title: High definition infrared spectroscopic imaging for lymph node histopathology.
abstract: Chemical imaging is a rapidly emerging field in which molecular information within samples can be used to predict biological function and recognize disease without the use of stains or manual identification. In Fourier transform infrared (FT-IR) spectroscopic imaging, molecular absorption contrast provides a large signal relative to noise. Due to the long mid-IR wavelengths and sub-optimal instrument design, however, pixel sizes have historically been much larger than cells. This limits both the accuracy of the technique in identifying small regions, as well as the ability to visualize single cells. Here we obtain data with micron-sized sampling using a tabletop FT-IR instrument, and demonstrate that the high-definition (HD) data lead to accurate identification of multiple cells in lymph nodes that was not previously possible. Highly accurate recognition of eight distinct classes - naïve and memory B cells, T cells, erythrocytes, connective tissue, fibrovascular network, smooth muscle, and light and dark zone activated B cells was achieved in healthy, reactive, and malignant lymph node biopsies using a random forest classifier. The results demonstrate that cells currently identifiable only through immunohistochemical stains and cumbersome manual recognition of optical microscopy images can now be distinguished to a similar level through a single IR spectroscopic image from a lymph node biopsy.
authors.affiliation: Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America; Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America.
authors.forename: L Suzanne
authors.initials: LS
authors.lastname: Leslie
authors.affiliation: Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America.
authors.forename: Tomasz P
authors.initials: TP
authors.lastname: Wrobel
authors.affiliation: Department of Electrical and Computer Engineering, University of Houston, Houston, Texas, United States America.
authors.forename: David
authors.initials: D
authors.lastname: Mayerich
authors.affiliation: Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America.
authors.forename: Snehal
authors.initials: S
authors.lastname: Bindra
authors.affiliation: Department of Pathology, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Rajyasree
authors.initials: R
authors.lastname: Emmadi
authors.affiliation: Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America; Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America; Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Illinois, United States of America; Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Illinois, United States of America; Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Illinois, United States of America; Department of Chemistry, University of Illinois at Urbana-Champaign, Illinois, United States of America.
authors.forename: Rohit
authors.initials: R
authors.lastname: Bhargava
mesh_terms: D000328:Adult; D000368:Aged; D001402:B-Lymphocytes / Q000473:pathology*; D004912:Erythrocytes / Q000473:pathology*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008875:Middle Aged; D057054:Molecular Imaging / Q000295:instrumentation / Q000379:methods; D009369:Neoplasms / Q000473:pathology*; D021701:Sentinel Lymph Node Biopsy; D017550:Spectroscopy, Fourier Transform Infrared; D013601:T-Lymphocytes / Q000473:pathology*