Vital-dye enhanced fluorescence imaging of GI mucosa: metaplasia, neoplasia, inflammation

Gastrointest Endosc. 2012 Apr;75(4):877-87. doi: 10.1016/j.gie.2011.10.004. Epub 2012 Jan 31.


Background: Confocal endomicroscopy has revolutionized endoscopy by offering subcellular images of the GI epithelium; however, the field of view is limited. Multiscale endoscopy platforms that use widefield imaging are needed to better direct the placement of high-resolution probes.

Design: Feasibility study.

Objective: This study evaluated the feasibility of a single agent, proflavine hemisulfate, as a contrast medium during both widefield and high-resolution imaging to characterize the morphologic changes associated with a variety of GI conditions.

Setting: The University of Texas MD Anderson Cancer Center, Houston, Texas, and Mount Sinai Medical Center, New York, New York. PATIENTS, INTERVENTIONS, AND MAIN OUTCOME MEASUREMENTS: Resected specimens were obtained from 15 patients undergoing EMR, esophagectomy, or colectomy. Proflavine hemisulfate, a vital fluorescent dye, was applied topically. The specimens were imaged with a widefield multispectral microscope and a high-resolution microendoscope. The images were compared with histopathologic examination.

Results: Widefield fluorescence imaging enhanced visualization of morphology, including the presence and spatial distribution of glands, glandular distortion, atrophy, and crowding. High-resolution imaging of widefield abnormal areas revealed that neoplastic progression corresponded to glandular heterogeneity and nuclear crowding in dysplasia, with glandular effacement in carcinoma. These widefield and high-resolution image features correlated well with the histopathologic features.

Limitations: This imaging approach must be validated in vivo with a larger sample size.

Conclusions: Multiscale proflavine-enhanced fluorescence imaging can delineate epithelial changes in a variety of GI conditions. Distorted glandular features seen with widefield imaging could serve as a critical bridge to high-resolution probe placement. An endoscopic platform combining the two modalities with a single vital dye may facilitate point-of-care decision making by providing real-time, in vivo diagnoses.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adenocarcinoma / pathology*
  • Colitis, Ulcerative / pathology
  • Colorectal Neoplasms / pathology*
  • Crohn Disease / pathology
  • Esophagus / pathology*
  • Feasibility Studies
  • Fluorescence
  • Fluorescent Dyes*
  • Humans
  • Intestinal Mucosa / pathology
  • Metaplasia / pathology
  • Microscopy / methods*
  • Proflavine*


  • Fluorescent Dyes
  • Proflavine