The future of colorectal imaging: computed tomographic colonography.

The development of colorectal cancer screening alternatives that are attractive to patients and effective for screening is critical for reducing this too-common and deadly disease. CTC is an exciting technique that is the only imaging alternative developed since the barium enema for colon screening. In the past few years, many obstacles to clinical implementation of CTC have been eliminated. For example, there is no longer any post-processing time, which was previously as long as 8 to 10 hours, and the interpretation time has been drastically reduced from 4 hours to 15 to 20 minutes. The majority of studies have demonstrated excellent results for detection of lesions > or = 1 cm, with few false positives. This examination will continue to improve with the development of automated (computer) detection programs and automated 3D rendering algorithms. In addition, cathartic bowel preparation, one of the biggest obstacles to patient compliance with colorectal cancer screening, may be eliminated if successful fecal tagging can be developed. The most important issue that remains is its performance in a screening population, and studies are currently underway to answer that important question.