def test_random_seeds_from_mask():
mask = np.random.random_integers(0, 1, size=(4, 6, 3))
seeds = random_seeds_from_mask(mask,
seeds_count=24,
seed_count_per_voxel=True)
assert_equal(mask.sum() * 24, len(seeds))
seeds = random_seeds_from_mask(mask,
seeds_count=0,
seed_count_per_voxel=True)
assert_equal(0, len(seeds))
mask[:] = False
mask[2, 2, 2] = True
seeds = random_seeds_from_mask(mask,
seeds_count=8,
seed_count_per_voxel=True)
assert_equal(mask.sum() * 8, len(seeds))
assert_true(np.all((seeds > 1.5) & (seeds < 2.5)))
seeds = random_seeds_from_mask(mask,
seeds_count=24,
seed_count_per_voxel=False)
assert_equal(24, len(seeds))
seeds = random_seeds_from_mask(mask,
seeds_count=0,
seed_count_per_voxel=False)
assert_equal(0, len(seeds))
mask[:] = False
mask[2, 2, 2] = True
seeds = random_seeds_from_mask(mask,
seeds_count=100,
seed_count_per_voxel=False)
assert_equal(100, len(seeds))
assert_true(np.all((seeds > 1.5) & (seeds < 2.5)))
mask = np.zeros((15, 15, 15))
mask[2:14, 2:14, 2:14] = 1
seeds_npv_2 = random_seeds_from_mask(mask,
seeds_count=2,
seed_count_per_voxel=True,
random_seed=0)[:150]
seeds_npv_3 = random_seeds_from_mask(mask,
seeds_count=3,
seed_count_per_voxel=True,
random_seed=0)[:150]
assert_true(np.all(seeds_npv_2 == seeds_npv_3))
seeds_nt_150 = random_seeds_from_mask(mask,
seeds_count=150,
seed_count_per_voxel=False,
random_seed=0)[:150]
seeds_nt_500 = random_seeds_from_mask(mask,
seeds_count=500,
seed_count_per_voxel=False,
random_seed=0)[:150]
assert_true(np.all(seeds_nt_150 == seeds_nt_500))
def test_random_seeds_from_mask():
mask = np.random.random_integers(0, 1, size=(4, 6, 3))
seeds = random_seeds_from_mask(mask, seeds_per_voxel=24)
assert_equal(mask.sum() * 24, len(seeds))
mask[:] = False
mask[2, 2, 2] = True
seeds = random_seeds_from_mask(mask, seeds_per_voxel=8)
assert_equal(mask.sum() * 8, len(seeds))
assert_true(np.all((seeds > 1.5) & (seeds < 2.5)))
def test_random_seeds_from_mask():
mask = np.random.random_integers(0, 1, size=(4, 6, 3))
seeds = random_seeds_from_mask(mask, seeds_per_voxel=24)
assert_equal(mask.sum() * 24, len(seeds))
mask[:] = False
mask[2, 2, 2] = True
seeds = random_seeds_from_mask(mask, seeds_per_voxel=8)
assert_equal(mask.sum() * 8, len(seeds))
assert_true(np.all((seeds > 1.5) & (seeds < 2.5)))
def test_random_seeds_from_mask():
mask = np.random.randint(0, 1, size=(4, 6, 3))
seeds = random_seeds_from_mask(mask,
seeds_count=24,
seed_count_per_voxel=True)
npt.assert_equal(mask.sum() * 24, len(seeds))
seeds = random_seeds_from_mask(mask,
seeds_count=0,
seed_count_per_voxel=True)
npt.assert_equal(0, len(seeds))
mask[:] = False
mask[2, 2, 2] = True
seeds = random_seeds_from_mask(mask,
seeds_count=8,
seed_count_per_voxel=True)
npt.assert_equal(mask.sum() * 8, len(seeds))
assert_true(np.all((seeds > 1.5) & (seeds < 2.5)))
seeds = random_seeds_from_mask(mask,
seeds_count=24,
seed_count_per_voxel=False)
npt.assert_equal(24, len(seeds))
seeds = random_seeds_from_mask(mask,
seeds_count=0,
seed_count_per_voxel=False)
npt.assert_equal(0, len(seeds))
mask[:] = False
mask[2, 2, 2] = True
seeds = random_seeds_from_mask(mask,
seeds_count=100,
seed_count_per_voxel=False)
npt.assert_equal(100, len(seeds))
assert_true(np.all((seeds > 1.5) & (seeds < 2.5)))
mask = np.zeros((15, 15, 15))
mask[2:14, 2:14, 2:14] = 1
seeds_npv_2 = random_seeds_from_mask(mask, seeds_count=2,
seed_count_per_voxel=True,
random_seed=0)[:150]
seeds_npv_3 = random_seeds_from_mask(mask, seeds_count=3,
seed_count_per_voxel=True,
random_seed=0)[:150]
assert_true(np.all(seeds_npv_2 == seeds_npv_3))
seeds_nt_150 = random_seeds_from_mask(mask, seeds_count=150,
seed_count_per_voxel=False,
random_seed=0)[:150]
seeds_nt_500 = random_seeds_from_mask(mask, seeds_count=500,
seed_count_per_voxel=False,
random_seed=0)[:150]
assert_true(np.all(seeds_nt_150 == seeds_nt_500))
def build_seed_list(mask_img_file, stream_affine, dens):
"""uses dipy tractography utilities in order to create a seed list for tractography
Parameters
----------
mask_img_file : str
path to mask of area to generate seeds for
stream_affine : ndarray
4x4 array with 1s diagonally and 0s everywhere else
dens : int
seed density
Returns
-------
ndarray
locations for the seeds
"""
mask_img = nib.load(mask_img_file)
mask_img_data = mask_img.get_data().astype("bool")
seeds = utils.random_seeds_from_mask(
mask_img_data,
affine=stream_affine,
seeds_count=int(dens),
seed_count_per_voxel=True,
)
return seeds
def track(self):
Tracker.track(self)
if self.streamlines is None:
if not self.options.random_seeds:
seeds = seeds_from_mask(self.data.binarymask, affine=self.data.aff)
else:
seeds = random_seeds_from_mask(self.data.binarymask,
seeds_count=self.options.seeds_count,
seed_count_per_voxel=self.options.seeds_per_voxel,
affine=self.data.aff)
self.seeds = seeds
def _get_seeds(data_container,
random_seeds=False,
seeds_count=30000,
seeds_per_voxel=False):
if not random_seeds:
return seeds_from_mask(data_container.binary_mask,
affine=data_container.aff)
else:
return random_seeds_from_mask(data_container.binary_mask,
seeds_count=seeds_count,
seed_count_per_voxel=seeds_per_voxel,
affine=data_container.aff)
def main():
parser = _build_arg_parser()
args = parser.parse_args()
for param in ['theta', 'curvature']:
# Default was removed for consistency.
if param not in args:
setattr(args, param, None)
assert_inputs_exist(parser, [args.sh_file, args.seed_file, args.mask_file])
assert_outputs_exists(parser, args, [args.output_file])
np.random.seed(args.seed)
mask_img = nib.load(args.mask_file)
mask_data = mask_img.get_data()
seeds = random_seeds_from_mask(
nib.load(args.seed_file).get_data(),
seeds_count=args.nts if 'nts' in args else args.npv,
seed_count_per_voxel='nts' not in args)
# Tracking is performed in voxel space
streamlines = LocalTracking(_get_direction_getter(args, mask_data),
BinaryTissueClassifier(mask_data),
seeds,
np.eye(4),
step_size=args.step_size,
max_cross=1,
maxlen=int(args.max_len / args.step_size) + 1,
fixedstep=True,
return_all=True)
filtered_streamlines = (s for s in streamlines
if args.min_len <= length(s) <= args.max_len)
if args.compress_streamlines:
filtered_streamlines = (compress_streamlines(s, args.tolerance_error)
for s in filtered_streamlines)
tractogram = LazyTractogram(lambda: filtered_streamlines,
affine_to_rasmm=mask_img.affine)
# Header with the affine/shape from mask image
header = {
Field.VOXEL_TO_RASMM: mask_img.affine.copy(),
Field.VOXEL_SIZES: mask_img.header.get_zooms(),
Field.DIMENSIONS: mask_img.shape,
Field.VOXEL_ORDER: ''.join(aff2axcodes(mask_img.affine))
}
# Use generator to save the streamlines on-the-fly
nib.streamlines.save(tractogram, args.output_file, header=header)
def build_seed_list(wm_mask, dens):
"""uses dipy tractography utilities in order to create a seed list for tractography
Parameters
----------
wm_mask : np.array
dens : int
seed density
Returns
-------
ndarray
locations for the seeds
"""
stream_affine = np.eye(4)
seeds = utils.random_seeds_from_mask(wm_mask,
affine=stream_affine,
seeds_count=int(dens),
seed_count_per_voxel=True)
return seeds
def execution(self, context):
mask_vol = aims.read(self.mask.fullPath())
h = mask_vol.header()
mask = np.asarray(mask_vol)[..., 0]
mask = mask.astype(bool)
voxel_size = np.array(h['voxel_size'])
if len(voxel_size) == 4:
voxel_size[-1] = 1
elif len(voxel_size) == 3:
voxel_size = np.concatenate((voxel_size, np.ones(1)))
scaling = np.diag(voxel_size)
seeds = random_seeds_from_mask(mask,
seeds_count=self.seed_number,
seed_count_per_voxel=self.number_per_voxel,
affine=scaling)
np.savetxt(self.seeds.fullPath(), seeds)
transformManager = getTransformationManager()
transformManager.copyReferential(self.mask, self.seeds)
print 'We use the roi_radius={},\nand the response is {},\nthe ratio is {},\nusing {} of voxels'.format(radius, response, ratio, nvl)
print 'fitting CSD model'
st2 = time.time()
sphere = get_sphere('symmetric724')
csd_model = ConstrainedSphericalDeconvModel(gtab, response, sh_order=8)
csd_peaks = peaks_from_model(csd_model, data, sphere = sphere, relative_peak_threshold=0.1, min_separation_angle=25,mask=mask, return_sh=True, parallel=True, normalize_peaks=True)
et2 = time.time() - st2
print 'fitting CSD model finished, running time is {}'.format(et2)
print 'seeding begins, using np.random.seed(123)'
st3 = time.time()
np.random.seed(123)
seeds = utils.random_seeds_from_mask(mask, 4)
for i in range(len(seeds)):
if seeds[i][0]>199.:
seeds[i][0]=398-seeds[i][0]
if seeds[i][1]>399.:
seeds[i][1]=798-seeds[i][1]
if seeds[i][2]>199.:
seeds[i][2]=398-seeds[i][2]
for j in range(3):
if seeds[i][j]<0.:
seeds[i][j]=-seeds[i][j]
et3 = time.time() - st3
print 'seeding transformation finished, the total seeds are {}, running time is {}'.format(seeds.shape[0], et3)
print 'generating streamlines begins'
st4 = time.time()
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 run_tractography(fdwi,
fbval,
fbvec,
fwmparc,
mod_func,
mod_type,
seed_density=20):
"""
mod_func : 'str'
'csd' or 'csa'
mod_type : 'str'
'det' or 'prob'
seed_density : int, default=20
Seeding density for tractography
"""
# Getting default params
sphere = get_sphere("repulsion724")
stream_affine = np.eye(4)
# Loading data
print("Loading Data...")
dwi, gtab, wm_mask = load_data(fdwi, fbval, fbvec, fwmparc)
# Make tissue classifier
tiss_classifier = BinaryStoppingCriterion(wm_mask)
if mod_func == "csd":
mod = csd_mod_est(gtab, dwi, wm_mask)
elif mod_func == "csa":
mod = odf_mod_est(gtab)
# Build seed list
seeds = utils.random_seeds_from_mask(
wm_mask,
affine=stream_affine,
seeds_count=int(seed_density),
seed_count_per_voxel=True,
)
# Make streamlines
if mod_type == "det":
print("Obtaining peaks from model...")
direction_getter = peaks_from_model(
mod,
dwi,
sphere,
relative_peak_threshold=0.5,
min_separation_angle=25,
mask=wm_mask,
npeaks=5,
normalize_peaks=True,
)
elif mod_type == "prob":
print("Preparing probabilistic tracking...")
print("Fitting model to data...")
mod_fit = mod.fit(dwi, wm_mask)
print("Building direction-getter...")
try:
print(
"Proceeding using spherical harmonic coefficient from model estimation..."
)
direction_getter = ProbabilisticDirectionGetter.from_shcoeff(
mod_fit.shm_coeff, max_angle=60.0, sphere=sphere)
except:
print("Proceeding using FOD PMF from model estimation...")
fod = mod_fit.odf(sphere)
pmf = fod.clip(min=0)
direction_getter = ProbabilisticDirectionGetter.from_pmf(
pmf, max_angle=60.0, sphere=sphere)
print("Running Local Tracking")
streamline_generator = LocalTracking(
direction_getter,
tiss_classifier,
seeds,
stream_affine,
step_size=0.5,
return_all=True,
)
print("Reconstructing tractogram streamlines...")
streamlines = Streamlines(streamline_generator)
tracks = Streamlines([track for track in streamlines if len(track) > 60])
return tracks
def main():
parser = _build_arg_parser()
args = parser.parse_args()
if args.isVerbose:
logging.basicConfig(level=logging.DEBUG)
assert_inputs_exist(parser, [args.sh_file, args.seed_file, args.mask_file])
assert_outputs_exist(parser, args, [args.output_file])
if not nib.streamlines.is_supported(args.output_file):
parser.error('Invalid output streamline file format (must be trk or ' +
'tck): {0}'.format(args.output_file))
if not args.min_length > 0:
parser.error('minL must be > 0, {}mm was provided.'.format(
args.min_length))
if args.max_length < args.min_length:
parser.error(
'maxL must be > than minL, (minL={}mm, maxL={}mm).'.format(
args.min_length, args.max_length))
if args.compress:
if args.compress < 0.001 or args.compress > 1:
logging.warning(
'You are using an error rate of {}.\nWe recommend setting it '
'between 0.001 and 1.\n0.001 will do almost nothing to the '
'tracts while 1 will higly compress/linearize the tracts'.
format(args.compress))
if args.npv and args.npv <= 0:
parser.error('Number of seeds per voxel must be > 0.')
if args.nt and args.nt <= 0:
parser.error('Total number of seeds must be > 0.')
mask_img = nib.load(args.mask_file)
mask_data = mask_img.get_data()
# Make sure the mask is isotropic. Else, the strategy used
# when providing information to dipy (i.e. working as if in voxel space)
# will not yield correct results.
fodf_sh_img = nib.load(args.sh_file)
if not np.allclose(np.mean(fodf_sh_img.header.get_zooms()[:3]),
fodf_sh_img.header.get_zooms()[0],
atol=1.e-3):
parser.error(
'SH file is not isotropic. Tracking cannot be ran robustly.')
if args.npv:
nb_seeds = args.npv
seed_per_vox = True
elif args.nt:
nb_seeds = args.nt
seed_per_vox = False
else:
nb_seeds = 1
seed_per_vox = True
voxel_size = fodf_sh_img.header.get_zooms()[0]
vox_step_size = args.step_size / voxel_size
seed_img = nib.load(args.seed_file)
seeds = track_utils.random_seeds_from_mask(
seed_img.get_data(),
seeds_count=nb_seeds,
seed_count_per_voxel=seed_per_vox,
random_seed=args.seed)
# Tracking is performed in voxel space
max_steps = int(args.max_length / args.step_size) + 1
streamlines = LocalTracking(_get_direction_getter(args, mask_data),
BinaryTissueClassifier(mask_data),
seeds,
np.eye(4),
step_size=vox_step_size,
max_cross=1,
maxlen=max_steps,
fixedstep=True,
return_all=True,
random_seed=args.seed)
scaled_min_length = args.min_length / voxel_size
scaled_max_length = args.max_length / voxel_size
filtered_streamlines = (
s for s in streamlines
if scaled_min_length <= length(s) <= scaled_max_length)
if args.compress:
filtered_streamlines = (compress_streamlines(s, args.compress)
for s in filtered_streamlines)
tractogram = LazyTractogram(lambda: filtered_streamlines,
affine_to_rasmm=seed_img.affine)
filetype = nib.streamlines.detect_format(args.output_file)
header = create_header_from_anat(seed_img, base_filetype=filetype)
# Use generator to save the streamlines on-the-fly
nib.streamlines.save(tractogram, args.output_file, header=header)
def main():
t_init = perf_counter()
parser = _build_arg_parser()
args = parser.parse_args()
if args.verbose:
logging.basicConfig(level=logging.INFO)
assert_inputs_exist(parser, [args.in_odf, args.in_mask, args.in_seed])
assert_outputs_exist(parser, args, args.out_tractogram)
if args.compress is not None:
verify_compression_th(args.compress)
odf_sh_img = nib.load(args.in_odf)
mask = get_data_as_mask(nib.load(args.in_mask))
seed_mask = get_data_as_mask(nib.load(args.in_seed))
odf_sh = odf_sh_img.get_fdata(dtype=np.float32)
t0 = perf_counter()
if args.npv:
nb_seeds = args.npv
seed_per_vox = True
elif args.nt:
nb_seeds = args.nt
seed_per_vox = False
else:
nb_seeds = 1
seed_per_vox = True
# Seeds are returned with origin `center`.
# However, GPUTracker expects origin to be `corner`.
# Therefore, we need to shift the seed positions by half voxel.
seeds = random_seeds_from_mask(seed_mask,
np.eye(4),
seeds_count=nb_seeds,
seed_count_per_voxel=seed_per_vox,
random_seed=args.rng_seed) + 0.5
logging.info('Generated {0} seed positions in {1:.2f}s.'.format(
len(seeds),
perf_counter() - t0))
voxel_size = odf_sh_img.header.get_zooms()[0]
vox_step_size = args.step_size / voxel_size
vox_max_length = args.max_length / voxel_size
vox_min_length = args.min_length / voxel_size
min_strl_len = int(vox_min_length / vox_step_size) + 1
max_strl_len = int(vox_max_length / vox_step_size) + 1
# initialize tracking
tracker = GPUTacker(odf_sh, mask, seeds, vox_step_size, min_strl_len,
max_strl_len, args.theta, args.sh_basis,
args.batch_size, args.forward_only, args.rng_seed)
# wrapper for tracker.track() yielding one TractogramItem per
# streamline for use with the LazyTractogram.
def tracks_generator_wrapper():
for strl, seed in tracker.track():
# seed must be saved in voxel space, with origin `center`.
dps = {'seeds': seed - 0.5} if args.save_seeds else {}
# TODO: Investigate why the streamline must NOT be shifted to
# origin `corner` for LazyTractogram.
strl *= voxel_size # in mm.
if args.compress:
strl = compress_streamlines(strl, args.compress)
yield TractogramItem(strl, dps, {})
# instantiate tractogram
tractogram = LazyTractogram.from_data_func(tracks_generator_wrapper)
tractogram.affine_to_rasmm = odf_sh_img.affine
filetype = nib.streamlines.detect_format(args.out_tractogram)
reference = get_reference_info(odf_sh_img)
header = create_tractogram_header(filetype, *reference)
# Use generator to save the streamlines on-the-fly
nib.streamlines.save(tractogram, args.out_tractogram, header=header)
logging.info('Saved tractogram to {0}.'.format(args.out_tractogram))
# Total runtime
logging.info('Total runtime of {0:.2f}s.'.format(perf_counter() - t_init))
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 main():
parser = _build_args_parser()
args = parser.parse_args()
if args.isVerbose:
logging.basicConfig(level=logging.DEBUG)
assert_inputs_exist(parser, [
args.sh_file, args.seed_file, args.map_include_file,
args.map_exclude_file
])
assert_outputs_exist(parser, args, [args.output_file])
if not nib.streamlines.is_supported(args.output_file):
parser.error('Invalid output streamline file format (must be trk or ' +
'tck): {0}'.format(args.output_file))
if not args.min_length > 0:
parser.error('minL must be > 0, {}mm was provided.'.format(
args.min_length))
if args.max_length < args.min_length:
parser.error(
'maxL must be > than minL, (minL={}mm, maxL={}mm).'.format(
args.min_length, args.max_length))
if args.compress:
if args.compress < 0.001 or args.compress > 1:
logging.warning(
'You are using an error rate of {}.\nWe recommend setting it '
'between 0.001 and 1.\n0.001 will do almost nothing to the '
'tracts while 1 will higly compress/linearize the tracts'.
format(args.compress))
if args.particles <= 0:
parser.error('--particles must be >= 1.')
if args.back_tracking <= 0:
parser.error('PFT backtracking distance must be > 0.')
if args.forward_tracking <= 0:
parser.error('PFT forward tracking distance must be > 0.')
if args.npv and args.npv <= 0:
parser.error('Number of seeds per voxel must be > 0.')
if args.nt and args.nt <= 0:
parser.error('Total number of seeds must be > 0.')
fodf_sh_img = nib.load(args.sh_file)
fodf_sh_img = nib.load(args.sh_file)
if not np.allclose(np.mean(fodf_sh_img.header.get_zooms()[:3]),
fodf_sh_img.header.get_zooms()[0],
atol=1.e-3):
parser.error(
'SH file is not isotropic. Tracking cannot be ran robustly.')
tracking_sphere = HemiSphere.from_sphere(get_sphere('repulsion724'))
# Check if sphere is unit, since we couldn't find such check in Dipy.
if not np.allclose(np.linalg.norm(tracking_sphere.vertices, axis=1), 1.):
raise RuntimeError('Tracking sphere should be unit normed.')
sh_basis = args.sh_basis
if args.algo == 'det':
dgklass = DeterministicMaximumDirectionGetter
else:
dgklass = ProbabilisticDirectionGetter
theta = get_theta(args.theta, args.algo)
# Reminder for the future:
# pmf_threshold == clip pmf under this
# relative_peak_threshold is for initial directions filtering
# min_separation_angle is the initial separation angle for peak extraction
dg = dgklass.from_shcoeff(fodf_sh_img.get_data().astype(np.double),
max_angle=theta,
sphere=tracking_sphere,
basis_type=sh_basis,
pmf_threshold=args.sf_threshold,
relative_peak_threshold=args.sf_threshold_init)
map_include_img = nib.load(args.map_include_file)
map_exclude_img = nib.load(args.map_exclude_file)
voxel_size = np.average(map_include_img.get_header()['pixdim'][1:4])
tissue_classifier = None
if not args.act:
tissue_classifier = CmcTissueClassifier(map_include_img.get_data(),
map_exclude_img.get_data(),
step_size=args.step_size,
average_voxel_size=voxel_size)
else:
tissue_classifier = ActTissueClassifier(map_include_img.get_data(),
map_exclude_img.get_data())
if args.npv:
nb_seeds = args.npv
seed_per_vox = True
elif args.nt:
nb_seeds = args.nt
seed_per_vox = False
else:
nb_seeds = 1
seed_per_vox = True
voxel_size = fodf_sh_img.header.get_zooms()[0]
vox_step_size = args.step_size / voxel_size
seed_img = nib.load(args.seed_file)
seeds = track_utils.random_seeds_from_mask(
seed_img.get_data(),
seeds_count=nb_seeds,
seed_count_per_voxel=seed_per_vox,
random_seed=args.seed)
# Note that max steps is used once for the forward pass, and
# once for the backwards. This doesn't, in fact, control the real
# max length
max_steps = int(args.max_length / args.step_size) + 1
pft_streamlines = ParticleFilteringTracking(
dg,
tissue_classifier,
seeds,
np.eye(4),
max_cross=1,
step_size=vox_step_size,
maxlen=max_steps,
pft_back_tracking_dist=args.back_tracking,
pft_front_tracking_dist=args.forward_tracking,
particle_count=args.particles,
return_all=args.keep_all,
random_seed=args.seed)
scaled_min_length = args.min_length / voxel_size
scaled_max_length = args.max_length / voxel_size
filtered_streamlines = (
s for s in pft_streamlines
if scaled_min_length <= length(s) <= scaled_max_length)
if args.compress:
filtered_streamlines = (compress_streamlines(s, args.compress)
for s in filtered_streamlines)
tractogram = LazyTractogram(lambda: filtered_streamlines,
affine_to_rasmm=seed_img.affine)
filetype = nib.streamlines.detect_format(args.output_file)
header = create_header_from_anat(seed_img, base_filetype=filetype)
# Use generator to save the streamlines on-the-fly
nib.streamlines.save(tractogram, args.output_file, header=header)
from dipy.io.streamline import save_trk
from dipy.tracking import utils
fimg = "DTICAP_bet.nii.gz"
img = nib.load(fimg)
data = img.get_data()
fbval = "DTICAP.bval"
fbvec = "DTICAP.bvec"
affine = img.affine
bvals, bvecs = read_bvals_bvecs(fbval, fbvec)
gtab = gradient_table(bvals, bvecs)
mask, S0_mask = median_otsu(data[:, :, :, 0])
# create seeds
seeds = random_seeds_from_mask(mask, affine, seeds_count=1)
"""
fit the data to a Constant Solid Angle ODF Model. This model will estimate the
Orientation Distribution Function (ODF) at each voxel. The ODF is the
distribution of water diffusion as a function of direction. The peaks of an ODF
are good estimates for the orientation of tract segments at a point in the
image. Here, we use ``peaks_from_model`` to fit the data and calculated the
fiber directions in all voxels of the white matter.
"""
response, ratio = auto_response(gtab, data, roi_radius=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=.5,
def run_tracking(step_curv_combinations, recon_path, n_seeds_per_iter,
directget, maxcrossing, max_length, pft_back_tracking_dist,
pft_front_tracking_dist, particle_count, roi_neighborhood_tol,
waymask, min_length, track_type, min_separation_angle, sphere,
tiss_class, tissues4d, cache_dir):
import gc
import os
import h5py
from dipy.tracking import utils
from dipy.tracking.streamline import select_by_rois
from dipy.tracking.local_tracking import LocalTracking, \
ParticleFilteringTracking
from dipy.direction import (ProbabilisticDirectionGetter,
ClosestPeakDirectionGetter,
DeterministicMaximumDirectionGetter)
from nilearn.image import index_img
from pynets.dmri.track import prep_tissues
from nibabel.streamlines.array_sequence import ArraySequence
from nipype.utils.filemanip import copyfile, fname_presuffix
recon_path_tmp_path = fname_presuffix(recon_path,
suffix=f"_{step_curv_combinations}",
newpath=cache_dir)
copyfile(recon_path, recon_path_tmp_path, copy=True, use_hardlink=False)
if waymask is not None:
waymask_tmp_path = fname_presuffix(waymask,
suffix=f"_{step_curv_combinations}",
newpath=cache_dir)
copyfile(waymask, waymask_tmp_path, copy=True, use_hardlink=False)
else:
waymask_tmp_path = None
tissue_img = nib.load(tissues4d)
# Order:
B0_mask = index_img(tissue_img, 0)
atlas_img = index_img(tissue_img, 1)
atlas_data_wm_gm_int = index_img(tissue_img, 2)
t1w2dwi = index_img(tissue_img, 3)
gm_in_dwi = index_img(tissue_img, 4)
vent_csf_in_dwi = index_img(tissue_img, 5)
wm_in_dwi = index_img(tissue_img, 6)
tiss_classifier = prep_tissues(t1w2dwi, gm_in_dwi, vent_csf_in_dwi,
wm_in_dwi, tiss_class, B0_mask)
B0_mask_data = np.asarray(B0_mask.dataobj).astype("bool")
atlas_data = np.array(atlas_img.dataobj).astype("uint16")
atlas_data_wm_gm_int_data = np.asarray(
atlas_data_wm_gm_int.dataobj).astype("bool").astype("int16")
# Build mask vector from atlas for later roi filtering
parcels = []
i = 0
intensities = [i for i in np.unique(atlas_data) if i != 0]
for roi_val in intensities:
parcels.append(atlas_data == roi_val)
i += 1
del atlas_data
parcel_vec = list(np.ones(len(parcels)).astype("bool"))
with h5py.File(recon_path_tmp_path, 'r+') as hf:
mod_fit = hf['reconstruction'][:].astype('float32')
hf.close()
print("%s%s" % ("Curvature: ", step_curv_combinations[1]))
# Instantiate DirectionGetter
if directget == "prob" or directget == "probabilistic":
dg = ProbabilisticDirectionGetter.from_shcoeff(
mod_fit,
max_angle=float(step_curv_combinations[1]),
sphere=sphere,
min_separation_angle=min_separation_angle,
)
elif directget == "clos" or directget == "closest":
dg = ClosestPeakDirectionGetter.from_shcoeff(
mod_fit,
max_angle=float(step_curv_combinations[1]),
sphere=sphere,
min_separation_angle=min_separation_angle,
)
elif directget == "det" or directget == "deterministic":
maxcrossing = 1
dg = DeterministicMaximumDirectionGetter.from_shcoeff(
mod_fit,
max_angle=float(step_curv_combinations[1]),
sphere=sphere,
min_separation_angle=min_separation_angle,
)
else:
raise ValueError("ERROR: No valid direction getter(s) specified.")
print("%s%s" % ("Step: ", step_curv_combinations[0]))
# Perform wm-gm interface seeding, using n_seeds at a time
seeds = utils.random_seeds_from_mask(
atlas_data_wm_gm_int_data > 0,
seeds_count=n_seeds_per_iter,
seed_count_per_voxel=False,
affine=np.eye(4),
)
if len(seeds) == 0:
print(
UserWarning("No valid seed points found in wm-gm "
"interface..."))
return None
# print(seeds)
# Perform tracking
if track_type == "local":
streamline_generator = LocalTracking(
dg,
tiss_classifier,
seeds,
np.eye(4),
max_cross=int(maxcrossing),
maxlen=int(max_length),
step_size=float(step_curv_combinations[0]),
fixedstep=False,
return_all=True,
)
elif track_type == "particle":
streamline_generator = ParticleFilteringTracking(
dg,
tiss_classifier,
seeds,
np.eye(4),
max_cross=int(maxcrossing),
step_size=float(step_curv_combinations[0]),
maxlen=int(max_length),
pft_back_tracking_dist=pft_back_tracking_dist,
pft_front_tracking_dist=pft_front_tracking_dist,
particle_count=particle_count,
return_all=True,
)
else:
try:
raise ValueError("ERROR: No valid tracking method(s) specified.")
except ValueError:
import sys
sys.exit(0)
# Filter resulting streamlines by those that stay entirely
# inside the brain
try:
roi_proximal_streamlines = utils.target(streamline_generator,
np.eye(4),
B0_mask_data,
include=True)
except BaseException:
print('No streamlines found inside the brain! ' 'Check registrations.')
return None
# Filter resulting streamlines by roi-intersection
# characteristics
try:
roi_proximal_streamlines = \
nib.streamlines.array_sequence.ArraySequence(
select_by_rois(
roi_proximal_streamlines,
affine=np.eye(4),
rois=parcels,
include=parcel_vec,
mode="%s" % ("any" if waymask is not None else
"both_end"),
tol=roi_neighborhood_tol,
)
)
print("%s%s" % ("Filtering by: \nNode intersection: ",
len(roi_proximal_streamlines)))
except BaseException:
print('No streamlines found to connect any parcels! '
'Check registrations.')
return None
try:
roi_proximal_streamlines = nib.streamlines. \
array_sequence.ArraySequence(
[
s for s in roi_proximal_streamlines
if len(s) >= float(min_length)
]
)
print(f"Minimum fiber length >{min_length}mm: "
f"{len(roi_proximal_streamlines)}")
except BaseException:
print('No streamlines remaining after minimal length criterion.')
return None
if waymask is not None and os.path.isfile(waymask_tmp_path):
from nilearn.image import math_img
mask = math_img("img > 0.0075", img=nib.load(waymask_tmp_path))
waymask_data = np.asarray(mask.dataobj).astype("bool")
try:
roi_proximal_streamlines = roi_proximal_streamlines[utils.near_roi(
roi_proximal_streamlines,
np.eye(4),
waymask_data,
tol=roi_neighborhood_tol,
mode="all")]
print("%s%s" %
("Waymask proximity: ", len(roi_proximal_streamlines)))
except BaseException:
print('No streamlines remaining in waymask\'s vacinity.')
return None
out_streams = [s.astype("float32") for s in roi_proximal_streamlines]
del dg, seeds, roi_proximal_streamlines, streamline_generator, \
atlas_data_wm_gm_int_data, mod_fit, B0_mask_data
os.remove(recon_path_tmp_path)
gc.collect()
try:
return ArraySequence(out_streams)
except BaseException:
return None
def main():
parser = _build_arg_parser()
args = parser.parse_args()
if args.verbose:
logging.basicConfig(level=logging.DEBUG)
assert_inputs_exist(parser, [args.in_odf, args.in_seed, args.in_mask])
assert_outputs_exist(parser, args, args.out_tractogram)
if not nib.streamlines.is_supported(args.out_tractogram):
parser.error('Invalid output streamline file format (must be trk or ' +
'tck): {0}'.format(args.out_tractogram))
verify_streamline_length_options(parser, args)
verify_compression_th(args.compress)
verify_seed_options(parser, args)
mask_img = nib.load(args.in_mask)
mask_data = get_data_as_mask(mask_img, dtype=bool)
# Make sure the data is isotropic. Else, the strategy used
# when providing information to dipy (i.e. working as if in voxel space)
# will not yield correct results.
odf_sh_img = nib.load(args.in_odf)
if not np.allclose(np.mean(odf_sh_img.header.get_zooms()[:3]),
odf_sh_img.header.get_zooms()[0], atol=1e-03):
parser.error(
'ODF SH file is not isotropic. Tracking cannot be ran robustly.')
if args.npv:
nb_seeds = args.npv
seed_per_vox = True
elif args.nt:
nb_seeds = args.nt
seed_per_vox = False
else:
nb_seeds = 1
seed_per_vox = True
voxel_size = odf_sh_img.header.get_zooms()[0]
vox_step_size = args.step_size / voxel_size
seed_img = nib.load(args.in_seed)
seeds = track_utils.random_seeds_from_mask(
seed_img.get_fdata(dtype=np.float32),
np.eye(4),
seeds_count=nb_seeds,
seed_count_per_voxel=seed_per_vox,
random_seed=args.seed)
# Tracking is performed in voxel space
max_steps = int(args.max_length / args.step_size) + 1
streamlines_generator = LocalTracking(
_get_direction_getter(args),
BinaryStoppingCriterion(mask_data),
seeds, np.eye(4),
step_size=vox_step_size, max_cross=1,
maxlen=max_steps,
fixedstep=True, return_all=True,
random_seed=args.seed,
save_seeds=args.save_seeds)
scaled_min_length = args.min_length / voxel_size
scaled_max_length = args.max_length / voxel_size
if args.save_seeds:
filtered_streamlines, seeds = \
zip(*((s, p) for s, p in streamlines_generator
if scaled_min_length <= length(s) <= scaled_max_length))
data_per_streamlines = {'seeds': lambda: seeds}
else:
filtered_streamlines = \
(s for s in streamlines_generator
if scaled_min_length <= length(s) <= scaled_max_length)
data_per_streamlines = {}
if args.compress:
filtered_streamlines = (
compress_streamlines(s, args.compress)
for s in filtered_streamlines)
tractogram = LazyTractogram(lambda: filtered_streamlines,
data_per_streamlines,
affine_to_rasmm=seed_img.affine)
filetype = nib.streamlines.detect_format(args.out_tractogram)
reference = get_reference_info(seed_img)
header = create_tractogram_header(filetype, *reference)
# Use generator to save the streamlines on-the-fly
nib.streamlines.save(tractogram, args.out_tractogram, header=header)
fa = tensor_fit.fa
"""
In this simple example we can use FA to stop tracking. Here we stop tracking
when FA < 0.1.
"""
tissue_classifier = ThresholdTissueClassifier(fa, 0.1)
"""
Now, we need to set starting points for propagating each track. We call those
seeds. Using ``random_seeds_from_mask`` we can select a specific number of
seeds (``seeds_count``) in each voxel where the mask ``fa > 0.3`` is true.
"""
seeds = random_seeds_from_mask(fa > 0.3, seeds_count=1)
"""
For quality assurance we can also visualize a slice from the direction field
which we will use as the basis to perform the tracking.
"""
ren = window.Renderer()
ren.add(actor.peak_slicer(csd_peaks.peak_dirs,
csd_peaks.peak_values,
colors=None))
if interactive:
window.show(ren, size=(900, 900))
else:
window.record(ren, out_path='csd_direction_field.png', size=(900, 900))
def track_ensemble(dwi_data,
target_samples,
atlas_data_wm_gm_int,
parcels,
mod_fit,
tiss_classifier,
sphere,
directget,
curv_thr_list,
step_list,
track_type,
maxcrossing,
max_length,
roi_neighborhood_tol,
min_length,
waymask,
n_seeds_per_iter=100,
pft_back_tracking_dist=2,
pft_front_tracking_dist=1,
particle_count=15):
"""
Perform native-space ensemble tractography, restricted to a vector of ROI masks.
dwi_data : array
4D array of dwi data.
target_samples : int
Total number of streamline samples specified to generate streams.
atlas_data_wm_gm_int : array
3D int32 numpy array of atlas parcellation intensities from Nifti1Image in T1w-warped native diffusion space,
restricted to wm-gm interface.
parcels : list
List of 3D boolean numpy arrays of atlas parcellation ROI masks from a Nifti1Image in T1w-warped native
diffusion space.
mod : obj
Connectivity reconstruction model.
tiss_classifier : str
Tissue classification method.
sphere : obj
DiPy object for modeling diffusion directions on a sphere.
directget : str
The statistical approach to tracking. Options are: det (deterministic), closest (clos), boot (bootstrapped),
and prob (probabilistic).
curv_thr_list : list
List of integer curvature thresholds used to perform ensemble tracking.
step_list : list
List of float step-sizes used to perform ensemble tracking.
track_type : str
Tracking algorithm used (e.g. 'local' or 'particle').
maxcrossing : int
Maximum number if diffusion directions that can be assumed per voxel while tracking.
max_length : int
Maximum fiber length threshold in mm to restrict tracking.
roi_neighborhood_tol : float
Distance (in the units of the streamlines, usually mm). If any
coordinate in the streamline is within this distance from the center
of any voxel in the ROI, the filtering criterion is set to True for
this streamline, otherwise False. Defaults to the distance between
the center of each voxel and the corner of the voxel.
min_length : int
Minimum fiber length threshold in mm.
waymask : str
Path to a Nifti1Image in native diffusion space to constrain tractography.
n_seeds_per_iter : int
Number of seeds from which to initiate tracking for each unique ensemble combination.
By default this is set to 200.
particle_count
pft_back_tracking_dist : float
Distance in mm to back track before starting the particle filtering
tractography. The total particle filtering tractography distance is
equal to back_tracking_dist + front_tracking_dist. By default this is set to 2 mm.
pft_front_tracking_dist : float
Distance in mm to run the particle filtering tractography after the
the back track distance. The total particle filtering tractography
distance is equal to back_tracking_dist + front_tracking_dist. By
default this is set to 1 mm.
particle_count : int
Number of particles to use in the particle filter.
Returns
-------
streamlines : ArraySequence
DiPy list/array-like object of streamline points from tractography.
"""
from colorama import Fore, Style
from dipy.tracking import utils
from dipy.tracking.streamline import Streamlines, select_by_rois
from dipy.tracking.local_tracking import LocalTracking, ParticleFilteringTracking
from dipy.direction import ProbabilisticDirectionGetter, BootDirectionGetter, ClosestPeakDirectionGetter, DeterministicMaximumDirectionGetter
if waymask:
waymask_data = nib.load(waymask).get_fdata().astype('bool')
# Commence Ensemble Tractography
parcel_vec = list(np.ones(len(parcels)).astype('bool'))
streamlines = nib.streamlines.array_sequence.ArraySequence()
ix = 0
circuit_ix = 0
stream_counter = 0
while int(stream_counter) < int(target_samples):
for curv_thr in curv_thr_list:
print("%s%s" % ('Curvature: ', curv_thr))
# Instantiate DirectionGetter
if directget == 'prob':
dg = ProbabilisticDirectionGetter.from_shcoeff(
mod_fit, max_angle=float(curv_thr), sphere=sphere)
elif directget == 'boot':
dg = BootDirectionGetter.from_data(dwi_data,
mod_fit,
max_angle=float(curv_thr),
sphere=sphere)
elif directget == 'clos':
dg = ClosestPeakDirectionGetter.from_shcoeff(
mod_fit, max_angle=float(curv_thr), sphere=sphere)
elif directget == 'det':
dg = DeterministicMaximumDirectionGetter.from_shcoeff(
mod_fit, max_angle=float(curv_thr), sphere=sphere)
else:
raise ValueError(
'ERROR: No valid direction getter(s) specified.')
for step in step_list:
print("%s%s" % ('Step: ', step))
# Perform wm-gm interface seeding, using n_seeds at a time
seeds = utils.random_seeds_from_mask(
atlas_data_wm_gm_int > 0,
seeds_count=n_seeds_per_iter,
seed_count_per_voxel=False,
affine=np.eye(4))
if len(seeds) == 0:
raise RuntimeWarning(
'Warning: No valid seed points found in wm-gm interface...'
)
print(seeds)
# Perform tracking
if track_type == 'local':
streamline_generator = LocalTracking(
dg,
tiss_classifier,
seeds,
np.eye(4),
max_cross=int(maxcrossing),
maxlen=int(max_length),
step_size=float(step),
return_all=True)
elif track_type == 'particle':
streamline_generator = ParticleFilteringTracking(
dg,
tiss_classifier,
seeds,
np.eye(4),
max_cross=int(maxcrossing),
step_size=float(step),
maxlen=int(max_length),
pft_back_tracking_dist=pft_back_tracking_dist,
pft_front_tracking_dist=pft_front_tracking_dist,
particle_count=particle_count,
return_all=True)
else:
raise ValueError(
'ERROR: No valid tracking method(s) specified.')
# Filter resulting streamlines by roi-intersection characteristics
roi_proximal_streamlines = Streamlines(
select_by_rois(streamline_generator,
affine=np.eye(4),
rois=parcels,
include=parcel_vec,
mode='any',
tol=roi_neighborhood_tol))
print("%s%s" %
('Qualifying Streamlines by node intersection: ',
len(roi_proximal_streamlines)))
roi_proximal_streamlines = nib.streamlines.array_sequence.ArraySequence(
[
s for s in roi_proximal_streamlines
if len(s) > float(min_length)
])
print("%s%s" %
('Qualifying Streamlines by minimum length criterion: ',
len(roi_proximal_streamlines)))
if waymask:
roi_proximal_streamlines = roi_proximal_streamlines[
utils.near_roi(roi_proximal_streamlines,
np.eye(4),
waymask_data,
tol=roi_neighborhood_tol,
mode='any')]
print("%s%s" %
('Qualifying Streamlines by waymask proximity: ',
len(roi_proximal_streamlines)))
# Repeat process until target samples condition is met
ix = ix + 1
for s in roi_proximal_streamlines:
stream_counter = stream_counter + len(s)
streamlines.append(s)
if int(stream_counter) >= int(target_samples):
break
else:
continue
# Cleanup memory
del seeds, roi_proximal_streamlines, streamline_generator
del dg
circuit_ix = circuit_ix + 1
print(
"%s%s%s%s%s" %
('Completed hyperparameter circuit: ', circuit_ix,
'...\nCumulative Streamline Count: ', Fore.CYAN, stream_counter))
print(Style.RESET_ALL)
print('\n')
return streamlines
# colors=None)
# slice_actor.RotateX(90)
# ren.add(slice_actor)
# if interactive:
# window.show(ren, size=(900, 900))
# else:
# ren.set_camera(position=[0,-1,0], focal_point=[0,0,0], view_up=[0,0,1])
# window.record(ren, out_path='csd_direction_bm.png', size=(900, 900))
print 'seeding begins, using np.random.seed(123)'
st3 = time.time()
np.random.seed(123)
#seeds = utils.random_seeds_from_mask(mask, 1) #does crash because of memory limitations
seeds = utils.random_seeds_from_mask(mask,
20000,
seed_count_per_voxel=False)
for i in range(len(seeds)):
if seeds[i][0] > 199.:
seeds[i][0] = 398 - seeds[i][0]
if seeds[i][1] > 399.:
seeds[i][1] = 798 - seeds[i][1]
if seeds[i][2] > 199.:
seeds[i][2] = 398 - seeds[i][2]
for j in range(3):
if seeds[i][j] < 0.:
seeds[i][j] = -seeds[i][j]
et3 = time.time() - st3
print 'seeding transformation finished, the total seeds are {}, running time is {}'.format(
seeds.shape[0], et3)
def run_tracking(step_curv_combinations,
recon_path,
n_seeds_per_iter,
directget,
maxcrossing,
max_length,
pft_back_tracking_dist,
pft_front_tracking_dist,
particle_count,
roi_neighborhood_tol,
waymask,
min_length,
track_type,
min_separation_angle,
sphere,
tiss_class,
tissues4d,
cache_dir,
min_seeds=100):
import gc
import os
import h5py
from dipy.tracking import utils
from dipy.tracking.streamline import select_by_rois
from dipy.tracking.local_tracking import LocalTracking, \
ParticleFilteringTracking
from dipy.direction import (ProbabilisticDirectionGetter,
ClosestPeakDirectionGetter,
DeterministicMaximumDirectionGetter)
from nilearn.image import index_img
from pynets.dmri.track import prep_tissues
from nibabel.streamlines.array_sequence import ArraySequence
from nipype.utils.filemanip import copyfile, fname_presuffix
import uuid
from time import strftime
run_uuid = f"{strftime('%Y%m%d_%H%M%S')}_{uuid.uuid4()}"
recon_path_tmp_path = fname_presuffix(
recon_path,
suffix=f"_{'_'.join([str(i) for i in step_curv_combinations])}_"
f"{run_uuid}",
newpath=cache_dir)
copyfile(recon_path, recon_path_tmp_path, copy=True, use_hardlink=False)
tissues4d_tmp_path = fname_presuffix(
tissues4d,
suffix=f"_{'_'.join([str(i) for i in step_curv_combinations])}_"
f"{run_uuid}",
newpath=cache_dir)
copyfile(tissues4d, tissues4d_tmp_path, copy=True, use_hardlink=False)
if waymask is not None:
waymask_tmp_path = fname_presuffix(
waymask,
suffix=f"_{'_'.join([str(i) for i in step_curv_combinations])}_"
f"{run_uuid}",
newpath=cache_dir)
copyfile(waymask, waymask_tmp_path, copy=True, use_hardlink=False)
else:
waymask_tmp_path = None
tissue_img = nib.load(tissues4d_tmp_path)
# Order:
B0_mask = index_img(tissue_img, 0)
atlas_img = index_img(tissue_img, 1)
seeding_mask = index_img(tissue_img, 2)
t1w2dwi = index_img(tissue_img, 3)
gm_in_dwi = index_img(tissue_img, 4)
vent_csf_in_dwi = index_img(tissue_img, 5)
wm_in_dwi = index_img(tissue_img, 6)
tiss_classifier = prep_tissues(t1w2dwi, gm_in_dwi, vent_csf_in_dwi,
wm_in_dwi, tiss_class, B0_mask)
B0_mask_data = np.asarray(B0_mask.dataobj).astype("bool")
seeding_mask = np.asarray(
seeding_mask.dataobj).astype("bool").astype("int16")
with h5py.File(recon_path_tmp_path, 'r+') as hf:
mod_fit = hf['reconstruction'][:].astype('float32')
print("%s%s" % ("Curvature: ", step_curv_combinations[1]))
# Instantiate DirectionGetter
if directget.lower() in ["probabilistic", "prob"]:
dg = ProbabilisticDirectionGetter.from_shcoeff(
mod_fit,
max_angle=float(step_curv_combinations[1]),
sphere=sphere,
min_separation_angle=min_separation_angle,
)
elif directget.lower() in ["closestpeaks", "cp"]:
dg = ClosestPeakDirectionGetter.from_shcoeff(
mod_fit,
max_angle=float(step_curv_combinations[1]),
sphere=sphere,
min_separation_angle=min_separation_angle,
)
elif directget.lower() in ["deterministic", "det"]:
maxcrossing = 1
dg = DeterministicMaximumDirectionGetter.from_shcoeff(
mod_fit,
max_angle=float(step_curv_combinations[1]),
sphere=sphere,
min_separation_angle=min_separation_angle,
)
else:
raise ValueError("ERROR: No valid direction getter(s) specified.")
print("%s%s" % ("Step: ", step_curv_combinations[0]))
# Perform wm-gm interface seeding, using n_seeds at a time
seeds = utils.random_seeds_from_mask(
seeding_mask > 0,
seeds_count=n_seeds_per_iter,
seed_count_per_voxel=False,
affine=np.eye(4),
)
if len(seeds) < min_seeds:
print(
UserWarning(
f"<{min_seeds} valid seed points found in wm-gm interface..."))
return None
# print(seeds)
# Perform tracking
if track_type == "local":
streamline_generator = LocalTracking(dg,
tiss_classifier,
seeds,
np.eye(4),
max_cross=int(maxcrossing),
maxlen=int(max_length),
step_size=float(
step_curv_combinations[0]),
fixedstep=False,
return_all=True,
random_seed=42)
elif track_type == "particle":
streamline_generator = ParticleFilteringTracking(
dg,
tiss_classifier,
seeds,
np.eye(4),
max_cross=int(maxcrossing),
step_size=float(step_curv_combinations[0]),
maxlen=int(max_length),
pft_back_tracking_dist=pft_back_tracking_dist,
pft_front_tracking_dist=pft_front_tracking_dist,
pft_max_trial=20,
particle_count=particle_count,
return_all=True,
random_seed=42)
else:
raise ValueError("ERROR: No valid tracking method(s) specified.")
# Filter resulting streamlines by those that stay entirely
# inside the brain
try:
roi_proximal_streamlines = utils.target(streamline_generator,
np.eye(4),
B0_mask_data.astype('bool'),
include=True)
except BaseException:
print('No streamlines found inside the brain! ' 'Check registrations.')
return None
del mod_fit, seeds, tiss_classifier, streamline_generator, \
B0_mask_data, seeding_mask, dg
B0_mask.uncache()
atlas_img.uncache()
t1w2dwi.uncache()
gm_in_dwi.uncache()
vent_csf_in_dwi.uncache()
wm_in_dwi.uncache()
atlas_img.uncache()
tissue_img.uncache()
gc.collect()
# Filter resulting streamlines by roi-intersection
# characteristics
atlas_data = np.array(atlas_img.dataobj).astype("uint16")
# Build mask vector from atlas for later roi filtering
parcels = []
i = 0
intensities = [i for i in np.unique(atlas_data) if i != 0]
for roi_val in intensities:
parcels.append(atlas_data == roi_val)
i += 1
parcel_vec = list(np.ones(len(parcels)).astype("bool"))
try:
roi_proximal_streamlines = \
nib.streamlines.array_sequence.ArraySequence(
select_by_rois(
roi_proximal_streamlines,
affine=np.eye(4),
rois=parcels,
include=parcel_vec,
mode="any",
tol=roi_neighborhood_tol,
)
)
print("%s%s" % ("Filtering by: \nNode intersection: ",
len(roi_proximal_streamlines)))
except BaseException:
print('No streamlines found to connect any parcels! '
'Check registrations.')
return None
try:
roi_proximal_streamlines = nib.streamlines. \
array_sequence.ArraySequence(
[
s for s in roi_proximal_streamlines
if len(s) >= float(min_length)
]
)
print(f"Minimum fiber length >{min_length}mm: "
f"{len(roi_proximal_streamlines)}")
except BaseException:
print('No streamlines remaining after minimal length criterion.')
return None
if waymask is not None and os.path.isfile(waymask_tmp_path):
waymask_data = np.asarray(
nib.load(waymask_tmp_path).dataobj).astype("bool")
try:
roi_proximal_streamlines = roi_proximal_streamlines[utils.near_roi(
roi_proximal_streamlines,
np.eye(4),
waymask_data,
tol=int(round(roi_neighborhood_tol * 0.50, 1)),
mode="all")]
print("%s%s" %
("Waymask proximity: ", len(roi_proximal_streamlines)))
del waymask_data
except BaseException:
print('No streamlines remaining in waymask\'s vacinity.')
return None
hf.close()
del parcels, atlas_data
tmp_files = [tissues4d_tmp_path, waymask_tmp_path, recon_path_tmp_path]
for j in tmp_files:
if j is not None:
if os.path.isfile(j):
os.system(f"rm -f {j} &")
if len(roi_proximal_streamlines) > 0:
return ArraySequence(
[s.astype("float32") for s in roi_proximal_streamlines])
else:
return None
def dwi_dipy_run(dwi_dir,
node_size,
dir_path,
conn_model,
parc,
atlas_select,
network,
wm_mask=None):
from dipy.reconst.dti import TensorModel, quantize_evecs
from dipy.reconst.csdeconv import ConstrainedSphericalDeconvModel, recursive_response
from dipy.tracking.local import LocalTracking, ActTissueClassifier
from dipy.tracking import utils
from dipy.direction import peaks_from_model
from dipy.tracking.eudx import EuDX
from dipy.data import get_sphere, default_sphere
from dipy.core.gradients import gradient_table
from dipy.io import read_bvals_bvecs
from dipy.tracking.streamline import Streamlines
from dipy.direction import ProbabilisticDirectionGetter, ClosestPeakDirectionGetter, BootDirectionGetter
from nibabel.streamlines import save as save_trk
from nibabel.streamlines import Tractogram
##
dwi_dir = '/Users/PSYC-dap3463/Downloads/bedpostx_s002'
img_pve_csf = nib.load(
'/Users/PSYC-dap3463/Downloads/002_all/tmp/reg_a/t1w_vent_csf_diff_dwi.nii.gz'
)
img_pve_wm = nib.load(
'/Users/PSYC-dap3463/Downloads/002_all/tmp/reg_a/t1w_wm_in_dwi_bin.nii.gz'
)
img_pve_gm = nib.load(
'/Users/PSYC-dap3463/Downloads/002_all/tmp/reg_a/t1w_gm_mask_dwi.nii.gz'
)
labels_img = nib.load(
'/Users/PSYC-dap3463/Downloads/002_all/tmp/reg_a/dwi_aligned_atlas.nii.gz'
)
num_total_samples = 10000
tracking_method = 'boot' # Options are 'boot', 'prob', 'peaks', 'closest'
procmem = [2, 4]
##
if parc is True:
node_size = 'parc'
dwi_img = "%s%s" % (dwi_dir, '/dwi.nii.gz')
nodif_brain_mask_path = "%s%s" % (dwi_dir, '/nodif_brain_mask.nii.gz')
bvals = "%s%s" % (dwi_dir, '/bval')
bvecs = "%s%s" % (dwi_dir, '/bvec')
dwi_img = nib.load(dwi_img)
data = dwi_img.get_data()
[bvals, bvecs] = read_bvals_bvecs(bvals, bvecs)
gtab = gradient_table(bvals, bvecs)
gtab.b0_threshold = min(bvals)
sphere = get_sphere('symmetric724')
# Loads mask and ensures it's a true binary mask
mask_img = nib.load(nodif_brain_mask_path)
mask = mask_img.get_data()
mask = mask > 0
# Fit a basic tensor model first
model = TensorModel(gtab)
ten = model.fit(data, mask)
fa = ten.fa
# Tractography
if conn_model == 'csd':
print('Tracking with csd model...')
elif conn_model == 'tensor':
print('Tracking with tensor model...')
else:
raise RuntimeError("%s%s" % (conn_model, ' is not a valid model.'))
# Combine seed counts from voxel with seed counts total
wm_mask_data = img_pve_wm.get_data()
wm_mask_data[0, :, :] = False
wm_mask_data[:, 0, :] = False
wm_mask_data[:, :, 0] = False
seeds = utils.seeds_from_mask(wm_mask_data,
density=1,
affine=dwi_img.get_affine())
seeds_rnd = utils.random_seeds_from_mask(ten.fa > 0.02,
seeds_count=num_total_samples,
seed_count_per_voxel=True)
seeds_all = np.vstack([seeds, seeds_rnd])
# Load tissue maps and prepare tissue classifier (Anatomically-Constrained Tractography (ACT))
background = np.ones(img_pve_gm.shape)
background[(img_pve_gm.get_data() + img_pve_wm.get_data() +
img_pve_csf.get_data()) > 0] = 0
include_map = img_pve_gm.get_data()
include_map[background > 0] = 1
exclude_map = img_pve_csf.get_data()
act_classifier = ActTissueClassifier(include_map, exclude_map)
if conn_model == 'tensor':
ind = quantize_evecs(ten.evecs, sphere.vertices)
streamline_generator = EuDX(a=fa,
ind=ind,
seeds=seeds_all,
odf_vertices=sphere.vertices,
a_low=0.05,
step_sz=.5)
elif conn_model == 'csd':
print('Tracking with CSD model...')
response = recursive_response(
gtab,
data,
mask=img_pve_wm.get_data().astype('bool'),
sh_order=8,
peak_thr=0.01,
init_fa=0.05,
init_trace=0.0021,
iter=8,
convergence=0.001,
parallel=True)
csd_model = ConstrainedSphericalDeconvModel(gtab, response)
if tracking_method == 'boot':
dg = BootDirectionGetter.from_data(data,
csd_model,
max_angle=30.,
sphere=default_sphere)
elif tracking_method == 'prob':
try:
print(
'First attempting to build the direction getter directly from the spherical harmonic representation of the FOD...'
)
csd_fit = csd_model.fit(
data, mask=img_pve_wm.get_data().astype('bool'))
dg = ProbabilisticDirectionGetter.from_shcoeff(
csd_fit.shm_coeff, max_angle=30., sphere=default_sphere)
except:
print(
'Sphereical harmonic not available for this model. Using peaks_from_model to represent the ODF of the model on a spherical harmonic basis instead...'
)
peaks = peaks_from_model(
csd_model,
data,
default_sphere,
.5,
25,
mask=img_pve_wm.get_data().astype('bool'),
return_sh=True,
parallel=True,
nbr_processes=procmem[0])
dg = ProbabilisticDirectionGetter.from_shcoeff(
peaks.shm_coeff, max_angle=30., sphere=default_sphere)
elif tracking_method == 'peaks':
dg = peaks_from_model(model=csd_model,
data=data,
sphere=default_sphere,
relative_peak_threshold=.5,
min_separation_angle=25,
mask=img_pve_wm.get_data().astype('bool'),
parallel=True,
nbr_processes=procmem[0])
elif tracking_method == 'closest':
csd_fit = csd_model.fit(data,
mask=img_pve_wm.get_data().astype('bool'))
pmf = csd_fit.odf(default_sphere).clip(min=0)
dg = ClosestPeakDirectionGetter.from_pmf(pmf,
max_angle=30.,
sphere=default_sphere)
streamline_generator = LocalTracking(dg,
act_classifier,
seeds_all,
affine=dwi_img.affine,
step_size=0.5)
del dg
try:
del csd_fit
except:
pass
try:
del response
except:
pass
try:
del csd_model
except:
pass
streamlines = Streamlines(streamline_generator, buffer_size=512)
save_trk(Tractogram(streamlines, affine_to_rasmm=dwi_img.affine),
'prob_streamlines.trk')
tracks = [sl for sl in streamlines if len(sl) > 1]
labels_data = labels_img.get_data().astype('int')
labels_affine = labels_img.affine
conn_matrix, grouping = utils.connectivity_matrix(
tracks,
labels_data,
affine=labels_affine,
return_mapping=True,
mapping_as_streamlines=True,
symmetric=True)
conn_matrix[:3, :] = 0
conn_matrix[:, :3] = 0
return conn_matrix
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 track_ensemble(target_samples, atlas_data_wm_gm_int, parcels, parcel_vec, mod_fit,
tiss_classifier, sphere, directget, curv_thr_list, step_list, track_type, maxcrossing, max_length,
n_seeds_per_iter=200):
from colorama import Fore, Style
from dipy.tracking import utils
from dipy.tracking.streamline import Streamlines, select_by_rois
from dipy.tracking.local import LocalTracking, ParticleFilteringTracking
from dipy.direction import ProbabilisticDirectionGetter, BootDirectionGetter, ClosestPeakDirectionGetter, DeterministicMaximumDirectionGetter
# Commence Ensemble Tractography
streamlines = nib.streamlines.array_sequence.ArraySequence()
ix = 0
circuit_ix = 0
stream_counter = 0
while int(stream_counter) < int(target_samples):
for curv_thr in curv_thr_list:
print("%s%s" % ('Curvature: ', curv_thr))
# Instantiate DirectionGetter
if directget == 'prob':
dg = ProbabilisticDirectionGetter.from_shcoeff(mod_fit, max_angle=float(curv_thr),
sphere=sphere)
elif directget == 'boot':
dg = BootDirectionGetter.from_shcoeff(mod_fit, max_angle=float(curv_thr),
sphere=sphere)
elif directget == 'closest':
dg = ClosestPeakDirectionGetter.from_shcoeff(mod_fit, max_angle=float(curv_thr),
sphere=sphere)
elif directget == 'det':
dg = DeterministicMaximumDirectionGetter.from_shcoeff(mod_fit, max_angle=float(curv_thr),
sphere=sphere)
else:
raise ValueError('ERROR: No valid direction getter(s) specified.')
for step in step_list:
print("%s%s" % ('Step: ', step))
# Perform wm-gm interface seeding, using n_seeds at a time
seeds = utils.random_seeds_from_mask(atlas_data_wm_gm_int > 0, seeds_count=n_seeds_per_iter,
seed_count_per_voxel=False, affine=np.eye(4))
if len(seeds) == 0:
raise RuntimeWarning('Warning: No valid seed points found in wm-gm interface...')
print(seeds)
# Perform tracking
if track_type == 'local':
streamline_generator = LocalTracking(dg, tiss_classifier, seeds, np.eye(4),
max_cross=int(maxcrossing), maxlen=int(max_length),
step_size=float(step), return_all=True)
elif track_type == 'particle':
streamline_generator = ParticleFilteringTracking(dg, tiss_classifier, seeds, np.eye(4),
max_cross=int(maxcrossing),
step_size=float(step),
maxlen=int(max_length),
pft_back_tracking_dist=2,
pft_front_tracking_dist=1,
particle_count=15, return_all=True)
else:
raise ValueError('ERROR: No valid tracking method(s) specified.')
# Filter resulting streamlines by roi-intersection characteristics
streamlines_more = Streamlines(select_by_rois(streamline_generator, parcels, parcel_vec.astype('bool'),
mode='any', affine=np.eye(4), tol=8))
# Repeat process until target samples condition is met
ix = ix + 1
for s in streamlines_more:
stream_counter = stream_counter + len(s)
streamlines.append(s)
if int(stream_counter) >= int(target_samples):
break
else:
continue
circuit_ix = circuit_ix + 1
print("%s%s%s%s%s" % ('Completed hyperparameter circuit: ', circuit_ix, '...\nCumulative Streamline Count: ',
Fore.CYAN, stream_counter))
print(Style.RESET_ALL)
print('\n')
return streamlines
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')
mask=mask,
relative_peak_threshold=.5,
min_separation_angle=25,
parallel=True)
# using the peak_slicer
peak_actor = actor.peak_slicer(csd_peaks.peak_dirs,
csd_peaks.peak_values,
colors=None)
slider(peak_actor, None)
#generating streamlines
tissue_classifier = ThresholdTissueClassifier(tenfit.fa, 0.1)
seeds = random_seeds_from_mask(tenfit.fa > 0.3, seeds_count=5)
streamline_generator = LocalTracking(csd_peaks,
tissue_classifier,
seeds,
affine=np.eye(4),
step_size=0.5,
return_all=True)
streamlines = Streamlines(streamline_generator)
show_streamlines(streamlines)
save_trk_n('streamlines.trk',
streamlines,
affine=affine,
fa = tensor_fit.fa
"""
In this simple example we can use FA to stop tracking. Here we stop tracking
when FA < 0.1.
"""
tissue_classifier = ThresholdTissueClassifier(fa, 0.1)
"""
Now, we need to set starting points for propagating each track. We call those
seeds. Using ``random_seeds_from_mask`` we can select a specific number of
seeds (``seeds_count``) in each voxel where the mask ``fa > 0.3`` is true.
"""
seeds = random_seeds_from_mask(fa > 0.3, seeds_count=1)
"""
For quality assurance we can also visualize a slice from the direction field
which we will use as the basis to perform the tracking.
"""
ren = window.Renderer()
ren.add(actor.peak_slicer(csd_peaks.peak_dirs,
csd_peaks.peak_values,
colors=None))
if interactive:
window.show(ren, size=(900, 900))
else:
window.record(ren, out_path='csd_direction_field.png', size=(900, 900))
def track_ensemble(target_samples, atlas_data_wm_gm_int, parcels, mod_fit, tiss_classifier, sphere, directget,
curv_thr_list, step_list, track_type, maxcrossing, roi_neighborhood_tol, min_length, waymask,
B0_mask, max_length=1000, n_seeds_per_iter=500, pft_back_tracking_dist=2, pft_front_tracking_dist=1,
particle_count=15, min_separation_angle=20):
"""
Perform native-space ensemble tractography, restricted to a vector of ROI masks.
target_samples : int
Total number of streamline samples specified to generate streams.
atlas_data_wm_gm_int : array
3D int32 numpy array of atlas parcellation intensities from Nifti1Image in T1w-warped native diffusion space,
restricted to wm-gm interface.
parcels : list
List of 3D boolean numpy arrays of atlas parcellation ROI masks from a Nifti1Image in T1w-warped native
diffusion space.
mod : obj
Connectivity reconstruction model.
tiss_classifier : str
Tissue classification method.
sphere : obj
DiPy object for modeling diffusion directions on a sphere.
directget : str
The statistical approach to tracking. Options are: det (deterministic), closest (clos), boot (bootstrapped),
and prob (probabilistic).
curv_thr_list : list
List of integer curvature thresholds used to perform ensemble tracking.
step_list : list
List of float step-sizes used to perform ensemble tracking.
track_type : str
Tracking algorithm used (e.g. 'local' or 'particle').
maxcrossing : int
Maximum number if diffusion directions that can be assumed per voxel while tracking.
roi_neighborhood_tol : float
Distance (in the units of the streamlines, usually mm). If any
coordinate in the streamline is within this distance from the center
of any voxel in the ROI, the filtering criterion is set to True for
this streamline, otherwise False. Defaults to the distance between
the center of each voxel and the corner of the voxel.
min_length : int
Minimum fiber length threshold in mm.
waymask : str
Path to a Nifti1Image in native diffusion space to constrain tractography.
B0_mask : str
File path to B0 brain mask.
max_length : int
Maximum number of steps to restrict tracking.
n_seeds_per_iter : int
Number of seeds from which to initiate tracking for each unique ensemble combination.
By default this is set to 200.
particle_count
pft_back_tracking_dist : float
Distance in mm to back track before starting the particle filtering
tractography. The total particle filtering tractography distance is
equal to back_tracking_dist + front_tracking_dist. By default this is set to 2 mm.
pft_front_tracking_dist : float
Distance in mm to run the particle filtering tractography after the
the back track distance. The total particle filtering tractography
distance is equal to back_tracking_dist + front_tracking_dist. By
default this is set to 1 mm.
particle_count : int
Number of particles to use in the particle filter.
min_separation_angle : float
The minimum angle between directions [0, 90].
Returns
-------
streamlines : ArraySequence
DiPy list/array-like object of streamline points from tractography.
References
----------
.. [1] Takemura, H., Caiafa, C. F., Wandell, B. A., & Pestilli, F. (2016).
Ensemble Tractography. PLoS Computational Biology.
https://doi.org/10.1371/journal.pcbi.1004692
"""
import gc
import time
from colorama import Fore, Style
from dipy.tracking import utils
from dipy.tracking.streamline import Streamlines, select_by_rois
from dipy.tracking.local_tracking import LocalTracking, ParticleFilteringTracking
from dipy.direction import (ProbabilisticDirectionGetter, ClosestPeakDirectionGetter,
DeterministicMaximumDirectionGetter)
start = time.time()
B0_mask_data = nib.load(B0_mask).get_fdata()
if waymask:
waymask_data = np.asarray(nib.load(waymask).dataobj).astype('bool')
# Commence Ensemble Tractography
parcel_vec = list(np.ones(len(parcels)).astype('bool'))
streamlines = nib.streamlines.array_sequence.ArraySequence()
circuit_ix = 0
stream_counter = 0
while int(stream_counter) < int(target_samples):
for curv_thr in curv_thr_list:
print("%s%s" % ('Curvature: ', curv_thr))
# Instantiate DirectionGetter
if directget == 'prob':
dg = ProbabilisticDirectionGetter.from_shcoeff(mod_fit, max_angle=float(curv_thr), sphere=sphere,
min_separation_angle=min_separation_angle)
elif directget == 'clos':
dg = ClosestPeakDirectionGetter.from_shcoeff(mod_fit, max_angle=float(curv_thr), sphere=sphere,
min_separation_angle=min_separation_angle)
elif directget == 'det':
dg = DeterministicMaximumDirectionGetter.from_shcoeff(mod_fit, max_angle=float(curv_thr), sphere=sphere,
min_separation_angle=min_separation_angle)
else:
raise ValueError('ERROR: No valid direction getter(s) specified.')
for step in step_list:
print("%s%s" % ('Step: ', step))
# Perform wm-gm interface seeding, using n_seeds at a time
seeds = utils.random_seeds_from_mask(atlas_data_wm_gm_int > 0, seeds_count=n_seeds_per_iter,
seed_count_per_voxel=False, affine=np.eye(4))
if len(seeds) == 0:
raise RuntimeWarning('Warning: No valid seed points found in wm-gm interface...')
# print(seeds)
# Perform tracking
if track_type == 'local':
streamline_generator = LocalTracking(dg, tiss_classifier, seeds, np.eye(4),
max_cross=int(maxcrossing), maxlen=int(max_length),
step_size=float(step), fixedstep=False, return_all=True)
elif track_type == 'particle':
streamline_generator = ParticleFilteringTracking(dg, tiss_classifier, seeds, np.eye(4),
max_cross=int(maxcrossing),
step_size=float(step),
maxlen=int(max_length),
pft_back_tracking_dist=pft_back_tracking_dist,
pft_front_tracking_dist=pft_front_tracking_dist,
particle_count=particle_count,
return_all=True)
else:
raise ValueError('ERROR: No valid tracking method(s) specified.')
# Filter resulting streamlines by those that stay entirely inside the brain
roi_proximal_streamlines = utils.target(streamline_generator, np.eye(4), B0_mask_data,
include=True)
# Filter resulting streamlines by roi-intersection characteristics
roi_proximal_streamlines = Streamlines(select_by_rois(roi_proximal_streamlines, affine=np.eye(4),
rois=parcels, include=parcel_vec,
mode='both_end',
tol=roi_neighborhood_tol))
print("%s%s" % ('Filtering by: \nnode intersection: ', len(roi_proximal_streamlines)))
if str(min_length) != '0':
roi_proximal_streamlines = nib.streamlines.array_sequence.ArraySequence([s for s in
roi_proximal_streamlines
if len(s) >=
float(min_length)])
print("%s%s" % ('Minimum length criterion: ', len(roi_proximal_streamlines)))
if waymask:
roi_proximal_streamlines = roi_proximal_streamlines[utils.near_roi(roi_proximal_streamlines,
np.eye(4),
waymask_data,
tol=roi_neighborhood_tol,
mode='any')]
print("%s%s" % ('Waymask proximity: ', len(roi_proximal_streamlines)))
out_streams = [s.astype('float32') for s in roi_proximal_streamlines]
streamlines.extend(out_streams)
stream_counter = stream_counter + len(out_streams)
# Cleanup memory
del seeds, roi_proximal_streamlines, streamline_generator, out_streams
gc.collect()
del dg
circuit_ix = circuit_ix + 1
print("%s%s%s%s%s%s" % ('Completed Hyperparameter Circuit: ', circuit_ix,
'\nCumulative Streamline Count: ', Fore.CYAN, stream_counter, "\n"))
print(Style.RESET_ALL)
print('Tracking Complete:\n', str(time.time() - start))
return streamlines