Basic Research
Copyright ©2007 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Apr 21, 2007; 13(15): 2160-2165
Published online Apr 21, 2007. doi: 10.3748/wjg.v13.i15.2160
In vivo subsurface morphological and functional cellular and subcellular imaging of the gastrointestinal tract with confocal mini-microscopy
Martin Goetz, Beena Memadathil, Stefan Biesterfeld, Constantin Schneider, Sebastian Gregor, Peter R Galle, Markus F Neurath, Ralf Kiesslich
Martin Goetz, Beena Memadathil, Constantin Schneider, Sebastian Gregor, Peter R Galle, Markus F Neurath, Ralf Kiesslich, I. Medical Clinic, Johannes Gutenberg-Universität, Mainz, Germany
Stefan Biesterfeld, Department of Pathology, Johannes Gutenberg-Universität, Mainz, Germany
Author contributions: All authors contributed equally to the work.
Supported by Group for Minimal-invasive Chirurgie, Johannes Gutenberg-Universität, Mainz, Germany
Correspondence to: Dr. Martin Goetz, I. Medical Clinic, Johannes Gutenberg-Universität, Mainz 55131, Germany. mgoetz@mail.uni-mainz.de
Telephone: +49-6131-171 Fax: +49-6131-17-5552
Received: December 15, 2006
Revised: December 26, 2006
Accepted: January 26, 2007
Published online: April 21, 2007
Abstract

AIM: To evaluate a newly developed hand-held confocal probe for in vivo microscopic imaging of the complete gastrointestinal tract in rodents.

METHODS: A novel rigid confocal probe (diameter 7 mm) was designed with optical features similar to the flexible endomicroscopy system for use in humans using a 488 nm single line laser for fluorophore excitation. Light emission was detected at 505 to 750 nm. The field of view was 475 μm × 475 μm. Optical slice thickness was 7 μm with a lateral resolution of 0.7 μm. Subsurface serial images at different depths (surface to 250 μm) were generated in real time at 1024 × 1024 pixels (0.8 frames/s) by placing the probe onto the tissue in gentle, stable contact. Tissue specimens were sampled for histopathological correlation.

RESULTS: The esophagus, stomach, small and large intestine and meso, liver, pancreas and gall bladder were visualised in vivo at high resolution in n = 48 mice. Real time microscopic imaging with the confocal mini-microscopy probe was easy to achieve. The different staining protocols (fluorescein, acriflavine, FITC-labelled dextran and L. esculentum lectin) each highlighted specific aspects of the tissue, and in vivo imaging correlated excellently with conventional histology. In vivo blood flow monitoring added a functional quality to morphologic imaging.

CONCLUSION: Confocal microscopy is feasible in vivo allowing the visualisation of the complete GI tract at high resolution even of subsurface tissue structures. The new confocal probe design evaluated in this study is compatible with laparoscopy and significantly expands the field of possible applications to intra-abdominal organs. It allows immediate testing of new in vivo staining and application options and therefore permits rapid transfer from animal studies to clinical use in patients.

Keywords: Confocal microscopy; in vivo imaging; Endomicroscopy; Fluorescence