Preliminary clinical experience of spiral CT virtual colonoscopy for detection of colorectal polyps

Objective: To evaluate spiral CT virtual colonoscopy (SCT VC) for detection of colorectal polyps. Methods: Spiral CT (SCT) was performed in 18 patients with breath holding. All data sets acquired with 4-5 mm collimation and overlapping reconstruction 50%-70% from SCT were transferred to workstation, and various opacities were assigned to generate SCTVC view. The results of SCT VC were confirmed by fibreoptic colonoscopy and (or) surgery. Results: SCTVC detected 71 colorectal polyps in 9 patients. One polyp was flat, while the others were sessile with dimension from 2 mm to 13 mm except 1 with 20 mm. Polyps <4 mm appeared blurred but some were seen clearly. Polyps >5 mm were well delineated and the number, size , morphology, and exact location could be ascertained. The sensitivity of SCTVC for polyp detection was >82%. Conclusion: SCTVC is a reliable, rapidly evolving technology that provides computer-simulated endoscopic visualization of the colonic polyps