Fig. 2.

(a) Radially resolved speckle decorrelation time constant τ(ρ) is polled versus distance ρ from the source. The inflection distance ρ′ is shown in the polt. At distances less than ρ′, most photons will only have traversed the fibrous cap and the decorrelation times will be higher. In contrast, at distances greater than ρ′, the majority of photons will have propagated through the necrotic core and the decorrelation time will be shorter. (b) Schematic of photon propagtion through two-layer model demonstrating the approximate location of ρ′ and z_max (ρ′).