Infrared spectroscopic imaging using focal plane arrays: applications to tissue analysis and histopathology

Infrared imaging spectroscopy has been used to investigate several biological systems. The imaging instrument is comprised of IR sensitive array detectors coupled with a step-scan interferometer and microscope. Each pixel on the array simultaneously measures an IR spectrum in frequency ranges that depend only on the type of array employed. As image contrast is provided solely by spatial variations in a sample's intrinsic chemistry, this technique enables researchers and clinicians to visualize a sample directly in terms of its chemical heterogeneities. We illustrate the capability and versatility of this technique for readily and non-invasively visualizing chemical complexity and for providing statistical data on sample heterogeneity. FT-IR spectroscopic imaging provides the means to better understand the molecular composition and architecture of biological materials, as well the ability to probe the biochemistry of diseased tissue states.