diff --git a/src/05-derivatives/05-diffusion-derivatives.md b/src/05-derivatives/05-diffusion-derivatives.md index 0b4b0427..d4207c03 100644 --- a/src/05-derivatives/05-diffusion-derivatives.md +++ b/src/05-derivatives/05-diffusion-derivatives.md @@ -337,15 +337,15 @@ in order to produce a [directionally-encoded colour](#data-dec), ### Orientation specification -| **Key name** | **Relevant [data representations](#data-representations)** | **Description** | -| --------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -| `AntipodalSymmetry` | [Spherical coordinates](#data-spherical), [3-vectors](#data-3vector), [spherical harmonics](#data-sh), [amplitudes](#data-amp), [probability distribution functions](#data-pdf), [parameter vectors](#data-param) | OPTIONAL. Boolean. Indicates whether orientation information should be interpreted as being antipodally symmetric. Assumed to be True if omitted. | -| `Directions` | [Amplitudes](#data-amp) | REQUIRED. List. Data are either [spherical coordinates (directions only)](#data-spherical) or [3-vectors](#data-3vector) with unit norm. Defines the dense directional basis set on which samples of a spherical function within each voxel are provided. | -| `FillValue` | [Spherical coordinates](#data-spherical), [3-vectors](#data-3vector) | OPTIONAL. Float; allowed values: { 0.0, NaN }. Value stored in image when number of discrete orientations in a voxel is fewer than the maximal number for that image. | -| `OrientationRepresentation` | All except [scalar](#data-scalar) | REQUIRED. String; allowed values: { `dec`, `unitspherical`, `spherical`, `unit3vector`, `3vector`, `sh`, `amp`, `pdf`, `param` }. The [data representation](#data-representations) used to encode orientation information within the NIfTI image. | -| `ReferenceAxes` | All except [scalar](#data-scalar) | REQUIRED. String; allowed values: { `ijk`, `xyz` }. Indicates whether the NIfTI image axes, or scanner-space axes, are used as reference axes for orientation information. | -| `SphericalHarmonicBasis` | [Spherical harmonics](#data-sh) | REQUIRED. String; allowed values: { `MRtrix3` }. Basis by which to define the interpretation of image values across volumes as spherical harmonics coefficients. | -| `SphericalHarmonicDegree` | [Spherical harmonics](#data-sh) | REQUIRED. Integer. Maximal degree of the spherical harmonic basis employed. | +| **Key name** | **Relevant [data representations](#data-representations)** | **Description** | +| --------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | +| `AntipodalSymmetry` | [Spherical coordinates](#data-spherical), [3-vectors](#data-3vector), [spherical harmonics](#data-sh), [amplitudes](#data-amp), [parameter vectors](#data-param) | OPTIONAL. Boolean. Indicates whether orientation information should be interpreted as being antipodally symmetric. Assumed to be True if omitted. | +| `Directions` | [Amplitudes](#data-amp) | REQUIRED. List. Data are either [spherical coordinates (directions only)](#data-spherical) or [3-vectors](#data-3vector) with unit norm. Defines the dense directional basis set on which samples of a spherical function within each voxel are provided. | +| `FillValue` | [Spherical coordinates](#data-spherical), [3-vectors](#data-3vector) | OPTIONAL. Float; allowed values: { 0.0, NaN }. Value stored in image when number of discrete orientations in a voxel is fewer than the maximal number for that image. | +| `OrientationRepresentation` | All except [scalar](#data-scalar) | REQUIRED. String; allowed values: { `dec`, `unitspherical`, `spherical`, `unit3vector`, `3vector`, `sh`, `amp`, `param` }. The [data representation](#data-representations) used to encode orientation information within the NIfTI image. | +| `ReferenceAxes` | All except [scalar](#data-scalar) | REQUIRED. String; allowed values: { `ijk`, `xyz` }. Indicates whether the NIfTI image axes, or scanner-space axes, are used as reference axes for orientation information. | +| `SphericalHarmonicBasis` | [Spherical harmonics](#data-sh) | REQUIRED. String; allowed values: { `MRtrix3` }. Basis by which to define the interpretation of image values across volumes as spherical harmonics coefficients. | +| `SphericalHarmonicDegree` | [Spherical harmonics](#data-sh) | REQUIRED. Integer. Maximal degree of the spherical harmonic basis employed. | If `AntipodalSymmetry` is True, then no constraints are imposed with respect to the domain on the 2-sphere in which orientations may be specified;