tedana.model.combine

Functions to optimally combine data across echoes.

Functions

make_optcom(data, t2s, tes, mask, combmode) Optimally combine BOLD data across TEs.
make_optcom(data, t2s, tes, mask, combmode, verbose=True)[source]

Optimally combine BOLD data across TEs.

Parameters:
  • data ((S x E x T) numpy.ndarray) – Concatenated BOLD data.
  • t2 ((S,) numpy.ndarray) – Estimated T2* values.
  • tes (numpy.ndarray) – Array of TEs, in seconds.
  • mask ((S,) numpy.ndarray) – Brain mask in 3D array.
  • combmode (str) – How to combine data. Either ‘ste’ or ‘t2s’.
  • verbose (bool, optional) – Whether to print status updates
Returns:

combined – Optimally combined data.

Return type:

(S x T) numpy.ndarray

Notes

  1. Estimate voxel- and TE-specific weights based on estimated T_2^*:

    w(T_2^*)_n = \frac{TE_n * exp(\frac{-TE}                {T_{2(est)}^*})}{\sum TE_n * exp(\frac{-TE}{T_{2(est)}^*})}

  2. Perform weighted average per voxel and TR across TEs based on weights estimated in the previous step.