def loc_track(path, default_sphere):
data, affine = load_nifti(path + 'data.nii.gz')
data[np.isnan(data) == 1] = 0
mask, affine = load_nifti(path + 'nodif_brain_mask.nii.gz')
mask[np.isnan(mask) == 1] = 0
mask[:, :, 2:] = 0
gtab = gradient_table(path + 'bvals', path + 'bvecs')
if os.path.exists(path + 'grad_dev.nii.gz'):
gd, affine_g = load_nifti(path + 'grad_dev.nii.gz')
else:
gd = None
csa_model = CsaOdfModel(gtab, smooth=1, sh_order=12)
peaks = peaks_from_model(csa_model,
data,
default_sphere,
relative_peak_threshold=0.99,
min_separation_angle=25,
mask=mask)
seedss = copy.deepcopy(mask)
seeds = utils.seeds_from_mask(seedss, affine, [2, 2, 2])
stopping_criterion = ThresholdStoppingCriterion(mask, 0)
tracked = tracking(peaks,
stopping_criterion,
seeds,
affine,
graddev=gd,
sphere=default_sphere)
tracked.localTracking()
return tracked
def test_eudx_tracker():
"""This tests that the Peaks And Metrics Direction Getter plays nice
LocalTracking and produces reasonable streamlines in a simple example.
"""
sphere = HemiSphere.from_sphere(unit_octahedron)
# A simple image with three possible configurations, a vertical tract,
# a horizontal tract and a crossing
peaks_values_lookup = np.array([[0., 0.],
[1., 0.],
[1., 0.],
[0.5, 0.5]])
peaks_indices_lookup = np.array([[-1, -1],
[0, -1],
[1, -1],
[0, 1]])
# EuDXDirectionGetter needs at 3 slices on each axis to work
simple_image = np.zeros([5, 6, 3], dtype=int)
simple_image[:, :, 1] = np.array([[0, 1, 0, 1, 0, 0],
[0, 1, 0, 1, 0, 0],
[0, 3, 2, 2, 2, 0],
[0, 1, 0, 0, 0, 0],
[0, 1, 0, 0, 0, 0],
])
dg = PeaksAndMetrics()
dg.sphere = sphere
dg.peak_values = peaks_values_lookup[simple_image]
dg.peak_indices = peaks_indices_lookup[simple_image]
dg.ang_thr = 90
mask = (simple_image >= 0).astype(float)
sc = ThresholdStoppingCriterion(mask, 0.5)
seeds = [np.array([1., 1., 1.]),
np.array([2., 4., 1.]),
np.array([1., 3., 1.]),
np.array([4., 4., 1.])]
streamlines = LocalTracking(dg, sc, seeds, np.eye(4), 1.)
expected = [np.array([[0., 1., 1.],
[1., 1., 1.],
[2., 1., 1.],
[3., 1., 1.],
[4., 1., 1.]]),
np.array([[2., 0., 1.],
[2., 1., 1.],
[2., 2., 1.],
[2., 3., 1.],
[2., 4., 1.],
[2., 5., 1.]]),
np.array([[0., 3., 1.],
[1., 3., 1.],
[2., 3., 1.],
[2., 4., 1.],
[2., 5., 1.]]),
np.array([[4., 4., 1.]])]
for i, sl in enumerate(streamlines):
npt.assert_(np.allclose(sl, expected[i]))
def probal(Threshold=.2,
data_list=None,
seed='.',
one_node=False,
two_node=False):
time0 = time.time()
print("begin loading data, time:", time.time() - time0)
data = data_list['DWI']
affine = data_list['affine']
img = data_list['img']
labels = data_list['labels']
gtab = data_list['gtab']
head_mask = data_list['head_mask']
if type(seed) != str:
seed_mask = seed
else:
seed_mask = (labels == 2) * (head_mask == 1)
white_matter = (labels == 2) * (head_mask == 1)
seeds = utils.seeds_from_mask(seed_mask, affine, density=1)
print("begin reconstruction, time:", time.time() - time0)
response, ratio = auto_response_ssst(gtab, data, roi_radii=10, fa_thr=0.7)
csd_model = ConstrainedSphericalDeconvModel(gtab, response, sh_order=6)
csd_fit = csd_model.fit(data, mask=white_matter)
csa_model = CsaOdfModel(gtab, sh_order=6)
gfa = csa_model.fit(data, mask=white_matter).gfa
stopping_criterion = ThresholdStoppingCriterion(gfa, Threshold)
print("begin tracking, time:", time.time() - time0)
fod = csd_fit.odf(small_sphere)
pmf = fod.clip(min=0)
prob_dg = ProbabilisticDirectionGetter.from_pmf(pmf,
max_angle=30.,
sphere=small_sphere)
streamline_generator = LocalTracking(prob_dg,
stopping_criterion,
seeds,
affine,
step_size=.5)
streamlines = Streamlines(streamline_generator)
sft = StatefulTractogram(streamlines, img, Space.RASMM)
if one_node or two_node:
sft.to_vox()
streamlines = reduct_seed_ROI(sft.streamlines, seed_mask, one_node,
two_node)
sft = StatefulTractogram(streamlines, img, Space.VOX)
sft._vox_to_rasmm()
print("begin saving, time:", time.time() - time0)
output = 'tractogram_probabilistic.trk'
save_trk(sft, output)
print("finished, time:", time.time() - time0)
def track(self):
SeedBasedTracker.track(self)
if self.streamlines is not None:
return
roi_r = Config.get_config().getint("CSDTracking", "autoResponseRoiRadius",
fallback="10")
fa_thr = Config.get_config().getfloat("CSDTracking", "autoResponseFaThreshold",
fallback="0.7")
response, _ = auto_response_ssst(self.data.gtab, self.data.dwi, roi_radii=roi_r, fa_thr=fa_thr)
csd_model = ConstrainedSphericalDeconvModel(self.data.gtab, response)
relative_peak_thr = Config.get_config().getfloat("CSDTracking", "relativePeakTreshold",
fallback="0.5")
min_separation_angle = Config.get_config().getfloat("CSDTracking", "minimumSeparationAngle",
fallback="25")
direction_getter = peaks_from_model(model=csd_model,
data=self.data.dwi,
sphere=get_sphere('symmetric724'),
mask=self.data.binarymask,
relative_peak_threshold=relative_peak_thr,
min_separation_angle=min_separation_angle,
parallel=False)
dti_fit = dti.TensorModel(self.data.gtab, fit_method='LS')
dti_fit = dti_fit.fit(self.data.dwi, mask=self.data.binarymask)
self._track(ThresholdStoppingCriterion(dti_fit.fa, self.options.fa_threshold),
direction_getter)
Cache.get_cache().set(self.id, self.streamlines)
def basic_tracking(name=None,
data_path=None,
output_path='.',
Threshold=.20,
data_list=None):
time0 = time.time()
print("begin loading data, time:", time.time() - time0)
if data_list == None:
data, affine, img, labels, gtab, head_mask = get_data(name, data_path)
else:
data = data_list['DWI']
affine = data_list['affine']
img = data_list['img']
labels = data_list['labels']
gtab = data_list['gtab']
head_mask = data_list['head_mask']
seed_mask = (labels == 2) * (head_mask == 1)
white_matter = (labels == 2) * (head_mask == 1)
seeds = utils.seeds_from_mask(seed_mask, affine, density=1)
print('begin reconstruction, time:', time.time() - time0)
from dipy.reconst.csdeconv import auto_response_ssst
from dipy.reconst.shm import CsaOdfModel
from dipy.data import default_sphere
from dipy.direction import peaks_from_model
response, ratio = auto_response_ssst(gtab, data, roi_radii=10, fa_thr=0.7)
csa_model = CsaOdfModel(gtab, sh_order=6)
csa_peaks = peaks_from_model(csa_model,
data,
default_sphere,
relative_peak_threshold=.8,
min_separation_angle=45,
mask=white_matter)
stopping_criterion = ThresholdStoppingCriterion(csa_peaks.gfa, Threshold)
print("begin tracking, time:", time.time() - time0)
# Initialization of LocalTracking. The computation happens in the next step.
streamlines_generator = LocalTracking(csa_peaks,
stopping_criterion,
seeds,
affine=affine,
step_size=.5)
# Generate streamlines object
streamlines = Streamlines(streamlines_generator)
print('begin saving, time:', time.time() - time0)
from dipy.io.stateful_tractogram import Space, StatefulTractogram
from dipy.io.streamline import save_trk
sft = StatefulTractogram(streamlines, img, Space.RASMM)
output = output_path + '/tractogram_EuDX_' + name + '.trk'
save_trk(sft, output, streamlines)
def create_stopping_criterion(self, csa_model):
tensor_model = dti.TensorModel(self.gtab)
tenfit = tensor_model.fit(self.data, mask=self.white_mask)
fa = fractional_anisotropy(tenfit.evals)
stopping_criterion = ThresholdStoppingCriterion(fa, 0.18)
# gfa = csa_model.fit(self.data, mask=self.white_mask).gfa
# stopping_criterion = ThresholdStoppingCriterion(gfa, self.stopping_threshold)
return stopping_criterion
def PFT_tracking(name=None, data_path=None, output_path='.', Threshold=.20):
time0 = time.time()
print("begin loading data, time:", time.time() - time0)
data, affine, img, labels, gtab, head_mask = get_data(name, data_path)
seed_mask = (labels == 2) * (head_mask == 1)
white_matter = (labels == 2) * (head_mask == 1)
seeds = utils.seeds_from_mask(seed_mask, affine, density=1)
print('begin reconstruction, time:', time.time() - time0)
response, ratio = auto_response_ssst(gtab, data, roi_radii=10, fa_thr=0.7)
csd_model = ConstrainedSphericalDeconvModel(gtab, response)
csd_fit = csd_model.fit(data, mask=white_matter)
csa_model = CsaOdfModel(gtab, sh_order=6)
gfa = csa_model.fit(data, mask=white_matter).gfa
stopping_criterion = ThresholdStoppingCriterion(gfa, Threshold)
dg = ProbabilisticDirectionGetter.from_shcoeff(csd_fit.shm_coeff,
max_angle=20.,
sphere=default_sphere)
#seed_mask = (labels == 2)
#seed_mask[pve_wm_data < 0.5] = 0
seeds = utils.seeds_from_mask(seed_mask, affine, density=1)
#voxel_size = np.average(voxel_size[1:4])
step_size = 0.2
#cmc_criterion = CmcStoppingCriterion.from_pve(pve_wm_data,
# pve_gm_data,
# pve_csf_data,
# step_size=step_size,
# average_voxel_size=voxel_size)
# Particle Filtering Tractography
pft_streamline_generator = ParticleFilteringTracking(
dg,
stopping_criterion,
seeds,
affine,
max_cross=1,
step_size=step_size,
maxlen=1000,
pft_back_tracking_dist=2,
pft_front_tracking_dist=1,
particle_count=15,
return_all=False)
streamlines = Streamlines(pft_streamline_generator)
sft = StatefulTractogram(streamlines, img, Space.RASMM)
output = output_path + '/tractogram_pft_' + name + '.trk'
def create_fa_classifier(gtab, data, white_matter):
import dipy.reconst.dti as dti
from dipy.reconst.dti import fractional_anisotropy
from dipy.tracking.stopping_criterion import ThresholdStoppingCriterion
tensor_model = dti.TensorModel(gtab)
tenfit = tensor_model.fit(data, mask=white_matter)
fa = fractional_anisotropy(tenfit.evals)
classifier = ThresholdStoppingCriterion(fa, 0.18)
return fa, classifier
def _fa_sc(self):
import dipy.reconst.dti as dti
from dipy.reconst.dti import fractional_anisotropy
from dipy.tracking.stopping_criterion import ThresholdStoppingCriterion
tensor_model = dti.TensorModel(self.gtab)
tenfit = tensor_model.fit(self.data, mask=self.tissue_labels == 2)
fa = fractional_anisotropy(tenfit.evals)
classifier = ThresholdStoppingCriterion(fa,
self.parameters_dict['fa_th'])
self.classifier = classifier
def test_threshold_stopping_criterion():
"""This tests that the thresholdy stopping criterion returns expected
streamline statuses.
"""
tissue_map = np.random.random((4, 4, 4))
ttc = ThresholdStoppingCriterion(tissue_map.astype('float32'), 0.5)
# Test voxel center
for ind in ndindex(tissue_map.shape):
pts = np.array(ind, dtype='float64')
state = ttc.check_point(pts)
if tissue_map[ind] > 0.5:
npt.assert_equal(state, int(StreamlineStatus.TRACKPOINT))
else:
npt.assert_equal(state, int(StreamlineStatus.ENDPOINT))
# Test random points in voxel
inds = [[0, 1.4, 2.2], [0, 2.3, 2.3], [0, 2.2, 1.3], [0, 0.9, 2.2],
[0, 2.8, 1.1], [0, 1.1, 3.3], [0, 2.1, 1.9], [0, 3.1, 3.1],
[0, 0.1, 0.1], [0, 0.9, 0.5], [0, 0.9, 0.5], [0, 2.9, 0.1]]
for pts in inds:
pts = np.array(pts, dtype='float64')
state = ttc.check_point(pts)
res = scipy.ndimage.map_coordinates(tissue_map,
np.reshape(pts, (3, 1)),
order=1,
mode='nearest')
if res > 0.5:
npt.assert_equal(state, int(StreamlineStatus.TRACKPOINT))
else:
npt.assert_equal(state, int(StreamlineStatus.ENDPOINT))
# Test outside points
outside_pts = [[100, 100, 100], [0, -1, 1], [0, 10, 2], [0, 0.5, -0.51],
[0, -0.51, 0.1]]
for pts in outside_pts:
pts = np.array(pts, dtype='float64')
state = ttc.check_point(pts)
npt.assert_equal(state, int(StreamlineStatus.OUTSIDEIMAGE))
def get_dti_streamlines(data_container,
random_seeds=False,
seeds_count=30000,
seeds_per_voxel=False,
step_width=1.0,
max_angle=30.0,
fa_threshold=0.15):
"""
Tracks and returns CSD Streamlines for the given DataContainer.
Parameters
----------
data_container
The DataContainer we would like to track streamlines on
random_seeds
A boolean indicating whether we would like to use random seeds
seeds_count
If we use random seeds, this specifies the seed count
seeds_per_voxel
If True, the seed count is specified per voxel
step_width
The step width used while tracking
fa_threshold
The FA threshold to use to stop tracking
max_angle
The maximum allowed angle between incoming and outgoing angle, float between 0.0 and 90.0 deg
Returns
-------
Streamlines
A list of Streamlines
"""
seeds = _get_seeds(data_container, random_seeds, seeds_count,
seeds_per_voxel)
dti_fit = TensorModel(data_container.gtab).fit(
data_container.dwi, mask=data_container.binary_mask)
dti_fit_odf = dti_fit.odf(sphere=default_sphere)
direction_getter = DeterministicMaximumDirectionGetter.from_pmf(
dti_fit_odf, max_angle=max_angle, sphere=default_sphere)
classifier = ThresholdStoppingCriterion(dti_fit.fa, fa_threshold)
streamlines_generator = LocalTracking(direction_getter,
classifier,
seeds,
data_container.aff,
step_size=step_width)
streamlines = Streamlines(streamlines_generator)
return streamlines
def track(self):
SeedBasedTracker.track(self)
if self.streamlines is not None:
return
dti_model = TensorModel(self.data.gtab)
dti_fit = dti_model.fit(self.data.dwi, mask=self.data.binarymask)
dti_fit_odf = dti_fit.odf(sphere=default_sphere)
max_angle = Config.get_config().getfloat("DTITracking", "maxAngle", fallback="30.0")
direction_getter = DeterministicMaximumDirectionGetter.from_pmf(dti_fit_odf,
max_angle=max_angle,
sphere=default_sphere)
self._track(ThresholdStoppingCriterion(dti_fit.fa, self.options.fa_threshold),
direction_getter)
Cache.get_cache().set(self.id, self.streamlines)
def ClosestPeak(name=None, data_path=None, output_path='.', Threshold=.20):
time0 = time.time()
print("begin loading data, time:", time.time() - time0)
data, affine, img, labels, gtab, head_mask = get_data(name, data_path)
seed_mask = (labels == 2) * (head_mask == 1)
white_matter = (labels == 2) * (head_mask == 1)
seeds = utils.seeds_from_mask(seed_mask, affine, density=1)
print("begin reconstruction, time:", time.time() - time0)
response, ratio = auto_response_ssst(gtab, data, roi_radii=10, fa_thr=0.7)
csd_model = ConstrainedSphericalDeconvModel(gtab, response, sh_order=6)
#csd_fit = csd_model.fit(data, mask=white_matter)
#pmf = csd_fit.odf(small_sphere).clip(min=0)
peak_dg = BootDirectionGetter.from_data(data,
csd_model,
max_angle=30.,
sphere=small_sphere)
csa_model = CsaOdfModel(gtab, sh_order=6)
gfa = csa_model.fit(data, mask=white_matter).gfa
stopping_criterion = ThresholdStoppingCriterion(gfa, Threshold)
#from dipy.data import small_sphere
print("begin tracking, time:", time.time() - time0)
#detmax_dg = DeterministicMaximumDirectionGetter.from_shcoeff(
# csd_fit.shm_coeff, max_angle=30., sphere=default_sphere)
streamline_generator = LocalTracking(peak_dg,
stopping_criterion,
seeds,
affine,
step_size=.5)
streamlines = Streamlines(streamline_generator)
sft = StatefulTractogram(streamlines, img, Space.RASMM)
print("begin saving, time:", time.time() - time0)
output = output_path + '/tractogram_ClosestPeak_' + name + '.trk'
save_trk(sft, output)
print("finished, time:", time.time() - time0)
def _core_run(self, stopping_path, use_binary_mask, stopping_thr,
seeding_path, seed_density, step_size, direction_getter,
out_tract, save_seeds):
stop, affine = load_nifti(stopping_path)
if use_binary_mask:
stopping_criterion = BinaryStoppingCriterion(stop > stopping_thr)
else:
stopping_criterion = ThresholdStoppingCriterion(stop, stopping_thr)
logging.info('stopping criterion done')
seed_mask, _ = load_nifti(seeding_path)
seeds = \
utils.seeds_from_mask(
seed_mask,
density=[seed_density, seed_density, seed_density],
affine=affine)
logging.info('seeds done')
tracking_result = LocalTracking(direction_getter,
stopping_criterion,
seeds,
affine,
step_size=step_size,
save_seeds=save_seeds)
logging.info('LocalTracking initiated')
if save_seeds:
streamlines, seeds = zip(*tracking_result)
seeds = {'seeds': seeds}
else:
streamlines = list(tracking_result)
seeds = {}
sft = StatefulTractogram(streamlines,
seeding_path,
Space.RASMM,
data_per_streamline=seeds)
save_tractogram(sft, out_tract, bbox_valid_check=False)
logging.info('Saved {0}'.format(out_tract))
seeds = utils.seeds_from_mask(seed_mask, affine, density=1)
# Generalized FA to be used as stopping criterion
'''
csa_model = CsaOdfModel(gtab, sh_order=6)
gfa = csa_model.fit(d_img, mask=mask).gfa
gfa_img= np.transpose(gfa, [2,1,0])
gfa_img= sitk.GetImageFromArray(gfa_img)
gfa_img.SetDirection(ref_dir)
gfa_img.SetOrigin(ref_org)
gfa_img.SetSpacing(ref_spc)
sitk.WriteImage(gfa_img, dav_dir + 'gfa.mhd')'''
#stopping_criterion = ThresholdStoppingCriterion(gfa, .20)
stopping_criterion = ThresholdStoppingCriterion(FA, .15)
###########################################################
if run_DL_tractography:
# Run the proposed method
X = tf.placeholder("float32", [None, n_sig])
Y = tf.placeholder("float32", [None, n_fod])
p_keep_hidden = tf.placeholder("float")
Y_p_un = dk_model.davood_reg_net(X,
n_feat_vec,
p_keep_hidden,
def determine(name=None,
data_path=None,
output_path='.',
Threshold=.20,
data_list=None,
seed='.',
minus_ROI_mask='.',
one_node=False,
two_node=False):
time0 = time.time()
print("begin loading data, time:", time.time() - time0)
if data_list == None:
data, affine, img, labels, gtab, head_mask = get_data(name, data_path)
else:
data = data_list['DWI']
affine = data_list['affine']
img = data_list['img']
labels = data_list['labels']
gtab = data_list['gtab']
head_mask = data_list['head_mask']
print(type(seed))
if type(seed) != str:
seed_mask = seed
else:
seed_mask = (labels == 2) * (head_mask == 1)
white_matter = (labels == 2) * (head_mask == 1)
seeds = utils.seeds_from_mask(seed_mask, affine, density=1)
print("begin reconstruction, time:", time.time() - time0)
response, ratio = auto_response_ssst(gtab, data, roi_radii=10, fa_thr=0.7)
csd_model = ConstrainedSphericalDeconvModel(gtab, response, sh_order=6)
csd_fit = csd_model.fit(data, mask=white_matter)
csa_model = CsaOdfModel(gtab, sh_order=6)
gfa = csa_model.fit(data, mask=white_matter).gfa
stopping_criterion = ThresholdStoppingCriterion(gfa, Threshold)
#from dipy.data import small_sphere
print("begin tracking, time:", time.time() - time0)
detmax_dg = DeterministicMaximumDirectionGetter.from_shcoeff(
csd_fit.shm_coeff, max_angle=30., sphere=default_sphere)
streamline_generator = LocalTracking(detmax_dg,
stopping_criterion,
seeds,
affine,
step_size=.5)
streamlines = Streamlines(streamline_generator)
sft = StatefulTractogram(streamlines, img, Space.RASMM)
if one_node or two_node:
sft.to_vox()
streamlines = reduct_seed_ROI(sft.streamlines, seed_mask, one_node,
two_node)
if type(minus_ROI_mask) != str:
streamlines = minus_ROI(streamlines=streamlines,
ROI=minus_ROI_mask)
sft = StatefulTractogram(streamlines, img, Space.VOX)
sft._vox_to_rasmm()
print("begin saving, time:", time.time() - time0)
output = output_path + '/tractogram_deterministic_' + name + '.trk'
save_trk(sft, output)
print("finished, time:", time.time() - time0)
def track(params_file,
directions="det",
max_angle=30.,
sphere=None,
seed_mask=None,
seed_threshold=0,
n_seeds=1,
random_seeds=False,
rng_seed=None,
stop_mask=None,
stop_threshold=0,
step_size=0.5,
min_length=10,
max_length=1000,
odf_model="DTI",
tracker="local"):
"""
Tractography
Parameters
----------
params_file : str, nibabel img.
Full path to a nifti file containing CSD spherical harmonic
coefficients, or nibabel img with model params.
directions : str
How tracking directions are determined.
One of: {"det" | "prob"}
max_angle : float, optional.
The maximum turning angle in each step. Default: 30
sphere : Sphere object, optional.
The discretization of direction getting. default:
dipy.data.default_sphere.
seed_mask : array, optional.
Float or binary mask describing the ROI within which we seed for
tracking.
Default to the entire volume (all ones).
seed_threshold : float, optional.
A value of the seed_mask below which tracking is terminated.
Default to 0.
n_seeds : int or 2D array, optional.
The seeding density: if this is an int, it is is how many seeds in each
voxel on each dimension (for example, 2 => [2, 2, 2]). If this is a 2D
array, these are the coordinates of the seeds. Unless random_seeds is
set to True, in which case this is the total number of random seeds
to generate within the mask.
random_seeds : bool
Whether to generate a total of n_seeds random seeds in the mask.
Default: False.
rng_seed : int
random seed used to generate random seeds if random_seeds is
set to True. Default: None
stop_mask : array or str, optional.
If array: A float or binary mask that determines a stopping criterion
(e.g. FA).
If tuple: it contains a sequence that is interpreted as:
(pve_wm, pve_gm, pve_csf), each item of which is either a string
(full path) or a nibabel img to be used in particle filtering
tractography.
A tuple is required if tracker is set to "pft".
Defaults to no stopping (all ones).
stop_threshold : float or tuple, optional.
If float, this a value of the stop_mask below which tracking is
terminated (and stop_mask has to be an array).
If str, "CMC" for Continuous Map Criterion [Girard2014]_.
"ACT" for Anatomically-constrained tractography [Smith2012]_.
A string is required if the tracker is set to "pft".
Defaults to 0 (this means that if no stop_mask is passed,
we will stop only at the edge of the image).
step_size : float, optional.
The size (in mm) of a step of tractography. Default: 1.0
min_length: int, optional
The miminal length (mm) in a streamline. Default: 10
max_length: int, optional
The miminal length (mm) in a streamline. Default: 1000
odf_model : str, optional
One of {"DTI", "CSD", "DKI", "MSMT"}. Defaults to use "DTI"
tracker : str, optional
Which strategy to use in tracking. This can be the standard local
tracking ("local") or Particle Filtering Tracking ([Girard2014]_).
One of {"local", "pft"}. Default: "local"
Returns
-------
list of streamlines ()
References
----------
.. [Girard2014] Girard, G., Whittingstall, K., Deriche, R., &
Descoteaux, M. Towards quantitative connectivity analysis: reducing
tractography biases. NeuroImage, 98, 266-278, 2014.
"""
logger = logging.getLogger('AFQ.tractography')
logger.info("Loading Image...")
if isinstance(params_file, str):
params_img = nib.load(params_file)
else:
params_img = params_file
model_params = params_img.get_fdata()
affine = params_img.affine
odf_model = odf_model.upper()
directions = directions.lower()
logger.info("Generating Seeds...")
if isinstance(n_seeds, int):
if seed_mask is None:
seed_mask = np.ones(params_img.shape[:3])
elif seed_mask.dtype != 'bool':
seed_mask = seed_mask > seed_threshold
if random_seeds:
seeds = dtu.random_seeds_from_mask(seed_mask,
seeds_count=n_seeds,
seed_count_per_voxel=False,
affine=affine,
random_seed=rng_seed)
else:
seeds = dtu.seeds_from_mask(seed_mask,
density=n_seeds,
affine=affine)
else:
# If user provided an array, we'll use n_seeds as the seeds:
seeds = n_seeds
if sphere is None:
sphere = dpd.default_sphere
logger.info("Getting Directions...")
if directions == "det":
dg = DeterministicMaximumDirectionGetter
elif directions == "prob":
dg = ProbabilisticDirectionGetter
if odf_model == "DTI" or odf_model == "DKI" or odf_model == "FWDTI":
evals = model_params[..., :3]
evecs = model_params[..., 3:12].reshape(params_img.shape[:3] + (3, 3))
odf = tensor_odf(evals, evecs, sphere)
dg = dg.from_pmf(odf, max_angle=max_angle, sphere=sphere)
elif odf_model == "CSD" or "MSMT":
dg = dg.from_shcoeff(model_params, max_angle=max_angle, sphere=sphere)
if tracker == "local":
if stop_mask is None:
stop_mask = np.ones(params_img.shape[:3])
if stop_mask.dtype == 'bool':
stopping_criterion = ThresholdStoppingCriterion(stop_mask, 0.5)
else:
stopping_criterion = ThresholdStoppingCriterion(
stop_mask, stop_threshold)
my_tracker = VerboseLocalTracking
elif tracker == "pft":
if not isinstance(stop_threshold, str):
raise RuntimeError(
"You are using PFT tracking, but did not provide a string ",
"'stop_threshold' input. ",
"Possible inputs are: 'CMC' or 'ACT'")
if not (isinstance(stop_mask, Iterable) and len(stop_mask) == 3):
raise RuntimeError(
"You are using PFT tracking, but did not provide a length "
"3 iterable for `stop_mask`. "
"Expected a (pve_wm, pve_gm, pve_csf) tuple.")
pves = []
pve_imgs = []
vox_sizes = []
for ii, pve in enumerate(stop_mask):
if isinstance(pve, str):
img = nib.load(pve)
else:
img = pve
pve_imgs.append(img)
pves.append(pve_imgs[-1].get_fdata())
average_voxel_size = np.mean(vox_sizes)
pve_wm_img, pve_gm_img, pve_csf_img = pve_imgs
pve_wm_data, pve_gm_data, pve_csf_data = pves
pve_wm_data = resample(pve_wm_data, model_params[...,
0], pve_wm_img.affine,
params_img.affine).get_fdata()
pve_gm_data = resample(pve_gm_data, model_params[...,
0], pve_gm_img.affine,
params_img.affine).get_fdata()
pve_csf_data = resample(pve_csf_data, model_params[..., 0],
pve_csf_img.affine,
params_img.affine).get_fdata()
vox_sizes.append(np.mean(params_img.header.get_zooms()[:3]))
my_tracker = VerboseParticleFilteringTracking
if stop_threshold == "CMC":
stopping_criterion = CmcStoppingCriterion.from_pve(
pve_wm_data,
pve_gm_data,
pve_csf_data,
step_size=step_size,
average_voxel_size=average_voxel_size)
elif stop_threshold == "ACT":
stopping_criterion = ActStoppingCriterion.from_pve(
pve_wm_data, pve_gm_data, pve_csf_data)
logger.info("Tracking...")
return _tracking(my_tracker,
seeds,
dg,
stopping_criterion,
params_img,
step_size=step_size,
min_length=min_length,
max_length=max_length,
random_seed=rng_seed)
def sfm_tracking(name=None,
data_path=None,
output_path='.',
Threshold=.20,
data_list=None,
return_streamlines=False,
save_track=True,
seed='.',
minus_ROI_mask='.',
one_node=False,
two_node=False):
time0 = time.time()
print("begin loading data, time:", time.time() - time0)
if data_list == None:
data, affine, img, labels, gtab, head_mask = get_data(name, data_path)
else:
data = data_list['DWI']
affine = data_list['affine']
img = data_list['img']
labels = data_list['labels']
gtab = data_list['gtab']
head_mask = data_list['head_mask']
if type(seed) != str:
seed_mask = seed
else:
seed_mask = (labels == 2) * (head_mask == 1)
white_matter = (labels == 2) * (head_mask == 1)
seeds = utils.seeds_from_mask(seed_mask, affine, density=1)
print('begin reconstruction, time:', time.time() - time0)
from dipy.reconst.csdeconv import auto_response_ssst
from dipy.reconst.shm import CsaOdfModel
from dipy.data import default_sphere
from dipy.direction import peaks_from_model
response, ratio = auto_response_ssst(gtab, data, roi_radii=10, fa_thr=0.7)
sphere = get_sphere()
sf_model = sfm.SparseFascicleModel(gtab,
sphere=sphere,
l1_ratio=0.5,
alpha=0.001,
response=response[0])
pnm = peaks_from_model(sf_model,
data,
sphere,
relative_peak_threshold=.5,
min_separation_angle=25,
mask=white_matter,
parallel=True)
stopping_criterion = ThresholdStoppingCriterion(pnm.gfa, Threshold)
#seeds = utils.seeds_from_mask(white_matter, affine, density=1)
print('begin tracking, time:', time.time() - time0)
streamline_generator = LocalTracking(pnm,
stopping_criterion,
seeds,
affine,
step_size=.5)
streamlines = Streamlines(streamline_generator)
print('begin saving, time:', time.time() - time0)
from dipy.io.stateful_tractogram import Space, StatefulTractogram
from dipy.io.streamline import save_trk
if save_track:
sft = StatefulTractogram(streamlines, img, Space.RASMM)
if one_node or two_node:
sft.to_vox()
streamlines = reduct_seed_ROI(sft.streamlines, seed_mask, one_node,
two_node)
if type(minus_ROI_mask) != str:
streamlines = minus_ROI(streamlines=streamlines,
ROI=minus_ROI_mask)
sft = StatefulTractogram(streamlines, img, Space.VOX)
sft._vox_to_rasmm()
output = output_path + '/tractogram_sfm_' + name + '.trk'
save_trk(sft, output, streamlines)
if return_streamlines:
return streamlines
def run(context):
####################################################
# Get the path to input files and other parameter #
####################################################
analysis_data = context.fetch_analysis_data()
settings = analysis_data['settings']
postprocessing = settings['postprocessing']
dataset = settings['dataset']
if dataset == "HCPL":
dwi_file_handle = context.get_files('input', modality='HARDI')[0]
dwi_file_path = dwi_file_handle.download('/root/')
bvalues_file_handle = context.get_files(
'input', reg_expression='.*prep.bvalues.hcpl.txt')[0]
bvalues_file_path = bvalues_file_handle.download('/root/')
bvecs_file_handle = context.get_files(
'input', reg_expression='.*prep.gradients.hcpl.txt')[0]
bvecs_file_path = bvecs_file_handle.download('/root/')
elif dataset == "DSI":
dwi_file_handle = context.get_files('input', modality='DSI')[0]
dwi_file_path = dwi_file_handle.download('/root/')
bvalues_file_handle = context.get_files(
'input', reg_expression='.*prep.bvalues.txt')[0]
bvalues_file_path = bvalues_file_handle.download('/root/')
bvecs_file_handle = context.get_files(
'input', reg_expression='.*prep.gradients.txt')[0]
bvecs_file_path = bvecs_file_handle.download('/root/')
else:
context.set_progress(message='Wrong dataset parameter')
inject_file_handle = context.get_files(
'input', reg_expression='.*prep.inject.nii.gz')[0]
inject_file_path = inject_file_handle.download('/root/')
VUMC_ROIs_file_handle = context.get_files(
'input', reg_expression='.*VUMC_ROIs.nii.gz')[0]
VUMC_ROIs_file_path = VUMC_ROIs_file_handle.download('/root/')
###############################
# _____ _____ _______ __ #
# | __ \_ _| __ \ \ / / #
# | | | || | | |__) \ \_/ / #
# | | | || | | ___/ \ / #
# | |__| || |_| | | | #
# |_____/_____|_| |_| #
# #
###############################
########################################################################################
# _______ _ __ __ _______ _ __ #
# |__ __| | | | \/ | |__ __| | | / _| #
# | |_ __ __ _ ___| | ___ _| \ / | ___| |_ __ __ _ ___| | _| |_ __ _ ___ ___ #
# | | '__/ _` |/ __| |/ / | | | |\/| |/ __| | '__/ _` |/ __| |/ / _/ _` |/ __/ _ \ #
# | | | | (_| | (__| <| |_| | | | | (__| | | | (_| | (__| <| || (_| | (_| __/ #
# |_|_| \__,_|\___|_|\_\\__, |_| |_|\___|_|_| \__,_|\___|_|\_\_| \__,_|\___\___| #
# __/ | #
# |___/ #
# #
# #
# IronTract Team #
########################################################################################
#################
# Load the data #
#################
dwi_img = nib.load(dwi_file_path)
bvals, bvecs = read_bvals_bvecs(bvalues_file_path,
bvecs_file_path)
gtab = gradient_table(bvals, bvecs)
############################################
# Extract the brain mask from the b0 image #
############################################
_, brain_mask = median_otsu(dwi_img.get_data()[:, :, :, 0],
median_radius=2, numpass=1)
##################################################################
# Fit the tensor model and compute the fractional anisotropy map #
##################################################################
context.set_progress(message='Processing voxel-wise DTI metrics.')
tenmodel = TensorModel(gtab)
tenfit = tenmodel.fit(dwi_img.get_data(), mask=brain_mask)
FA = fractional_anisotropy(tenfit.evals)
stopping_criterion = ThresholdStoppingCriterion(FA, 0.2)
sphere = get_sphere("repulsion724")
seed_mask_img = nib.load(inject_file_path)
affine = seed_mask_img.affine
seeds = utils.random_seeds_from_mask(seed_mask_img.get_data(),
affine,
seed_count_per_voxel=True,
seeds_count=5000)
if dataset == "HCPL":
################################################
# Compute Fiber Orientation Distribution (CSD) #
################################################
context.set_progress(message='Processing voxel-wise FOD estimation.')
response, _ = auto_response_ssst(gtab, dwi_img.get_data(),
roi_radii=10, fa_thr=0.7)
csd_model = ConstrainedSphericalDeconvModel(gtab, response, sh_order=8)
csd_fit = csd_model.fit(dwi_img.get_data(), mask=brain_mask)
shm = csd_fit.shm_coeff
prob_dg = ProbabilisticDirectionGetter.from_shcoeff(shm,
max_angle=20.,
sphere=sphere,
pmf_threshold=0.1)
elif dataset == "DSI":
context.set_progress(message='Processing voxel-wise DSI estimation.')
dsmodel = DiffusionSpectrumModel(gtab)
dsfit = dsmodel.fit(dwi_img.get_data())
ODFs = dsfit.odf(sphere)
prob_dg = ProbabilisticDirectionGetter.from_pmf(ODFs,
max_angle=20.,
sphere=sphere,
pmf_threshold=0.01)
###########################################
# Compute DIPY Probabilistic Tractography #
###########################################
context.set_progress(message='Processing tractography.')
streamline_generator = LocalTracking(prob_dg, stopping_criterion, seeds,
affine, step_size=.2, max_cross=1)
streamlines = Streamlines(streamline_generator)
# sft = StatefulTractogram(streamlines, seed_mask_img, Space.RASMM)
# streamlines_file_path = "/root/streamlines.trk"
# save_trk(sft, streamlines_file_path)
###########################################################################
# Compute 3D volumes for the IronTract Challenge. For 'EPFL', we only #
# keep streamlines with length > 1mm. We compute the visitation count #
# image and apply a small gaussian smoothing. The gaussian smoothing #
# is especially usefull to increase voxel coverage of deterministic #
# algorithms. The log of the smoothed visitation count map is then #
# iteratively thresholded producing 200 volumes/operation points. #
# For VUMC, additional streamline filtering is done using anatomical #
# priors (keeping only streamlines that intersect with at least one ROI). #
###########################################################################
if postprocessing in ["EPFL", "ALL"]:
context.set_progress(message='Processing density map (EPFL)')
volume_folder = "/root/vol_epfl"
output_epfl_zip_file_path = "/root/TrackyMcTrackface_EPFL_example.zip"
os.mkdir(volume_folder)
lengths = length(streamlines)
streamlines = streamlines[lengths > 1]
density = utils.density_map(streamlines, affine, seed_mask_img.shape)
density = scipy.ndimage.gaussian_filter(density.astype("float32"), 0.5)
log_density = np.log10(density + 1)
max_density = np.max(log_density)
for i, t in enumerate(np.arange(0, max_density, max_density / 200)):
nbr = str(i)
nbr = nbr.zfill(3)
mask = log_density >= t
vol_filename = os.path.join(volume_folder,
"vol" + nbr + "_t" + str(t) + ".nii.gz")
nib.Nifti1Image(mask.astype("int32"), affine,
seed_mask_img.header).to_filename(vol_filename)
shutil.make_archive(output_epfl_zip_file_path[:-4], 'zip', volume_folder)
if postprocessing in ["VUMC", "ALL"]:
context.set_progress(message='Processing density map (VUMC)')
ROIs_img = nib.load(VUMC_ROIs_file_path)
volume_folder = "/root/vol_vumc"
output_vumc_zip_file_path = "/root/TrackyMcTrackface_VUMC_example.zip"
os.mkdir(volume_folder)
lengths = length(streamlines)
streamlines = streamlines[lengths > 1]
rois = ROIs_img.get_fdata().astype(int)
_, grouping = utils.connectivity_matrix(streamlines, affine, rois,
inclusive=True,
return_mapping=True,
mapping_as_streamlines=False)
streamlines = streamlines[grouping[(0, 1)]]
density = utils.density_map(streamlines, affine, seed_mask_img.shape)
density = scipy.ndimage.gaussian_filter(density.astype("float32"), 0.5)
log_density = np.log10(density + 1)
max_density = np.max(log_density)
for i, t in enumerate(np.arange(0, max_density, max_density / 200)):
nbr = str(i)
nbr = nbr.zfill(3)
mask = log_density >= t
vol_filename = os.path.join(volume_folder,
"vol" + nbr + "_t" + str(t) + ".nii.gz")
nib.Nifti1Image(mask.astype("int32"), affine,
seed_mask_img.header).to_filename(vol_filename)
shutil.make_archive(output_vumc_zip_file_path[:-4], 'zip', volume_folder)
###################
# Upload the data #
###################
context.set_progress(message='Uploading results...')
#context.upload_file(fa_file_path, 'fa.nii.gz')
# context.upload_file(fod_file_path, 'fod.nii.gz')
# context.upload_file(streamlines_file_path, 'streamlines.trk')
if postprocessing in ["EPFL", "ALL"]:
context.upload_file(output_epfl_zip_file_path,
'TrackyMcTrackface_' + dataset +'_EPFL.zip')
if postprocessing in ["VUMC", "ALL"]:
context.upload_file(output_vumc_zip_file_path,
'TrackyMcTrackface_' + dataset +'_VUMC.zip')
def get_csd_streamlines(data_container,
random_seeds=False,
seeds_count=30000,
seeds_per_voxel=False,
step_width=1.0,
roi_r=10,
auto_response_fa_threshold=0.7,
fa_threshold=0.15,
relative_peak_threshold=0.5,
min_separation_angle=25):
"""
Tracks and returns CSD Streamlines for the given DataContainer.
Parameters
----------
data_container
The DataContainer we would like to track streamlines on
random_seeds
A boolean indicating whether we would like to use random seeds
seeds_count
If we use random seeds, this specifies the seed count
seeds_per_voxel
If True, the seed count is specified per voxel
step_width
The step width used while tracking
roi_r
The radii of the cuboid roi for the automatic estimation of single-shell single-tissue response function using FA.
auto_response_fa_threshold
The FA threshold for the automatic estimation of single-shell single-tissue response function using FA.
fa_threshold
The FA threshold to use to stop tracking
relative_peak_threshold
The relative peak threshold to use to get peaks from the CSDModel
min_separation_angle
The minimal separation angle of peaks
Returns
-------
Streamlines
A list of Streamlines
"""
seeds = _get_seeds(data_container, random_seeds, seeds_count,
seeds_per_voxel)
response, _ = auto_response_ssst(data_container.gtab,
data_container.dwi,
roi_radii=roi_r,
fa_thr=auto_response_fa_threshold)
csd_model = ConstrainedSphericalDeconvModel(data_container.gtab, response)
direction_getter = peaks_from_model(
model=csd_model,
data=data_container.dwi,
sphere=get_sphere('symmetric724'),
mask=data_container.binary_mask,
relative_peak_threshold=relative_peak_threshold,
min_separation_angle=min_separation_angle,
parallel=False)
dti_fit = dti.TensorModel(data_container.gtab, fit_method='LS').fit(
data_container.dwi, mask=data_container.binary_mask)
classifier = ThresholdStoppingCriterion(dti_fit.fa, fa_threshold)
streamlines_generator = LocalTracking(direction_getter,
classifier,
seeds,
data_container.aff,
step_size=step_width)
streamlines = Streamlines(streamlines_generator)
return streamlines
def track(params_file, directions="det", max_angle=30., sphere=None,
seed_mask=None, n_seeds=1, random_seeds=False, stop_mask=None,
stop_threshold=0, step_size=0.5, min_length=10, max_length=1000,
odf_model="DTI"):
"""
Tractography
Parameters
----------
params_file : str, nibabel img.
Full path to a nifti file containing CSD spherical harmonic
coefficients, or nibabel img with model params.
directions : str
How tracking directions are determined.
One of: {"deterministic" | "probablistic"}
max_angle : float, optional.
The maximum turning angle in each step. Default: 30
sphere : Sphere object, optional.
The discretization of direction getting. default:
dipy.data.default_sphere.
seed_mask : array, optional.
Binary mask describing the ROI within which we seed for tracking.
Default to the entire volume.
n_seeds : int or 2D array, optional.
The seeding density: if this is an int, it is is how many seeds in each
voxel on each dimension (for example, 2 => [2, 2, 2]). If this is a 2D
array, these are the coordinates of the seeds. Unless random_seeds is
set to True, in which case this is the total number of random seeds
to generate within the mask.
random_seeds : bool
Whether to generate a total of n_seeds random seeds in the mask.
Default: XXX.
stop_mask : array, optional.
A floating point value that determines a stopping criterion (e.g. FA).
Default to no stopping (all ones).
stop_threshold : float, optional.
A value of the stop_mask below which tracking is terminated. Default to
0 (this means that if no stop_mask is passed, we will stop only at
the edge of the image)
step_size : float, optional.
The size (in mm) of a step of tractography. Default: 1.0
min_length: int, optional
The miminal length (mm) in a streamline. Default: 10
max_length: int, optional
The miminal length (mm) in a streamline. Default: 250
odf_model : str, optional
One of {"DTI", "CSD"}. Defaults to use "DTI"
Returns
-------
list of streamlines ()
"""
logger = logging.getLogger('AFQ.tractography')
logger.info("Loading Image...")
if isinstance(params_file, str):
params_img = nib.load(params_file)
else:
params_img = params_file
model_params = params_img.get_fdata()
affine = params_img.affine
logger.info("Generating Seeds...")
if isinstance(n_seeds, int):
if seed_mask is None:
seed_mask = np.ones(params_img.shape[:3])
if random_seeds:
seeds = dtu.random_seeds_from_mask(seed_mask, seeds_count=n_seeds,
seed_count_per_voxel=False,
affine=affine)
else:
seeds = dtu.seeds_from_mask(seed_mask,
density=n_seeds,
affine=affine)
else:
# If user provided an array, we'll use n_seeds as the seeds:
seeds = n_seeds
if sphere is None:
sphere = dpd.default_sphere
logger.info("Getting Directions...")
if directions == "det":
dg = DeterministicMaximumDirectionGetter
elif directions == "prob":
dg = ProbabilisticDirectionGetter
if odf_model == "DTI" or odf_model == "DKI":
evals = model_params[..., :3]
evecs = model_params[..., 3:12].reshape(params_img.shape[:3] + (3, 3))
odf = tensor_odf(evals, evecs, sphere)
dg = dg.from_pmf(odf, max_angle=max_angle, sphere=sphere)
elif odf_model == "CSD":
dg = dg.from_shcoeff(model_params, max_angle=max_angle, sphere=sphere)
if stop_mask is None:
stop_mask = np.ones(params_img.shape[:3])
threshold_classifier = ThresholdStoppingCriterion(stop_mask,
stop_threshold)
logger.info("Tracking...")
return _local_tracking(seeds, dg, threshold_classifier, params_img,
step_size=step_size, min_length=min_length,
max_length=max_length)
def tracking(image,
bvecs,
bvals,
wm,
seeds,
fibers,
prune_length=3,
rseed=42,
plot=False,
proba=False,
verbose=False):
# Pipelines transcribed from:
# https://dipy.org/documentation/1.1.1./examples_built/tracking_introduction_eudx/#example-tracking-introduction-eudx
# https://dipy.org/documentation/1.1.1./examples_built/tracking_probabilistic/
# Load Images
dwi_loaded = nib.load(image)
dwi_data = dwi_loaded.get_fdata()
wm_loaded = nib.load(wm)
wm_data = wm_loaded.get_fdata()
seeds_loaded = nib.load(seeds)
seeds_data = seeds_loaded.get_fdata()
seeds = utils.seeds_from_mask(seeds_data, dwi_loaded.affine, density=2)
# Load B-values & B-vectors
# NB. Use aligned b-vecs if providing eddy-aligned data
bvals, bvecs = read_bvals_bvecs(bvals, bvecs)
gtab = gradient_table(bvals, bvecs)
csa_model = CsaOdfModel(gtab, sh_order=6)
# Set stopping criterion
gfa = csa_model.fit(dwi_data, mask=wm_data).gfa
stop_criterion = ThresholdStoppingCriterion(gfa, .25)
if proba:
# Establish ODF model
response, ratio = auto_response(gtab,
dwi_data,
roi_radius=10,
fa_thr=0.7)
csd_model = ConstrainedSphericalDeconvModel(gtab, response, sh_order=6)
csd_fit = csd_model.fit(dwi_data, mask=wm_data)
# Create Probabilisitic direction getter
fod = csd_fit.odf(default_sphere)
pmf = fod.clip(min=0)
prob_dg = ProbabilisticDirectionGetter.from_pmf(pmf,
max_angle=30.,
sphere=default_sphere)
# Use the probabilisitic direction getter as the dg
dg = prob_dg
else:
# Establish ODF model
csa_peaks = peaks_from_model(csa_model,
dwi_data,
default_sphere,
relative_peak_threshold=0.8,
min_separation_angle=45,
mask=wm_data)
# Use the CSA peaks as the dg
dg = csa_peaks
# Create generator and perform tracing
s_generator = LocalTracking(dg,
stop_criterion,
seeds,
dwi_loaded.affine,
0.5,
random_seed=rseed)
streamlines = Streamlines(s_generator)
# Prune streamlines
streamlines = ArraySequence(
[strline for strline in streamlines if len(strline) > prune_length])
sft = StatefulTractogram(streamlines, dwi_loaded, Space.RASMM)
# Save streamlines
save_trk(sft, fibers + ".trk")
# Visualize fibers
if plot and has_fury:
from dipy.viz import window, actor, colormap as cmap
# Create the 3D display.
r = window.Renderer()
r.add(actor.line(streamlines, cmap.line_colors(streamlines)))
window.record(r, out_path=fibers + '.png', size=(800, 800))
hardi_img, gtab, labels_img = read_stanford_labels()
data = hardi_img.get_data()
labels = labels_img.get_data()
affine = hardi_img.affine
white_matter = (labels == 1) | (labels == 2)
csa_model = CsaOdfModel(gtab, sh_order=6)
csa_peaks = peaks_from_model(csa_model,
data,
default_sphere,
relative_peak_threshold=.8,
min_separation_angle=45,
mask=white_matter)
stopping_criterion = ThresholdStoppingCriterion(csa_peaks.gfa, .25)
seed_mask = labels == 2
seeds = utils.seeds_from_mask(seed_mask, affine, density=[1, 1, 1])
# Initialization of LocalTracking. The computation happens in the next step.
streamlines = LocalTracking(csa_peaks,
stopping_criterion,
seeds,
affine,
step_size=2)
# Compute streamlines and store as a list.
streamlines = Streamlines(streamlines)
"""
We will create a streamline actor from the streamlines.
def test_maximum_deterministic_tracker():
"""This tests that the Maximum Deterministic Direction Getter plays nice
LocalTracking and produces reasonable streamlines in a simple example.
"""
sphere = HemiSphere.from_sphere(unit_octahedron)
# A simple image with three possible configurations, a vertical tract,
# a horizontal tract and a crossing
pmf_lookup = np.array([[0., 0., 1.], [1., 0., 0.], [0., 1., 0.],
[.4, .6, 0.]])
simple_image = np.array([
[0, 1, 0, 0, 0, 0],
[0, 1, 0, 0, 0, 0],
[0, 3, 2, 2, 2, 0],
[0, 1, 0, 0, 0, 0],
[0, 1, 0, 0, 0, 0],
])
simple_image = simple_image[..., None]
pmf = pmf_lookup[simple_image]
seeds = [np.array([1., 1., 0.])] * 30
mask = (simple_image > 0).astype(float)
sc = ThresholdStoppingCriterion(mask, .5)
dg = DeterministicMaximumDirectionGetter.from_pmf(pmf,
90,
sphere,
pmf_threshold=0.1)
streamlines = LocalTracking(dg, sc, seeds, np.eye(4), 1.)
expected = [
np.array([[0., 1., 0.], [1., 1., 0.], [2., 1., 0.], [2., 2., 0.],
[2., 3., 0.], [2., 4., 0.]]),
np.array([[0., 1., 0.], [1., 1., 0.], [2., 1., 0.], [3., 1., 0.],
[4., 1., 0.]]),
np.array([[0., 1., 0.], [1., 1., 0.], [2., 1., 0.]])
]
def allclose(x, y):
return x.shape == y.shape and np.allclose(x, y)
for sl in streamlines:
if not allclose(sl, expected[0]):
raise AssertionError()
# The first path is not possible if 90 degree turns are excluded
dg = DeterministicMaximumDirectionGetter.from_pmf(pmf,
80,
sphere,
pmf_threshold=0.1)
streamlines = LocalTracking(dg, sc, seeds, np.eye(4), 1.)
for sl in streamlines:
npt.assert_(np.allclose(sl, expected[1]))
# Both path are not possible if 90 degree turns are exclude and
# if pmf_threshold is larger than 0.67. Streamlines should stop at
# the crossing.
# 0.4/0.6 < 2/3, multiplying the pmf should not change the ratio
dg = DeterministicMaximumDirectionGetter.from_pmf(10 * pmf,
80,
sphere,
pmf_threshold=0.67)
streamlines = LocalTracking(dg, sc, seeds, np.eye(4), 1.)
for sl in streamlines:
npt.assert_(np.allclose(sl, expected[2]))
def test_probabilistic_odf_weighted_tracker():
"""This tests that the Probabalistic Direction Getter plays nice
LocalTracking and produces reasonable streamlines in a simple example.
"""
sphere = HemiSphere.from_sphere(unit_octahedron)
# A simple image with three possible configurations, a vertical tract,
# a horizontal tract and a crossing
pmf_lookup = np.array([[0., 0., 1.], [1., 0., 0.], [0., 1., 0.],
[.6, .4, 0.]])
simple_image = np.array([
[0, 1, 0, 0, 0, 0],
[0, 1, 0, 0, 0, 0],
[0, 3, 2, 2, 2, 0],
[0, 1, 0, 0, 0, 0],
[0, 1, 0, 0, 0, 0],
])
simple_image = simple_image[..., None]
pmf = pmf_lookup[simple_image]
seeds = [np.array([1., 1., 0.])] * 30
mask = (simple_image > 0).astype(float)
sc = ThresholdStoppingCriterion(mask, .5)
dg = ProbabilisticDirectionGetter.from_pmf(pmf,
90,
sphere,
pmf_threshold=0.1)
streamlines = LocalTracking(dg, sc, seeds, np.eye(4), 1.)
expected = [
np.array([[0., 1., 0.], [1., 1., 0.], [2., 1., 0.], [2., 2., 0.],
[2., 3., 0.], [2., 4., 0.]]),
np.array([[0., 1., 0.], [1., 1., 0.], [2., 1., 0.], [3., 1., 0.],
[4., 1., 0.]])
]
def allclose(x, y):
return x.shape == y.shape and np.allclose(x, y)
path = [False, False]
for sl in streamlines:
if allclose(sl, expected[0]):
path[0] = True
elif allclose(sl, expected[1]):
path[1] = True
else:
raise AssertionError()
npt.assert_(all(path))
# The first path is not possible if 90 degree turns are excluded
dg = ProbabilisticDirectionGetter.from_pmf(pmf,
80,
sphere,
pmf_threshold=0.1)
streamlines = LocalTracking(dg, sc, seeds, np.eye(4), 1.)
for sl in streamlines:
npt.assert_(np.allclose(sl, expected[1]))
# The first path is not possible if pmf_threshold > 0.67
# 0.4/0.6 < 2/3, multiplying the pmf should not change the ratio
dg = ProbabilisticDirectionGetter.from_pmf(10 * pmf,
90,
sphere,
pmf_threshold=0.67)
streamlines = LocalTracking(dg, sc, seeds, np.eye(4), 1.)
for sl in streamlines:
npt.assert_(np.allclose(sl, expected[1]))
# Test non WM seed position
seeds = [[0, 0, 0], [5, 5, 5]]
streamlines = LocalTracking(dg,
sc,
seeds,
np.eye(4),
0.2,
max_cross=1,
return_all=True)
streamlines = Streamlines(streamlines)
npt.assert_(len(streamlines[0]) == 1) # INVALIDPOINT
npt.assert_(len(streamlines[1]) == 1) # OUTSIDEIMAGE
# Test that all points are within the image volume
seeds = seeds_from_mask(np.ones(mask.shape), np.eye(4), density=2)
streamline_generator = LocalTracking(dg,
sc,
seeds,
np.eye(4),
0.5,
return_all=True)
streamlines = Streamlines(streamline_generator)
for s in streamlines:
npt.assert_(np.all((s + 0.5).astype(int) >= 0))
npt.assert_(np.all((s + 0.5).astype(int) < mask.shape))
# Test that the number of streamline return with return_all=True equal the
# number of seeds places
npt.assert_(np.array([len(streamlines) == len(seeds)]))
# Test reproducibility
tracking_1 = Streamlines(
LocalTracking(dg, sc, seeds, np.eye(4), 0.5, random_seed=0))._data
tracking_2 = Streamlines(
LocalTracking(dg, sc, seeds, np.eye(4), 0.5, random_seed=0))._data
npt.assert_equal(tracking_1, tracking_2)
def tracking(folder):
print('Tracking in ' + folder)
output_folder = folder + 'dipy_out/'
# make a folder to save new data into
try:
Path(output_folder).mkdir(parents=True, exist_ok=True)
except OSError:
print('Could not create output dir. Aborting...')
return
# load data
print('Loading data...')
img = nib.load(folder + 'data.nii.gz')
dmri = np.asarray(img.dataobj)
affine = img.affine
mask, _ = load_nifti(folder + 'nodif_brain_mask.nii.gz')
bvals, bvecs = read_bvals_bvecs(folder + 'bvals', folder + 'bvecs')
gtab = gradient_table(bvals, bvecs)
# extract peaksoutput_folder + 'peak_vals.nii.gz'
if Path(output_folder + 'peaks.pam5').exists():
peaks = load_peaks(output_folder + 'peaks.pam5')
else:
print('Extracting peaks...')
response, ration = auto_response(gtab, dmri, roi_radius=10, fa_thr=.7)
csd_model = ConstrainedSphericalDeconvModel(gtab, response)
peaks = peaks_from_model(model=csd_model,
data=dmri,
sphere=default_sphere,
relative_peak_threshold=.5,
min_separation_angle=25,
parallel=True)
save_peaks(output_folder + 'peaks.pam5', peaks, affine)
scaled = peaks.peak_dirs * np.repeat(
np.expand_dims(peaks.peak_values, -1), 3, -1)
cropped = scaled[:, :, :, :3, :].reshape(dmri.shape[:3] + (9, ))
save_nifti(output_folder + 'peaks.nii.gz', cropped, affine)
#save_nifti(output_folder + 'peak_dirs.nii.gz', peaks.peak_dirs, affine)
#save_nifti(output_folder + 'peak_vals.nii.gz', peaks.peak_values, affine)
# tracking
print('Tracking...')
maskdata, mask = median_otsu(dmri,
vol_idx=range(0, dmri.shape[3]),
median_radius=3,
numpass=1,
autocrop=True,
dilate=2)
tensor_model = TensorModel(gtab, fit_method='WLS')
tensor_fit = tensor_model.fit(maskdata)
fa = fractional_anisotropy(tensor_fit.evals)
fa[np.isnan(fa)] = 0
bla = np.average(fa)
tissue_classifier = ThresholdStoppingCriterion(fa, .1)
seeds = random_seeds_from_mask(fa > 1e-5, affine, seeds_count=1)
streamline_generator = LocalTracking(direction_getter=peaks,
stopping_criterion=tissue_classifier,
seeds=seeds,
affine=affine,
step_size=.5)
streamlines = Streamlines(streamline_generator)
save_trk(StatefulTractogram(streamlines, img, Space.RASMM),
output_folder + 'whole_brain.trk')
- 'ENDPOINT': stops at a position where metric_map < threshold; the streamline
reached the target stopping area.
- 'OUTSIDEIMAGE': stops at a position outside of metric_map; the streamline
reached an area outside the image where no direction data is available.
- 'TRACKPOINT': stops at a position because no direction is available; the
streamline is stopping where metric_map >= threshold, but there is no valid
direction to follow.
- 'INVALIDPOINT': N/A.
"""
tensor_model = TensorModel(gtab)
tenfit = tensor_model.fit(data, mask=labels > 0)
FA = fractional_anisotropy(tenfit.evals)
threshold_criterion = ThresholdStoppingCriterion(FA, .2)
fig = plt.figure()
mask_fa = FA.copy()
mask_fa[mask_fa < 0.2] = 0
plt.xticks([])
plt.yticks([])
plt.imshow(mask_fa[:, :, data.shape[2] // 2].T,
cmap='gray',
origin='lower',
interpolation='nearest')
fig.tight_layout()
fig.savefig('threshold_fa.png')
"""
.. figure:: threshold_fa.png
:align: center
sphere=sphere) rumba_fit = rumba.fit(data, mask=white_matter) odf = rumba_fit.odf() # fODF f_wm = rumba_fit.f_wm # white matter volume fractions """ To establish stopping criterion, a common technique is to use the Generalized Fractional Anisotropy (GFA). One point of caution is that RUMBA-SD by default separates the fODF from an isotropic compartment. This can bias GFA results computed on the fODF, although it will still generally be an effective criterion. However, an alternative stopping criterion that takes advantage of this feature is to use RUMBA-SD's white matter volume fraction map. """ stopping_criterion = ThresholdStoppingCriterion(f_wm, .25) """ We can visualize a slice of this mask. """ import matplotlib.pyplot as plt sli = f_wm.shape[2] // 2 plt.figure() plt.subplot(1, 2, 1).set_axis_off() plt.imshow(f_wm[:, :, sli].T, cmap='gray', origin='lower') plt.subplot(1, 2, 2).set_axis_off() plt.imshow((f_wm[:, :, sli] > 0.25).T, cmap='gray', origin='lower')
seed_mask = (labels == 2) white_matter = (labels == 1) | (labels == 2) seeds = utils.seeds_from_mask(seed_mask, affine, density=1) response, ratio = auto_response(gtab, data, roi_radius=10, fa_thr=0.7) csd_model = ConstrainedSphericalDeconvModel(gtab, response, sh_order=6) csd_fit = csd_model.fit(data, mask=white_matter) """ We use the GFA of the CSA model to build a stopping criterion. """ from dipy.reconst.shm import CsaOdfModel csa_model = CsaOdfModel(gtab, sh_order=6) gfa = csa_model.fit(data, mask=white_matter).gfa stopping_criterion = ThresholdStoppingCriterion(gfa, .25) """ The Fiber Orientation Distribution (FOD) of the CSD model estimates the distribution of small fiber bundles within each voxel. We can use this distribution for probabilistic fiber tracking. One way to do this is to represent the FOD using a discrete sphere. This discrete FOD can be used by the ``ProbabilisticDirectionGetter`` as a PMF for sampling tracking directions. We need to clip the FOD to use it as a PMF because the latter cannot have negative values. Ideally, the FOD should be strictly positive, but because of noise and/or model failures sometimes it can have negative values. """ from dipy.direction import ProbabilisticDirectionGetter from dipy.data import small_sphere from dipy.io.stateful_tractogram import Space, StatefulTractogram from dipy.io.streamline import save_trk
def QCSA_tractmake(data, affine, vox_size, gtab, mask, masktype, header, step_size, peak_processes, outpathtrk, subject='NA',
ratio=1, overwrite=False, get_params=False, doprune=False, figspath=None, verbose=None):
# Compute odfs in Brain Mask
t2 = time()
if os.path.isfile(outpathtrk) and not overwrite:
txt = "Subject already saved at "+outpathtrk
print(txt)
streamlines_generator = None
params = None
return outpathtrk, streamlines_generator, params
csa_model = CsaOdfModel(gtab, 6)
if peak_processes == 1:
parallel = False
else:
parallel = True
if verbose:
send_mail("Starting calculation of Constant solid angle model for subject " + subject,subject="CSA model start")
wholemask = np.where(mask == 0, False, True)
print(f"There are {peak_processes} and {parallel} here")
csa_peaks = peaks_from_model(model=csa_model,
data=data,
sphere=peaks.default_sphere, # issue with complete sphere
mask=wholemask,
relative_peak_threshold=.5,
min_separation_angle=25,
parallel=parallel,
nbr_processes=peak_processes)
duration = time() - t2
if verbose:
print(subject + ' CSA duration %.3f' % (duration,))
t3 = time()
if verbose:
send_mail('Computing classifier for local tracking for subject ' + subject +
',it has been ' + str(round(duration)) + 'seconds since the start of tractmaker',subject="Seed computation" )
print('Computing classifier for local tracking for subject ' + subject)
if masktype == "FA":
#tensor_model = dti.TensorModel(gtab)
#tenfit = tensor_model.fit(data, mask=labels > 0)
#FA = fractional_anisotropy(tenfit.evals)
FA_threshold = 0.05
classifier = ThresholdStoppingCriterion(mask, FA_threshold)
if figspath is not None:
fig = plt.figure()
mask_fa = mask.copy()
mask_fa[mask_fa < FA_threshold] = 0
plt.xticks([])
plt.yticks([])
plt.imshow(mask_fa[:, :, data.shape[2] // 2].T, cmap='gray', origin='lower',
interpolation='nearest')
fig.tight_layout()
fig.savefig(figspath + 'threshold_fa.png')
else:
classifier = BinaryStoppingCriterion(wholemask)
# generates about 2 seeds per voxel
# seeds = utils.random_seeds_from_mask(fa > .2, seeds_count=2,
# affine=np.eye(4))
# generates about 2 million streamlines
# seeds = utils.seeds_from_mask(fa > .2, density=1,
# affine=np.eye(4))
if verbose:
print('Computing seeds')
seeds = utils.seeds_from_mask(wholemask, density=1,
affine=np.eye(4))
#streamlines_generator = local_tracking.local_tracker(csa_peaks,classifier,seeds,affine=np.eye(4),step_size=step_size)
if verbose:
print('Computing the local tracking')
duration = time() - t2
send_mail('Start of the local tracking ' + ',it has been ' + str(round(duration)) +
'seconds since the start of tractmaker', subject="Seed computation")
#stepsize = 2 #(by default)
stringstep = str(step_size)
stringstep = stringstep.replace(".", "_")
if verbose:
print("stringstep is "+stringstep)
streamlines_generator = LocalTracking(csa_peaks, classifier,
seeds, affine=np.eye(4), step_size=step_size)
if verbose:
duration = time() - t2
txt = 'About to save streamlines at ' + outpathtrk + ',it has been ' + str(round(duration)) + \
'seconds since the start of tractmaker',
send_mail(txt,subject="Tract saving" )
cutoff = 2
if doprune:
streamlines_generator = prune_streamlines(list(streamlines_generator), data[:, :, :, 0], cutoff=cutoff,
verbose=verbose)
myheader = create_tractogram_header(outpathtrk, *header)
sg = lambda: (s for i, s in enumerate(streamlines_generator) if i % ratio == 0)
save_trk_heavy_duty(outpathtrk, streamlines=sg,
affine=affine, header=myheader,
shape=mask.shape, vox_size=vox_size)
else:
sg = lambda: (s for i, s in enumerate(streamlines_generator) if i % ratio == 0)
myheader = create_tractogram_header(outpathtrk, *header)
save_trk_heavy_duty(outpathtrk, streamlines=sg,
affine=affine, header=myheader,
shape=mask.shape, vox_size=vox_size)
if verbose:
duration = time() - t2
txt = "Tract files were saved at "+outpathtrk + ',it has been ' + str(round(duration)) + \
'seconds since the start of tractmaker'
print(txt)
send_mail(txt,subject="Tract saving" )
# save everything - will generate a 20+ GBytes of data - hard to manipulate
# possibly add parameter in csv file or other to decide whether to save large tractogram file
# outpathfile=outpath+subject+"bmCSA_detr"+stringstep+".trk"
# myheader=create_tractogram_header(outpathfile,*get_reference_info(fdwi))
duration3 = time() - t2
if verbose:
print(duration3)
print(subject + ' Tracking duration %.3f' % (duration3,))
send_mail("Finished file save at "+outpathtrk+" with tracking duration of " + str(duration3) + "seconds",
subject="file save update" )
if get_params:
numtracts, minlength, maxlength, meanlength, stdlength = get_trk_params(streamlines_generator, verbose)
params = [numtracts, minlength, maxlength, meanlength, stdlength]
if verbose:
print("For subject " + str(subject) + " the number of tracts is " + str(numtracts) + ", the minimum length is " +
str(minlength) + ", the maximum length is " + str(maxlength) + ", the mean length is " +
str(meanlength) + ", the std is " + str(stdlength))
else:
params = None
return outpathtrk, streamlines_generator, params
