')
bet_dilate = pe.Node(fsl.DilateImage(operation='max',
kernel_shape='sphere',
kernel_size=6.0,
internal_datatype='char'),
name='skullstrip_first_dilate')
bet_mask = pe.Node(fsl.ApplyMask(), name='skullstrip_first_mask')
# Use AFNI's unifize for T2 constrast & fix header
unifize = pe.Node(
afni.Unifize(
t2=True,
outputtype='NIFTI_GZ',
# Default -clfrac is 0.1, 0.4 was too conservative
# -rbt because I'm a Jedi AFNI Master (see 3dUnifize's documentation)
args='-clfrac 0.2 -rbt 18.3 65.0 90.0',
out_file="uni.nii.gz"),
name='unifize')
fixhdr_unifize = pe.Node(CopyXForm(), name='fixhdr_unifize', mem_gb=0.1)
# Run ANFI's 3dAutomask to extract a refined brain mask
skullstrip_second_pass = pe.Node(afni.Automask(dilate=1,
outputtype='NIFTI_GZ'),
name='skullstrip_second_pass')
fixhdr_skullstrip2 = pe.Node(CopyXForm(),
name='fixhdr_skullstrip2',
mem_gb=0.1)
# Take intersection of both masks
combine_masks = pe.Node(fsl.BinaryMaths(operation='mul'),
name='combine_masks')
# Compute masked brain
apply_mask = pe.Node(fsl.ApplyMask(), name='apply_mask')
if not pre_mask:
bold_template = get_template('MNI152NLin2009cAsym',
resolution=2,
desc='fMRIPrep',
suffix='boldref')
brain_mask = get_template('MNI152NLin2009cAsym',
resolution=2,
desc='brain',
suffix='mask')
# Initialize transforms with antsAI
init_aff = pe.Node(AI(fixed_image=str(bold_template),
fixed_image_mask=str(brain_mask),
metric=('Mattes', 32, 'Regular', 0.2),
transform=('Affine', 0.1),
search_factor=(20, 0.12),
principal_axes=False,
convergence=(10, 1e-6, 10),
verbose=True),
name='init_aff',
n_procs=omp_nthreads)
# Registration().version may be None
if parseversion(Registration().version or '0.0.0') > Version('2.2.0'):
init_aff.inputs.search_grid = (40, (0, 40, 40))
# Set up spatial normalization
norm = pe.Node(Registration(from_file=pkgr_fn(
'fmriprep.data', 'epi_atlasbased_brainmask.json')),
name='norm',
n_procs=omp_nthreads)
norm.inputs.fixed_image = str(bold_template)
map_brainmask = pe.Node(ApplyTransforms(interpolation='MultiLabel',
float=True,
input_image=str(brain_mask)),
name='map_brainmask')
workflow.connect([
(inputnode, init_aff, [('in_file', 'moving_image')]),
(inputnode, map_brainmask, [('in_file', 'reference_image')]),
(inputnode, norm, [('in_file', 'moving_image')]),
(init_aff, norm, [('output_transform', 'initial_moving_transform')
]),
(norm, map_brainmask, [('reverse_invert_flags',
'invert_transform_flags'),
('reverse_transforms', 'transforms')]),
(map_brainmask, pre_dilate, [('output_image', 'in_file')]),
])
else:
workflow.connect([
(inputnode, pre_dilate, [('pre_mask', 'in_file')]),
])
workflow.connect([
(inputnode, check_hdr, [('in_file', 'reference')]),
(pre_dilate, check_hdr, [('out_file', 'in_file')]),
(check_hdr, n4_correct, [('out_file', 'mask_image')]),
(inputnode, n4_correct, [('in_file', 'input_image')]),
(inputnode, fixhdr_unifize, [('in_file', 'hdr_file')]),
(inputnode, fixhdr_skullstrip2, [('in_file', 'hdr_file')]),
(n4_correct, skullstrip_first_pass, [('output_image', 'in_file')]),
(skullstrip_first_pass, bet_dilate, [('mask_file', 'in_file')]),
(bet_dilate, bet_mask, [('out_file', 'mask_file')]),
(skullstrip_first_pass, bet_mask, [('out_file', 'in_file')]),
(bet_mask, unifize, [('out_file', 'in_file')]),
(unifize, fixhdr_unifize, [('out_file', 'in_file')]),
(fixhdr_unifize, skullstrip_second_pass, [('out_file', 'in_file')]),
(skullstrip_first_pass, combine_masks, [('mask_file', 'in_file')]),
(skullstrip_second_pass, fixhdr_skullstrip2, [('out_file', 'in_file')
]),
(fixhdr_skullstrip2, combine_masks, [('out_file', 'operand_file')]),
(fixhdr_unifize, apply_mask, [('out_file', 'in_file')]),
(combine_masks, apply_mask, [('out_file', 'mask_file')]),
(combine_masks, outputnode, [('out_file', 'mask_file')]),
(apply_mask, outputnode, [('out_file', 'skull_stripped_file')]),
(n4_correct, outputnode, [('output_image', 'bias_corrected_file')]),
])
return workflow
def init_enhance_and_skullstrip_bold_wf(
brainmask_thresh=0.5,
name="enhance_and_skullstrip_bold_wf",
omp_nthreads=1,
pre_mask=False,
):
"""
Enhance and run brain extraction on a BOLD EPI image.
This workflow takes in a :abbr:`BOLD (blood-oxygen level-dependant)`
:abbr:`fMRI (functional MRI)` average/summary (e.g., a reference image
averaging non-steady-state timepoints), and sharpens the histogram
with the application of the N4 algorithm for removing the
:abbr:`INU (intensity non-uniformity)` bias field and calculates a signal
mask.
Steps of this workflow are:
1. Calculate a tentative mask by registering (9-parameters) to *fMRIPrep*'s
:abbr:`EPI (echo-planar imaging)` -*boldref* template, which
is in MNI space.
The tentative mask is obtained by resampling the MNI template's
brainmask into *boldref*-space.
2. Binary dilation of the tentative mask with a sphere of 3mm diameter.
3. Run ANTs' ``N4BiasFieldCorrection`` on the input
:abbr:`BOLD (blood-oxygen level-dependant)` average, using the
mask generated in 1) instead of the internal Otsu thresholding.
4. Calculate a loose mask using FSL's ``bet``, with one mathematical morphology
dilation of one iteration and a sphere of 6mm as structuring element.
5. Mask the :abbr:`INU (intensity non-uniformity)`-corrected image
with the latest mask calculated in 3), then use AFNI's ``3dUnifize``
to *standardize* the T2* contrast distribution.
6. Calculate a mask using AFNI's ``3dAutomask`` after the contrast
enhancement of 4).
7. Calculate a final mask as the intersection of 4) and 6).
8. Apply final mask on the enhanced reference.
Step 1 can be skipped if the ``pre_mask`` argument is set to ``True`` and
a tentative mask is passed in to the workflow throught the ``pre_mask``
Nipype input.
Workflow graph
.. workflow ::
:graph2use: orig
:simple_form: yes
from niworkflows.func.util import init_enhance_and_skullstrip_bold_wf
wf = init_enhance_and_skullstrip_bold_wf(omp_nthreads=1)
.. _N4BiasFieldCorrection: https://hdl.handle.net/10380/3053
Parameters
----------
brainmask_thresh: :obj:`float`
Lower threshold for the probabilistic brainmask to obtain
the final binary mask (default: 0.5).
name : str
Name of workflow (default: ``enhance_and_skullstrip_bold_wf``)
omp_nthreads : int
number of threads available to parallel nodes
pre_mask : bool
Indicates whether the ``pre_mask`` input will be set (and thus, step 1
should be skipped).
Inputs
------
in_file : str
BOLD image (single volume)
pre_mask : bool
A tentative brain mask to initialize the workflow (requires ``pre_mask``
parameter set ``True``).
Outputs
-------
bias_corrected_file : str
the ``in_file`` after `N4BiasFieldCorrection`_
skull_stripped_file : str
the ``bias_corrected_file`` after skull-stripping
mask_file : str
mask of the skull-stripped input file
out_report : str
reportlet for the skull-stripping
"""
workflow = Workflow(name=name)
inputnode = pe.Node(niu.IdentityInterface(fields=["in_file", "pre_mask"]),
name="inputnode")
outputnode = pe.Node(
niu.IdentityInterface(
fields=["mask_file", "skull_stripped_file", "bias_corrected_file"
]),
name="outputnode",
)
# Dilate pre_mask
pre_dilate = pe.Node(
fsl.DilateImage(
operation="max",
kernel_shape="sphere",
kernel_size=3.0,
internal_datatype="char",
),
name="pre_mask_dilate",
)
# Ensure mask's header matches reference's
check_hdr = pe.Node(MatchHeader(),
name="check_hdr",
run_without_submitting=True)
# Run N4 normally, force num_threads=1 for stability (images are small, no need for >1)
n4_correct = pe.Node(
N4BiasFieldCorrection(dimension=3,
copy_header=True,
bspline_fitting_distance=200),
shrink_factor=2,
name="n4_correct",
n_procs=1,
)
n4_correct.inputs.rescale_intensities = True
# Create a generous BET mask out of the bias-corrected EPI
skullstrip_first_pass = pe.Node(fsl.BET(frac=0.2, mask=True),
name="skullstrip_first_pass")
bet_dilate = pe.Node(
fsl.DilateImage(
operation="max",
kernel_shape="sphere",
kernel_size=6.0,
internal_datatype="char",
),
name="skullstrip_first_dilate",
)
bet_mask = pe.Node(fsl.ApplyMask(), name="skullstrip_first_mask")
# Use AFNI's unifize for T2 constrast & fix header
unifize = pe.Node(
afni.Unifize(
t2=True,
outputtype="NIFTI_GZ",
# Default -clfrac is 0.1, 0.4 was too conservative
# -rbt because I'm a Jedi AFNI Master (see 3dUnifize's documentation)
args="-clfrac 0.2 -rbt 18.3 65.0 90.0",
out_file="uni.nii.gz",
),
name="unifize",
)
fixhdr_unifize = pe.Node(CopyXForm(), name="fixhdr_unifize", mem_gb=0.1)
# Run ANFI's 3dAutomask to extract a refined brain mask
skullstrip_second_pass = pe.Node(afni.Automask(dilate=1,
outputtype="NIFTI_GZ"),
name="skullstrip_second_pass")
fixhdr_skullstrip2 = pe.Node(CopyXForm(),
name="fixhdr_skullstrip2",
mem_gb=0.1)
# Take intersection of both masks
combine_masks = pe.Node(fsl.BinaryMaths(operation="mul"),
name="combine_masks")
# Compute masked brain
apply_mask = pe.Node(fsl.ApplyMask(), name="apply_mask")
if not pre_mask:
from ..interfaces.nibabel import Binarize
bold_template = get_template("MNI152NLin2009cAsym",
resolution=2,
desc="fMRIPrep",
suffix="boldref")
brain_mask = get_template("MNI152NLin2009cAsym",
resolution=2,
desc="brain",
suffix="mask")
# Initialize transforms with antsAI
init_aff = pe.Node(
AI(
fixed_image=str(bold_template),
fixed_image_mask=str(brain_mask),
metric=("Mattes", 32, "Regular", 0.2),
transform=("Affine", 0.1),
search_factor=(20, 0.12),
principal_axes=False,
convergence=(10, 1e-6, 10),
verbose=True,
),
name="init_aff",
n_procs=omp_nthreads,
)
# Registration().version may be None
if parseversion(Registration().version or "0.0.0") > Version("2.2.0"):
init_aff.inputs.search_grid = (40, (0, 40, 40))
# Set up spatial normalization
norm = pe.Node(
Registration(from_file=pkgr_fn("niworkflows.data",
"epi_atlasbased_brainmask.json")),
name="norm",
n_procs=omp_nthreads,
)
norm.inputs.fixed_image = str(bold_template)
map_brainmask = pe.Node(
ApplyTransforms(
interpolation="BSpline",
float=True,
# Use the higher resolution and probseg for numerical stability in rounding
input_image=str(
get_template(
"MNI152NLin2009cAsym",
resolution=1,
label="brain",
suffix="probseg",
)),
),
name="map_brainmask",
)
binarize_mask = pe.Node(Binarize(thresh_low=brainmask_thresh),
name="binarize_mask")
# fmt: off
workflow.connect([
(inputnode, init_aff, [("in_file", "moving_image")]),
(inputnode, map_brainmask, [("in_file", "reference_image")]),
(inputnode, norm, [("in_file", "moving_image")]),
(init_aff, norm, [("output_transform", "initial_moving_transform")
]),
(norm, map_brainmask, [
("reverse_invert_flags", "invert_transform_flags"),
("reverse_transforms", "transforms"),
]),
(map_brainmask, binarize_mask, [("output_image", "in_file")]),
(binarize_mask, pre_dilate, [("out_mask", "in_file")]),
])
# fmt: on
else:
# fmt: off
workflow.connect([
(inputnode, pre_dilate, [("pre_mask", "in_file")]),
])
# fmt: on
# fmt: off
workflow.connect([
(inputnode, check_hdr, [("in_file", "reference")]),
(pre_dilate, check_hdr, [("out_file", "in_file")]),
(check_hdr, n4_correct, [("out_file", "mask_image")]),
(inputnode, n4_correct, [("in_file", "input_image")]),
(inputnode, fixhdr_unifize, [("in_file", "hdr_file")]),
(inputnode, fixhdr_skullstrip2, [("in_file", "hdr_file")]),
(n4_correct, skullstrip_first_pass, [("output_image", "in_file")]),
(skullstrip_first_pass, bet_dilate, [("mask_file", "in_file")]),
(bet_dilate, bet_mask, [("out_file", "mask_file")]),
(skullstrip_first_pass, bet_mask, [("out_file", "in_file")]),
(bet_mask, unifize, [("out_file", "in_file")]),
(unifize, fixhdr_unifize, [("out_file", "in_file")]),
(fixhdr_unifize, skullstrip_second_pass, [("out_file", "in_file")]),
(skullstrip_first_pass, combine_masks, [("mask_file", "in_file")]),
(skullstrip_second_pass, fixhdr_skullstrip2, [("out_file", "in_file")
]),
(fixhdr_skullstrip2, combine_masks, [("out_file", "operand_file")]),
(fixhdr_unifize, apply_mask, [("out_file", "in_file")]),
(combine_masks, apply_mask, [("out_file", "mask_file")]),
(combine_masks, outputnode, [("out_file", "mask_file")]),
(apply_mask, outputnode, [("out_file", "skull_stripped_file")]),
(n4_correct, outputnode, [("output_image", "bias_corrected_file")]),
])
# fmt: on
return workflow
def run(options):
# fix!
out_dir = os.path.join('option', '1')
err_dir = os.path.join('option', '2')
data_dir = os.path.join('option', '3')
work_dir = os.path.join('something', 'else')
# Workflow
merica_wf = pe.Workflow('merica_wf')
merica_wf.base_dir = work_dir
inputspec = pe.Node(util.IdentityInterface(fields=options.keys()),
name='inputspec')
# Node: subject_iterable
run_iterable = pe.Node(util.IdentityInterface(fields=['run'],
mandatory_inputs=True),
name='run_iterable')
run_iterable.iterables = ('run', runs)
info = dict(mri_files=[['run']])
# Create a datasource node to get the mri files
datasource = pe.Node(nio.DataGrabber(infields=['run'],
outfields=info.keys()),
name='datasource')
datasource.inputs.template = '*'
datasource.inputs.base_directory = abspath(data_dir)
datasource.inputs.field_template = dict(mri_files='%s/func/*.nii.gz')
datasource.inputs.template_args = info
datasource.inputs.sort_filelist = True
datasource.inputs.ignore_exception = False
datasource.inputs.raise_on_empty = True
meica_wf.connect(run_iterable, 'run', datasource, 'run')
# Create a Function node to rename output files
getsubs = pe.Node(util.Function(input_names=['run', 'mri_files'],
output_names=['subs'],
function=get_subs),
name='getsubs')
getsubs.inputs.ignore_exception = False
meica_wf.connect(run_iterable, 'run', getsubs, 'run')
meica_wf.connect(datasource, 'mri_files', getsubs, 'mri_files')
get_cm = pe.Node(util.Function(input_names=['fname'],
output_names=['x', 'y', 'z'],
function=find_CM),
name='get_cm')
get_obliquity = pe.Node(util.Function(input_names=['fname'],
output_names=['angmerit'],
function=check_obliquity),
name='get_cm')
if get_obliquity.is_oblique == True:
deoblique = pe.Node(afni.Warp(deoblique=True)
name='deoblique')
merica_wf.connect(upstream, 't1', deoblique, 'in_file')
warpspeed = pe.Node(afni.Warp(args='-card2oblique -newgrid 1.0'))
if skull-stripped == False:
unifeyes = pe.Node(afni.Unifize()
name='unifeyes')
if get_obliquity.is_oblique == True:
merica_wf.connect(deoblique, 'out_file', unifeyes, 'in_file')
else:
merica_wf.connect(upstream, 't1', unifeyes, 'in_file')
skullstrip = pe.Node(afni.SkullStrip(args='-shrink_fac_bot_lim 0.3 -orig_vol')
name='skullstrip')
autobots = pe.Node(afni.Autobox()
name='autobots')
merica_wf.connect(skullstrip, 'out_file', autobots, 'in_file')
# Moving on to functional preprocessing, be back later!
if despike == True:
despike = pe.Node(afni.Despike()
name='despike')
if skull-stripped == False:
merica_wf.connect(autobots, 'out_file', despike, 'in_file')
else:
merica_wf.connect(upstream, 't1', despike, 'in_file')
meica_wf.connect(run_iterable, 'run', get_cm, 'fname')
meica_wf.connect(run_iterable, 'run', get_cm, 'fname')
def init_enhance_and_skullstrip_asl_wf(
brainmask_thresh=0.5,
name="enhance_and_skullstrip_asl_wf",
omp_nthreads=1,
pre_mask=False,
):
"""
Enhance and run brain extraction on a ASL image.
This workflow takes in a :abbr:`ASL (Aretrrail Spin Labeling)`
average/summary (e.g., a reference image
averaging non-steady-state timepoints), and sharpens the histogram
with the application of the N4 algorithm for removing the
:abbr:`INU (intensity non-uniformity)` bias field and calculates a signal
mask.
Steps of this workflow are:
1. Calculate a tentative mask by registering (9-parameters) to *fMRIPrep*'s
:abbr:`EPI (echo-planar imaging)` -*aslref* template, which
is in MNI space.
The tentative mask is obtained by resampling the MNI template's
brainmask into *aslref*-space.
2. Binary dilation of the tentative mask with a sphere of 3mm diameter.
3. Run ANTs' ``N4BiasFieldCorrection`` on the input
:abbr:`ASL (arterial spin labeling)` average, using the
mask generated in 1) instead of the internal Otsu thresholding.
4. Calculate a loose mask using FSL's ``bet``, with one mathematical morphology
dilation of one iteration and a sphere of 6mm as structuring element.
5. Mask the :abbr:`INU (intensity non-uniformity)`-corrected image
with the latest mask calculated in 3), then use AFNI's ``3dUnifize``
to *standardize* the T2* contrast distribution.
6. Calculate a mask using AFNI's ``3dAutomask`` after the contrast
enhancement of 4).
7. Calculate a final mask as the intersection of 4) and 6).
8. Apply final mask on the enhanced reference.
Step 1 can be skipped if the ``pre_mask`` argument is set to ``True`` and
a tentative mask is passed in to the workflow throught the ``pre_mask``
Nipype input.
Workflow graph
.. workflow ::
:graph2use: orig
:simple_form: yes
from niworkflows.func.util import init_enhance_and_skullstrip_asl_wf
wf = init_enhance_and_skullstrip_asl_wf(omp_nthreads=1)
.. _N4BiasFieldCorrection: https://hdl.handle.net/10380/3053
Parameters
----------
brainmask_thresh: :obj:`float`
Lower threshold for the probabilistic brainmask to obtain
the final binary mask (default: 0.5).
name : str
Name of workflow (default: ``enhance_and_skullstrip_asl_wf``)
omp_nthreads : int
number of threads available to parallel nodes
pre_mask : bool
Indicates whether the ``pre_mask`` input will be set (and thus, step 1
should be skipped).
Inputs
------
in_file : str
ASL image (single volume)
pre_mask : bool
A tentative brain mask to initialize the workflow (requires ``pre_mask``
parameter set ``True``).
Outputs
-------
bias_corrected_file : str
the ``in_file`` after `N4BiasFieldCorrection`_
skull_stripped_file : str
the ``bias_corrected_file`` after skull-stripping
mask_file : str
mask of the skull-stripped input file
out_report : str
reportlet for the skull-stripping
"""
workflow = Workflow(name=name)
inputnode = pe.Node(niu.IdentityInterface(fields=["in_file", "pre_mask"]),
name="inputnode")
outputnode = pe.Node(
niu.IdentityInterface(
fields=["mask_file", "skull_stripped_file", "bias_corrected_file"
]),
name="outputnode",
)
pre_mask = pre_mask
# Ensure mask's header matches reference's
#check_hdr = pe.Node(MatchHeader(), name="check_hdr", run_without_submitting=True)
# Run N4 normally, force num_threads=1 for stability (images are small, no need for >1)
n4_correct = pe.Node(
N4BiasFieldCorrection(dimension=3,
copy_header=True,
bspline_fitting_distance=200),
shrink_factor=2,
name="n4_correct",
n_procs=1,
)
n4_correct.inputs.rescale_intensities = True
# Create a generous BET mask out of the bias-corrected EPI
skullstrip_first_pass = pe.Node(fsl.BET(frac=0.2, mask=True),
name="skullstrip_first_pass")
bet_dilate = pe.Node(
fsl.DilateImage(
operation="max",
kernel_shape="sphere",
kernel_size=6.0,
internal_datatype="char",
),
name="skullstrip_first_dilate",
)
bet_mask = pe.Node(fsl.ApplyMask(), name="skullstrip_first_mask")
# Use AFNI's unifize for T2 constrast & fix header
unifize = pe.Node(
afni.Unifize(
t2=True,
outputtype="NIFTI_GZ",
# Default -clfrac is 0.1, 0.4 was too conservative
# -rbt because I'm a Jedi AFNI Master (see 3dUnifize's documentation)
args="-clfrac 0.2 -rbt 18.3 65.0 90.0",
out_file="uni.nii.gz",
),
name="unifize",
)
fixhdr_unifize = pe.Node(CopyXForm(), name="fixhdr_unifize", mem_gb=0.1)
# Run ANFI's 3dAutomask to extract a refined brain mask
skullstrip_second_pass = pe.Node(afni.Automask(dilate=1,
outputtype="NIFTI_GZ"),
name="skullstrip_second_pass")
fixhdr_skullstrip2 = pe.Node(CopyXForm(),
name="fixhdr_skullstrip2",
mem_gb=0.1)
# Take intersection of both masks
combine_masks = pe.Node(fsl.BinaryMaths(operation="mul"),
name="combine_masks")
# Compute masked brain
apply_mask = pe.Node(fsl.ApplyMask(), name="apply_mask")
#binarize_mask = pe.Node(Binarize(thresh_low=brainmask_thresh), name="binarize_mask")
# fmt: off
workflow.connect([
(inputnode, n4_correct, [("in_file", "mask_image")]),
(inputnode, n4_correct, [("in_file", "input_image")]),
(inputnode, fixhdr_unifize, [("in_file", "hdr_file")]),
(inputnode, fixhdr_skullstrip2, [("in_file", "hdr_file")]),
(n4_correct, skullstrip_first_pass, [("output_image", "in_file")]),
(skullstrip_first_pass, bet_dilate, [("mask_file", "in_file")]),
(bet_dilate, bet_mask, [("out_file", "mask_file")]),
(skullstrip_first_pass, bet_mask, [("out_file", "in_file")]),
(bet_mask, unifize, [("out_file", "in_file")]),
(unifize, fixhdr_unifize, [("out_file", "in_file")]),
(fixhdr_unifize, skullstrip_second_pass, [("out_file", "in_file")]),
(skullstrip_first_pass, combine_masks, [("mask_file", "in_file")]),
(skullstrip_second_pass, fixhdr_skullstrip2, [("out_file", "in_file")
]),
(fixhdr_skullstrip2, combine_masks, [("out_file", "operand_file")]),
(fixhdr_unifize, apply_mask, [("out_file", "in_file")]),
(combine_masks, apply_mask, [("out_file", "mask_file")]),
(combine_masks, outputnode, [("out_file", "mask_file")]),
(apply_mask, outputnode, [("out_file", "skull_stripped_file")]),
(n4_correct, outputnode, [("output_image", "bias_corrected_file")]),
])
# fmt: on
return workflow
def coregister_fmri_session(session_data,
t_r,
write_dir,
brain_volume,
use_rats_tool=True,
slice_timing=True,
prior_rigid_body_registration=False,
caching=False,
voxel_size_x=.1,
voxel_size_y=.1,
verbose=True,
**environ_kwargs):
"""
Coregistration of the subject's functional and anatomical images.
The functional volume is aligned to the anatomical, first with a rigid body
registration and then on a per-slice basis (only a fine correction, this is
mostly for correction of EPI distortion).
Parameters
----------
session_data : sammba.registration.SessionData
Single animal data, giving paths to its functional and anatomical
image, as well as it identifier.
t_r : float
Repetition time for the EPI, in seconds.
write_dir : str
Directory to save the output and temporary images.
brain_volume : int
Volume of the brain in mm3 used for brain extraction.
Typically 400 for mouse and 1800 for rat.
use_rats_tool : bool, optional
If True, brain mask is computed using RATS Mathematical Morphology.
Otherwise, a histogram-based brain segmentation is used.
prior_rigid_body_registration : bool, optional
If True, a rigid-body registration of the anat to the func is performed
prior to the warp. Useful if the images headers have missing/wrong
information.
voxel_size_x : float, optional
Resampling resolution for the x-axis, in mm.
voxel_size_y : float, optional
Resampling resolution for the y-axis, in mm.
caching : bool, optional
Wether or not to use caching.
verbose : bool, optional
If True, all steps are verbose. Note that caching implies some
verbosity in any case.
environ_kwargs : extra arguments keywords
Extra arguments keywords, passed to interfaces environ variable.
Returns
-------
the same sequence with each animal_data updated: the following attributes
are added
- `output_dir_` : str
Path to the output directory.
- `coreg_func_` : str
Path to paths to the coregistered functional image.
- `coreg_anat_` : str
Path to paths to the coregistered functional image.
- `coreg_transform_` : str
Path to the transform from anat to func.
Notes
-----
If `use_rats_tool` is turned on, RATS tool is used for brain extraction
and has to be cited. For more information, see
`RATS <http://www.iibi.uiowa.edu/content/rats-overview/>`_
"""
func_filename = session_data.func
anat_filename = session_data.anat
environ = {'AFNI_DECONFLICT': 'OVERWRITE'}
for (key, value) in environ_kwargs.items():
environ[key] = value
if verbose:
terminal_output = 'allatonce'
else:
terminal_output = 'none'
if use_rats_tool:
if segmentation.interfaces.Info().version() is None:
raise ValueError('Can not locate RATS')
else:
ComputeMask = segmentation.MathMorphoMask
else:
ComputeMask = segmentation.HistogramMask
if ants.base.Info().version is None:
raise ValueError('Can not locate ANTS')
if caching:
memory = Memory(write_dir)
tshift = memory.cache(afni.TShift)
clip_level = memory.cache(afni.ClipLevel)
volreg = memory.cache(afni.Volreg)
allineate = memory.cache(afni.Allineate)
tstat = memory.cache(afni.TStat)
compute_mask = memory.cache(ComputeMask)
calc = memory.cache(afni.Calc)
allineate = memory.cache(afni.Allineate)
allineate2 = memory.cache(afni.Allineate)
unifize = memory.cache(afni.Unifize)
bias_correct = memory.cache(ants.N4BiasFieldCorrection)
catmatvec = memory.cache(afni.CatMatvec)
warp = memory.cache(afni.Warp)
resample = memory.cache(afni.Resample)
slicer = memory.cache(afni.ZCutUp)
warp_apply = memory.cache(afni.NwarpApply)
qwarp = memory.cache(afni.Qwarp)
merge = memory.cache(afni.Zcat)
copy_geom = memory.cache(fsl.CopyGeom)
overwrite = False
for step in [
tshift, volreg, allineate, allineate2, tstat, compute_mask,
calc, unifize, resample, slicer, warp_apply, qwarp, merge
]:
step.interface().set_default_terminal_output(terminal_output)
else:
tshift = afni.TShift(terminal_output=terminal_output).run
clip_level = afni.ClipLevel().run
volreg = afni.Volreg(terminal_output=terminal_output).run
allineate = afni.Allineate(terminal_output=terminal_output).run
allineate2 = afni.Allineate(terminal_output=terminal_output
).run # TODO: remove after fixed bug
tstat = afni.TStat(terminal_output=terminal_output).run
compute_mask = ComputeMask().run
calc = afni.Calc(terminal_output=terminal_output).run
unifize = afni.Unifize(terminal_output=terminal_output).run
bias_correct = ants.N4BiasFieldCorrection(
terminal_output=terminal_output).run
catmatvec = afni.CatMatvec().run
warp = afni.Warp().run
resample = afni.Resample(terminal_output=terminal_output).run
slicer = afni.ZCutUp(terminal_output=terminal_output).run
warp_apply = afni.NwarpApply(terminal_output=terminal_output).run
qwarp = afni.Qwarp(terminal_output=terminal_output).run
merge = afni.Zcat(terminal_output=terminal_output).run
copy_geom = fsl.CopyGeom(terminal_output=terminal_output).run
overwrite = True
session_data._check_inputs()
output_dir = os.path.join(os.path.abspath(write_dir),
session_data.animal_id)
session_data._set_output_dir_(output_dir)
current_dir = os.getcwd()
os.chdir(output_dir)
output_files = []
#######################################
# Correct functional for slice timing #
#######################################
if slice_timing:
out_tshift = tshift(in_file=func_filename,
outputtype='NIFTI_GZ',
tpattern='altplus',
tr=str(t_r),
environ=environ)
func_filename = out_tshift.outputs.out_file
output_files.append(func_filename)
################################################
# Register functional volumes to the first one #
################################################
# XXX why do you need a thresholded image ?
out_clip_level = clip_level(in_file=func_filename)
out_calc_threshold = calc(in_file_a=func_filename,
expr='ispositive(a-{0}) * a'.format(
out_clip_level.outputs.clip_val),
outputtype='NIFTI_GZ')
thresholded_filename = out_calc_threshold.outputs.out_file
out_volreg = volreg( # XXX dfile not saved
in_file=thresholded_filename,
outputtype='NIFTI_GZ',
environ=environ,
oned_file=fname_presuffix(thresholded_filename,
suffix='Vr.1Dfile.1D',
use_ext=False),
oned_matrix_save=fname_presuffix(thresholded_filename,
suffix='Vr.aff12.1D',
use_ext=False))
# Apply the registration to the whole head
out_allineate = allineate(in_file=func_filename,
master=func_filename,
in_matrix=out_volreg.outputs.oned_matrix_save,
out_file=fname_presuffix(func_filename,
suffix='Av'),
environ=environ)
# 3dAllineate removes the obliquity. This is not a good way to readd it as
# removes motion correction info in the header if it were an AFNI file...as
# it happens it's NIfTI which does not store that so irrelevant!
out_copy_geom = copy_geom(dest_file=out_allineate.outputs.out_file,
in_file=out_volreg.outputs.out_file)
allineated_filename = out_copy_geom.outputs.out_file
# Create a (hopefully) nice mean image for use in the registration
out_tstat = tstat(in_file=allineated_filename,
args='-mean',
outputtype='NIFTI_GZ',
environ=environ)
# Update outputs
output_files.extend([
thresholded_filename, out_volreg.outputs.oned_matrix_save,
out_volreg.outputs.out_file, out_volreg.outputs.md1d_file,
allineated_filename, out_tstat.outputs.out_file
])
###########################################
# Corret anat and func for intensity bias #
###########################################
# Correct the functional average for intensities bias
out_bias_correct = bias_correct(input_image=out_tstat.outputs.out_file)
unbiased_func_filename = out_bias_correct.outputs.output_image
# Bias correct the antomical image
out_unifize = unifize(in_file=anat_filename,
outputtype='NIFTI_GZ',
environ=environ)
unbiased_anat_filename = out_unifize.outputs.out_file
# Update outputs
output_files.extend([unbiased_func_filename, unbiased_anat_filename])
#############################################
# Rigid-body registration anat -> mean func #
#############################################
if prior_rigid_body_registration:
# Mask the mean functional volume outside the brain.
out_clip_level = clip_level(in_file=unbiased_func_filename)
out_compute_mask_func = compute_mask(
in_file=unbiased_func_filename,
volume_threshold=brain_volume,
intensity_threshold=int(out_clip_level.outputs.clip_val))
out_cacl_func = calc(in_file_a=unbiased_func_filename,
in_file_b=out_compute_mask_func.outputs.out_file,
expr='a*b',
outputtype='NIFTI_GZ',
environ=environ)
# Mask the anatomical volume outside the brain.
out_clip_level = clip_level(in_file=unbiased_anat_filename)
out_compute_mask_anat = compute_mask(
in_file=unbiased_anat_filename,
volume_threshold=brain_volume,
intensity_threshold=int(out_clip_level.outputs.clip_val))
out_cacl_anat = calc(in_file_a=unbiased_anat_filename,
in_file_b=out_compute_mask_anat.outputs.out_file,
expr='a*b',
outputtype='NIFTI_GZ',
environ=environ)
# Compute the transformation from functional to anatomical brain
# XXX: why in this sense
out_allineate = allineate2(
in_file=out_cacl_func.outputs.out_file,
reference=out_cacl_anat.outputs.out_file,
out_matrix=fname_presuffix(out_cacl_func.outputs.out_file,
suffix='_shr.aff12.1D',
use_ext=False),
center_of_mass='',
warp_type='shift_rotate',
out_file=fname_presuffix(out_cacl_func.outputs.out_file,
suffix='_shr'),
environ=environ)
rigid_transform_file = out_allineate.outputs.out_matrix
output_files.extend([
out_compute_mask_func.outputs.out_file,
out_cacl_func.outputs.out_file,
out_compute_mask_anat.outputs.out_file,
out_cacl_anat.outputs.out_file, rigid_transform_file,
out_allineate.outputs.out_file
])
# apply the inverse transform to register the anatomical to the func
catmatvec_out_file = fname_presuffix(rigid_transform_file,
suffix='INV')
out_catmatvec = catmatvec(in_file=[(rigid_transform_file, 'I')],
oneline=True,
out_file=catmatvec_out_file)
output_files.append(out_catmatvec.outputs.out_file)
out_allineate = allineate(in_file=unbiased_anat_filename,
master=unbiased_func_filename,
in_matrix=out_catmatvec.outputs.out_file,
out_file=fname_presuffix(
unbiased_anat_filename,
suffix='_shr_in_func_space'),
environ=environ)
allineated_anat_filename = out_allineate.outputs.out_file
output_files.append(allineated_anat_filename)
else:
allineated_anat_filename = unbiased_anat_filename
############################################
# Nonlinear registration anat -> mean func #
############################################
# 3dWarp doesn't put the obliquity in the header, so do it manually
# This step generates one file per slice and per time point, so we are
# making sure they are removed at the end
out_warp = warp(in_file=allineated_anat_filename,
oblique_parent=unbiased_func_filename,
interp='quintic',
gridset=unbiased_func_filename,
outputtype='NIFTI_GZ',
verbose=True,
environ=environ)
registered_anat_filename = out_warp.outputs.out_file
registered_anat_oblique_filename = fix_obliquity(registered_anat_filename,
unbiased_func_filename,
verbose=verbose)
# Concatenate all the anat to func tranforms
mat_filename = fname_presuffix(registered_anat_filename,
suffix='_warp.mat',
use_ext=False)
# XXX Handle this correctly according to caching
if not os.path.isfile(mat_filename):
np.savetxt(mat_filename, [out_warp.runtime.stdout], fmt='%s')
output_files.append(mat_filename)
transform_filename = fname_presuffix(registered_anat_filename,
suffix='_anat_to_func.aff12.1D',
use_ext=False)
if prior_rigid_body_registration:
_ = catmatvec(in_file=[(mat_filename, 'ONELINE'),
(rigid_transform_file, 'ONELINE')],
oneline=True,
out_file=transform_filename)
else:
_ = catmatvec(in_file=[(mat_filename, 'ONELINE')],
oneline=True,
out_file=transform_filename)
##################################################
# Per-slice non-linear registration func -> anat #
##################################################
# Slice anatomical image
anat_img = nibabel.load(registered_anat_oblique_filename)
anat_n_slices = anat_img.header.get_data_shape()[2]
sliced_registered_anat_filenames = []
for slice_n in range(anat_n_slices):
out_slicer = slicer(in_file=registered_anat_oblique_filename,
keep='{0} {0}'.format(slice_n),
out_file=fname_presuffix(
registered_anat_oblique_filename,
suffix='Sl%d' % slice_n),
environ=environ)
oblique_slice = fix_obliquity(out_slicer.outputs.out_file,
registered_anat_oblique_filename,
verbose=verbose)
sliced_registered_anat_filenames.append(oblique_slice)
# Slice mean functional
sliced_bias_corrected_filenames = []
img = nibabel.load(func_filename)
n_slices = img.header.get_data_shape()[2]
for slice_n in range(n_slices):
out_slicer = slicer(in_file=unbiased_func_filename,
keep='{0} {0}'.format(slice_n),
out_file=fname_presuffix(unbiased_func_filename,
suffix='Sl%d' % slice_n),
environ=environ)
oblique_slice = fix_obliquity(out_slicer.outputs.out_file,
unbiased_func_filename,
verbose=verbose)
sliced_bias_corrected_filenames.append(oblique_slice)
# Below line is to deal with slices where there is no signal (for example
# rostral end of some anatomicals)
# The inverse warp frequently fails, Resampling can help it work better
# XXX why specifically .1 in voxel_size ?
voxel_size_z = anat_img.header.get_zooms()[2]
resampled_registered_anat_filenames = []
for sliced_registered_anat_filename in sliced_registered_anat_filenames:
out_resample = resample(in_file=sliced_registered_anat_filename,
voxel_size=(voxel_size_x, voxel_size_y,
voxel_size_z),
outputtype='NIFTI_GZ',
environ=environ)
resampled_registered_anat_filenames.append(
out_resample.outputs.out_file)
resampled_bias_corrected_filenames = []
for sliced_bias_corrected_filename in sliced_bias_corrected_filenames:
out_resample = resample(in_file=sliced_bias_corrected_filename,
voxel_size=(voxel_size_x, voxel_size_y,
voxel_size_z),
outputtype='NIFTI_GZ',
environ=environ)
resampled_bias_corrected_filenames.append(
out_resample.outputs.out_file)
# single slice non-linear functional to anatomical registration
warped_slices = []
warp_filenames = []
for (resampled_bias_corrected_filename,
resampled_registered_anat_filename) in zip(
resampled_bias_corrected_filenames,
resampled_registered_anat_filenames):
warped_slice = fname_presuffix(resampled_bias_corrected_filename,
suffix='_qw')
out_qwarp = qwarp(
in_file=resampled_bias_corrected_filename,
base_file=resampled_registered_anat_filename,
iwarp=True, # XXX: is this necessary
noneg=True,
blur=[0],
nmi=True,
noXdis=True,
allineate=True,
allineate_opts='-parfix 1 0 -parfix 2 0 -parfix 3 0 '
'-parfix 4 0 -parfix 5 0 -parfix 6 0 '
'-parfix 7 0 -parfix 9 0 '
'-parfix 10 0 -parfix 12 0',
out_file=warped_slice,
environ=environ)
warped_slices.append(out_qwarp.outputs.warped_source)
warp_filenames.append(out_qwarp.outputs.source_warp)
output_files.append(out_qwarp.outputs.base_warp)
# There are files geenrated by the allineate option
output_files.extend([
fname_presuffix(out_qwarp.outputs.warped_source, suffix='_Allin'),
fname_presuffix(out_qwarp.outputs.warped_source,
suffix='_Allin.nii',
use_ext=False),
fname_presuffix(out_qwarp.outputs.warped_source,
suffix='_Allin.aff12.1D',
use_ext=False)
])
# Resample the mean volume back to the initial resolution,
voxel_size = nibabel.load(unbiased_func_filename).header.get_zooms()
resampled_warped_slices = []
for warped_slice in warped_slices:
out_resample = resample(in_file=warped_slice,
voxel_size=voxel_size,
outputtype='NIFTI_GZ',
environ=environ)
resampled_warped_slices.append(out_resample.outputs.out_file)
# fix the obliquity
resampled_warped_slices_oblique = []
for (sliced_registered_anat_filename,
resampled_warped_slice) in zip(sliced_registered_anat_filenames,
resampled_warped_slices):
oblique_slice = fix_obliquity(resampled_warped_slice,
sliced_registered_anat_filename,
verbose=verbose)
resampled_warped_slices_oblique.append(oblique_slice)
# slice functional
sliced_func_filenames = []
for slice_n in range(n_slices):
out_slicer = slicer(in_file=allineated_filename,
keep='{0} {0}'.format(slice_n),
out_file=fname_presuffix(allineated_filename,
suffix='Sl%d' % slice_n),
environ=environ)
oblique_slice = fix_obliquity(out_slicer.outputs.out_file,
allineated_filename,
verbose=verbose)
sliced_func_filenames.append(oblique_slice)
# Apply the precomputed warp slice by slice
warped_func_slices = []
for (sliced_func_filename, warp_filename) in zip(sliced_func_filenames,
warp_filenames):
out_warp_apply = warp_apply(in_file=sliced_func_filename,
master=sliced_func_filename,
warp=warp_filename,
out_file=fname_presuffix(
sliced_func_filename, suffix='_qw'),
environ=environ)
warped_func_slices.append(out_warp_apply.outputs.out_file)
# Finally, merge all slices !
out_merge_func = merge(in_files=warped_func_slices,
outputtype='NIFTI_GZ',
environ=environ)
# Fix the obliquity
merged_oblique = fix_obliquity(out_merge_func.outputs.out_file,
allineated_filename,
verbose=verbose)
# Update the fmri data
setattr(session_data, "coreg_func_", merged_oblique)
setattr(session_data, "coreg_anat_", registered_anat_oblique_filename)
setattr(session_data, "coreg_transform_", transform_filename)
os.chdir(current_dir)
# Collect the outputs
output_files.extend(sliced_registered_anat_filenames +
sliced_bias_corrected_filenames +
resampled_registered_anat_filenames +
resampled_bias_corrected_filenames + warped_slices +
warp_filenames + resampled_warped_slices_oblique +
sliced_func_filenames + warped_func_slices)
if not caching:
for out_file in output_files:
if os.path.isfile(out_file):
os.remove(out_file)
def init_enhance_and_skullstrip_bold_wf(name='enhance_and_skullstrip_bold_wf',
omp_nthreads=1,
enhance_t2=False):
"""
This workflow takes in a :abbr:`BOLD (blood-oxygen level-dependant)`
:abbr:`fMRI (functional MRI)` average/summary (e.g. a reference image
averaging non-steady-state timepoints), and sharpens the histogram
with the application of the N4 algorithm for removing the
:abbr:`INU (intensity non-uniformity)` bias field and calculates a signal
mask.
Steps of this workflow are:
1. Calculate a conservative mask using Nilearn's ``create_epi_mask``.
2. Run ANTs' ``N4BiasFieldCorrection`` on the input
:abbr:`BOLD (blood-oxygen level-dependant)` average, using the
mask generated in 1) instead of the internal Otsu thresholding.
3. Calculate a loose mask using FSL's ``bet``, with one mathematical morphology
dilation of one iteration and a sphere of 6mm as structuring element.
4. Mask the :abbr:`INU (intensity non-uniformity)`-corrected image
with the latest mask calculated in 3), then use AFNI's ``3dUnifize``
to *standardize* the T2* contrast distribution.
5. Calculate a mask using AFNI's ``3dAutomask`` after the contrast
enhancement of 4).
6. Calculate a final mask as the intersection of 3) and 5).
7. Apply final mask on the enhanced reference.
.. workflow ::
:graph2use: orig
:simple_form: yes
from fmriprep.workflows.bold.util import init_enhance_and_skullstrip_bold_wf
wf = init_enhance_and_skullstrip_bold_wf(omp_nthreads=1)
**Parameters**
name : str
Name of workflow (default: ``enhance_and_skullstrip_bold_wf``)
omp_nthreads : int
number of threads available to parallel nodes
enhance_t2 : bool
perform logarithmic transform of input BOLD image to improve contrast
before calculating the preliminary mask
**Inputs**
in_file
BOLD image (single volume)
**Outputs**
bias_corrected_file
the ``in_file`` after `N4BiasFieldCorrection`_
skull_stripped_file
the ``bias_corrected_file`` after skull-stripping
mask_file
mask of the skull-stripped input file
out_report
reportlet for the skull-stripping
.. _N4BiasFieldCorrection: https://hdl.handle.net/10380/3053
"""
workflow = Workflow(name=name)
inputnode = pe.Node(niu.IdentityInterface(fields=['in_file']),
name='inputnode')
outputnode = pe.Node(niu.IdentityInterface(
fields=['mask_file', 'skull_stripped_file', 'bias_corrected_file']),
name='outputnode')
# Create a loose mask to avoid N4 internal's Otsu mask
n4_mask = pe.Node(MaskEPI(upper_cutoff=0.75,
enhance_t2=enhance_t2,
opening=1,
no_sanitize=True),
name='n4_mask')
# Run N4 normally, force num_threads=1 for stability (images are small, no need for >1)
n4_correct = pe.Node(ants.N4BiasFieldCorrection(dimension=3,
copy_header=True),
name='n4_correct',
n_procs=1)
# Create a generous BET mask out of the bias-corrected EPI
skullstrip_first_pass = pe.Node(fsl.BET(frac=0.2, mask=True),
name='skullstrip_first_pass')
bet_dilate = pe.Node(fsl.DilateImage(operation='max',
kernel_shape='sphere',
kernel_size=6.0,
internal_datatype='char'),
name='skullstrip_first_dilate')
bet_mask = pe.Node(fsl.ApplyMask(), name='skullstrip_first_mask')
# Use AFNI's unifize for T2 constrast & fix header
unifize = pe.Node(
afni.Unifize(
t2=True,
outputtype='NIFTI_GZ',
# Default -clfrac is 0.1, 0.4 was too conservative
# -rbt because I'm a Jedi AFNI Master (see 3dUnifize's documentation)
args='-clfrac 0.2 -rbt 18.3 65.0 90.0',
out_file="uni.nii.gz"),
name='unifize')
fixhdr_unifize = pe.Node(CopyXForm(), name='fixhdr_unifize', mem_gb=0.1)
# Run ANFI's 3dAutomask to extract a refined brain mask
skullstrip_second_pass = pe.Node(afni.Automask(dilate=1,
outputtype='NIFTI_GZ'),
name='skullstrip_second_pass')
fixhdr_skullstrip2 = pe.Node(CopyXForm(),
name='fixhdr_skullstrip2',
mem_gb=0.1)
# Take intersection of both masks
combine_masks = pe.Node(fsl.BinaryMaths(operation='mul'),
name='combine_masks')
# Compute masked brain
apply_mask = pe.Node(fsl.ApplyMask(), name='apply_mask')
workflow.connect([
(inputnode, n4_mask, [('in_file', 'in_files')]),
(inputnode, n4_correct, [('in_file', 'input_image')]),
(inputnode, fixhdr_unifize, [('in_file', 'hdr_file')]),
(inputnode, fixhdr_skullstrip2, [('in_file', 'hdr_file')]),
(n4_mask, n4_correct, [('out_mask', 'mask_image')]),
(n4_correct, skullstrip_first_pass, [('output_image', 'in_file')]),
(skullstrip_first_pass, bet_dilate, [('mask_file', 'in_file')]),
(bet_dilate, bet_mask, [('out_file', 'mask_file')]),
(skullstrip_first_pass, bet_mask, [('out_file', 'in_file')]),
(bet_mask, unifize, [('out_file', 'in_file')]),
(unifize, fixhdr_unifize, [('out_file', 'in_file')]),
(fixhdr_unifize, skullstrip_second_pass, [('out_file', 'in_file')]),
(skullstrip_first_pass, combine_masks, [('mask_file', 'in_file')]),
(skullstrip_second_pass, fixhdr_skullstrip2, [('out_file', 'in_file')
]),
(fixhdr_skullstrip2, combine_masks, [('out_file', 'operand_file')]),
(fixhdr_unifize, apply_mask, [('out_file', 'in_file')]),
(combine_masks, apply_mask, [('out_file', 'mask_file')]),
(combine_masks, outputnode, [('out_file', 'mask_file')]),
(apply_mask, outputnode, [('out_file', 'skull_stripped_file')]),
(n4_correct, outputnode, [('output_image', 'bias_corrected_file')]),
])
return workflow
def create_pipeline_graph(pipeline_name, graph_file,
graph_kind='hierarchical'):
"""Creates pipeline graph for a given piepline.
Parameters
----------
pipeline_name : one of {'anat_to_common_rigid', 'anat_to_common_affine',
'anat_to_common_nonlinear'}
Pipeline name.
graph_file : str.
Path to save the graph image to.
graph_kind : one of {'orig', 'hierarchical', 'flat', 'exec', 'colored'}, optional.
The kind of the graph, passed to
nipype.pipeline.workflows.Workflow().write_graph
"""
pipeline_names = ['anats_to_common_rigid', 'anats_to_common_affine',
'anats_to_common_nonlinear']
if pipeline_name not in pipeline_names:
raise NotImplementedError(
'Pipeline name must be one of {0}, you entered {1}'.format(
pipeline_names, pipeline_name))
graph_kinds = ['orig', 'hierarchical', 'flat', 'exec', 'colored']
if graph_kind not in graph_kinds:
raise ValueError(
'Graph kind must be one of {0}, you entered {1}'.format(
graph_kinds, graph_kind))
workflow = pe.Workflow(name=pipeline_name)
#######################################################################
# Specify rigid body registration pipeline steps
unifize = pe.Node(interface=afni.Unifize(), name='bias_correct')
clip_level = pe.Node(interface=afni.ClipLevel(),
name='compute_mask_threshold')
compute_mask = pe.Node(interface=interfaces.MathMorphoMask(),
name='compute_brain_mask')
apply_mask = pe.Node(interface=afni.Calc(), name='apply_brain_mask')
center_mass = pe.Node(interface=afni.CenterMass(),
name='compute_and_set_cm_in_header')
refit_copy = pe.Node(afni.Refit(), name='copy_cm_in_header')
tcat1 = pe.Node(afni.TCat(), name='concatenate_across_individuals1')
tstat1 = pe.Node(afni.TStat(), name='compute_average1')
undump = pe.Node(afni.Undump(), name='create_empty_template')
refit_set = pe.Node(afni.Refit(), name='set_cm_in_header')
resample1 = pe.Node(afni.Resample(), name='resample1')
resample2 = pe.Node(afni.Resample(), name='resample2')
shift_rotate = pe.Node(afni.Allineate(), name='shift_rotate')
apply_allineate1 = pe.Node(afni.Allineate(), name='apply_transform1')
tcat2 = pe.Node(afni.TCat(), name='concatenate_across_individuals2')
tstat2 = pe.Node(afni.TStat(), name='compute_average2')
tcat3 = pe.Node(afni.TCat(), name='concatenate_across_individuals3')
tstat3 = pe.Node(afni.TStat(), name='compute_average3')
workflow.add_nodes([unifize, clip_level, compute_mask, apply_mask,
center_mass,
refit_copy, tcat1, tstat1, undump, refit_set,
resample1, resample2, shift_rotate, apply_allineate1,
tcat2, tstat2, tcat3, tstat3])
#######################################################################
# and connections
workflow.connect(unifize, 'out_file', clip_level, 'in_file')
workflow.connect(clip_level, 'clip_val',
compute_mask, 'intensity_threshold')
workflow.connect(unifize, 'out_file', compute_mask, 'in_file')
workflow.connect(compute_mask, 'out_file', apply_mask, 'in_file_a')
workflow.connect(unifize, 'out_file', apply_mask, 'in_file_b')
workflow.connect(apply_mask, 'out_file',
center_mass, 'in_file')
workflow.connect(unifize, 'out_file', refit_copy, 'in_file')
workflow.connect(center_mass, 'out_file',
refit_copy, 'duporigin_file')
workflow.connect(center_mass, 'out_file', tcat1, 'in_files')
workflow.connect(tcat1, 'out_file', tstat1, 'in_file')
workflow.connect(tstat1, 'out_file', undump, 'in_file')
workflow.connect(undump, 'out_file', refit_set, 'in_file')
workflow.connect(refit_set, 'out_file', resample1, 'master')
workflow.connect(refit_copy, 'out_file', resample1, 'in_file')
workflow.connect(refit_set, 'out_file', resample2, 'master')
workflow.connect(center_mass, 'out_file', resample2, 'in_file')
workflow.connect(resample2, 'out_file', tcat2, 'in_files')
workflow.connect(tcat2, 'out_file', tstat2, 'in_file')
workflow.connect(tstat2, 'out_file', shift_rotate, 'reference')
workflow.connect(resample2, 'out_file', shift_rotate, 'in_file')
workflow.connect(tstat2, 'out_file', apply_allineate1, 'master')
workflow.connect(resample1, 'out_file',
apply_allineate1, 'in_file')
workflow.connect(shift_rotate, 'out_matrix',
apply_allineate1, 'in_matrix')
workflow.connect(apply_allineate1, 'out_file', tcat3, 'in_files')
workflow.connect(tcat3, 'out_file', tstat3, 'in_file')
if pipeline_name in ['anats_to_common_affine',
'anat_to_common_nonlinear']:
mask = pe.Node(afni.MaskTool(), name='generate_count_mask')
allineate = pe.Node(afni.Allineate(), name='allineate')
catmatvec = pe.Node(afni.CatMatvec(), name='concatenate_transforms')
apply_allineate2 = pe.Node(afni.Allineate(), name='apply_transform2')
tcat3 = pe.Node(
afni.TCat(), name='concatenate_across_individuals4')
tstat3 = pe.Node(afni.TStat(), name='compute_average4')
workflow.add_nodes([mask, allineate, catmatvec, apply_allineate2,
tcat3, tstat3])
workflow.connect(tcat2, 'out_file', mask, 'in_file')
workflow.connect(mask, 'out_file', allineate, 'weight')
workflow.connect(apply_allineate1, 'out_file',
allineate, 'in_file')
workflow.connect(allineate, 'out_matrix',
catmatvec, 'in_file')
#XXX how can we enter multiple files ?
workflow.connect(catmatvec, 'out_file',
apply_allineate2, 'in_matrix')
workflow.connect(resample1, 'out_file',
apply_allineate2, 'in_file')
workflow.connect(apply_allineate2, 'out_file', tcat3, 'in_files')
workflow.connect(tcat3, 'out_file', tstat3, 'in_file')
if pipeline_name == 'anats_to_common_nonlinear':
pass
graph_file_root, graph_file_ext = os.path.splitext(graph_file)
if graph_file_ext:
_ = workflow.write_graph(graph2use=graph_kind,
format=graph_file_ext[1:],
dotfilename=graph_file_root)
else:
_ = workflow.write_graph(graph2use=graph_kind,
dotfilename=graph_file_root)
def init_enhance_and_skullstrip_dwi_wf(
name="enhance_and_skullstrip_dwi_wf", omp_nthreads=1
):
"""
Enhance a *b0* reference and perform brain extraction.
This workflow takes in a *b0* reference image and sharpens the histogram
with the application of the N4 algorithm for removing the
:abbr:`INU (intensity non-uniformity)` bias field and calculates a signal
mask.
Steps of this workflow are:
1. Run ANTs' ``N4BiasFieldCorrection`` on the input
dwi reference image and mask.
2. Calculate a loose mask using FSL's ``bet``, with one mathematical morphology
dilation of one iteration and a sphere of 6mm as structuring element.
3. Mask the :abbr:`INU (intensity non-uniformity)`-corrected image
with the latest mask calculated in 3), then use AFNI's ``3dUnifize``
to *standardize* the T2* contrast distribution.
4. Calculate a mask using AFNI's ``3dAutomask`` after the contrast
enhancement of 4).
5. Calculate a final mask as the intersection of 2) and 4).
6. Apply final mask on the enhanced reference.
Workflow Graph:
.. workflow ::
:graph2use: orig
:simple_form: yes
from dmriprep.workflows.dwi.util import init_enhance_and_skullstrip_dwi_wf
wf = init_enhance_and_skullstrip_dwi_wf(omp_nthreads=1)
.. _N4BiasFieldCorrection: https://hdl.handle.net/10380/3053
Parameters
----------
name : str
Name of workflow (default: ``enhance_and_skullstrip_dwi_wf``)
omp_nthreads : int
number of threads available to parallel nodes
Inputs
------
in_file
The *b0* reference (single volume)
pre_mask
initial mask
Outputs
-------
bias_corrected_file
the ``in_file`` after `N4BiasFieldCorrection`_
skull_stripped_file
the ``bias_corrected_file`` after skull-stripping
mask_file
mask of the skull-stripped input file
out_report
reportlet for the skull-stripping
"""
from niworkflows.interfaces.header import CopyXForm
from niworkflows.interfaces.fixes import (
FixN4BiasFieldCorrection as N4BiasFieldCorrection,
)
from niworkflows.interfaces.nibabel import ApplyMask
workflow = Workflow(name=name)
inputnode = pe.Node(
niu.IdentityInterface(fields=["in_file", "pre_mask"]), name="inputnode"
)
outputnode = pe.Node(
niu.IdentityInterface(
fields=["mask_file", "skull_stripped_file", "bias_corrected_file"]
),
name="outputnode",
)
# Run N4 normally, force num_threads=1 for stability (images are small, no need for >1)
n4_correct = pe.Node(
N4BiasFieldCorrection(
dimension=3, copy_header=True, bspline_fitting_distance=200
),
shrink_factor=2,
name="n4_correct",
n_procs=1,
)
n4_correct.inputs.rescale_intensities = True
# Create a generous BET mask out of the bias-corrected EPI
skullstrip_first_pass = pe.Node(
fsl.BET(frac=0.2, mask=True), name="skullstrip_first_pass"
)
bet_dilate = pe.Node(
fsl.DilateImage(
operation="max",
kernel_shape="sphere",
kernel_size=6.0,
internal_datatype="char",
),
name="skullstrip_first_dilate",
)
bet_mask = pe.Node(fsl.ApplyMask(), name="skullstrip_first_mask")
# Use AFNI's unifize for T2 contrast & fix header
unifize = pe.Node(
afni.Unifize(
t2=True,
outputtype="NIFTI_GZ",
args="-clfrac 0.2 -rbt 18.3 65.0 90.0",
out_file="uni.nii.gz",
),
name="unifize",
)
fixhdr_unifize = pe.Node(CopyXForm(), name="fixhdr_unifize", mem_gb=0.1)
# Run AFNI's 3dAutomask to extract a refined brain mask
skullstrip_second_pass = pe.Node(
afni.Automask(dilate=1, outputtype="NIFTI_GZ"), name="skullstrip_second_pass"
)
fixhdr_skullstrip2 = pe.Node(CopyXForm(), name="fixhdr_skullstrip2", mem_gb=0.1)
# Take intersection of both masks
combine_masks = pe.Node(fsl.BinaryMaths(operation="mul"), name="combine_masks")
normalize = pe.Node(niu.Function(function=_normalize), name="normalize")
# Compute masked brain
apply_mask = pe.Node(ApplyMask(), name="apply_mask")
# fmt:off
workflow.connect([
(inputnode, n4_correct, [("in_file", "input_image"),
("pre_mask", "mask_image")]),
(inputnode, fixhdr_unifize, [("in_file", "hdr_file")]),
(inputnode, fixhdr_skullstrip2, [("in_file", "hdr_file")]),
(n4_correct, skullstrip_first_pass, [("output_image", "in_file")]),
(skullstrip_first_pass, bet_dilate, [("mask_file", "in_file")]),
(bet_dilate, bet_mask, [("out_file", "mask_file")]),
(skullstrip_first_pass, bet_mask, [("out_file", "in_file")]),
(bet_mask, unifize, [("out_file", "in_file")]),
(unifize, fixhdr_unifize, [("out_file", "in_file")]),
(fixhdr_unifize, skullstrip_second_pass, [("out_file", "in_file")]),
(skullstrip_first_pass, combine_masks, [("mask_file", "in_file")]),
(skullstrip_second_pass, fixhdr_skullstrip2, [("out_file", "in_file")]),
(fixhdr_skullstrip2, combine_masks, [("out_file", "operand_file")]),
(combine_masks, apply_mask, [("out_file", "in_mask")]),
(combine_masks, outputnode, [("out_file", "mask_file")]),
(n4_correct, normalize, [("output_image", "in_file")]),
(normalize, apply_mask, [("out", "in_file")]),
(normalize, outputnode, [("out", "bias_corrected_file")]),
(apply_mask, outputnode, [("out_file", "skull_stripped_file")]),
]
)
# fmt:on
return workflow
def afni_wf(name='AFNISkullStripWorkflow', unifize=False, n4_nthreads=1):
"""
Skull-stripping workflow
Originally derived from the `codebase of the
QAP <https://github.com/preprocessed-connectomes-project/\
quality-assessment-protocol/blob/master/qap/anatomical_preproc.py#L105>`_.
Now, this workflow includes :abbr:`INU (intensity non-uniformity)` correction
using the N4 algorithm and (optionally) intensity harmonization using
ANFI's ``3dUnifize``.
"""
workflow = pe.Workflow(name=name)
inputnode = pe.Node(niu.IdentityInterface(fields=['in_file']),
name='inputnode')
outputnode = pe.Node(niu.IdentityInterface(
fields=['bias_corrected', 'out_file', 'out_mask', 'bias_image']),
name='outputnode')
inu_n4 = pe.Node(ants.N4BiasFieldCorrection(dimension=3,
save_bias=True,
num_threads=n4_nthreads,
copy_header=True),
n_procs=n4_nthreads,
name='inu_n4')
sstrip = pe.Node(afni.SkullStrip(outputtype='NIFTI_GZ'), name='skullstrip')
sstrip_orig_vol = pe.Node(afni.Calc(expr='a*step(b)',
outputtype='NIFTI_GZ'),
name='sstrip_orig_vol')
binarize = pe.Node(fsl.Threshold(args='-bin', thresh=1.e-3),
name='binarize')
if unifize:
# Add two unifize steps, pre- and post- skullstripping.
inu_uni_0 = pe.Node(afni.Unifize(outputtype='NIFTI_GZ'),
name='unifize_pre_skullstrip')
inu_uni_1 = pe.Node(afni.Unifize(gm=True, outputtype='NIFTI_GZ'),
name='unifize_post_skullstrip')
workflow.connect([
(inu_n4, inu_uni_0, [('output_image', 'in_file')]),
(inu_uni_0, sstrip, [('out_file', 'in_file')]),
(inu_uni_0, sstrip_orig_vol, [('out_file', 'in_file_a')]),
(sstrip_orig_vol, inu_uni_1, [('out_file', 'in_file')]),
(inu_uni_1, outputnode, [('out_file', 'out_file')]),
(inu_uni_0, outputnode, [('out_file', 'bias_corrected')]),
])
else:
workflow.connect([
(inputnode, sstrip_orig_vol, [('in_file', 'in_file_a')]),
(inu_n4, sstrip, [('output_image', 'in_file')]),
(sstrip_orig_vol, outputnode, [('out_file', 'out_file')]),
(inu_n4, outputnode, [('output_image', 'bias_corrected')]),
])
# Remaining connections
workflow.connect([
(sstrip, sstrip_orig_vol, [('out_file', 'in_file_b')]),
(inputnode, inu_n4, [('in_file', 'input_image')]),
(sstrip_orig_vol, binarize, [('out_file', 'in_file')]),
(binarize, outputnode, [('out_file', 'out_mask')]),
(inu_n4, outputnode, [('bias_image', 'bias_image')]),
])
return workflow
io_S3DataGrabber.inputs.sort_filelist = True
io_S3DataGrabber.inputs.template = 'sub-01/anat/sub-01_T1w.nii.gz'
io_S3DataGrabber.inputs.anon = True
io_S3DataGrabber.inputs.bucket_path = 'ds000101/ds000101_R2.0.0/uncompressed/'
io_S3DataGrabber.inputs.local_directory = '/tmp'
#Wraps command **bet**
fsl_BET = pe.Node(interface=fsl.BET(), name='fsl_BET', iterfield=[''])
#Wraps command **3dTshift**
afni_TShift = pe.Node(interface=afni.TShift(),
name='afni_TShift',
iterfield=[''])
#Wraps command **3dUnifize**
afni_Unifize = pe.Node(interface=afni.Unifize(),
name='afni_Unifize',
iterfield=[''])
#Generic datagrabber module that wraps around glob in an
io_S3DataGrabber_2 = pe.Node(io.S3DataGrabber(), name='io_S3DataGrabber_2')
#Wraps command **fslreorient2std**
fsl_Reorient2Std = pe.Node(interface=fsl.Reorient2Std(),
name='fsl_Reorient2Std',
iterfield=[''])
#Wraps command **fslreorient2std**
fsl_Reorient2Std_1 = pe.Node(interface=fsl.Reorient2Std(),
name='fsl_Reorient2Std_1',
iterfield=[''])
def afni_wf(name="AFNISkullStripWorkflow", unifize=False, n4_nthreads=1):
"""
Create a skull-stripping workflow based on AFNI's tools.
Originally derived from the `codebase of the QAP
<https://github.com/preprocessed-connectomes-project/quality-assessment-protocol/blob/master/qap/anatomical_preproc.py#L105>`_.
Now, this workflow includes :abbr:`INU (intensity non-uniformity)` correction
using the N4 algorithm and (optionally) intensity harmonization using
ANFI's ``3dUnifize``.
Workflow Graph
.. workflow::
:graph2use: orig
:simple_form: yes
from niworkflows.anat.skullstrip import afni_wf
wf = afni_wf()
Parameters
----------
n4_nthreads : int
number of cpus N4 bias field correction can utilize.
unifize : bool
whether AFNI's ``3dUnifize`` should be applied (default: ``False``).
name : str
name for the workflow hierarchy of Nipype
Inputs
------
in_file : str
input T1w image.
Outputs
-------
bias_corrected : str
path to the bias corrected input MRI.
out_file : str
path to the skull-stripped image.
out_mask : str
path to the generated brain mask.
bias_image : str
path to the B1 inhomogeneity field.
"""
workflow = pe.Workflow(name=name)
inputnode = pe.Node(niu.IdentityInterface(fields=["in_file"]),
name="inputnode")
outputnode = pe.Node(
niu.IdentityInterface(
fields=["bias_corrected", "out_file", "out_mask", "bias_image"]),
name="outputnode",
)
inu_n4 = pe.Node(
N4BiasFieldCorrection(
dimension=3,
save_bias=True,
num_threads=n4_nthreads,
rescale_intensities=True,
copy_header=True,
),
n_procs=n4_nthreads,
name="inu_n4",
)
sstrip = pe.Node(afni.SkullStrip(outputtype="NIFTI_GZ"), name="skullstrip")
sstrip_orig_vol = pe.Node(afni.Calc(expr="a*step(b)",
outputtype="NIFTI_GZ"),
name="sstrip_orig_vol")
binarize = pe.Node(Binarize(thresh_low=0.0), name="binarize")
if unifize:
# Add two unifize steps, pre- and post- skullstripping.
inu_uni_0 = pe.Node(afni.Unifize(outputtype="NIFTI_GZ"),
name="unifize_pre_skullstrip")
inu_uni_1 = pe.Node(afni.Unifize(gm=True, outputtype="NIFTI_GZ"),
name="unifize_post_skullstrip")
# fmt: off
workflow.connect([
(inu_n4, inu_uni_0, [("output_image", "in_file")]),
(inu_uni_0, sstrip, [("out_file", "in_file")]),
(inu_uni_0, sstrip_orig_vol, [("out_file", "in_file_a")]),
(sstrip_orig_vol, inu_uni_1, [("out_file", "in_file")]),
(inu_uni_1, outputnode, [("out_file", "out_file")]),
(inu_uni_0, outputnode, [("out_file", "bias_corrected")]),
])
# fmt: on
else:
# fmt: off
workflow.connect([
(inputnode, sstrip_orig_vol, [("in_file", "in_file_a")]),
(inu_n4, sstrip, [("output_image", "in_file")]),
(sstrip_orig_vol, outputnode, [("out_file", "out_file")]),
(inu_n4, outputnode, [("output_image", "bias_corrected")]),
])
# fmt: on
# Remaining connections
# fmt: off
workflow.connect([
(sstrip, sstrip_orig_vol, [("out_file", "in_file_b")]),
(inputnode, inu_n4, [("in_file", "input_image")]),
(sstrip_orig_vol, binarize, [("out_file", "in_file")]),
(binarize, outputnode, [("out_mask", "out_mask")]),
(inu_n4, outputnode, [("bias_image", "bias_image")]),
])
# fmt: on
return workflow
NodeHash_30bb950.inputs.bucket = 'openneuro'
NodeHash_30bb950.inputs.bucket_path = 'ds000101/ds000101_R2.0.0/uncompressed/'
NodeHash_30bb950.inputs.local_directory = '/tmp'
NodeHash_30bb950.inputs.sort_filelist = True
NodeHash_30bb950.inputs.template = 'sub-01/anat/sub-01_T1w.nii.gz'
#Wraps command **N4BiasFieldCorrection**
NodeHash_1ea4b50 = pe.Node(interface=ants.N4BiasFieldCorrection(),
name='NodeName_1ea4b50')
NodeHash_1ea4b50.inputs.copy_header = False
NodeHash_1ea4b50.inputs.dimension = 3
NodeHash_1ea4b50.inputs.num_threads = 4
NodeHash_1ea4b50.inputs.save_bias = True
#Wraps command **3dUnifize**
NodeHash_291d6d0 = pe.Node(interface=afni.Unifize(), name='NodeName_291d6d0')
NodeHash_291d6d0.inputs.outputtype = 'NIFTI_GZ'
#Wraps command **3dSkullStrip**
NodeHash_1ddfa30 = pe.Node(interface=afni.SkullStrip(),
name='NodeName_1ddfa30')
NodeHash_1ddfa30.inputs.outputtype = 'NIFTI_GZ'
#Wraps command **3dcalc**
NodeHash_3bd6370 = pe.Node(interface=afni.Calc(), name='NodeName_3bd6370')
NodeHash_3bd6370.inputs.expr = 'a*step(b)'
NodeHash_3bd6370.inputs.outputtype = 'NIFTI_GZ'
#Wraps command **fslmaths**
NodeHash_49ddb10 = pe.Node(interface=fsl.Threshold(), name='NodeName_49ddb10')
NodeHash_49ddb10.inputs.args = '-bin'
