Figure 7.

Multispectral photoacoustic (PA) imaging of prostate. PA images are acquired at multiple laser wavelengths. Each wavelength image is a composite image of all the tissue constituents such as deoxy-hemoglobin (dHb), oxy-hemoglobin (HbO₂), lipid and water. Chromophore analysis was performed to extract PA images showing absorption of individual constituents from the multi-wavelength images. All the PA images are co-registered with histopathology and photograph of the gross specimen. (a) Photograph of gross prostate specimen (b) Histopathology of prostate with malignant region encircled. (c) Composite PA image acquired at 760 nm wavelength (d) Composite PA image acquired at 850 nm wavelength (e) PA image showing absorption of dHb (f) PA image showing absorption of HbO2. Higher absorption of dHb was seen in the region of interest corresponding to malignant prostate tissue compared to HbO₂.