Colonoscopía virtual: realidad en un hospital público / Virtual colonoscopy: reality in a public hospital

Colon cancer is the third cause of death by cancer in Chile. Virtual CT colonoscopy (VC) is a non-invasive imaging technique in development. The most common indications of VC are screening of colonic polyp, incomplete conventional colonoscopy and staging of colorectal tumors. The objective of our study is to show our experience with this method in the Radiology Unit of Hospital Padre Hurtado. We reviewed 15 VC, corresponding to 15 patients (10 female and 5 male), with ages between 18 and 75. Six exams showed no significant findings (40%), 4 diverticular diseases (26,6%), 3 colon cancers (20%), and 2 familial polyposis (13,3%). VC proved to be an accesible method, well tolerated by the patients, less invasive than conventional colonoscopy and with no complications in our series. It also constitutes for us an excellent study method in patients where conventional colonoscopy is incomplete. We obtained an adecuate correlation with conventional colonosocopy, when this method was performed. Evaluation of the data obtained from VC requires a trained radiologist and, in some occasions, prolonged time for analysis and interpretation of the results.

El cáncer de colon es la tercera causa de muerte por cáncer en Chile. La colonoscopía virtual (CV) es una técnica de imagen no invasiva en desarrollo. Sus indicaciones habituales son: screening y detección de pólipos en el colon, colonoscopía convencional fallida o incompleta y, etapificación de tumores colorrectales. El objetivo de nuestro trabajo fue mostrar nuestra experiencia con este método diagnóstico en el Servicio de Imagenología del Hospital Padre Hurtado. Se revisaron 15 exámenes de CV que correspondieron a 15 pacientes (10 mujeres y 5 hombres), con edades entre 18 y 75 años. Los estudios mostraron 6 casos sin hallazgos patológicos significativos (40%), 4 enfermedades diverticulares (26,6%), 3 neoplasias de colon (20%) y 2 poliposis familiares (13,3%). La colonoscopía por TC resultó ser una técnica accesible, bien tolerada por los pacientes, menos invasiva que la fibrocolonoscopía y sin complicaciones. Además, para nosotros constituye un excelente método de estudio, sobretodo en aquellos pacientes en los cuales la fibrocolonoscopía resultó fallida o incompleta. Se obtuvo una buena correlación con colonoscopía convencional, cuando ésta se pudo realizar. El post-proceso de los datos requiere de entrenamiento del radiólogo y, algunas veces, tiempo prolongado para el análisis e interpretación de los resultados.

Evaluation of Colon Pattern using Virtual CT Colonoscopy in Patients with Difficult Colonscopic Insertion / 대한소화기내시경학회지

BACKGROUND/AIMS: The successful colonoscopic insertion has been predicted by several clinical factors including female gender, obesity, poor bowel preparation, and a history of surgery. In addition, anatomical differences, such as Kudo's pattern (B, C of the sigmoid colon), rotation of the hepatic and splenic flexure, and the diameter of the sigmoid colon have also been considered to affect the success of colonoscopic insertion. The aim of this study was to evaluate the anatomical factors using virtual CT colonscopy in the case where the colonoscopic insertion is difficult. METHODS: From April 2005 to June 2005, 32 patients who experienced a delayed insertion time > or =10 minutes during colonoscopy (Group I) and other 34 patients whose insertion time was <10 minutes (Group II) were examined by virtual CT colonoscopy. The shape of the sigmoid colon was compared with Kudo's pattern, rotation of hepatic (HFR) and splenic flexure (SFR), and the diameter of the most distended sigmoid colon at the supine position (SCD) in both groups. Excessive SFR or HFR was defined if the splenic flexure or hepatic flexure was rotated by more than 360 degrees from the natural course of the colon. RESULTS: There were significant differences between group I (M : F=16 : 16, mean age: 61.7+/-13.8, SCD: 40.9+/-7.4 mm) and group II (M : F=25 : 9, mean age: 46.9+/-11.4, SCD: 39.7+/-7.2 mm) in terms of gender, age, BMI (24.1+/-3.5 kg/m2 in group I, 23.5+/-2.1 kg/m2 in group II), and the colonoscopic insertion time (18.1 minutes in group I, 6.3 minutes in group II). The Kudo's pattern was as follows: pattern A : B : C=23.3% : 36.7% : 40.0% in group I, and pattern A : B : C=50.0% : 37.5% : 12.5% in group II. Excessive rotation of the splenic flexure was 50% in group I, and 21.9% in group II. However, there were no clinical significant difference in bowel preparation, sedation, previous bowel operation, the type of cathartics and SCD. CONCLUSIONS: Anatomical differences can affect a difficult colonoscopic insertion, which includes shape of the sigmoid colon, excessive rotation of the splenic flexure. However a further large randomized trial study will be needed.

Evaluation of Colon Pattern using Virtual CT Colonoscopy in Patients with Difficult Colonscopic Insertion / 대한소화기내시경학회지

BACKGROUND/AIMS: The successful colonoscopic insertion has been predicted by several clinical factors including female gender, obesity, poor bowel preparation, and a history of surgery. In addition, anatomical differences, such as Kudo's pattern (B, C of the sigmoid colon), rotation of the hepatic and splenic flexure, and the diameter of the sigmoid colon have also been considered to affect the success of colonoscopic insertion. The aim of this study was to evaluate the anatomical factors using virtual CT colonscopy in the case where the colonoscopic insertion is difficult. METHODS: From April 2005 to June 2005, 32 patients who experienced a delayed insertion time > or =10 minutes during colonoscopy (Group I) and other 34 patients whose insertion time was <10 minutes (Group II) were examined by virtual CT colonoscopy. The shape of the sigmoid colon was compared with Kudo's pattern, rotation of hepatic (HFR) and splenic flexure (SFR), and the diameter of the most distended sigmoid colon at the supine position (SCD) in both groups. Excessive SFR or HFR was defined if the splenic flexure or hepatic flexure was rotated by more than 360 degrees from the natural course of the colon. RESULTS: There were significant differences between group I (M : F=16 : 16, mean age: 61.7+/-13.8, SCD: 40.9+/-7.4 mm) and group II (M : F=25 : 9, mean age: 46.9+/-11.4, SCD: 39.7+/-7.2 mm) in terms of gender, age, BMI (24.1+/-3.5 kg/m2 in group I, 23.5+/-2.1 kg/m2 in group II), and the colonoscopic insertion time (18.1 minutes in group I, 6.3 minutes in group II). The Kudo's pattern was as follows: pattern A : B : C=23.3% : 36.7% : 40.0% in group I, and pattern A : B : C=50.0% : 37.5% : 12.5% in group II. Excessive rotation of the splenic flexure was 50% in group I, and 21.9% in group II. However, there were no clinical significant difference in bowel preparation, sedation, previous bowel operation, the type of cathartics and SCD. CONCLUSIONS: Anatomical differences can affect a difficult colonoscopic insertion, which includes shape of the sigmoid colon, excessive rotation of the splenic flexure. However a further large randomized trial study will be needed.

Virtual CT colonoscopy in diagnosis of colorectal proliferative lesions / 中华消化杂志

Objective To evaluate the ability of virtual CT colonoscopy to detect colorectal proliferative lesions in endoscopically proven patients and its clinical application prospects. Methods Virtual colonoscopy was performed using thin section helical computed tomography of the abdomen and pelvis in 23 patients with conventional colonoscopic findings suggestive of abnormalities within 1 hour. The data from CT scanning was processed by computer with specific commercial software, two and three dimensional reconstruction was subsequently made. Results The diagnosis of colorectal carcinomas was made on virtual colonoscopy in 21 cases, among which 20 cases were endoscopically diagnosed as cancers and 1 case was found sigmoid stricture of unknown causes, that was finally confirmed surgically and pathologically. All polyps greater than 11 mm were identified both by conventional endoscopy and virtual colonoscopy. 19 polyps with size of 6～10 mm were detected on virtual colonoscopy, the location and size of 13 polyps were in accordance with those of endoscopic findings, 2 false positive polyps were reported in 6 newly detected polyps. Virtual colonoscopy correctly localized all 21 cancers, compared with 18 using conventional colonoscopy. Conclusion Virtual colonoscopy is a valuable clinical method in diagnosis of colorectal cancers and polyps with size larger than 6 mm, and it is a good indication for colonic stricture and colonoscopy intolerable patients.