def run(self,
input_files,
bvalues_files,
bvectors_files,
mask_files,
b0_threshold=50,
bvecs_tol=0.01,
save_metrics=[],
out_dir='',
out_tensor='tensors.nii.gz',
out_fa='fa.nii.gz',
out_ga='ga.nii.gz',
out_rgb='rgb.nii.gz',
out_md='md.nii.gz',
out_ad='ad.nii.gz',
out_rd='rd.nii.gz',
out_mode='mode.nii.gz',
out_evec='evecs.nii.gz',
out_eval='evals.nii.gz',
nifti_tensor=True):
""" Workflow for tensor reconstruction and for computing DTI metrics.
using Weighted Least-Squares.
Performs a tensor reconstruction on the files by 'globing'
``input_files`` and saves the DTI metrics in a directory specified by
``out_dir``.
Parameters
----------
input_files : string
Path to the input volumes. This path may contain wildcards to
process multiple inputs at once.
bvalues_files : string
Path to the bvalues files. This path may contain wildcards to use
multiple bvalues files at once.
bvectors_files : string
Path to the bvectors files. This path may contain wildcards to use
multiple bvectors files at once.
mask_files : string
Path to the input masks. This path may contain wildcards to use
multiple masks at once.
b0_threshold : float, optional
Threshold used to find b0 volumes.
bvecs_tol : float, optional
Threshold used to check that norm(bvec) = 1 +/- bvecs_tol
b-vectors are unit vectors.
save_metrics : variable string, optional
List of metrics to save.
Possible values: fa, ga, rgb, md, ad, rd, mode, tensor, evec, eval
out_dir : string, optional
Output directory. (default current directory)
out_tensor : string, optional
Name of the tensors volume to be saved.
Per default, this will be saved following the nifti standard:
with the tensor elements as Dxx, Dxy, Dyy, Dxz, Dyz, Dzz on the
last (5th) dimension of the volume (shape: (i, j, k, 1, 6)). If
`nifti_tensor` is False, this will be saved in an alternate format
that is used by other software (e.g., FSL): a
4-dimensional volume (shape (i, j, k, 6)) with Dxx, Dxy, Dxz, Dyy,
Dyz, Dzz on the last dimension.
out_fa : string, optional
Name of the fractional anisotropy volume to be saved.
out_ga : string, optional
Name of the geodesic anisotropy volume to be saved.
out_rgb : string, optional
Name of the color fa volume to be saved.
out_md : string, optional
Name of the mean diffusivity volume to be saved.
out_ad : string, optional
Name of the axial diffusivity volume to be saved.
out_rd : string, optional
Name of the radial diffusivity volume to be saved.
out_mode : string, optional
Name of the mode volume to be saved.
out_evec : string, optional
Name of the eigenvectors volume to be saved.
out_eval : string, optional
Name of the eigenvalues to be saved.
nifti_tensor : bool, optional
Whether the tensor is saved in the standard Nifti format or in an
alternate format
that is used by other software (e.g., FSL): a
4-dimensional volume (shape (i, j, k, 6)) with
Dxx, Dxy, Dxz, Dyy, Dyz, Dzz on the last dimension.
References
----------
.. [1] Basser, P.J., Mattiello, J., LeBihan, D., 1994. Estimation of
the effective self-diffusion tensor from the NMR spin echo. J Magn
Reson B 103, 247-254.
.. [2] Basser, P., Pierpaoli, C., 1996. Microstructural and
physiological features of tissues elucidated by quantitative
diffusion-tensor MRI. Journal of Magnetic Resonance 111, 209-219.
.. [3] Lin-Ching C., Jones D.K., Pierpaoli, C. 2005. RESTORE: Robust
estimation of tensors by outlier rejection. MRM 53: 1088-1095
.. [4] hung, SW., Lu, Y., Henry, R.G., 2006. Comparison of bootstrap
approaches for estimation of uncertainties of DTI parameters.
NeuroImage 33, 531-541.
"""
io_it = self.get_io_iterator()
for dwi, bval, bvec, mask, otensor, ofa, oga, orgb, omd, oad, orad, \
omode, oevecs, oevals in io_it:
logging.info('Computing DTI metrics for {0}'.format(dwi))
data, affine = load_nifti(dwi)
if mask is not None:
mask = load_nifti_data(mask).astype(bool)
tenfit, _ = self.get_fitted_tensor(data, mask, bval, bvec,
b0_threshold, bvecs_tol)
if not save_metrics:
save_metrics = [
'fa', 'md', 'rd', 'ad', 'ga', 'rgb', 'mode', 'evec',
'eval', 'tensor'
]
FA = fractional_anisotropy(tenfit.evals)
FA[np.isnan(FA)] = 0
FA = np.clip(FA, 0, 1)
if 'tensor' in save_metrics:
tensor_vals = lower_triangular(tenfit.quadratic_form)
if nifti_tensor:
ten_img = nifti1_symmat(tensor_vals, affine=affine)
else:
alt_order = [0, 1, 3, 2, 4, 5]
ten_img = nib.Nifti1Image(
tensor_vals[..., alt_order].astype(np.float32), affine)
nib.save(ten_img, otensor)
if 'fa' in save_metrics:
save_nifti(ofa, FA.astype(np.float32), affine)
if 'ga' in save_metrics:
GA = geodesic_anisotropy(tenfit.evals)
save_nifti(oga, GA.astype(np.float32), affine)
if 'rgb' in save_metrics:
RGB = color_fa(FA, tenfit.evecs)
save_nifti(orgb, np.array(255 * RGB, 'uint8'), affine)
if 'md' in save_metrics:
MD = mean_diffusivity(tenfit.evals)
save_nifti(omd, MD.astype(np.float32), affine)
if 'ad' in save_metrics:
AD = axial_diffusivity(tenfit.evals)
save_nifti(oad, AD.astype(np.float32), affine)
if 'rd' in save_metrics:
RD = radial_diffusivity(tenfit.evals)
save_nifti(orad, RD.astype(np.float32), affine)
if 'mode' in save_metrics:
MODE = get_mode(tenfit.quadratic_form)
save_nifti(omode, MODE.astype(np.float32), affine)
if 'evec' in save_metrics:
save_nifti(oevecs, tenfit.evecs.astype(np.float32), affine)
if 'eval' in save_metrics:
save_nifti(oevals, tenfit.evals.astype(np.float32), affine)
dname_ = os.path.dirname(oevals)
if dname_ == '':
logging.info('DTI metrics saved in current directory')
else:
logging.info('DTI metrics saved in {0}'.format(dname_))
def run(self,
input_files,
bvalues_files,
bvectors_files,
mask_files,
b0_threshold=50.0,
save_metrics=[],
out_dir='',
out_dt_tensor='dti_tensors.nii.gz',
out_fa='fa.nii.gz',
out_ga='ga.nii.gz',
out_rgb='rgb.nii.gz',
out_md='md.nii.gz',
out_ad='ad.nii.gz',
out_rd='rd.nii.gz',
out_mode='mode.nii.gz',
out_evec='evecs.nii.gz',
out_eval='evals.nii.gz',
out_dk_tensor="dki_tensors.nii.gz",
out_mk="mk.nii.gz",
out_ak="ak.nii.gz",
out_rk="rk.nii.gz"):
""" Workflow for Diffusion Kurtosis reconstruction and for computing
DKI metrics. Performs a DKI reconstruction on the files by 'globing'
``input_files`` and saves the DKI metrics in a directory specified by
``out_dir``.
Parameters
----------
input_files : string
Path to the input volumes. This path may contain wildcards to
process multiple inputs at once.
bvalues_files : string
Path to the bvalues files. This path may contain wildcards to use
multiple bvalues files at once.
bvectors_files : string
Path to the bvalues files. This path may contain wildcards to use
multiple bvalues files at once.
mask_files : string
Path to the input masks. This path may contain wildcards to use
multiple masks at once. (default: No mask used)
b0_threshold : float, optional
Threshold used to find b0 volumes.
save_metrics : variable string, optional
List of metrics to save.
Possible values: fa, ga, rgb, md, ad, rd, mode, tensor, evec, eval
out_dir : string, optional
Output directory. (default current directory)
out_dt_tensor : string, optional
Name of the tensors volume to be saved.
out_dk_tensor : string, optional
Name of the tensors volume to be saved.
out_fa : string, optional
Name of the fractional anisotropy volume to be saved.
out_ga : string, optional
Name of the geodesic anisotropy volume to be saved.
out_rgb : string, optional
Name of the color fa volume to be saved.
out_md : string, optional
Name of the mean diffusivity volume to be saved.
out_ad : string, optional
Name of the axial diffusivity volume to be saved.
out_rd : string, optional
Name of the radial diffusivity volume to be saved.
out_mode : string, optional
Name of the mode volume to be saved.
out_evec : string, optional
Name of the eigenvectors volume to be saved.
out_eval : string, optional
Name of the eigenvalues to be saved.
out_mk : string, optional
Name of the mean kurtosis to be saved.
out_ak : string, optional
Name of the axial kurtosis to be saved.
out_rk : string, optional
Name of the radial kurtosis to be saved.
References
----------
.. [1] Tabesh, A., Jensen, J.H., Ardekani, B.A., Helpern, J.A., 2011.
Estimation of tensors and tensor-derived measures in diffusional
kurtosis imaging. Magn Reson Med. 65(3), 823-836
.. [2] Jensen, Jens H., Joseph A. Helpern, Anita Ramani, Hanzhang Lu,
and Kyle Kaczynski. 2005. Diffusional Kurtosis Imaging: The
Quantification of Non-Gaussian Water Diffusion by Means of Magnetic
Resonance Imaging. MRM 53 (6):1432-40.
"""
io_it = self.get_io_iterator()
for (dwi, bval, bvec, mask, otensor, ofa, oga, orgb, omd, oad, orad,
omode, oevecs, oevals, odk_tensor, omk, oak, ork) in io_it:
logging.info('Computing DKI metrics for {0}'.format(dwi))
data, affine = load_nifti(dwi)
if mask is not None:
mask = load_nifti_data(mask).astype(bool)
dkfit, _ = self.get_fitted_tensor(data, mask, bval, bvec,
b0_threshold)
if not save_metrics:
save_metrics = [
'mk', 'rk', 'ak', 'fa', 'md', 'rd', 'ad', 'ga', 'rgb',
'mode', 'evec', 'eval', 'dt_tensor', 'dk_tensor'
]
evals, evecs, kt = split_dki_param(dkfit.model_params)
FA = fractional_anisotropy(evals)
FA[np.isnan(FA)] = 0
FA = np.clip(FA, 0, 1)
if 'dt_tensor' in save_metrics:
tensor_vals = lower_triangular(dkfit.quadratic_form)
correct_order = [0, 1, 3, 2, 4, 5]
tensor_vals_reordered = tensor_vals[..., correct_order]
save_nifti(otensor, tensor_vals_reordered.astype(np.float32),
affine)
if 'dk_tensor' in save_metrics:
save_nifti(odk_tensor, dkfit.kt.astype(np.float32), affine)
if 'fa' in save_metrics:
save_nifti(ofa, FA.astype(np.float32), affine)
if 'ga' in save_metrics:
GA = geodesic_anisotropy(dkfit.evals)
save_nifti(oga, GA.astype(np.float32), affine)
if 'rgb' in save_metrics:
RGB = color_fa(FA, dkfit.evecs)
save_nifti(orgb, np.array(255 * RGB, 'uint8'), affine)
if 'md' in save_metrics:
MD = mean_diffusivity(dkfit.evals)
save_nifti(omd, MD.astype(np.float32), affine)
if 'ad' in save_metrics:
AD = axial_diffusivity(dkfit.evals)
save_nifti(oad, AD.astype(np.float32), affine)
if 'rd' in save_metrics:
RD = radial_diffusivity(dkfit.evals)
save_nifti(orad, RD.astype(np.float32), affine)
if 'mode' in save_metrics:
MODE = get_mode(dkfit.quadratic_form)
save_nifti(omode, MODE.astype(np.float32), affine)
if 'evec' in save_metrics:
save_nifti(oevecs, dkfit.evecs.astype(np.float32), affine)
if 'eval' in save_metrics:
save_nifti(oevals, dkfit.evals.astype(np.float32), affine)
if 'mk' in save_metrics:
save_nifti(omk, dkfit.mk().astype(np.float32), affine)
if 'ak' in save_metrics:
save_nifti(oak, dkfit.ak().astype(np.float32), affine)
if 'rk' in save_metrics:
save_nifti(ork, dkfit.rk().astype(np.float32), affine)
logging.info('DKI metrics saved in {0}'.format(
os.path.dirname(oevals)))
def run(self,
input_files,
bvalues_files,
bvectors_files,
mask_files,
b0_threshold=0.0,
bvecs_tol=0.01,
save_metrics=[],
out_dir='',
out_tensor='tensors.nii.gz',
out_fa='fa.nii.gz',
out_ga='ga.nii.gz',
out_rgb='rgb.nii.gz',
out_md='md.nii.gz',
out_ad='ad.nii.gz',
out_rd='rd.nii.gz',
out_mode='mode.nii.gz',
out_evec='evecs.nii.gz',
out_eval='evals.nii.gz'):
""" Workflow for tensor reconstruction and for computing DTI metrics.
using Weighted Least-Squares.
Performs a tensor reconstruction on the files by 'globing'
``input_files`` and saves the DTI metrics in a directory specified by
``out_dir``.
Parameters
----------
input_files : string
Path to the input volumes. This path may contain wildcards to
process multiple inputs at once.
bvalues_files : string
Path to the bvalues files. This path may contain wildcards to use
multiple bvalues files at once.
bvectors_files : string
Path to the bvectors files. This path may contain wildcards to use
multiple bvectors files at once.
mask_files : string
Path to the input masks. This path may contain wildcards to use
multiple masks at once. (default: No mask used)
b0_threshold : float, optional
Threshold used to find b=0 directions (default 0.0)
bvecs_tol : float, optional
Threshold used to check that norm(bvec) = 1 +/- bvecs_tol
b-vectors are unit vectors (default 0.01)
save_metrics : variable string, optional
List of metrics to save.
Possible values: fa, ga, rgb, md, ad, rd, mode, tensor, evec, eval
(default [] (all))
out_dir : string, optional
Output directory (default input file directory)
out_tensor : string, optional
Name of the tensors volume to be saved (default 'tensors.nii.gz')
out_fa : string, optional
Name of the fractional anisotropy volume to be saved
(default 'fa.nii.gz')
out_ga : string, optional
Name of the geodesic anisotropy volume to be saved
(default 'ga.nii.gz')
out_rgb : string, optional
Name of the color fa volume to be saved (default 'rgb.nii.gz')
out_md : string, optional
Name of the mean diffusivity volume to be saved
(default 'md.nii.gz')
out_ad : string, optional
Name of the axial diffusivity volume to be saved
(default 'ad.nii.gz')
out_rd : string, optional
Name of the radial diffusivity volume to be saved
(default 'rd.nii.gz')
out_mode : string, optional
Name of the mode volume to be saved (default 'mode.nii.gz')
out_evec : string, optional
Name of the eigenvectors volume to be saved
(default 'evecs.nii.gz')
out_eval : string, optional
Name of the eigenvalues to be saved (default 'evals.nii.gz')
References
----------
.. [1] Basser, P.J., Mattiello, J., LeBihan, D., 1994. Estimation of
the effective self-diffusion tensor from the NMR spin echo. J Magn
Reson B 103, 247-254.
.. [2] Basser, P., Pierpaoli, C., 1996. Microstructural and
physiological features of tissues elucidated by quantitative
diffusion-tensor MRI. Journal of Magnetic Resonance 111, 209-219.
.. [3] Lin-Ching C., Jones D.K., Pierpaoli, C. 2005. RESTORE: Robust
estimation of tensors by outlier rejection. MRM 53: 1088-1095
.. [4] hung, SW., Lu, Y., Henry, R.G., 2006. Comparison of bootstrap
approaches for estimation of uncertainties of DTI parameters.
NeuroImage 33, 531-541.
"""
io_it = self.get_io_iterator()
for dwi, bval, bvec, mask, otensor, ofa, oga, orgb, omd, oad, orad, \
omode, oevecs, oevals in io_it:
logging.info('Computing DTI metrics for {0}'.format(dwi))
img = nib.load(dwi)
data = img.get_data()
affine = img.affine
if mask is not None:
mask = nib.load(mask).get_data().astype(np.bool)
tenfit, _ = self.get_fitted_tensor(data, mask, bval, bvec,
b0_threshold, bvecs_tol)
if not save_metrics:
save_metrics = [
'fa', 'md', 'rd', 'ad', 'ga', 'rgb', 'mode', 'evec',
'eval', 'tensor'
]
FA = fractional_anisotropy(tenfit.evals)
FA[np.isnan(FA)] = 0
FA = np.clip(FA, 0, 1)
if 'tensor' in save_metrics:
tensor_vals = lower_triangular(tenfit.quadratic_form)
correct_order = [0, 1, 3, 2, 4, 5]
tensor_vals_reordered = tensor_vals[..., correct_order]
fiber_tensors = nib.Nifti1Image(
tensor_vals_reordered.astype(np.float32), affine)
nib.save(fiber_tensors, otensor)
if 'fa' in save_metrics:
fa_img = nib.Nifti1Image(FA.astype(np.float32), affine)
nib.save(fa_img, ofa)
if 'ga' in save_metrics:
GA = geodesic_anisotropy(tenfit.evals)
ga_img = nib.Nifti1Image(GA.astype(np.float32), affine)
nib.save(ga_img, oga)
if 'rgb' in save_metrics:
RGB = color_fa(FA, tenfit.evecs)
rgb_img = nib.Nifti1Image(np.array(255 * RGB, 'uint8'), affine)
nib.save(rgb_img, orgb)
if 'md' in save_metrics:
MD = mean_diffusivity(tenfit.evals)
md_img = nib.Nifti1Image(MD.astype(np.float32), affine)
nib.save(md_img, omd)
if 'ad' in save_metrics:
AD = axial_diffusivity(tenfit.evals)
ad_img = nib.Nifti1Image(AD.astype(np.float32), affine)
nib.save(ad_img, oad)
if 'rd' in save_metrics:
RD = radial_diffusivity(tenfit.evals)
rd_img = nib.Nifti1Image(RD.astype(np.float32), affine)
nib.save(rd_img, orad)
if 'mode' in save_metrics:
MODE = get_mode(tenfit.quadratic_form)
mode_img = nib.Nifti1Image(MODE.astype(np.float32), affine)
nib.save(mode_img, omode)
if 'evec' in save_metrics:
evecs_img = nib.Nifti1Image(tenfit.evecs.astype(np.float32),
affine)
nib.save(evecs_img, oevecs)
if 'eval' in save_metrics:
evals_img = nib.Nifti1Image(tenfit.evals.astype(np.float32),
affine)
nib.save(evals_img, oevals)
dname_ = os.path.dirname(oevals)
if dname_ == '':
logging.info('DTI metrics saved in current directory')
else:
logging.info('DTI metrics saved in {0}'.format(dname_))
def run(self, input_files, bvalues, bvectors, mask_files, b0_threshold=0.0,
save_metrics=[],
out_dir='', out_tensor='tensors.nii.gz', out_fa='fa.nii.gz',
out_ga='ga.nii.gz', out_rgb='rgb.nii.gz', out_md='md.nii.gz',
out_ad='ad.nii.gz', out_rd='rd.nii.gz', out_mode='mode.nii.gz',
out_evec='evecs.nii.gz', out_eval='evals.nii.gz'):
""" Workflow for tensor reconstruction and for computing DTI metrics.
Performs a tensor reconstruction on the files by 'globing'
``input_files`` and saves the DTI metrics in a directory specified by
``out_dir``.
Parameters
----------
input_files : string
Path to the input volumes. This path may contain wildcards to
process multiple inputs at once.
bvalues : string
Path to the bvalues files. This path may contain wildcards to use
multiple bvalues files at once.
bvectors : string
Path to the bvalues files. This path may contain wildcards to use
multiple bvalues files at once.
mask_files : string
Path to the input masks. This path may contain wildcards to use
multiple masks at once. (default: No mask used)
b0_threshold : float, optional
Threshold used to find b=0 directions (default 0.0)
save_metrics : variable string, optional
List of metrics to save.
Possible values: fa, ga, rgb, md, ad, rd, mode, tensor, evec, eval
(default [] (all))
out_dir : string, optional
Output directory (default input file directory)
out_tensor : string, optional
Name of the tensors volume to be saved (default 'tensors.nii.gz')
out_fa : string, optional
Name of the fractional anisotropy volume to be saved
(default 'fa.nii.gz')
out_ga : string, optional
Name of the geodesic anisotropy volume to be saved
(default 'ga.nii.gz')
out_rgb : string, optional
Name of the color fa volume to be saved (default 'rgb.nii.gz')
out_md : string, optional
Name of the mean diffusivity volume to be saved
(default 'md.nii.gz')
out_ad : string, optional
Name of the axial diffusivity volume to be saved
(default 'ad.nii.gz')
out_rd : string, optional
Name of the radial diffusivity volume to be saved
(default 'rd.nii.gz')
out_mode : string, optional
Name of the mode volume to be saved (default 'mode.nii.gz')
out_evec : string, optional
Name of the eigenvectors volume to be saved
(default 'evecs.nii.gz')
out_eval : string, optional
Name of the eigenvalues to be saved (default 'evals.nii.gz')
"""
io_it = self.get_io_iterator()
for dwi, bval, bvec, mask, otensor, ofa, oga, orgb, omd, oad, orad, \
omode, oevecs, oevals in io_it:
logging.info('Computing DTI metrics for {0}'.format(dwi))
img = nib.load(dwi)
data = img.get_data()
affine = img.get_affine()
if mask is None:
mask = None
else:
mask = nib.load(mask).get_data().astype(np.bool)
tenfit, _ = self.get_fitted_tensor(data, mask, bval, bvec,
b0_threshold)
if not save_metrics:
save_metrics = ['fa', 'md', 'rd', 'ad', 'ga', 'rgb', 'mode',
'evec', 'eval', 'tensor']
FA = fractional_anisotropy(tenfit.evals)
FA[np.isnan(FA)] = 0
FA = np.clip(FA, 0, 1)
if 'tensor' in save_metrics:
tensor_vals = lower_triangular(tenfit.quadratic_form)
correct_order = [0, 1, 3, 2, 4, 5]
tensor_vals_reordered = tensor_vals[..., correct_order]
fiber_tensors = nib.Nifti1Image(tensor_vals_reordered.astype(
np.float32), affine)
nib.save(fiber_tensors, otensor)
if 'fa' in save_metrics:
fa_img = nib.Nifti1Image(FA.astype(np.float32), affine)
nib.save(fa_img, ofa)
if 'ga' in save_metrics:
GA = geodesic_anisotropy(tenfit.evals)
ga_img = nib.Nifti1Image(GA.astype(np.float32), affine)
nib.save(ga_img, oga)
if 'rgb' in save_metrics:
RGB = color_fa(FA, tenfit.evecs)
rgb_img = nib.Nifti1Image(np.array(255 * RGB, 'uint8'), affine)
nib.save(rgb_img, orgb)
if 'md' in save_metrics:
MD = mean_diffusivity(tenfit.evals)
md_img = nib.Nifti1Image(MD.astype(np.float32), affine)
nib.save(md_img, omd)
if 'ad' in save_metrics:
AD = axial_diffusivity(tenfit.evals)
ad_img = nib.Nifti1Image(AD.astype(np.float32), affine)
nib.save(ad_img, oad)
if 'rd' in save_metrics:
RD = radial_diffusivity(tenfit.evals)
rd_img = nib.Nifti1Image(RD.astype(np.float32), affine)
nib.save(rd_img, orad)
if 'mode' in save_metrics:
MODE = get_mode(tenfit.quadratic_form)
mode_img = nib.Nifti1Image(MODE.astype(np.float32), affine)
nib.save(mode_img, omode)
if 'evec' in save_metrics:
evecs_img = nib.Nifti1Image(tenfit.evecs.astype(np.float32), affine)
nib.save(evecs_img, oevecs)
if 'eval' in save_metrics:
evals_img = nib.Nifti1Image(tenfit.evals.astype(np.float32), affine)
nib.save(evals_img, oevals)
logging.info('DTI metrics saved in {0}'.
format(os.path.dirname(oevals)))
def run(self,
input_files,
bvalues,
bvectors,
mask_files,
b0_threshold=0.0,
save_metrics=[],
out_dir='',
out_tensor='tensors.nii.gz',
out_fa='fa.nii.gz',
out_ga='ga.nii.gz',
out_rgb='rgb.nii.gz',
out_md='md.nii.gz',
out_ad='ad.nii.gz',
out_rd='rd.nii.gz',
out_mode='mode.nii.gz',
out_evec='evecs.nii.gz',
out_eval='evals.nii.gz'):
""" Workflow for tensor reconstruction and for computing DTI metrics.
Performs a tensor reconstruction on the files by 'globing'
``input_files`` and saves the DTI metrics in a directory specified by
``out_dir``.
Parameters
----------
input_files : string
Path to the input volumes. This path may contain wildcards to
process multiple inputs at once.
bvalues : string
Path to the bvalues files. This path may contain wildcards to use
multiple bvalues files at once.
bvectors : string
Path to the bvalues files. This path may contain wildcards to use
multiple bvalues files at once.
mask_files : string
Path to the input masks. This path may contain wildcards to use
multiple masks at once. (default: No mask used)
b0_threshold : float, optional
Threshold used to find b=0 directions (default 0.0)
save_metrics : variable string, optional
List of metrics to save.
Possible values: fa, ga, rgb, md, ad, rd, mode, tensor, evec, eval
(default [] (all))
out_dir : string, optional
Output directory (default input file directory)
out_tensor : string, optional
Name of the tensors volume to be saved (default 'tensors.nii.gz')
out_fa : string, optional
Name of the fractional anisotropy volume to be saved
(default 'fa.nii.gz')
out_ga : string, optional
Name of the geodesic anisotropy volume to be saved
(default 'ga.nii.gz')
out_rgb : string, optional
Name of the color fa volume to be saved (default 'rgb.nii.gz')
out_md : string, optional
Name of the mean diffusivity volume to be saved
(default 'md.nii.gz')
out_ad : string, optional
Name of the axial diffusivity volume to be saved
(default 'ad.nii.gz')
out_rd : string, optional
Name of the radial diffusivity volume to be saved
(default 'rd.nii.gz')
out_mode : string, optional
Name of the mode volume to be saved (default 'mode.nii.gz')
out_evec : string, optional
Name of the eigenvectors volume to be saved
(default 'evecs.nii.gz')
out_eval : string, optional
Name of the eigenvalues to be saved (default 'evals.nii.gz')
"""
io_it = self.get_io_iterator()
for dwi, bval, bvec, mask, otensor, ofa, oga, orgb, omd, oad, orad, \
omode, oevecs, oevals in io_it:
logging.info('Computing DTI metrics for {0}'.format(dwi))
img = nib.load(dwi)
data = img.get_data()
affine = img.get_affine()
if mask is None:
mask = None
else:
mask = nib.load(mask).get_data().astype(np.bool)
tenfit, _ = self.get_fitted_tensor(data, mask, bval, bvec,
b0_threshold)
if not save_metrics:
save_metrics = [
'fa', 'md', 'rd', 'ad', 'ga', 'rgb', 'mode', 'evec',
'eval', 'tensor'
]
FA = fractional_anisotropy(tenfit.evals)
FA[np.isnan(FA)] = 0
FA = np.clip(FA, 0, 1)
if 'tensor' in save_metrics:
tensor_vals = lower_triangular(tenfit.quadratic_form)
correct_order = [0, 1, 3, 2, 4, 5]
tensor_vals_reordered = tensor_vals[..., correct_order]
fiber_tensors = nib.Nifti1Image(
tensor_vals_reordered.astype(np.float32), affine)
nib.save(fiber_tensors, otensor)
if 'fa' in save_metrics:
fa_img = nib.Nifti1Image(FA.astype(np.float32), affine)
nib.save(fa_img, ofa)
if 'ga' in save_metrics:
GA = geodesic_anisotropy(tenfit.evals)
ga_img = nib.Nifti1Image(GA.astype(np.float32), affine)
nib.save(ga_img, oga)
if 'rgb' in save_metrics:
RGB = color_fa(FA, tenfit.evecs)
rgb_img = nib.Nifti1Image(np.array(255 * RGB, 'uint8'), affine)
nib.save(rgb_img, orgb)
if 'md' in save_metrics:
MD = mean_diffusivity(tenfit.evals)
md_img = nib.Nifti1Image(MD.astype(np.float32), affine)
nib.save(md_img, omd)
if 'ad' in save_metrics:
AD = axial_diffusivity(tenfit.evals)
ad_img = nib.Nifti1Image(AD.astype(np.float32), affine)
nib.save(ad_img, oad)
if 'rd' in save_metrics:
RD = radial_diffusivity(tenfit.evals)
rd_img = nib.Nifti1Image(RD.astype(np.float32), affine)
nib.save(rd_img, orad)
if 'mode' in save_metrics:
MODE = get_mode(tenfit.quadratic_form)
mode_img = nib.Nifti1Image(MODE.astype(np.float32), affine)
nib.save(mode_img, omode)
if 'evec' in save_metrics:
evecs_img = nib.Nifti1Image(tenfit.evecs.astype(np.float32),
affine)
nib.save(evecs_img, oevecs)
if 'eval' in save_metrics:
evals_img = nib.Nifti1Image(tenfit.evals.astype(np.float32),
affine)
nib.save(evals_img, oevals)
logging.info('DTI metrics saved in {0}'.format(
os.path.dirname(oevals)))
def run(self, input_files, bvalues_files, bvectors_files, mask_files,
b0_threshold=50.0, save_metrics=[],
out_dir='', out_dt_tensor='dti_tensors.nii.gz', out_fa='fa.nii.gz',
out_ga='ga.nii.gz', out_rgb='rgb.nii.gz', out_md='md.nii.gz',
out_ad='ad.nii.gz', out_rd='rd.nii.gz', out_mode='mode.nii.gz',
out_evec='evecs.nii.gz', out_eval='evals.nii.gz',
out_dk_tensor="dki_tensors.nii.gz",
out_mk="mk.nii.gz", out_ak="ak.nii.gz", out_rk="rk.nii.gz"):
""" Workflow for Diffusion Kurtosis reconstruction and for computing
DKI metrics. Performs a DKI reconstruction on the files by 'globing'
``input_files`` and saves the DKI metrics in a directory specified by
``out_dir``.
Parameters
----------
input_files : string
Path to the input volumes. This path may contain wildcards to
process multiple inputs at once.
bvalues_files : string
Path to the bvalues files. This path may contain wildcards to use
multiple bvalues files at once.
bvectors_files : string
Path to the bvalues files. This path may contain wildcards to use
multiple bvalues files at once.
mask_files : string
Path to the input masks. This path may contain wildcards to use
multiple masks at once. (default: No mask used)
b0_threshold : float, optional
Threshold used to find b=0 directions (default 0.0)
save_metrics : variable string, optional
List of metrics to save.
Possible values: fa, ga, rgb, md, ad, rd, mode, tensor, evec, eval
(default [] (all))
out_dir : string, optional
Output directory (default input file directory)
out_dt_tensor : string, optional
Name of the tensors volume to be saved
(default: 'dti_tensors.nii.gz')
out_dk_tensor : string, optional
Name of the tensors volume to be saved
(default 'dki_tensors.nii.gz')
out_fa : string, optional
Name of the fractional anisotropy volume to be saved
(default 'fa.nii.gz')
out_ga : string, optional
Name of the geodesic anisotropy volume to be saved
(default 'ga.nii.gz')
out_rgb : string, optional
Name of the color fa volume to be saved (default 'rgb.nii.gz')
out_md : string, optional
Name of the mean diffusivity volume to be saved
(default 'md.nii.gz')
out_ad : string, optional
Name of the axial diffusivity volume to be saved
(default 'ad.nii.gz')
out_rd : string, optional
Name of the radial diffusivity volume to be saved
(default 'rd.nii.gz')
out_mode : string, optional
Name of the mode volume to be saved (default 'mode.nii.gz')
out_evec : string, optional
Name of the eigenvectors volume to be saved
(default 'evecs.nii.gz')
out_eval : string, optional
Name of the eigenvalues to be saved (default 'evals.nii.gz')
out_mk : string, optional
Name of the mean kurtosis to be saved (default: 'mk.nii.gz')
out_ak : string, optional
Name of the axial kurtosis to be saved (default: 'ak.nii.gz')
out_rk : string, optional
Name of the radial kurtosis to be saved (default: 'rk.nii.gz')
References
----------
.. [1] Tabesh, A., Jensen, J.H., Ardekani, B.A., Helpern, J.A., 2011.
Estimation of tensors and tensor-derived measures in diffusional
kurtosis imaging. Magn Reson Med. 65(3), 823-836
.. [2] Jensen, Jens H., Joseph A. Helpern, Anita Ramani, Hanzhang Lu,
and Kyle Kaczynski. 2005. Diffusional Kurtosis Imaging: The
Quantification of Non-Gaussian Water Diffusion by Means of Magnetic
Resonance Imaging. MRM 53 (6):1432-40.
"""
io_it = self.get_io_iterator()
for (dwi, bval, bvec, mask, otensor, ofa, oga, orgb, omd, oad, orad,
omode, oevecs, oevals, odk_tensor, omk, oak, ork) in io_it:
logging.info('Computing DKI metrics for {0}'.format(dwi))
data, affine = load_nifti(dwi)
if mask is not None:
mask = nib.load(mask).get_data().astype(np.bool)
dkfit, _ = self.get_fitted_tensor(data, mask, bval, bvec,
b0_threshold)
if not save_metrics:
save_metrics = ['mk', 'rk', 'ak', 'fa', 'md', 'rd', 'ad', 'ga',
'rgb', 'mode', 'evec', 'eval', 'dt_tensor',
'dk_tensor']
evals, evecs, kt = split_dki_param(dkfit.model_params)
FA = fractional_anisotropy(evals)
FA[np.isnan(FA)] = 0
FA = np.clip(FA, 0, 1)
if 'dt_tensor' in save_metrics:
tensor_vals = lower_triangular(dkfit.quadratic_form)
correct_order = [0, 1, 3, 2, 4, 5]
tensor_vals_reordered = tensor_vals[..., correct_order]
save_nifti(otensor, tensor_vals_reordered.astype(np.float32),
affine)
if 'dk_tensor' in save_metrics:
save_nifti(odk_tensor, dkfit.kt.astype(np.float32), affine)
if 'fa' in save_metrics:
save_nifti(ofa, FA.astype(np.float32), affine)
if 'ga' in save_metrics:
GA = geodesic_anisotropy(dkfit.evals)
save_nifti(oga, GA.astype(np.float32), affine)
if 'rgb' in save_metrics:
RGB = color_fa(FA, dkfit.evecs)
save_nifti(orgb, np.array(255 * RGB, 'uint8'), affine)
if 'md' in save_metrics:
MD = mean_diffusivity(dkfit.evals)
save_nifti(omd, MD.astype(np.float32), affine)
if 'ad' in save_metrics:
AD = axial_diffusivity(dkfit.evals)
save_nifti(oad, AD.astype(np.float32), affine)
if 'rd' in save_metrics:
RD = radial_diffusivity(dkfit.evals)
save_nifti(orad, RD.astype(np.float32), affine)
if 'mode' in save_metrics:
MODE = get_mode(dkfit.quadratic_form)
save_nifti(omode, MODE.astype(np.float32), affine)
if 'evec' in save_metrics:
save_nifti(oevecs, dkfit.evecs.astype(np.float32), affine)
if 'eval' in save_metrics:
save_nifti(oevals, dkfit.evals.astype(np.float32), affine)
if 'mk' in save_metrics:
save_nifti(omk, dkfit.mk().astype(np.float32), affine)
if 'ak' in save_metrics:
save_nifti(oak, dkfit.ak().astype(np.float32), affine)
if 'rk' in save_metrics:
save_nifti(ork, dkfit.rk().astype(np.float32), affine)
logging.info('DKI metrics saved in {0}'.
format(os.path.dirname(oevals)))
def run(self, input_files, bvalues_files, bvectors_files, mask_files,
b0_threshold=50, bvecs_tol=0.01, save_metrics=[],
out_dir='', out_tensor='tensors.nii.gz', out_fa='fa.nii.gz',
out_ga='ga.nii.gz', out_rgb='rgb.nii.gz', out_md='md.nii.gz',
out_ad='ad.nii.gz', out_rd='rd.nii.gz', out_mode='mode.nii.gz',
out_evec='evecs.nii.gz', out_eval='evals.nii.gz'):
""" Workflow for tensor reconstruction and for computing DTI metrics.
using Weighted Least-Squares.
Performs a tensor reconstruction on the files by 'globing'
``input_files`` and saves the DTI metrics in a directory specified by
``out_dir``.
Parameters
----------
input_files : string
Path to the input volumes. This path may contain wildcards to
process multiple inputs at once.
bvalues_files : string
Path to the bvalues files. This path may contain wildcards to use
multiple bvalues files at once.
bvectors_files : string
Path to the bvectors files. This path may contain wildcards to use
multiple bvectors files at once.
mask_files : string
Path to the input masks. This path may contain wildcards to use
multiple masks at once. (default: No mask used)
b0_threshold : float, optional
Threshold used to find b=0 directions (default 0.0)
bvecs_tol : float, optional
Threshold used to check that norm(bvec) = 1 +/- bvecs_tol
b-vectors are unit vectors (default 0.01)
save_metrics : variable string, optional
List of metrics to save.
Possible values: fa, ga, rgb, md, ad, rd, mode, tensor, evec, eval
(default [] (all))
out_dir : string, optional
Output directory (default input file directory)
out_tensor : string, optional
Name of the tensors volume to be saved (default 'tensors.nii.gz')
out_fa : string, optional
Name of the fractional anisotropy volume to be saved
(default 'fa.nii.gz')
out_ga : string, optional
Name of the geodesic anisotropy volume to be saved
(default 'ga.nii.gz')
out_rgb : string, optional
Name of the color fa volume to be saved (default 'rgb.nii.gz')
out_md : string, optional
Name of the mean diffusivity volume to be saved
(default 'md.nii.gz')
out_ad : string, optional
Name of the axial diffusivity volume to be saved
(default 'ad.nii.gz')
out_rd : string, optional
Name of the radial diffusivity volume to be saved
(default 'rd.nii.gz')
out_mode : string, optional
Name of the mode volume to be saved (default 'mode.nii.gz')
out_evec : string, optional
Name of the eigenvectors volume to be saved
(default 'evecs.nii.gz')
out_eval : string, optional
Name of the eigenvalues to be saved (default 'evals.nii.gz')
References
----------
.. [1] Basser, P.J., Mattiello, J., LeBihan, D., 1994. Estimation of
the effective self-diffusion tensor from the NMR spin echo. J Magn
Reson B 103, 247-254.
.. [2] Basser, P., Pierpaoli, C., 1996. Microstructural and
physiological features of tissues elucidated by quantitative
diffusion-tensor MRI. Journal of Magnetic Resonance 111, 209-219.
.. [3] Lin-Ching C., Jones D.K., Pierpaoli, C. 2005. RESTORE: Robust
estimation of tensors by outlier rejection. MRM 53: 1088-1095
.. [4] hung, SW., Lu, Y., Henry, R.G., 2006. Comparison of bootstrap
approaches for estimation of uncertainties of DTI parameters.
NeuroImage 33, 531-541.
"""
io_it = self.get_io_iterator()
for dwi, bval, bvec, mask, otensor, ofa, oga, orgb, omd, oad, orad, \
omode, oevecs, oevals in io_it:
logging.info('Computing DTI metrics for {0}'.format(dwi))
data, affine = load_nifti(dwi)
if mask is not None:
mask = nib.load(mask).get_data().astype(np.bool)
tenfit, _ = self.get_fitted_tensor(data, mask, bval, bvec,
b0_threshold, bvecs_tol)
if not save_metrics:
save_metrics = ['fa', 'md', 'rd', 'ad', 'ga', 'rgb', 'mode',
'evec', 'eval', 'tensor']
FA = fractional_anisotropy(tenfit.evals)
FA[np.isnan(FA)] = 0
FA = np.clip(FA, 0, 1)
if 'tensor' in save_metrics:
tensor_vals = lower_triangular(tenfit.quadratic_form)
correct_order = [0, 1, 3, 2, 4, 5]
tensor_vals_reordered = tensor_vals[..., correct_order]
save_nifti(otensor, tensor_vals_reordered.astype(np.float32),
affine)
if 'fa' in save_metrics:
save_nifti(ofa, FA.astype(np.float32), affine)
if 'ga' in save_metrics:
GA = geodesic_anisotropy(tenfit.evals)
save_nifti(oga, GA.astype(np.float32), affine)
if 'rgb' in save_metrics:
RGB = color_fa(FA, tenfit.evecs)
save_nifti(orgb, np.array(255 * RGB, 'uint8'), affine)
if 'md' in save_metrics:
MD = mean_diffusivity(tenfit.evals)
save_nifti(omd, MD.astype(np.float32), affine)
if 'ad' in save_metrics:
AD = axial_diffusivity(tenfit.evals)
save_nifti(oad, AD.astype(np.float32), affine)
if 'rd' in save_metrics:
RD = radial_diffusivity(tenfit.evals)
save_nifti(orad, RD.astype(np.float32), affine)
if 'mode' in save_metrics:
MODE = get_mode(tenfit.quadratic_form)
save_nifti(omode, MODE.astype(np.float32), affine)
if 'evec' in save_metrics:
save_nifti(oevecs, tenfit.evecs.astype(np.float32), affine)
if 'eval' in save_metrics:
save_nifti(oevals, tenfit.evals.astype(np.float32), affine)
dname_ = os.path.dirname(oevals)
if dname_ == '':
logging.info('DTI metrics saved in current directory')
else:
logging.info(
'DTI metrics saved in {0}'.format(dname_))
