Spectral Pathology: general discussion

Abstract

Parvez Haris opened the discussion of the introductory lecture by Max Diem: Varying degrees of accuracy have been obtained for discrimination between cancerous and non-cancerous tissues using vibrational spectroscopic methods. What are the explanations for these variations in accuracy between cancerous and non-cancerous tissues and how do they correlate with accuracy from other techniques including histopathology? It was reported that changes in a specic protein (PDL-1) in tissue sections were detected by FTIR spectroscopic imaging, to compare cancerous with non-cancerous tissues. This is very interesting but needs to be proven with additional data as peaks in the spectra of complex tissue samples could arise from not only chemical differences but physical differences associated with changes in tissue stiffness, dynamics etc. Therefore, combining histopathology, proteomics, metabolomics and ultrasound elastography with vibrational spectroscopic imaging could pave the way for a better understanding of the changes associated with cancer and could also improve our understanding of the vibrational spectra of cells and tissues. Basic studies on understanding the factors inuencing spectral changes in tissues need to be better understood for the technique to be widely accepted as a tool for cancer diagnosis.Rohit Bhargava replied: Variations in accuracy arise from at least the following factors:1. Measurement noise, unless it is reduced to a level where it does not affect classication (see ref. 1).2. Population variance, person to person variance, tumor heterogeneity and clinic-to-clinic variations that likely arise from sample processing. For a complete discussion of all factors see ref. 2.3. Shortcomings in the design of experiments, especially in assessing condence intervals as related to sample sizes (see the article by Pounder, Reddy and This journal is

Metasurface‐Enhanced Mid‐Infrared Spectrochemical Imaging of Tissues

“…Due to the difficulties associated with the biochemical interpretation of individual vibrational bands in congested MIR spectra from complex biological samples, the spectral data are traditionally processed as a fingerprint and analyzed using bioinformatic tools. [ 19 ] Therefore, resolving vibrational resonances is critical for chemometric applications to enrich fingerprint data and increase chemical selectivity. To demonstrate the strong fingerprinting capabilities of the SE‐MIRSI approach, we performed band assignment analyses on the SE‐MIRSI spectra and compared our findings with standard MIRSI.…”

“…[16][17][18] Thus, to unleash the full potential of MIRSI as an effective chemical tissue imaging method, there is an unmet need for new measurement modalities to mitigate chemical versus morphological ambiguity and address spectral congestion in heterogeneous samples. [19] Recently, harnessing light via nanoengineered materials has enabled light confinement beyond the diffraction limit of conventional optical imaging. [20][21][22] Specifically, resonant electromagnetic metasurfaces can generate exceptional field confinement within ultrathin volumes and thus can enhance light-matter interactions in optical spectroscopies.…”

“…[ 16–18 ] Thus, to unleash the full potential of MIRSI as an effective chemical tissue imaging method, there is an unmet need for new measurement modalities to mitigate chemical versus morphological ambiguity and address spectral congestion in heterogeneous samples. [ 19 ]…”

Infrared Spectroscopic Imaging Advances as an Analytical Technology for Biomedical Sciences

“…A large majority of applications are in the biomedical domain, and we especially focus on describing several interesting directions of the same. An exceptional collection of studies on different applications, some underlying technology, − and lively integrated discussions − has been published as part of a report on a Faraday Discussions meeting. Recent reviews, as mentioned previously, in biomedical sciences, plants, polymers, and forensics remain relevant.…”