Example #1
0
def test_multivox_dsi():
    data, gtab = dsi_deconv_voxels()
    DS = DiffusionSpectrumDeconvModel(gtab)

    DSfit = DS.fit(data)
    PDF = DSfit.pdf()
    assert_equal(data.shape[:-1] + (35, 35, 35), PDF.shape)
    assert_equal(np.alltrue(np.isreal(PDF)), True)
Example #2
0
def test_multivox_dsi():
    data, gtab = dsi_deconv_voxels()
    DS = DiffusionSpectrumDeconvModel(gtab)
    sphere = get_sphere('symmetric724')

    DSfit = DS.fit(data)
    PDF = DSfit.pdf()
    assert_equal(data.shape[:-1] + (35, 35, 35), PDF.shape)
    assert_equal(np.alltrue(np.isreal(PDF)), True)
def dsid(training, category, snr, denoised, odeconv, tv, method, weight=0.1):

    data, affine, gtab, mask, evals, S0, prefix = prepare(training,
                                                          category,
                                                          snr,
                                                          denoised,
                                                          odeconv,
                                                          tv,
                                                          method)
    


    model = DiffusionSpectrumDeconvModel(gtab)

    fit = model.fit(data, mask)

    sphere = get_sphere('symmetric724')   

    odf = fit.odf(sphere)

    if odeconv == True:

        odf_sh = sf_to_sh(odf, sphere, sh_order=8,
                          basis_type='mrtrix')

        # # nib.save(nib.Nifti1Image(odf_sh, affine), model_tag + 'odf_sh.nii.gz')

        

        reg_sphere = get_sphere('symmetric724')

        fodf_sh = odf_sh_to_sharp(odf_sh,
                                  reg_sphere, basis='mrtrix', ratio=3.8 / 16.6,
                                  sh_order=8, Lambda=1., tau=1.)

        # # nib.save(nib.Nifti1Image(odf_sh, affine), model_tag + 'fodf_sh.nii.gz')

        fodf_sh[np.isnan(fodf_sh)]=0

        r, theta, phi = cart2sphere(sphere.x, sphere.y, sphere.z)
        B_regul, m, n = real_sph_harm_mrtrix(8, theta[:, None], phi[:, None])

        fodf = np.dot(fodf_sh, B_regul.T)

        odf = fodf

    if tv == True:

        odf = tv_denoise_4d(odf, weight=weight)

    save_odfs_peaks(training, odf, affine, sphere, dres, prefix)
Example #4
0
def test_dsi():
    # load repulsion 724 sphere
    sphere = default_sphere
    # load icosahedron sphere
    sphere2 = create_unit_sphere(5)
    btable = np.loadtxt(get_fnames('dsi515btable'))
    gtab = gradient_table(btable[:, 0], btable[:, 1:])
    data, golden_directions = sticks_and_ball(gtab,
                                              d=0.0015,
                                              S0=100,
                                              angles=[(0, 0), (90, 0)],
                                              fractions=[50, 50],
                                              snr=None)

    ds = DiffusionSpectrumDeconvModel(gtab)

    # repulsion724
    dsfit = ds.fit(data)
    odf = dsfit.odf(sphere)
    directions, _, _ = peak_directions(odf, sphere, .35, 25)
    assert_equal(len(directions), 2)
    assert_almost_equal(angular_similarity(directions, golden_directions), 2,
                        1)

    # 5 subdivisions
    dsfit = ds.fit(data)
    odf2 = dsfit.odf(sphere2)
    directions, _, _ = peak_directions(odf2, sphere2, .35, 25)
    assert_equal(len(directions), 2)
    assert_almost_equal(angular_similarity(directions, golden_directions), 2,
                        1)

    assert_equal(dsfit.pdf().shape, 3 * (ds.qgrid_size, ))
    sb_dummies = sticks_and_ball_dummies(gtab)
    for sbd in sb_dummies:
        data, golden_directions = sb_dummies[sbd]
        odf = ds.fit(data).odf(sphere2)
        directions, _, _ = peak_directions(odf, sphere2, .35, 25)
        if len(directions) <= 3:
            assert_equal(len(directions), len(golden_directions))
        if len(directions) > 3:
            assert_equal(gfa(odf) < 0.1, True)

    assert_raises(ValueError,
                  DiffusionSpectrumDeconvModel,
                  gtab,
                  qgrid_size=16)
Example #5
0
def test_dsi():
    # load symmetric 724 sphere
    sphere = get_sphere('symmetric724')
    # load icosahedron sphere
    sphere2 = create_unit_sphere(5)
    btable = np.loadtxt(get_data('dsi515btable'))
    gtab = gradient_table(btable[:, 0], btable[:, 1:])
    data, golden_directions = SticksAndBall(gtab, d=0.0015,
                                            S0=100, angles=[(0, 0), (90, 0)],
                                            fractions=[50, 50], snr=None)

    ds = DiffusionSpectrumDeconvModel(gtab)

    # symmetric724
    dsfit = ds.fit(data)
    odf = dsfit.odf(sphere)
    directions, _, _ = peak_directions(odf, sphere, .35, 25)
    assert_equal(len(directions), 2)
    assert_almost_equal(angular_similarity(directions, golden_directions),
                        2, 1)

    # 5 subdivisions
    dsfit = ds.fit(data)
    odf2 = dsfit.odf(sphere2)
    directions, _, _ = peak_directions(odf2, sphere2, .35, 25)
    assert_equal(len(directions), 2)
    assert_almost_equal(angular_similarity(directions, golden_directions),
                        2, 1)

    assert_equal(dsfit.pdf().shape, 3 * (ds.qgrid_size, ))
    sb_dummies = sticks_and_ball_dummies(gtab)
    for sbd in sb_dummies:
        data, golden_directions = sb_dummies[sbd]
        odf = ds.fit(data).odf(sphere2)
        directions, _, _ = peak_directions(odf, sphere2, .35, 25)
        if len(directions) <= 3:
            assert_equal(len(directions), len(golden_directions))
        if len(directions) > 3:
            assert_equal(gfa(odf) < 0.1, True)

    assert_raises(ValueError, DiffusionSpectrumDeconvModel, gtab, qgrid_size=16)
sphere = get_sphere('symmetric724').subdivide(1)

odf_gt = multi_tensor_odf(sphere.vertices,
                          evals,
                          angles=directions,
                          fractions=fractions)
"""
Perform the reconstructions with standard DSI and DSI with deconvolution.
"""

dsi_model = DiffusionSpectrumModel(gtab)

dsi_odf = dsi_model.fit(signal).odf(sphere)

dsid_model = DiffusionSpectrumDeconvModel(gtab)

dsid_odf = dsid_model.fit(signal).odf(sphere)
"""
Finally, we can visualize the ground truth ODF, together with the DSI and DSI
with deconvolution ODFs and observe that with the deconvolved method it is
easier to resolve the correct fiber directions because the ODF is sharper.
"""

from dipy.viz import window, actor

# Enables/disables interactive visualization
interactive = False

ren = window.Renderer()
Example #7
0
                         fractions=fractions, snr=None)

sphere = get_sphere('symmetric724').subdivide(1)

odf_gt = multi_tensor_odf(sphere.vertices, evals, angles=directions,
                          fractions=fractions)

"""
Perform the reconstructions with standard DSI and DSI with deconvolution.
"""

dsi_model = DiffusionSpectrumModel(gtab)

dsi_odf = dsi_model.fit(signal).odf(sphere)

dsid_model = DiffusionSpectrumDeconvModel(gtab)

dsid_odf = dsid_model.fit(signal).odf(sphere)

"""
Finally, we can visualize the ground truth ODF, together with the DSI and DSI
with deconvolution ODFs and observe that with the deconvolved method it is
easier to resolve the correct fiber directions because the ODF is sharper.
"""

from dipy.viz import fvtk

ren = fvtk.ren()

odfs = np.vstack((odf_gt, dsi_odf, dsid_odf))[:, None, None]
Example #8
0

    gqi_vector = np.real(H(proj * model.Lambda / np.pi))

    return np.dot(data, gqi_vector), proj

odf, proj = optimal_transform(gqi_model, data, sphere)


from dipy.viz import fvtk

r = fvtk.ren()
fvtk.add(r, fvtk.sphere_funcs(gqi_odf, sphere))
fvtk.show(r)

dsi_model = DiffusionSpectrumDeconvModel(gtab)
dsi_odf = dsi_model.fit(data).odf(sphere)

fvtk.clear(r)
fvtk.add(r, fvtk.sphere_funcs(dsi_odf, sphere))
fvtk.show(r)

fvtk.clear(r)
fvtk.add(r, fvtk.sphere_funcs(odf, sphere))
fvtk.show(r)


def investigate_internals():

    def bvl_min_max(b_vector, sphere, sampling_length):
        bv = np.dot(gqi_model.b_vector, sphere.vertices.T)
def dmri_recon(sid,
               data_dir,
               out_dir,
               resolution,
               recon='csd',
               dirs='',
               num_threads=2):
    import tempfile
    #tempfile.tempdir = '/om/scratch/Fri/ksitek/'

    import os
    oldval = None
    if 'MKL_NUM_THREADS' in os.environ:
        oldval = os.environ['MKL_NUM_THREADS']
    os.environ['MKL_NUM_THREADS'] = '%d' % num_threads
    ompoldval = None
    if 'OMP_NUM_THREADS' in os.environ:
        ompoldval = os.environ['OMP_NUM_THREADS']
    os.environ['OMP_NUM_THREADS'] = '%d' % num_threads
    import nibabel as nib
    import numpy as np
    from glob import glob

    if resolution == '0.2mm':
        filename = 'Reg_S64550_nii4d.nii'
        #filename = 'angular_resample/dwi_%s.nii.gz'%dirs
        fimg = os.path.abspath(glob(os.path.join(data_dir, filename))[0])
    else:
        filename = 'Reg_S64550_nii4d_resamp-%s.nii.gz' % (resolution)
        fimg = os.path.abspath(
            glob(os.path.join(data_dir, 'resample', filename))[0])
    print("dwi file = %s" % fimg)
    fbval = os.path.abspath(
        glob(os.path.join(data_dir, 'bvecs', 'camino_120_RAS.bvals'))[0])
    print("bval file = %s" % fbval)
    fbvec = os.path.abspath(
        glob(os.path.join(data_dir, 'bvecs',
                          'camino_120_RAS_flipped-xy.bvecs'))[0])
    #                                          'angular_resample',
    #                                          'dwi_%s.bvecs'%dirs))[0])
    print("bvec file = %s" % fbvec)
    img = nib.load(fimg)
    data = img.get_fdata()

    affine = img.get_affine()

    prefix = sid

    from dipy.io import read_bvals_bvecs
    bvals, bvecs = read_bvals_bvecs(fbval, fbvec)
    '''
    from dipy.core.gradients import vector_norm
    b0idx = []
    for idx, val in enumerate(bvals):
        if val < 1:
            pass
            #bvecs[idx] = [1, 0, 0]
        else:
            b0idx.append(idx)
            #print "b0idx=%d"%idx
    #print "input bvecs:"
    #print bvecs
    bvecs[b0idx, :] = bvecs[b0idx, :]/vector_norm(bvecs[b0idx])[:, None]
    #print "bvecs after normalization:"
    #print bvecs
    '''

    from dipy.core.gradients import gradient_table
    gtab = gradient_table(bvals, bvecs)
    gtab.bvecs.shape == bvecs.shape
    gtab.bvecs
    gtab.bvals.shape == bvals.shape
    gtab.bvals

    #from dipy.segment.mask import median_otsu
    #b0_mask, mask = median_otsu(data[:, :, :, b0idx].mean(axis=3).squeeze(), 4, 4)

    if resolution == '0.2mm':
        mask_name = 'Reg_S64550_nii_b0-slice_mask.nii.gz'
        fmask1 = os.path.join(data_dir, mask_name)
    else:
        mask_name = 'Reg_S64550_nii_b0-slice_mask_resamp-%s.nii.gz' % (
            resolution)
        fmask1 = os.path.join(data_dir, 'resample', mask_name)
    print("fmask file = %s" % fmask1)
    mask = nib.load(fmask1).get_fdata()
    ''' DTI model & save metrics '''
    from dipy.reconst.dti import TensorModel
    print("running tensor model")
    tenmodel = TensorModel(gtab)
    tenfit = tenmodel.fit(data, mask)

    from dipy.reconst.dti import fractional_anisotropy
    print("running FA")
    FA = fractional_anisotropy(tenfit.evals)
    FA[np.isnan(FA)] = 0
    fa_img = nib.Nifti1Image(FA, img.get_affine())
    tensor_fa_file = os.path.abspath('%s_tensor_fa.nii.gz' % (prefix))
    nib.save(fa_img, tensor_fa_file)

    from dipy.reconst.dti import axial_diffusivity
    print("running AD")
    AD = axial_diffusivity(tenfit.evals)
    AD[np.isnan(AD)] = 0
    ad_img = nib.Nifti1Image(AD, img.get_affine())
    tensor_ad_file = os.path.abspath('%s_tensor_ad.nii.gz' % (prefix))
    nib.save(ad_img, tensor_ad_file)

    from dipy.reconst.dti import radial_diffusivity
    print("running RD")
    RD = radial_diffusivity(tenfit.evals)
    RD[np.isnan(RD)] = 0
    rd_img = nib.Nifti1Image(RD, img.get_affine())
    tensor_rd_file = os.path.abspath('%s_tensor_rd.nii.gz' % (prefix))
    nib.save(rd_img, tensor_rd_file)

    from dipy.reconst.dti import mean_diffusivity
    print("running MD")
    MD = mean_diffusivity(tenfit.evals)
    MD[np.isnan(MD)] = 0
    md_img = nib.Nifti1Image(MD, img.get_affine())
    tensor_md_file = os.path.abspath('%s_tensor_md.nii.gz' % (prefix))
    nib.save(md_img, tensor_md_file)

    evecs = tenfit.evecs
    evec_img = nib.Nifti1Image(evecs, img.get_affine())
    tensor_evec_file = os.path.abspath('%s_tensor_evec.nii.gz' % (prefix))
    nib.save(evec_img, tensor_evec_file)
    ''' ODF model '''
    useFA = True
    print("creating %s model" % recon)
    if recon == 'csd':
        from dipy.reconst.csdeconv import ConstrainedSphericalDeconvModel
        from dipy.reconst.csdeconv import auto_response
        response, ratio = auto_response(gtab, data, roi_radius=10,
                                        fa_thr=0.5)  # 0.7

        model = ConstrainedSphericalDeconvModel(gtab, response)
        useFA = True
        return_sh = True
    elif recon == 'csa':
        from dipy.reconst.shm import CsaOdfModel, normalize_data
        model = CsaOdfModel(gtab, sh_order=8)
        useFA = True
        return_sh = True
    elif recon == 'gqi':
        from dipy.reconst.gqi import GeneralizedQSamplingModel
        model = GeneralizedQSamplingModel(gtab)
        return_sh = False
    else:
        raise ValueError('only csd, csa supported currently')
        from dipy.reconst.dsi import (DiffusionSpectrumDeconvModel,
                                      DiffusionSpectrumModel)
        model = DiffusionSpectrumDeconvModel(gtab)
    '''reconstruct ODFs'''
    from dipy.data import get_sphere
    sphere = get_sphere('symmetric724')
    #odfs = fit.odf(sphere)

    # with CSD/GQI, uses > 50GB per core; don't get greedy with cores!
    from dipy.reconst.peaks import peaks_from_model
    print("running peaks_from_model")
    peaks = peaks_from_model(
        model=model,
        data=data,
        sphere=sphere,
        mask=mask,
        return_sh=return_sh,
        return_odf=False,
        normalize_peaks=True,
        npeaks=5,
        relative_peak_threshold=.5,
        min_separation_angle=10,  #25,
        parallel=num_threads > 1,
        nbr_processes=num_threads)

    # save the peaks
    from dipy.io.peaks import save_peaks
    peaks_file = os.path.abspath('%s_peaks.pam5' % (prefix))
    save_peaks(peaks_file, peaks)

    # save the spherical harmonics
    shm_coeff_file = os.path.abspath('%s_shm_coeff.nii.gz' % (prefix))
    if return_sh:
        shm_coeff = peaks.shm_coeff
        nib.save(nib.Nifti1Image(shm_coeff, img.get_affine()), shm_coeff_file)
    else:
        # if it's not a spherical model, output it as an essentially null file
        np.savetxt(shm_coeff_file, [0])

    # save the generalized fractional anisotropy image
    gfa_img = nib.Nifti1Image(peaks.gfa, img.get_affine())
    model_gfa_file = os.path.abspath('%s_%s_gfa.nii.gz' % (prefix, recon))
    nib.save(gfa_img, model_gfa_file)

    #from dipy.reconst.dti import quantize_evecs
    #peak_indices = quantize_evecs(tenfit.evecs, sphere.vertices)
    #eu = EuDX(FA, peak_indices, odf_vertices = sphere.vertices,
    #a_low=0.2, seeds=10**6, ang_thr=35)
    ''' probabilistic tracking '''
    '''
    from dipy.direction import ProbabilisticDirectionGetter
    from dipy.tracking.local import LocalTracking
    from dipy.tracking.streamline import Streamlines
    from dipy.io.streamline import save_trk

    prob_dg = ProbabilisticDirectionGetter.from_shcoeff(shm_coeff,
                                                        max_angle=45.,
                                                        sphere=sphere)
    streamlines_generator = LocalTracking(prob_dg,
                                          affine,
                                          step_size=.5,
                                          max_cross=1)

    # Generate streamlines object
    streamlines = Streamlines(streamlines_generator)

    affine = img.get_affine()
    vox_size=fa_img.get_header().get_zooms()[:3]

    fname = os.path.abspath('%s_%s_prob_streamline.trk' % (prefix, recon))
    save_trk(fname, streamlines, affine, vox_size=vox_size)
    '''
    ''' deterministic tracking with EuDX method'''
    from dipy.tracking.eudx import EuDX
    print("reconstructing with EuDX")
    if useFA:
        eu = EuDX(
            FA,
            peaks.peak_indices[..., 0],
            odf_vertices=sphere.vertices,
            a_low=0.001,  # default is 0.0239
            seeds=10**6,
            ang_thr=75)
    else:
        eu = EuDX(
            peaks.gfa,
            peaks.peak_indices[..., 0],
            odf_vertices=sphere.vertices,
            #a_low=0.1,
            seeds=10**6,
            ang_thr=45)

    sl_fname = os.path.abspath('%s_%s_det_streamline.trk' % (prefix, recon))

    # trying new dipy.io.streamline module, per email to neuroimaging list
    # 2018.04.05
    from nibabel.streamlines import Field
    from nibabel.orientations import aff2axcodes
    affine = img.get_affine()
    vox_size = fa_img.get_header().get_zooms()[:3]
    fov_shape = FA.shape[:3]

    if vox_size is not None and fov_shape is not None:
        hdr = {}
        hdr[Field.VOXEL_TO_RASMM] = affine.copy()
        hdr[Field.VOXEL_SIZES] = vox_size
        hdr[Field.DIMENSIONS] = fov_shape
        hdr[Field.VOXEL_ORDER] = "".join(aff2axcodes(affine))

    tractogram = nib.streamlines.Tractogram(eu)
    tractogram.affine_to_rasmm = affine
    trk_file = nib.streamlines.TrkFile(tractogram, header=hdr)
    nib.streamlines.save(trk_file, sl_fname)

    if oldval:
        os.environ['MKL_NUM_THREADS'] = oldval
    else:
        del os.environ['MKL_NUM_THREADS']
    if ompoldval:
        os.environ['OMP_NUM_THREADS'] = ompoldval
    else:
        del os.environ['OMP_NUM_THREADS']

    print('all output files created')

    return (tensor_fa_file, tensor_evec_file, model_gfa_file, sl_fname, affine,
            tensor_ad_file, tensor_rd_file, tensor_md_file, shm_coeff_file,
            peaks_file)
Example #10
0

gq = GeneralizedQSamplingModel(gtab_full, sampling_length=3.5)

gqfit = gq.fit(SS)
gqodf = gqfit.odf(sphere)

gqdir, _, _ = peak_directions(gqodf, sphere, .35, 15)

print angular_similarity(sticks, gqdir)

grid_size = 35
dds = DiffusionSpectrumDeconvModel(gtab_full,
                                   qgrid_size=grid_size,
                                   r_start=0.2 * (grid_size // 2),
                                   r_end=0.7 * (grid_size // 2),
                                   r_step=0.02 * (grid_size // 2),
                                   filter_width=np.inf,
                                   normalize_peaks=False)


ddsfit = dds.fit(SS)
ddsodf = ddsfit.odf(sphere)

ddsdir, _, _ = peak_directions(ddsodf, sphere, .35, 15)

print angular_similarity(sticks, ddsdir)


grid_size = 35
ds = DiffusionSpectrumModel(gtab_full,
Example #11
0
def dmri_recon(sid, data_dir, out_dir, resolution, recon='csd', num_threads=2):
    import tempfile
    #tempfile.tempdir = '/om/scratch/Fri/ksitek/'

    import os
    oldval = None
    if 'MKL_NUM_THREADS' in os.environ:
        oldval = os.environ['MKL_NUM_THREADS']
    os.environ['MKL_NUM_THREADS'] = '%d' % num_threads
    ompoldval = None
    if 'OMP_NUM_THREADS' in os.environ:
        ompoldval = os.environ['OMP_NUM_THREADS']
    os.environ['OMP_NUM_THREADS'] = '%d' % num_threads
    import nibabel as nib
    import numpy as np
    from glob import glob

    if resolution == '0.2mm':
        filename = 'Reg_S64550_nii4d.nii'
        fimg = os.path.abspath(glob(os.path.join(data_dir, filename))[0])
    else:
        filename = 'Reg_S64550_nii4d_resamp-%s.nii.gz'%(resolution)
        fimg = os.path.abspath(glob(os.path.join(data_dir, 'resample', filename))[0])
    print("dwi file = %s"%fimg)
    fbvec = os.path.abspath(glob(os.path.join(data_dir, 'bvecs',
                                              'camino_120_RAS_flipped-xy.bvecs'))[0])
    print("bvec file = %s"%fbvec)
    fbval = os.path.abspath(glob(os.path.join(data_dir, 'bvecs',
                                              'camino_120_RAS.bvals'))[0])
    print("bval file = %s"%fbval)
    img = nib.load(fimg)
    data = img.get_data()

    affine = img.get_affine()

    prefix = sid

    from dipy.io import read_bvals_bvecs
    from dipy.core.gradients import vector_norm
    bvals, bvecs = read_bvals_bvecs(fbval, fbvec)

    b0idx = []
    for idx, val in enumerate(bvals):
        if val < 1:
            pass
            #bvecs[idx] = [1, 0, 0]
        else:
            b0idx.append(idx)
            #print "b0idx=%d"%idx
    #print "input bvecs:"
    #print bvecs
    bvecs[b0idx, :] = bvecs[b0idx, :]/vector_norm(bvecs[b0idx])[:, None]
    #print "bvecs after normalization:"
    #print bvecs


    from dipy.core.gradients import gradient_table
    gtab = gradient_table(bvals, bvecs)
    gtab.bvecs.shape == bvecs.shape
    gtab.bvecs
    gtab.bvals.shape == bvals.shape
    gtab.bvals


    from dipy.reconst.csdeconv import auto_response
    response, ratio = auto_response(gtab, data, roi_radius=10, fa_thr=0.1) # 0.7

    #from dipy.segment.mask import median_otsu
    #b0_mask, mask = median_otsu(data[:, :, :, b0idx].mean(axis=3).squeeze(), 4, 4)

    if resolution == '0.2mm':
        mask_name = 'Reg_S64550_nii_b0-slice_mask.nii.gz'
        fmask1 = os.path.join(data_dir, mask_name)
    else:
        mask_name = 'Reg_S64550_nii_b0-slice_mask_resamp-%s.nii.gz'%(resolution)
        fmask1 = os.path.join(data_dir, 'resample', mask_name)
    print("fmask file = %s"%fmask1)
    mask = nib.load(fmask1).get_data()

    useFA = True
    print("creating model")
    if recon == 'csd':
        from dipy.reconst.csdeconv import ConstrainedSphericalDeconvModel
        model = ConstrainedSphericalDeconvModel(gtab, response)
        useFA = True
    elif recon == 'csa':
        from dipy.reconst.shm import CsaOdfModel, normalize_data
        model = CsaOdfModel(gtab, 4)
        useFA = False
    else:
        raise ValueError('only csd, csa supported currently')
        from dipy.reconst.dsi import (DiffusionSpectrumDeconvModel,
                                      DiffusionSpectrumModel)
        model = DiffusionSpectrumDeconvModel(gtab)
    fit = model.fit(data)

    from dipy.data import get_sphere
    sphere = get_sphere('symmetric724')
    #odfs = fit.odf(sphere)

    from dipy.reconst.peaks import peaks_from_model
    print("running peaks_from_model")
    peaks = peaks_from_model(model=model,
                             data=data,
                             sphere=sphere,
                             mask=mask,
                             return_sh=True,
                             return_odf=False,
                             normalize_peaks=True,
                             npeaks=5,
                             relative_peak_threshold=.5,
                             min_separation_angle=25,
                             parallel=num_threads > 1,
                             nbr_processes=num_threads)

    from dipy.reconst.dti import TensorModel
    print("running tensor model")
    tenmodel = TensorModel(gtab)
    tenfit = tenmodel.fit(data, mask)

    from dipy.reconst.dti import fractional_anisotropy
    print("running FA")
    FA = fractional_anisotropy(tenfit.evals)
    FA[np.isnan(FA)] = 0
    fa_img = nib.Nifti1Image(FA, img.get_affine())
    tensor_fa_file = os.path.abspath('%s_tensor_fa.nii.gz' % (prefix))
    nib.save(fa_img, tensor_fa_file)

    from dipy.reconst.dti import axial_diffusivity
    print("running AD")
    AD = axial_diffusivity(tenfit.evals)
    AD[np.isnan(AD)] = 0
    ad_img = nib.Nifti1Image(AD, img.get_affine())
    tensor_ad_file = os.path.abspath('%s_tensor_ad.nii.gz' % (prefix))
    nib.save(ad_img, tensor_ad_file)

    from dipy.reconst.dti import radial_diffusivity
    print("running RD")
    RD = radial_diffusivity(tenfit.evals)
    RD[np.isnan(RD)] = 0
    rd_img = nib.Nifti1Image(RD, img.get_affine())
    tensor_rd_file = os.path.abspath('%s_tensor_rd.nii.gz' % (prefix))
    nib.save(rd_img, tensor_rd_file)

    from dipy.reconst.dti import mean_diffusivity
    print("running MD")
    MD = mean_diffusivity(tenfit.evals)
    MD[np.isnan(MD)] = 0
    md_img = nib.Nifti1Image(MD, img.get_affine())
    tensor_md_file = os.path.abspath('%s_tensor_md.nii.gz' % (prefix))
    nib.save(md_img, tensor_md_file)

    evecs = tenfit.evecs
    evec_img = nib.Nifti1Image(evecs, img.get_affine())
    tensor_evec_file = os.path.abspath('%s_tensor_evec.nii.gz' % (prefix))
    nib.save(evec_img, tensor_evec_file)

    shm_coeff = fit.shm_coeff
    shm_coeff_file = os.path.abspath('%s_shm_coeff.nii.gz' % (prefix))
    nib.save(nib.Nifti1Image(shm_coeff, img.get_affine()), shm_coeff_file)

    #from dipy.reconst.dti import quantize_evecs
    #peak_indices = quantize_evecs(tenfit.evecs, sphere.vertices)
    #eu = EuDX(FA, peak_indices, odf_vertices = sphere.vertices,
               #a_low=0.2, seeds=10**6, ang_thr=35)

    fa_img = nib.Nifti1Image(peaks.gfa, img.get_affine())
    model_gfa_file = os.path.abspath('%s_%s_gfa.nii.gz' % (prefix, recon))
    nib.save(fa_img, model_gfa_file)

    from dipy.tracking.eudx import EuDX
    print("reconstructing with EuDX")
    if useFA:
        eu = EuDX(FA, peaks.peak_indices[..., 0],
                  odf_vertices = sphere.vertices,
                  #a_low=0.1,
                  seeds=10**6,
                  ang_thr=45)
    else:
        eu = EuDX(peaks.gfa, peaks.peak_indices[..., 0],
                  odf_vertices = sphere.vertices,
                  #a_low=0.1,
                  seeds=10**6,
                  ang_thr=45)

    sl_fname = os.path.abspath('%s_%s_streamline.trk' % (prefix, recon))
    """
    #import dipy.tracking.metrics as dmetrics
    streamlines = ((sl, None, None) for sl in eu) # if dmetrics.length(sl) > 15)

    hdr = nib.trackvis.empty_header()
    hdr['voxel_size'] = fa_img.get_header().get_zooms()[:3]
    hdr['voxel_order'] = 'RAS' #LAS
    hdr['dim'] = FA.shape[:3]

    nib.trackvis.write(sl_fname, streamlines, hdr, points_space='voxel')
    """
    # trying new dipy.io.streamline module, per email to neuroimaging list
    # 2018.04.05
    from nibabel.streamlines import Field
    from nibabel.orientations import aff2axcodes
    affine = img.get_affine()
    vox_size=fa_img.get_header().get_zooms()[:3]
    fov_shape=FA.shape[:3]

    if vox_size is not None and fov_shape is not None:
        hdr = {}
        hdr[Field.VOXEL_TO_RASMM] = affine.copy()
        hdr[Field.VOXEL_SIZES] = vox_size
        hdr[Field.DIMENSIONS] = fov_shape
        hdr[Field.VOXEL_ORDER] = "".join(aff2axcodes(affine))

    tractogram = nib.streamlines.Tractogram(eu)
    tractogram.affine_to_rasmm = affine
    trk_file = nib.streamlines.TrkFile(tractogram, header=hdr)
    nib.streamlines.save(trk_file, sl_fname)

    if oldval:
        os.environ['MKL_NUM_THREADS'] = oldval
    else:
        del os.environ['MKL_NUM_THREADS']
    if ompoldval:
        os.environ['OMP_NUM_THREADS'] = ompoldval
    else:
        del os.environ['OMP_NUM_THREADS']

    assert tensor_fa_file
    assert tensor_evec_file
    assert model_gfa_file
    assert tensor_ad_file
    assert tensor_rd_file
    assert tensor_md_file
    assert shm_coeff_file
    print('all output files created')

    return tensor_fa_file, tensor_evec_file, model_gfa_file, sl_fname, affine, tensor_ad_file, tensor_rd_file, tensor_md_file, shm_coeff_file