We describe a new mid-infrared (mid-IR) imaging method specifically designed to augment the H + E tissue staining protocol. Images are taken with bespoke IR filters at wavelengths that enable chemical maps to be generated, corresponding to the cytoplasmic (amide) and nuclear (phosphodiester) components of unstained oesophageal tissue sections. A suitably calibrated combination of these generates false colour computer images that reproduce not only the tissue morphology, but also accurate and quantitative distributions of the nuclear-to-cytoplasmic ratio throughout the tissue section. This parameter is a well documented marker of malignancy, and because the images can be taken and interpreted by clinically trained personnel in a few seconds, we believe this new "digistain" approach makes spectroscopic mid-IR imaging techniques available for the first time as a practical, specific and sensitive augmentation to standard clinical cancer diagnosis methods.

Abstract-This paper presents a diagnosis method for articular cartilage damage using polarization-sensitive optical coherence tomography (PS-OCT). Through signal analysis, the optical characteristics of intact cartilage and different types of mild lesions within cartilages can be quantified from measures such as the scattering coefficient (μ s ), effective anisotropy factor (g eff ), and birefringence coefficient (Δn). Our preliminary investigation using porcine articular cartilage indicated that both subsurface morphological changes and apparent variations in optical properties, which may be the early signs of cartilage degeneration, were found in three types of diseased cartilages.

In this study, we evaluated the effectiveness of using swept-source optical coherence tomography (SS-OCT) to monitor the enhancement of hepatocellular carcinoma (HCC) cell invasiveness by radiation. SS-OCT images were acquired and recorded to obtain three-dimensional datasets at discrete time points of 12, 24 and 48 h after irradiating HepG2 cells with 7.5 Gy. The cell migration distance in three-dimensional tissue models was quantified from images of radiation-induced and sham-irradiated cells, and this method was compared with the conventional Boyden chamber assay conducted at the same time points. SS-OCT measurements show that most cells were found near the gel surface, but a few were much deeper. Among those HCC cells with a high degree of migration capability, the mean migration distances at 24 h and 48 h were significantly greater for irradiated cells than for sham-irradiated cells (0.7 +/- 0.23 mm versus 0.65 +/- 0.26 mm at 24 h, P = 0.019 and 0.84 +/- 0.30 mm versus 0.65 +/- 0.524 mm at 48 h, P = 0.009). The results of radiation-enhanced invasion in HCC cells obtained by the non-invasive, quantitative SS-OCT method were consistent with those obtained using the traditional assay for measuring biological invasion.