Artificial intelligence for dysplasia detection during surveillance colonoscopy in patients with ulcerative colitis: A cross-sectional, non-inferiority, diagnostic test comparison study.

BACKGROUND AND STUDY AIM: High-definition virtual chromoendoscopy, along with targeted biopsies, is recommended for dysplasia surveillance in ulcerative colitis patients at risk for colorectal cancer. Computer-aided detection (CADe) systems aim to improve colonic adenoma detection, however their efficacy in detecting polyps and adenomas in this context remains unclear. This study evaluates the CADe Discovery™ system's effectiveness in detecting colonic dysplasia in ulcerative colitis patients at risk for colorectal cancer. PATIENTS AND METHODS: A prospective cross-sectional, non-inferiority, diagnostic test comparison study was conducted on ulcerative colitis patients undergoing colorectal cancer surveillance colonoscopy between January 2021 and April 2021. Patients underwent virtual chromoendoscopy (VCE) with iSCAN 1 and 3 with optical enhancement. One endoscopist, blinded to CADe Discovery™ system results, examined colon sections, while a second endoscopist concurrently reviewed CADe images. Suspicious areas detected by both techniques underwent resection. Proportions of dysplastic lesions and patients with dysplasia detected by VCE or CADe were calculated. RESULTS: Fifty-two patients were included, and 48 lesions analyzed. VCE and CADe each detected 9 cases of dysplasia (21.4% and 20.0%, respectively; p=0.629) in 8 patients and 7 patients (15.4% vs. 13.5%, respectively; p=0.713). Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy for dysplasia detection using VCE or CADe were 90% and 90%, 13% and 5%, 21% and 2%, 83% and 67%, and 29.2% and 22.9%, respectively. CONCLUSIONS: The CADe Discovery™ system shows similar diagnostic performance to VCE with iSCAN in detecting colonic dysplasia in ulcerative colitis patients at risk for colorectal cancer.

Cromoendoscopia Virtual y Magnificación Endoscópica: diagnostico precoz del carcinoma de células escamosas del canal anal / Virtual Chromoendoscopy in the early diagnosis of squamous cell carcinoma of the anal canal

El canal anal es la porción distal del tracto digestivo y mide entre 2,5 a 4 cm. de longitud. El cáncer del canal anal es una enfermedad relativamente rara, siendo el carcinoma de células escamosas el más frecuente, con una sobrevida de 5 años de aproximadamente 58%. En los años recientes existe un aumento en la incidencia y prevalencia de la neoplasia intraepitelial y del cáncer del canal anal. El diagnóstico temprano de la neoplasia intraepitelial y del cáncer precóz del canal anal, permite una adecuada estrategia terapéutica curativa. La endoscopia mediante la técnica de la cromoendoscopia virtual y magnificación endoscópica, logra la detección y caracterización de la neoplasia intraepitelial y del carcinoma precoz de células escamosas del canal anal, mediante la observación de las alteraciones en la arquitectura microvascular subepitelial, con alta seguridad diagnóstica. Se presenta la experiencia con 4 pacientes con carcinoma precóz de células escamosas del canal anal, detectados por cromoendoscopia virtual + magnificación y su correlación endoscópica e histológica.

The anal canal is the terminal portion of the digestive tract. The anal canal is 2.5 to 4cm in lenght. The cancer of anal canal is a relatively rare malignancy and the most frequent is the type squamous cell carcinoma, accounting for a 5 year survival of 58 %. The endoscopic evaluation of microvascular pattern of superficial lesions of the anal canal, by virtual chromoendoscopy and magnifying endoscopy, achieves the diagnosis of intraepithelial neoplasia and early squamous cell carcinoma of the anal canal. Here we report our experience in 4 patients with early squamous cell carcinoma and show the endoscopy-histopathological correlation. The early diagnosis of the disease, permit curative treatment with local resection.

Experiencia con cromoendoscopia virtual computarizada (FICE) para la descripción y caracterización de lesiones colorectales / Experience with computed virtual chromoendoscopy (FICE) for description and characterization of colorectal lesions

La cromoendoscopia virtual computarizada es la técnica de estimación espectral basada en el procesamiento aritmética de imágenes capturadas por el video endoscopio. Este estudio incluye 247 pacientes a quienes se le realizó Colonoscopia en el período comprendido entre Abril 2007 y Mayo 2009 (83/33,5 % hombres, 164/66,5 % mujeres). La comparación fue realizada entre la visualización endoscópica con FICE, las imágenes grabadas y el diagnóstico histológico final realizado mediante biopsias, polipectomia o mucosectomia evaluados por dos patólogos expertas en patología gastrointestinal. La aplicación de esta nueva técnica combinada con magnificación constituye un área prometedora en la descripción de cambios patológicos mínimos de la mucosa y microvasculares. Permite incrementar la correlación entre las imágenes endoscópicas y los resultados histopatologicos.

The computed virtual chromoendoscopy imaging technique is based on narrowing the bandwidth of the conventional endoscopic image arithmetically, using spectral estimation technology. This study includes 247 consecutive patients (83/33.5% males, 164/66.5% females) who had a colonoscopy performed between April 2007 and May 2009. A comparison was made between direct visualization with FICE and recorded images and the fi nal diagnosis made by biopsy, polipectomy or endoscopic mucosal resection. The sampling was evaluated by two experts’ GI pathologist. The application of this new technology combined with high resolution endoscopy has promising areas of development in the description of pathologic mucosal changes and microvessels. This advanced technology allows an increased correlation between the images processed and the histological results.