interfaces.mrtrix3.preprocess

DWIDenoise

Link to code

Wraps the executable command dwidenoise.

Denoise DWI data and estimate the noise level based on the optimal threshold for PCA.

DWI data denoising and noise map estimation by exploiting data redundancy in the PCA domain using the prior knowledge that the eigenspectrum of random covariance matrices is described by the universal Marchenko Pastur distribution.

Important note: image denoising must be performed as the first step of the image processing pipeline. The routine will fail if interpolation or smoothing has been applied to the data prior to denoising.

Note that this function does not correct for non-Gaussian noise biases.

For more information, see <https://mrtrix.readthedocs.io/en/latest/reference/commands/dwidenoise.html>

Example

>>> import nipype.interfaces.mrtrix3 as mrt
>>> denoise = mrt.DWIDenoise()
>>> denoise.inputs.in_file = 'dwi.mif'
>>> denoise.inputs.mask = 'mask.mif'
>>> denoise.cmdline                               
'dwidenoise -mask mask.mif dwi.mif dwi_denoised.mif'
>>> denoise.run()                                 

Inputs:

[Mandatory]
in_file: (an existing file name)
        input DWI image
        argument: ``%s``, position: -2

[Optional]
mask: (an existing file name)
        mask image
        argument: ``-mask %s``, position: 1
extent: (a tuple of the form: (an integer (int or long), an integer
          (int or long), an integer (int or long)))
        set the window size of the denoising filter. (default = 5,5,5)
        argument: ``-extent %d,%d,%d``
noise: (a file name)
        noise map
        argument: ``-noise %s``
out_file: (a file name)
        the output denoised DWI image
        argument: ``%s``, position: -1
nthreads: (an integer (int or long))
        number of threads. if zero, the number of available cpus will be
        used
        argument: ``-nthreads %d``
grad_file: (an existing file name)
        dw gradient scheme (MRTrix format
        argument: ``-grad %s``
grad_fsl: (a tuple of the form: (an existing file name, an existing
          file name))
        (bvecs, bvals) dw gradient scheme (FSL format
        argument: ``-fslgrad %s %s``
bval_scale: ('yes' or 'no')
        specifies whether the b - values should be scaled by the square of
        the corresponding DW gradient norm, as often required for multishell
        or DSI DW acquisition schemes. The default action can also be set in
        the MRtrix config file, under the BValueScaling entry. Valid choices
        are yes / no, true / false, 0 / 1 (default: true).
        argument: ``-bvalue_scaling %s``
in_bvec: (an existing file name)
        bvecs file in FSL format
        argument: ``-fslgrad %s %s``
in_bval: (an existing file name)
        bvals file in FSL format
args: (a unicode string)
        Additional parameters to the command
        argument: ``%s``
environ: (a dictionary with keys which are a bytes or None or a value
          of class 'str' and with values which are a bytes or None or a
          value of class 'str', nipype default value: {})
        Environment variables

Outputs:

out_file: (an existing file name)
        the output denoised DWI image

ResponseSD

Link to code

Wraps the executable command dwi2response.

Estimate response function(s) for spherical deconvolution using the specified algorithm.

Example

>>> import nipype.interfaces.mrtrix3 as mrt
>>> resp = mrt.ResponseSD()
>>> resp.inputs.in_file = 'dwi.mif'
>>> resp.inputs.algorithm = 'tournier'
>>> resp.inputs.grad_fsl = ('bvecs', 'bvals')
>>> resp.cmdline                               
'dwi2response tournier -fslgrad bvecs bvals -lmax 8 dwi.mif wm.txt'
>>> resp.run()                                 

# We can also pass in multiple harmonic degrees in the case of multi-shell >>> resp.inputs.max_sh = [6,8,10] >>> resp.cmdline ‘dwi2response tournier -fslgrad bvecs bvals -lmax 6,8,10 dwi.mif wm.txt’

Inputs:

[Mandatory]
algorithm: ('msmt_5tt' or 'dhollander' or 'tournier' or 'tax')
        response estimation algorithm (multi-tissue)
        argument: ``%s``, position: 1
in_file: (an existing file name)
        input DWI image
        argument: ``%s``, position: -5

[Optional]
mtt_file: (a file name)
        input 5tt image
        argument: ``%s``, position: -4
wm_file: (a file name, nipype default value: wm.txt)
        output WM response text file
        argument: ``%s``, position: -3
gm_file: (a file name)
        output GM response text file
        argument: ``%s``, position: -2
csf_file: (a file name)
        output CSF response text file
        argument: ``%s``, position: -1
in_mask: (an existing file name)
        provide initial mask image
        argument: ``-mask %s``
max_sh: (a list of items which are an integer (int or long), nipype
          default value: [8])
        maximum harmonic degree of response function - single value for
        single-shell response, list for multi-shell response
        argument: ``-lmax %s``
nthreads: (an integer (int or long))
        number of threads. if zero, the number of available cpus will be
        used
        argument: ``-nthreads %d``
grad_file: (an existing file name)
        dw gradient scheme (MRTrix format
        argument: ``-grad %s``
grad_fsl: (a tuple of the form: (an existing file name, an existing
          file name))
        (bvecs, bvals) dw gradient scheme (FSL format
        argument: ``-fslgrad %s %s``
bval_scale: ('yes' or 'no')
        specifies whether the b - values should be scaled by the square of
        the corresponding DW gradient norm, as often required for multishell
        or DSI DW acquisition schemes. The default action can also be set in
        the MRtrix config file, under the BValueScaling entry. Valid choices
        are yes / no, true / false, 0 / 1 (default: true).
        argument: ``-bvalue_scaling %s``
in_bvec: (an existing file name)
        bvecs file in FSL format
        argument: ``-fslgrad %s %s``
in_bval: (an existing file name)
        bvals file in FSL format
args: (a unicode string)
        Additional parameters to the command
        argument: ``%s``
environ: (a dictionary with keys which are a bytes or None or a value
          of class 'str' and with values which are a bytes or None or a
          value of class 'str', nipype default value: {})
        Environment variables

Outputs:

wm_file: (a file name)
        output WM response text file
        argument: ``%s``
gm_file: (a file name)
        output GM response text file
        argument: ``%s``
csf_file: (a file name)
        output CSF response text file
        argument: ``%s``