Moving beyond color: The case for multispectral imaging in brightfield pathology

Abstract

A multispectral camera is capable of imaging a histologic slide at narrow bandwidths over the range of the visible spectrum. While several uses for multispectral imaging (MSI) have been demonstrated in pathology [1,2], there is no unified consensus over when and how MSI might benefit automated analysis [3,4]. In this work, we use a linear-algebra framework to investigate the relationship between the spectral image and its standard-image counterpart. The multispectral "cube" is treated as an extension of a traditional image in a high-dimensional color space. The concept of metamers is introduced and used to derive regions of the visible spectrum where MSI may provide an advantage. Furthermore, histological stains which are amenable to analysis by MSI are reported. We show the Commission internationale de l'éclairage (CIE) 1931 transformation from spectrum to color is nonneighborhood preserving. Empirical results are demonstrated on multispectral images of peripheral blood smears.

Automated Image Interpretation Computer-Assisted Diagnostics

“…Figure 13 (data courtesy of [113]) shows the plots for some routine stains. Our preliminary feasibility studies indicate that those stains which absorb heavily in regions where the colormatching coefficients are small are most likely to benefit from MSI technology, however, this line of thought warrants closer examination [119,120]. In the next phase of our experiments we will investigate the use of metamers for objectively determining those applications for which MSI would be most appropriate and test and optimize those metrics for the full range of specimens and stains under study.…”

A Practical Guide to Whole Slide Imaging: A White Paper From the Digital Pathology Association

“…This is often considered a superior option over standard broadband acquisition paradigms that combine chromatic information into a single representation (eg, RGB) where the chromatic information cannot be recovered. Multispectral imaging can therefore disentangle the complex chromatic attributes of stained tissue, with the potential to support multi-labeling studies, [73][74][75][76][77] improve color-based classification, 78 and provide more detailed chromatic information that may carry its own inherent prognostic significance. [79][80][81] Implementing multispectral imaging in WSI is difficult because it typically requires collecting and storing images at each wavelength examined, which results in much longer scan times and much larger file sizes.…”

Digital staining for histopathology multispectral images by the combined application of spectral enhancement and spectral transformation

“…With such imaging system it is possible to capture salient image features that are indistinguishable with human eyes [1][2][3][4][5][6]. In [3] the concept of digital staining using multispectral information was introduced.…”