Figure 4: Birefringence imaging of excised breast tumour sample exhibiting patches of low birefringence that are surrounded by regions of higher birefringence.

(a) Volume rendering of structural intensity signal (I) and (b) overlay of birefringence and structural signal (I,Δn). (c) Longitudinal cross-section (radial distance from needle versus pullback) of structural intensity signal (I) and (d) corresponding overlay (I,Δn), indicated in (a,b) by dashed lines. Scale bars are 500 μm, assuming a refractive index of tissue of n = 1.36. Colour range indicates birefringence of 0.18 × 10−3–2.2 × 10−3 and regions with a depolarization index <0.3 are displayed in greyscale only. Brightness range is −10–40 dB.