Module smv 

Simple Spherical Mean Value (SMV) background field removal

Basic SMV filtering: subtracts the spherical mean of the field. Simpler than SHARP (no deconvolution step).

local_field = field - SMV(field)

Reference pipeline

Not offered as a pipeline background removal. In the MEDI toolbox the same high-pass is applied inside MEDI_L1 with 'smv', radius (radius 5 mm by default, parse_QSM_input.m:13), together with the SMV-filtered dipole kernel (1 − S)·D and the mask eroded to where the SMV of the mask exceeds 0.999 (MEDI_L1.m:57-67), and on the PDF local field, not the total field (MEDI README.m:124,144). That is MediParams::smv, not this function.

Reference: Schweser, F., Deistung, A., Lehr, B.W., Reichenbach, J.R. (2011). “Quantitative imaging of intrinsic magnetic tissue properties using MRI signal phase.” NeuroImage, 54(4):2789-2807. https://doi.org/10.1016/j.neuroimage.2010.10.070

Reference implementation: https://github.com/kamesy/QSM.jl

Functions

smv

Simple SMV background field removal