Infrared spectroscopic imaging: A case study for digital molecular histopathology

The application of infrared (IR) spectroscopy to the systematic analysis of biological materials has been ongoing for more than 125 years. Recent technological developments and detailed theoretical understanding have resulted especially in instrumentation for imaging that has transformed analytical performance and enhanced the ability to extract useful information in shorter time frames. We provide an overview of IR spectroscopic imaging, with a focus on Fourier transform IR spectral acquisition, and practical aspects of making measurements for biomedical applications. The core aspects of the science of IR imaging and its subsequent use for histologic analysis are described. We discuss in-depth data acquisition, considerations for spectral fidelity, and spatial measures of performance that are important for biomedical analysis pipelines. The application of this technology and its potential is illustrated with a case study of application to extant problems in breast cancer pathology. Finally, a perspective on the emerging areas of progress for the technology is presented.