Virtual colonoscopy in paediatric patients Usefulness of a colon dissection technique.

OBJECTIVE: To determine the usefulness of perspective-filet view for polypoid lesions in paediatric patients in comparison with conventional virtual colonoscopy (VC) analysis and optical colonoscopy. METHODS: Sixty-one patients (mean age 5 years old) with a previous episode of rectal bleeding were studied using a 16 slices CT scanner. All patients underwent a colonic preparation. Two acquisitions were done in supine and prone positions with slices of 2mm thickness; increment 1mm, 30-50mA; 90-120kV. In a workstation an experienced radiologist reviewed images twice. The first read was done using the conventional virtual colonoscopy technique with the evaluation of two-dimensional (2D), three-dimensional (3D) and endoscopical images. Later, in a second session, perspective-filet view was used. It shows a 360 degrees unrolled visualization of the inner colon. The presence, size and location of the lesions were determined. A record of the reading time was made. RESULTS: At per patient evaluation the conventional virtual colonoscopy analysis obtained a sensitivity of 86% and a specificity of 98%. The perspective-filet view obtained a sensitivity of 91% and a specificity of 99%. In the evaluation on a per lesion basis the conventional analysis had a sensitivity of 81% and a specificity of 88%. Perspective-filet view, had a sensitivity of 82% and specificity of 90%. The average total reading time using conventional colonoscopy technique was 18+/-3min, versus 4+/-1min using the perspective-filet view. CONCLUSION: Virtual colon dissection with perspective-filet view is more time-efficient than conventional virtual colonoscopy evaluation with correct correlation in results.