Digital Histology of Breast Tumours
By trading-off on acquisition speed, the scanner we developed for our intra-operative study of wide local excisions in breast conserving surgery can also be used to perform digital histology with much higher resolution and detail definition. This is because the pre-sample mask placed before the sample to make the system sensitive to phase effects redefines the resolution properties of the system: with a proper acquisition scheme where the sample is laterally displaced at every projection angle as well as rotated, a final resolution equal to the size of the apertures in the pre-sample mask can be achieved, practically allowing a “user-defined” resolution. Application of this approach to tumour-bearing breast specimens revealed a wealth of previously undetectable details – notably necrosis and tissue response to chemotherapy, alongside much finer tumour strands. Notably this can be performed with exactly the same machine, simply by swapping masks and setting up a slightly different acquisition sequence.
Detail of a breast tumour images with the high resolution, high sensitivity phase scanner (a) and direct comparison to the histology gold standard (b). The yellow arrows point at (reduced-density) regions where the tissue responded to chemotherapy, and the red one at a residual infiltrating ductal carcinoma nodule.