mri.operators.fourier.orc_wrapper

This modules contains classes for Off-Resonance Correction (ORC)

Author

Guillaume Daval-Frérot <guillaume.davalfrerot@cea.fr>

class ORCFFTWrapper(fourier_op, field_map, time_vec, mask, coefficients='svd', weights='full', num_interpolators='auto', n_bins='auto')

Bases: mri.operators.base.OperatorBase

Off-Resonance Correction FFT Wrapper

This class is used to wrap any Fourier operator and change it into an off-resonance correction multi-linear operator using the method described in :cite: sutton2003 with different choices of coefficients described in :cite: fessler2005.

op(x, *args)

This method calculates a distorded masked Fourier transform of a N-D volume.

Parameters

x (numpy.ndarray) – input N-D array with the same shape as fourier_op.shape

Returns

Return type

masked distorded Fourier transform of the input volume

adj_op(x, *args)

This method calculates an inverse masked Fourier transform of a distorded N-D k-space.

Parameters

x (numpy.ndarray) – masked distorded N-D k-space

Returns

Return type

inverse Fourier transform of the distorded input k-space.