a) applying a 180° RF pulse to the sample, thereby yielding an inverted longitudinal magnetization M_z=−M₀ away from equilibrium;

b) during a selected inversion recovery time τ₁, allowing M_z to recover towards an equilibrium value of M_z=M₀ governed by a time constant T₁;

c) after the selected inversion recovery time τ₁, applying a 90° RF pulse for rotating the instantaneous M_z into a transverse plane M_x,y;

d) at a selected pulse-separation time τ_S, applying a second 90° RF pulse for rotating M_x,y within the transverse plane, creating observable magnetization by formation of a solid-echo;

e) sampling with discretized time steps the observable solid-echo magnetization during a time t following the applying of the second 90° RF pulse to acquire signal amplitude measurements as the observable transverse magnetization decays toward equilibrium with magnetization M_x,y=0, wherein, during the time t, a decay time constant is T*_2G;

f) repeating at least once, responsively to a recovery of the sample substantially to equilibrium, steps (a) to (e) with a different selected recovery time τ₁ in step (c); and

g) processing the solid-echo measurements to produce a T₁-T*_2G map for use in characterizing the sample, wherein the characterizing includes at least one of determining a structure and determining a plurality of components.