Diagnosis of elevated-type early gastric cancers by the optimal band imaging system

Background: The endoscopic diagnosis of an elevated-type early gastric cancer is often difficult. The optimal band imaging (OBI) system can reconstruct the best spectral images decomposed from ordinary endoscopic images with free selection of 3 wavelengths and provide unmagnified images with high light intensity as well as magnified images. Objective: To evaluate whether the 0131 system facilitates detection of the demarcation lines between ail elevated-type early gastric cancer and surrounding tissue and thus is more helpful for performing endoscopic therapy. Design: A prospective study. Setting: Jichi Medical University, Japan. Patients: Seventy-five patients, 81 lesions with an elevated-type early gastric cancer. Main Outcome Measurements: A comparison between 0131 images and conventional endoscopic images in the identification of the demarcation lines of an elevated-type early gastric cancer without magnification and the rate Of Success in identifying the abnormal surface structure of cancer by using low-magnified 0131 images. Results: Demarcation lines were easily identified in 0131 images, even without magnification, because such cancers Could be clearly distinguished from the Surrounding whitish atrophic mucosa. Inexperienced endoscopists Could determine demarcation lines with significantly greater accuracy with unmagnified 0131 images than with conventional images, With 40-fold magnification, irregular microstructural or nonstructural patterns were also found within cancer lesions in all cases studied but in none of the cases in the surrounding noncancerous mucosa. Conclusions: The new contrast images obtained with the OBI system enable better determination of the demarcation lines of elevated-type early gastric cancers, and this system may be useful for performing endoscopic therapy of this type of cancer as a new endoscopic modality (Gastrointest Endosc 2009;69:19-28.)