def _unwrap(fmap_data, mag_file, mask=None):
from math import pi
from nipype.interfaces.fsl import PRELUDE
magnii = nb.load(mag_file)
if mask is None:
mask = np.ones_like(fmap_data, dtype=np.uint8)
fmapmax = max(abs(fmap_data[mask > 0].min()), fmap_data[mask > 0].max())
fmap_data *= pi / fmapmax
nb.Nifti1Image(fmap_data, magnii.affine).to_filename('fmap_rad.nii.gz')
nb.Nifti1Image(mask, magnii.affine).to_filename('fmap_mask.nii.gz')
nb.Nifti1Image(magnii.get_fdata(dtype='float32'),
magnii.affine).to_filename('fmap_mag.nii.gz')
# Run prelude
res = PRELUDE(phase_file='fmap_rad.nii.gz',
magnitude_file='fmap_mag.nii.gz',
mask_file='fmap_mask.nii.gz').run()
unwrapped = nb.load(
res.outputs.unwrapped_phase_file).get_fdata(dtype='float32') * (fmapmax / pi)
return unwrapped
def create_workflow(unwarp_direction='y'):
workflow = Workflow(name='func_unwarp')
inputs = Node(
IdentityInterface(fields=[
# 'subject_id',
# 'session_id',
'funcs',
'funcmasks',
'fmap_phasediff',
'fmap_magnitude',
'fmap_mask',
]),
name='in')
outputs = Node(IdentityInterface(fields=[
'funcs',
'funcmasks',
]),
name='out')
# --- --- --- --- --- --- --- Convert to radians --- --- --- --- --- ---
# fslmaths $FUNCDIR/"$SUB"_B0_phase -div 100 -mul 3.141592653589793116
# -odt float $FUNCDIR/"$SUB"_B0_phase_rescaled
# in_file --> out_file
phase_radians = Node(fsl.ImageMaths(
op_string='-mul 3.141592653589793116 -div 100',
out_data_type='float',
suffix='_radians',
),
name='phaseRadians')
workflow.connect(inputs, 'fmap_phasediff', phase_radians, 'in_file')
# --- --- --- --- --- --- --- Unwrap Fieldmap --- --- --- --- --- ---
# --- Unwrap phase
# prelude -p $FUNCDIR/"$SUB"_B0_phase_rescaled
# -a $FUNCDIR/"$SUB"_B0_magnitude
# -o $FUNCDIR/"$SUB"_fmri_B0_phase_rescaled_unwrapped
# -m $FUNCDIR/"$SUB"_B0_magnitude_brain_mask
# magnitude_file, phase_file [, mask_file] --> unwrapped_phase_file
unwrap = MapNode(
PRELUDE(),
name='unwrap',
iterfield=['mask_file'],
)
workflow.connect([
(inputs, unwrap, [('fmap_magnitude', 'magnitude_file')]),
(inputs, unwrap, [('fmap_mask', 'mask_file')]),
(phase_radians, unwrap, [('out_file', 'phase_file')]),
])
# --- --- --- --- --- --- --- Convert to Radians / Sec --- --- --- --- ---
# fslmaths $FUNCDIR/"$SUB"_B0_phase_rescaled_unwrapped
# -mul 200 $FUNCDIR/"$SUB"_B0_phase_rescaled_unwrapped
rescale = MapNode(
fsl.ImageMaths(op_string='-mul 200'),
name='rescale',
iterfield=['in_file'],
)
workflow.connect(unwrap, 'unwrapped_phase_file', rescale, 'in_file')
# --- --- --- --- --- --- --- Unmask fieldmap --- --- --- --- ---
unmask_phase = MapNode(
FUGUE(
save_unmasked_fmap=True,
unwarp_direction=unwarp_direction,
),
name='unmask_phase',
iterfield=['mask_file', 'fmap_in_file'],
)
workflow.connect(rescale, 'out_file', unmask_phase, 'fmap_in_file')
workflow.connect(inputs, 'fmap_mask', unmask_phase, 'mask_file')
# --- --- --- --- --- --- --- Undistort functionals --- --- --- --- ---
# phasemap_in_file = phasediff
# mask_file = mask
# in_file = functional image
# dwell_time = 0.0005585 s
# unwarp_direction
undistort = MapNode(
FUGUE(
dwell_time=0.0005585,
# based on Process-NHP-MRI/Process_functional_data.md:
asym_se_time=0.020,
smooth3d=2.0,
median_2dfilter=True,
unwarp_direction=unwarp_direction,
),
name='undistort',
iterfield=['in_file', 'mask_file', 'fmap_in_file'],
)
workflow.connect(unmask_phase, 'fmap_out_file', undistort, 'fmap_in_file')
workflow.connect(inputs, 'fmap_mask', undistort, 'mask_file')
workflow.connect(inputs, 'funcs', undistort, 'in_file')
undistort_masks = undistort.clone('undistort_masks')
workflow.connect(unmask_phase, 'fmap_out_file', undistort_masks,
'fmap_in_file')
workflow.connect(inputs, 'fmap_mask', undistort_masks, 'mask_file')
workflow.connect(inputs, 'funcmasks', undistort_masks, 'in_file')
workflow.connect(undistort, 'unwarped_file', outputs, 'funcs')
workflow.connect(undistort_masks, 'unwarped_file', outputs, 'funcmasks')
return workflow
