Module constants 

Physical constants (gyromagnetic ratio). Physical constants shared across the crate.

Use these wherever QSM.rs converts between radians, Hz and ppm itself, and wherever a host converts QSM.rs’s outputs (e.g. ppm → Hz for a BIDS fieldmap), so both agree.

Ported methods that hard-code a different value in their authors’ code (DECOMPOSE’s 42.58, TGV-QSM’s 42.5781, HEIDI’s 2.67522128e8 rad/s/T, QSMART’s 2.675e8, …) keep that value locally, so the port matches the reference. Those sites say so; do not point them here.

Constants

GAMMA_BAR_HZ_PER_T

Proton reduced gyromagnetic ratio γ̄ = γ/2π, in Hz/T.

GAMMA_BAR_MHZ_PER_T

GAMMA_BAR_HZ_PER_T in MHz/T, for formulas written as 2π · γ̄[MHz/T] · B0 · TE (ppm → rad).

GAMMA_RAD_PER_S_PER_T

Proton gyromagnetic ratio γ = 2π·γ̄, in rad/s/T.