GS Coil Combine Comparison

Functions to compare coil combination methods.

This actually might belong in the examples, and it needs to be checked to make sure it still works.

mr_utils.coils.gs_comparison.gs_coil_combine_comparison.comparison_knee()

Coil by coil, Walsh method, and Inati iterative method for knee data.

mr_utils.coils.gs_comparison.gs_coil_combine_comparison.comparison_numerical_phantom(SNR=None)

Compare coil by coil, Walsh method, and Inati iterative method.

Parameters:SNR (float) – Signal to noise ratio.

mr_utils.coils.gs_comparison.gs_coil_combine_comparison.get_coil_sensitivity_maps()

Simulate coil sensitivity maps.

Returns:csms – List of coil sensitivity maps (arrays), one for each coil. Return type:list

mr_utils.coils.gs_comparison.gs_coil_combine_comparison.get_numerical_phantom_params(SNR=None)

Preset parameters for a numerical cylindrical phantom.

Parameters:SNR (float) – Signal to noise ratio, calculated: std = avg_signal/SNR. Returns:params – Parameter dictionary including noise_std, dim, pc_vals, and coil_nums fields. Return type:dictionary

mr_utils.coils.gs_comparison.gs_coil_combine_comparison.get_true_im_numerical_phantom()

Get reference bSSFP simulated phantom.

As the geometric solution to the elliptical signal model still has some residual banding, do it a few times at a bunch of different phase cycles to remove virually all banding. This ensures that the contrast will be comparable to the banded phantoms.

Returns:true_im – Banding free reference image with true bSSFP contrast. Return type:array_like

mr_utils.coils.gs_comparison.gs_coil_combine_comparison.ripple(im0)

Calculate % ripple metric using local patches of line.

Parameters:im0 (array_like) – Image to calculate ripple of. Returns:Percent ripple calculated by using local patches along a line through the center of im0 Return type:float

mr_utils.coils.gs_comparison.gs_coil_combine_comparison.ripple_normal(im)

Calculate % ripple metric.

Parameters:im (array_like) – Image to calculate ripple of. Returns:Percent ripple. Return type:float

Notes

A horizontal line is drawn through the center of the image. The percent ripple is calculated along this line.