nrrd.dwi.info

The teem/DTI-TK/3D Slicer convention for diffusion MRI data in NRRD files stores
the b-value in the field 'DWMRI_b-value' and one gradient vector per volume in the fields
'DWMRI_gradient_0000', 'DWMRI_gradient_0001' and so on. The optional 'measurement frame' field
is the rotation that maps the gradient vectors, which are given in the image (voxel) frame,
into the frame in which the gradients were measured. The values are returned exactly as they
are stored, i.e. in the image frame, together with the measurement frame, so that a caller can
apply it (or hand the values to the gradient table functions of this package, which expect
gradients in image axes as well).

internal

Provides functions to read and write neuroimaging data in various file formats, with a focus on 'FreeSurfer' formats. This includes, but is not limited to, the following file formats: 1) MGH/MGZ/NIFTI format files, which can contain multi-dimensional images or other data. Typically they contain time-series of three-dimensional brain scans acquired by magnetic resonance imaging (MRI). They can also contain vertex-wise measures of surface morphometry data. The MGH format is named after the Massachusetts General Hospital, and the MGZ format is a compressed version of the same format. 2) 'FreeSurfer' morphometry data files in binary 'curv' format. These contain vertex-wise surface measures, i.e., one scalar value for each vertex of a brain surface mesh. These are typically values like the cortical thickness or brain surface area at each vertex. 3) Annotation file format. This contains a brain surface parcellation derived from a cortical atlas. 4) Surface file format. Contains a brain surface mesh, given by a list of vertices and a list of faces.

Tim Schc3<a4>fer

freesurferformats

Read and Write 'FreeSurfer' Neuroimaging File Formats

Tim Schäfer

Van Essen Lab 

Montreal Neurological Institute (MNI) 

nrrd.dwi.info function

<dl><dt>fields</dt>
<dd>named list, the parsed header fields.</dd>
<dt>num_volumes</dt>
<dd>integer, the number of volumes (the size of the last axis), used to check the
number of gradients.</dd></dl>

Arguments

Parse the diffusion metadata of a NRRD header. — nrrd.dwi.info

<dl>

<dt>fields</dt>
<dd>named list, the parsed header fields.</dd>


<dt>num_volumes</dt>
<dd>integer, the number of volumes (the size of the last axis), used to check the
number of gradients.</dd>

</dl>

nrrd.dwi.info: Parse the diffusion metadata of a NRRD header.

Description

Usage

Value

Arguments