Schematic Description of Fiber Orientation Modeling. In this example, the Gaussian distribution of extracellular fat (panel A) was α = 15° and β = 30°. The chemical shift for each angle was calculated and represented as a Gaussian line with the appropriate amplitude. Panel A also shows a schematic of fiber orientation. Panel B illustrates conversion of orientation, θ, to ppm. Panel C shows a linear axis in ppm plus a subset of the amplitude-scaled individual signals of equal linewidth. These resonances are not equally spaced on the chemical shift axis. The final simulated spectrum, D, is the sum of 91 such resonances.