Electronic Endoscopy Research Articles

Simultaneous analysis of mucosal and submucosal hemodynamics using infrared electronic endoscopy: effects of intraluminal acid on ulcer scars.

This report describes the use of an infrared electronic endoscope for the assessment of gastric mucosal and submucosal hemodynamics in ulcer scars. The experimental ulcer scars were induced by acetic acid injection in five anesthetized dogs. Indices of mucosal hemoglobin content (IHb) and its oxygenation (ISO2) were calculated from reflectance spectra of the mucosa at 569, 577, 586, and 650 nm, which were obtained through an optic probe. The gastric submucosal vascular diameter was assessed by comparison with a reference wire under infrared endoscopic observation. The index of mucosal hemoglobin content measured by reflectance spectrophotometry was significantly higher at the ulcer scars than in the intact mucosa before the ulcer induction. Intraluminal administration of 0.2 N hydrochloric acid lowered IHb and ISO2 only at the ulcer scars. The diameters of the gastric submucosal veins beneath the ulcer scars decreased markedly after the acid administration. The results suggest abnormal responses of gastric mucosal and submucosal circulation at ulcer scars to intraluminal acid. Infrared electronic endoscopy is therefore a useful tool for the simultaneous analysis of mucosal and submucosal circulation in the stomach.

Usefulness of Real‐Time Band Enhancement in Differential Diagnosis of Colorectal Tumors

Abstract: Various forms of image processing have been attempted since the development of the electronic endoscope; band enhancement is an image processing technique designed to accentuate minute surface structures. We observed 161 colorectal tumors with an electronic colonoscope and compared the pit pattern identification rate among ordinary, edge‐enhanced and bandenhanced images. We found that the pit pattern identification rate was significantly higher with band‐enhanced than with other image types. Furthermore, band enhancement was especially useful in the differential diagnosis of small lesions. Accordingly, this technique was considered to be useful for determining endoscopic treatment indications for colorectal tumors.

Magnifying Observation of Ectopic Gastric Mucosa of the Cervical Esophagus

Abstract:We attempted to investigate the fine mucosal patterns of inlet patches using a transparent‐tip‐hood‐fitted magnifying electronic endoscope (Olympus, GIF‐200Z). The prevalence of inlet patch was 10.1%, 26 out of 257 patients undergoing screening endoscopic examination using a GIF‐200Z. This rate was higher than that of previous reports in Japan, higher in the young group than in the aged group, and higher in males than in females. The mean inlet patch size, measured by the new method using a transparent hood, was 5.2 mm. Large inlet patches, above 8.1 mm, were found more frequently in males than in females. The number of inlet patches in one patient was one in 19 patients and two in seven. The inlet patches were oval and had a smooth margin in 23 (69.7%) cases, and irregular in 10 (30.3%). The oval patches with smooth margins were significantly larger than those with an irregular form. The fine mucosal pattern of inlet patches was mixed with B, BC and C type. Inlet patches with acid production were suggested to be fewer in number than expected, and patients with an inlet patch appear to have minimal, if any, complaints. A transparent‐tip‐hood‐fitted magnifying electronic endoscope was thought to facilitate accurate diagnosis of the inlet patch.

An Attempt to Analyze Color Wavelengths with an Electronic Endoscope

Abstract:We attempted to measure the dominant wavelengths of gastric mucosal lesions and to extract and present color differences of the lesions in image form, by converting spectroscopic visual signals (composed of red, green and blue components) obtained from an electronic endoscope into digital color files. The dominant wavelength, as measured from signals input without gamma correction, was significantly shorter in gastric mucosa affected by atrophic gastritis and type lie early gastric cancer than in normal mucosa. This analysis revealed a significant difference in dominant wavelengths between the endoscopically normal mucosa of the stomach and that found to have been affected by early gastric carcinoma and atrophic gastritis. Color difference extraction allowed us to make a morphological characterization of the surface of type lie early gastric cancer, although this was possible in only one case. The results of this study suggest the diagnostic value of digital representation of the mucosal surface features provided by endoscopy. It is suggested that, in the future, analog endoscopic diagnosis will be replaced by digital endoscopic diagnosis and computerized endoscopic diagnosis.

Effects of TXA2 and TXA2 receptor antagonist (ONO-NT-126) on rat colonic mucosal microcirculation and model of inflammatory bowel disease observation with electronic endoscope

Effects of TXA2 and TXA2 receptor antagonist (ONO-NT-126) on rat colonic mucosal microcirculation and model of inflammatory bowel disease observation with electronic endoscope

Experience with Percutaneous Electronic Choledochoscopy

Abstract:Experience with percutaneous choledochoscopy using a prototype electronic choledochoscope (Pentax ECN‐1530) is presented herein. This electronic endoscope is 5.3 mm in outside diameter at the tip and has a forceps channel 2.0 mm in diameter. The outside diameter is 0.4 mm larger, while the forceps channel diameter is 0.2 mm smaller, than that of the conventional fiberoptic choledochoscope (FCN‐15X) produced by the same company. Although the new electronic choledochoscope could be inserted through a 16 Fr in size fistula, we considered an 18 Fr fistula to be preferable for insertion without resistance. Various types of accessory equipment for endoscopic treatment, such as an electrohydraulic Shockwave lithotriptor (EHL) and an Nd‐YAG laser, could be used without difficulty. The electronic choledochoscope was useful for examining bile duct carcinoma invasion to the hepatic side and evaluating the efficacy of various multi‐modal treatments, as it provided observation of the bile duct mucosa in great detail due to a very clear dynamic image. Moreover, endoscopic treatment was also greatly facilitated because it provided a clear view on a large, bright monitor screen for the surgeons. We therefore believe that this new electronic choledochoscope is very useful for the accurate diagnosis and treatment of biliary diseases.

Numerical evaluation of infrared ray electronic endoscopy (IREE) image for analysis of the mucosal blood flow (MBF): [formula omitted], H. Kohso, H. Akai, K. Morita, T. Kodama, K. Kashima. The Third Department of Internal Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan

Numerical evaluation of infrared ray electronic endoscopy (IREE) image for analysis of the mucosal blood flow (MBF): [formula omitted], H. Kohso, H. Akai, K. Morita, T. Kodama, K. Kashima. The Third Department of Internal Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan

10 Future developments in endoscopic imaging

Endoscopic imaging capabilities have significantly improved over the past 10 years. Improvements in fibreoptic technology have made possible the development of very thin endoscopes that can directly visualize the biliary and pancreatic ducts. The application of the CCD to endoscopy has made electronic endoscopy possible, and holds promise for stereoendoscopy. The ability to digitize endoscopic images can be developed to store, transmit, magnify, enhance and otherwise manipulate data obtained during endoscopy, and will probably be utilized routinely in the future. Laser and ultrasound technology are likely to enhance significantly our ability to examine ultrastructural aspects of gastrointestinal organs and surrounding tissues, and may play an important role in cancer surveillance programs. Vital staining techniques are likely to find widespread use in early cancer detection programmes, and may be useful to follow prospectively lesions observed or treated during endoscopy. Finally, the new developments in ‘virtual imaging’ may find applications in the field of gastrointestinal endoscopy and other ‘minimally invasive’ surgical procedures.

Statistical spectrum discrimination for endoscopic imaging

We design spectral functions for endoscopic color filters by applying a statistical classification method to discriminate between human gastric spectra of normal and bloody tissues. Estimated RGB color images are generated from light intensities taken through the color discriminant filters. We propose a visualization method for future electronic endoscopes which can display conventional color images with effective enhancement of bloody areas.

Color correction for colorimetric color reproduction in an electronic endoscope

A color correction method is presented for application in an electronic endoscope. This method performs color correction in the endoscope's input system using a simple 3 × 3 matrix to reproduce a colorimetrically correct color. The correction matrix is optimally designed using about 300 actual spectral reflectances of the gastric mucous membrane. The effectiveness of the proposed correction method is demonstrated both numerically and visually through computer simulation.

A New Method for Measurement of Gastric and Colonic Lesions with an Electronic Endoscope and Image Processor

Abstract:In order to measure the sizes of gastric and colonic lesions endoscopically, we established a system composed of an electronic endoscope, image processor, and personal computer. The long and short diameter of the lesion were calculated by a program which corrected the curvature radius of the lens of the endoscope and variables. 1) To evaluate its accuracy, we measured a 10 mm scale spherical model at different distances from the lens of the endoscope. The mean value was 9.7 mm, ranging from 9.0 to 10.9 mm. The rate of error was –0.38±4.4 % (mean±SE). 2) Using this system, we measured the sizes of 34 gastric and colonic lesions in 34 patients (3 with gastric cancers, 20 with gastric polyps, and 11 with colonic polyps), and compared them with the real sizes of the resected or polypectomized specimens. The rate of error was–1.1±1.3% (mean±SE). The results showed that our system was useful to evaluate the accurate sizes of gastric and colonic lesions endoscopically.

新しい上部消化管用電子内視鏡GIF-P230の使用経験

We examined the clinical usefulness of newly devised small-caliber electronic endoscope for upper gastrointestinal tract, GIF-P230 (Olympus) . Endoscopists examined the same 34 patients with GIF-P230 and its conventional type GIF-XQ200, and answered a questionnaire concerning scope insertion, and observation. Results showed that insertion of GIF-P230 into the pharynx and the doudenal bulb were more easy than that of GIF-XQ200, because the outer diameter of the former endoscope was 0.5mm smaller (8.7mm) than that of the latter scope, and the former scope consisted of high elastic polymers. Although this scope has only one light guide channel, the brightness at the TV monitor and photographs was sufficient. These results indicate that GIF-P230 is more useful for endoscopic diagnosis of upper gastrointestinal diseases than by the previous electronic endoscope.

電子内視鏡とレーザーを統合した光化学治療 (PDT) の照射用新デバイス

電子内視鏡とレーザーを統合した光化学治療 (PDT) の照射用新デバイス

Improved Color Reproduction of Electronic Endoscopes (II)

Improved Color Reproduction of Electronic Endoscopes (II)

A new method for distortion correction of electronic endoscope images

A new method to correct the barrel distortion of an electronic endoscope image is presented. A correction model assuming circularly symmetric distortion is introduced with the following model parameters: the center of distortion and the coefficients of polynomials representing the distortion correction in the radial direction. If the imaging system is distortion-free, straight lines in the object space should be imaged as straight lines. Based on this criterion, a distorted image of a standard pattern consisting of a grid of several straight lines is recorded, and the model parameters are then estimated as a basis for straightening distorted lines. This method has the advantage of not needing a careful placement of the standard pattern for calibration. Correction results are presented for the grid pattern chart to verify a sufficient degree of correction. Examples of distortion correction of real intestinal images and physicians' comments are also presented.

Data Compression of Electronic Endoscope Image and its Evaluation of Image Quality

Data Compression of Electronic Endoscope Image and its Evaluation of Image Quality

Improved Color Reproduction of Electronic Endoscopes

Improved Color Reproduction of Electronic Endoscopes

Electronic Endoscopy in Endoscopic Mucosal Resection(EMR) of Gastric Cancer

The role in which electronic endoscopy plays is important in EMR. It is useful in diagnosis and treatment of gastric cancer from a clinical viewpoint. EMR with use of electronic endoscopy allows better coordination between the operator and assistants, and thus improves the results further.

1 Electronic endoscopy and the future of gastrointestinal endoscopy

1 Electronic endoscopy and the future of gastrointestinal endoscopy

Initial Experience of Endoscopic Phonosurgery With aPrototype of the Therapeutic Rhinolarynx ElectronicEndoscope

We performed endoscopic phonosurgery in a patient with a laryngeal lesion using a prototype of the therapeutic rhino-larynx electronic endoscope connected to a video processor (Asahi Optical Co., Ltd.). This therapeutic electronic endoscope differs from the fiberoptic endoscope, because it contains an instrument channel and a miniature television camera attached to the tip of the endoscope, consisting of a small light-sensitive CCD chip. The dynamic image provided by this system is superior in resolution to that obtained by conventional flexible laryngofiberscopes. Using this therapeutic electronic endoscope and flexible forceps, we succeeded in removing a vocal fold polyp. This endoscope can be passed through the nasal passage into the laryngeal cavity. The therapeutic electronic endoscope is introduced and a clinical case is presented.