Figure 2.

PARS H&E images of unstained tissue in comparison to their standard histopathological preparations. The left column of images outlined in purple was taken with a brightfield microscope from an H&E stained slide requiring multiple steps of processing and staining (example shown at top of column). The right column outlined in orange, was taken with the PARS system from unstained tissue (example shown at the top of column) therefore eliminating the need for sample processing. (a) A conventional bright field H&E image of glioblastoma with solid tumor and microvascular proliferations (red outlines). (b) A rapid acquisition PARS image of the adjacent unstained brain tissue sample, with the region of solid tumoral tissue, and microvascular proliferations (red outlines), as in (a). (c) A standard bright field histopathological H&E image of a glioblastoma sample with a largely necrotic region (blue lines and stars), a thrombotic vessel (purple outline), and a region of solid tumor with microvascular proliferations (red outline). (d) A PARS image acquired in a rapid acquisition mode of the same section of glioblastoma tissue, with the largely necrotic region (blue line and stars) and thrombotic vessel (purple outline), and the solid tumor region with microvascular proliferations (red outline), as in (c). A close-up of tumor cells and microvascular proliferations at the boundary between these regions is shown enclosed in the green boxes. (e) A standard bright field histopathological H&E image of a brain tissue sample with infiltrating tumor cells, adjacent to solid tumor shown in (a)–(d). (f) A PARS multiwavelength simulated H&E image of the same section of brain tissue.