Table 1.

Parameter definitions

Parameter	Description
ρ (cm)	radial distance from source
Ω (sr)	camera acceptance angle
$E \left(\frac{mW}{{cm}^2}\right)$	irradiance at the excitation wavelength λx
zs (cm)	Distance between the phantom surface and the top of the fluorescent inclusion. Subscript s indicates one unknown depth
${\phi }_x \left(\frac{mW}{{cm}^2}\right)$	excitation fluence rate at zs
S (cm−1)	product of the fluorophore absorption coefficient and fluorescence quantum yield
Σm	fluorescence emission escaping at the surface at a radial distance ρ from the point source at zs
$C \left(\frac{\mu g}{ml}\right)$	fluorophore concentration
λx and λm (nm)	excitation and emission wavelengths
fx (mm−1)	spatial frequency
Mf (x,y,fx)z	fluorescence modulation amplitude at fx and for a given depth z
$I_0 (mW.sr.\frac{nm}{{cm}^2})$	source intensity
MTFsystem (x,y,fx)z	system total modulation transfer function at fx and z
Fm (x,y,fx)z	predicted spatially-resolved diffuse fluorescence in the spatial frequency domain for a source at depth z