World J Gastroenterol. 2010 Feb 28;16(8):915-20. doi: 10.3748/wjg.v16.i8.915.
Computed tomographic colonography (CTC) is a promising emerging technology for imaging of the colon. This concise review discusses the currently available data on CTC technique, test characteristics, acceptance, safety, cost-effectiveness, follow-up strategy, and extracolonic findings. In summary, CTC technique is still evolving, and further research is needed to clarify the role of automated colonic insufflation, smooth-muscle relaxants, intravenous and oral contrast, software rendering, and patient positioning. Currently, full bowel preparation is still required to achieve optimal results. The sensitivity for detecting large polyps (> 1 cm) can be as high as 85%, with specificity of up to 97%. These test characteristics are almost comparable to those of conventional colonoscopy. Patient acceptance of CTC is generally higher than that for colonoscopy, especially in patients who have never undergone either procedure. CTC is generally safe, although uncommon instances of colonic perforation have been documented. In terms of cost-effectiveness, most decision analyses have concluded that CTC would only be cost-effective if it were considerably cheaper than conventional colonoscopy. The proper follow-up strategy for small polyps or incidental extracolonic findings discovered during CTC is still under debate. At present, the exact clinical role of virtual colonoscopy still awaits determination. Even though widespread CTC screening is not available today, in the future there may eventually be a role for this technology. Technological advances in this area will undoubtedly continue, with multi-detector row CT scanners allowing thinner collimation and higher resolution images. Stool-tagging techniques are likely to evolve and may eventually allow for low-preparation CTC. Perceptual and fatigue-related reading errors can potentially be minimized with the help of computer-aided detection software. Further research will define the exact role of this promising technology in our diagnostic armamentarium.
计算机断层结肠成像（CTC）是一种很有前途的新兴结肠成像技术。本简明综述讨论了目前有关 CTC 技术、检测特性、可接受性、安全性、成本效益、随访策略以及结肠外发现的可用数据。总之，CTC 技术仍在不断发展，需要进一步研究以阐明自动结肠充气、平滑肌松弛剂、静脉和口服对比剂、软件渲染以及患者体位的作用。目前，仍需要充分的肠道准备才能获得最佳效果。检测大息肉（> 1 cm）的敏感性可高达 85%，特异性高达 97%。这些检测特性几乎可与传统结肠镜检查相媲美。与结肠镜检查相比，患者通常更能接受 CTC，尤其是那些从未接受过这两种检查的患者。虽然有少数穿孔的病例报道，但 CTC 通常是安全的。就成本效益而言，大多数决策分析得出的结论是，如果 CTC 比传统结肠镜检查便宜很多，那么它才具有成本效益。对于在 CTC 中发现的小息肉或偶然的结肠外发现，适当的随访策略仍存在争议。目前，虚拟结肠镜的确切临床作用仍有待确定。即使目前还不能进行广泛的 CTC 筛查，但在未来，这种技术可能最终会有其用武之地。该领域的技术进步无疑将继续，多排 CT 扫描仪允许更薄的准直和更高分辨率的图像。粪便标记技术可能会发展，并最终可能允许低准备 CTC。计算机辅助检测软件有助于最大限度地减少感知和疲劳相关的阅读错误。进一步的研究将确定这项有前途的技术在我们的诊断工具中的确切作用。
