Key Matlab functions used for making the results in this paper:

@ARTICLE{olafsson:18:fsr,
 author = {V. T. Olafsson and D. C. Noll and J. A. Fessler},
 title = {Fast spatial resolution analysis of quadratic penalized least-squares image reconstruction with separate real and imaginary roughness penalty: application to {MRI}},
 journal = {{IEEE Trans. Med. Imag.}},
 volume = 37,
 number = 2,
 pages = {{604--14}},
 month = feb,
 doi = {10.1109/TMI.2017.2768825},
 year = 2018
}

Requires MIRT
https://github.com/JeffFessler/mirt