Novel endoscopic imaging techniques toward in vivo observation of living cancer cells in the gastrointestinal tract

Clinical usefulness of endocytoscopy in the remission stage of ulcerative colitis: a pilot study

BACKGROUND

Histopathology can be used to detect ulcerative colitis (UC) relapse, but diagnosis of the disease activity by histopathology requires multiple biopsies to be taken. Magnifying endocytoscopy provides a method for real-time ultra-magnifying imaging. It was recently reported that the endocytoscopy system score (ECSS) correlates well with the histopathology of UC. Here we evaluated the clinical usefulness of endocytoscopy for accurately monitoring UC during remission.

METHODS

We performed endocytoscopy on 26 patients with UC in remission that had been diagnosed by conventional colonoscopy at our institution between January and April 2013. Endocytoscopy was performed at the area of the rectum where UC had been detected with conventional endoscopy. Biopsies were also taken from the same area and histopathology was evaluated by a single pathologist according to the Matts' grading system. The correlation between the relapse rate of UC and both the ECSS and the Matts' histopathological grade was evaluated.

RESULTS

The ECSS of the intestinal mucosa in UC showed a correlation with the Matts' histopathological grade (Spearman's |r| = 0.647). The patients were classified into two groups: those with an ECSS of 0-2 (Grade A, 12 cases) and those with an ECSS of 3-6 (Grade B, 10 cases). To date, three Grade B cases have relapsed and no Grade A cases have relapsed. The average post-endocytoscopy surveillance period was 446 ± 92 days.

CONCLUSIONS

The ECSS may be a predictive indicator for UC relapse since there was a correlation between the ECSS and the degree of inflammation as determined by histopathology.

Bronchoscopic observation of endobronchial tumor cells

A 68-year-old woman presented with cough and dyspnea. Chest x-ray film and computed tomography revealed atelectasis in the right upper lobe. She had a history of a bladder neoplasm, which was treated by cystectomy and chemotherapy. Flexible bronchoscopy revealed a polypoid tumor in the right upper lobe bronchus, protruding into the right main bronchus. Further, we observed the surface of the tumor by using the endocytoscopy system. The endocytoscopy system showed oval-shaped tumor cells with prominent nuclei on the surface of the tumor with a methylene blue dye staining. Biopsied specimen of the tumor demonstrated foci of metastatic urothelial carcinoma. These cancer cells were similar to the cell images of endocytoscopy system. This technology may have the potential to provide pathologic diagnosis during bronchoscopy.

Towards modeling of cardiac micro-structure with catheter-based confocal microscopy: a novel approach for dye delivery and tissue characterization

This work presents a methodology for modeling of cardiac tissue micro-structure. The approach is based on catheter-based confocal imaging systems, which are emerging as tools for diagnosis in various clinical disciplines. A limitation of these systems is that a fluorescent marker must be available in sufficient concentration in the imaged region. We introduce a novel method for the local delivery of fluorescent markers to cardiac tissue based on a hydro-gel carrier brought into contact with the tissue surface. The method was tested with living rabbit cardiac tissue and applied to acquire three-dimensional image stacks with a standard inverted confocal microscope and two-dimensional images with a catheter-based confocal microscope. We processed these image stacks to obtain spatial models and quantitative data on tissue microstructure. Volumes of atrial and ventricular myocytes were 4901 +/- 1713 and 10 299 +/-3598 mum (3) (mean+/-sd), respectively. Atrial and ventricular myocyte volume fractions were 72.4 +/-4.7% and 79.7 +/- 2.9% (mean +/-sd), respectively. Atrial and ventricular myocyte density was 165 571 +/- 55 836 and 86 957 +/- 32 280 cells/mm (3) (mean+/-sd), respectively. These statistical data and spatial descriptions of tissue microstructure provide important input for modeling studies of cardiac tissue function. We propose that the described methodology can also be used to characterize diseased tissue and allows for personalized modeling of cardiac tissue.

Quo vadis: another new colonoscope

In the past few years, several groups of investigators have developed colonoscopic instruments or accessories to speed up the examination and make it more tolerable for patients. The NeoGuide Endoscopy System has the computer processing ability to direct each 8-cm segment of its colonoscope to bend at the exact place where the leading segment turned around a corner. This follow-the-leader system is intended to reduce loops and ensure comfort through preventing excess pressure on the colon wall by making a turn without the usual maneuver of pushing on the wall to advance the scope.

Ex vivo visualization of Helicobacter pylori using an endocytoscopic probe

Observation of microorganisms by endoscopy has been technically difficult. In this study, we tried to visualize bacteria during endoscopic examination to provide a powerful tool for a diagnosis of gastrointestinal infection. We observed the bacterium Helicobacter pylori, cultured ex vivo, using a novel ultra-high "magnified endoscopy" system ("endocytoscopy" prototype, Olympus Medical Systems). Cultures were prepared from gastric mucus obtained from three gastric ulcer patients. H. pylori in the supernatant of the culture medium were observed directly by endocytoscopy. Staphylococcus aureus and red blood cells were used as controls. H. pylori in the culture medium were observed directly by endocytoscopy, and recorded using a video recorder. Live, moving bacteria can be visualized and recorded ex vivo using this new "endocytoscopy" technology.

Computer-aided diagnosis of dysplasia in Barrett's esophagus using endoscopic optical coherence tomography

Barrett's esophagus (BE) and associated adenocarcinoma have emerged as a major health care problem over the last two decades. Because of the widespread use of endoscopy, BE is being recognized increasingly in all Western countries. In clinical trials of endoscopic optical coherence tomography (EOCT), we defined certain image features that appear to be characteristic of precancerous (dysplastic) mucosa: decreased scattering and disorganization in the microscopic morphology. The objective of the present work is to develop computer-aided diagnosis (CAD) algorithms that aid the detection of dysplasia in BE. The image dataset used in the present study was derived from a total of 405 EOCT images (13 patients) that were paired with highly correlated histologic sections of corresponding biopsies. Of these, 106 images were included in the study. The CAD algorithm used was based on a standard texture analysis method (center-symmetric auto-correlation). Using histology as the reference standard, this CAD algorithm had a sensitivity of 82%, specificity of 74%, and accuracy of 83%. CAD has the potential to quantify and standardize the diagnosis of dysplasia and allows high throughput image evaluation for EOCT screening applications. With further refinements, CAD could also improve the accuracy of EOCT identification of dysplasia in BE.

Chromoendoscopy and magnifying endoscopy for Barrett's esophagus

Chromoendoscopy and magnification endoscopy are 2 endoscopic techniques used to improve visualization and diagnosis of gastrointestinal mucosa. This article summarizes the principles behind magnification endoscopy, with and without chromoendoscopy, for the diagnosis of Barrett's esophagus, dysplasia, and adenocarcinoma. Furthermore, this article discusses the possible clinical use of magnification endoscopy and chromoendoscopy in evaluating patients with chronic gastroesophageal reflux disease and Barrett's esophagus.