title: Raman spectroscopy in the diagnosis of ulcerative colitis.
abstract: BACKGROUND
  At present, the diagnosis of ulcerative colitis (UC) requires the histologic demonstration of characteristic mucosal inflammatory changes. A rapid and noninvasive diagnosis would be of value, especially if it could be adapted to a simple rectal probe. Raman spectroscopy creates a molecular fingerprint of substances by detecting laser light scattered from asymmetric, vibrating, and chemical bonds. We hypothesize that Raman spectroscopy can distinguish UC from non-UC colon tissue rapidly and accurately.
  
  
  METHODS
  Colon tissue specimens were obtained from patients operated at the Children's Hospital of Michigan, United States, including UC colon and non-UC colon. The samples were examined with a Renishaw inVia Raman microscope (Gloucestershire, United Kingdom) with a 785 nm laser. Principal component analysis and discriminant function analysis were used to classify groups. Final classification was evaluated against histologic diagnoses using leave-one-out cross-validation at a spectral level.
  
  
  RESULTS
  We compared Raman spectroscopy examination of colon specimens from four patients with UC and four patients without UC. A total of 801 spectra were recorded from colon specimens. We evaluated 100 spectra each from the mucosal and serosal surfaces of patients with UC and 260 spectra from the mucosal surface and 341 spectra from the serosal surface of the patients who did not have UC. For samples from the mucosal surface, the Raman analysis had a sensitivity of 82% and a specificity of 89%. For samples from the serosal surface, Raman spectroscopy had a sensitivity of 87% and a specificity of 93%. When considering each tissue sample and deciding the diagnosis based on the majority of spectra from that sample, there were no errors in the diagnosis.
  
  
  CONCLUSIONS
  Raman spectroscopy can distinguish UC from normal colon tissue rapidly and accurately. This technology offers the possibility of real-time diagnosis as well as the ability to study changes in UC-afflicted colon tissue that do not appear histologically.
authors.affiliation: Department of Pediatric Surgery, Children's Hospital of Michigan, Detroit, Michigan, United States.
authors.forename: Michelle Anne
authors.initials: MA
authors.lastname: Veenstra
authors.affiliation: Department of Electrical and Computer Engineering, Wayne State University, Detroit, Michigan, United States.
authors.forename: Olena
authors.initials: O
authors.lastname: Palyvoda
authors.affiliation: Department of General Surgery, Wayne State University, Detroit, Michigan, United States.
authors.forename: Hazem
authors.initials: H
authors.lastname: Alahwal
authors.affiliation: Department of General Surgery, Wayne State University, Detroit, Michigan, United States.
authors.forename: Marko
authors.initials: M
authors.lastname: Jovanovski
authors.affiliation: Department of Electrical and Computer Engineering, Wayne State University, Detroit, Michigan, United States.
authors.forename: Luke Anthony
authors.initials: LA
authors.lastname: Reisner
authors.affiliation: Department of Pediatric Surgery, Children's Hospital of Michigan, Detroit, Michigan, United States.
authors.forename: Brady
authors.initials: B
authors.lastname: King
authors.affiliation: Department of Pathology, Children's Hospital of Michigan, Detroit, Michigan, United States.
authors.forename: Janet
authors.initials: J
authors.lastname: Poulik
authors.affiliation: Department of Pediatric Surgery, Children's Hospital of Michigan, Detroit, Michigan, United States.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Klein
mesh_terms: D016022:Case-Control Studies; D002648:Child; D003093:Colitis, Ulcerative / Q000175:diagnosis* / Q000473:pathology; D003106:Colon / Q000473:pathology; D016002:Discriminant Analysis; D006801:Humans; D066298:In Vitro Techniques; D025341:Principal Component Analysis; D012680:Sensitivity and Specificity; D013059:Spectrum Analysis, Raman