Virtual colonoscopy with contrast cost-effective in detecting extracolonic lesions

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Most of the extracolonic lesions detected by CT colonography are lesions of low significance, and careful case selection and use of contrast enhancement would increase the effectiveness of exam, according to research published March 28 in the World Journal of Gastroenterology.

Extracolonic lesions are found in 15 to 85 percent of cases, with some being important lesions, such as extracolonic cancer or aortic aneurysm. In particular, the detection of significant lesions is very important. However, the incidence rates of significant extracolonic lesions vary from country to country, and most reports relate to the Western population.

Dong Il Park, MD, department of medicine, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital in Seoul, South Korea, and colleagues sought to determine the frequency and characteristics of extracolonic lesions detected using CT colonography.

The significance of extracolonic lesions was classified as high, intermediate, or low. Medical records were reviewed to establish whether further investigations were carried out pertaining to the extracolonic lesions that were detected by CT colonography.

Highly significant lesions included those requiring immediate surgical therapy, medical intervention and/or further investigation. Lesions of intermediate significance included conditions that do not require immediate therapy but would likely require further investigation, recognition or therapy at a later time. Lesions of low significance included benign conditions that do not require further medical therapy or additional work-up.

A total of 920 cases from seven university hospitals were included, and 692 extracolonic findings were found in 57.8 percent patients. Of 692 extracolonic findings, 8.7 percent were highly significant, 36.1 percent were of intermediate significance, and 55.2 percent were of low significance.

According to the results, CT colonography revealed fewer extracolonic findings in subjects who were without symptoms, younger, or who underwent CT colonography with no contrast enhancement.

"CT colonography with contrast enhancement showed higher cost-effectiveness in detecting highly significant extracolonic lesions in older subjects and in subjects with symptoms. Most of the extracolonic findings detected using CT colonography were of less significant lesions. The role of CT colonography would be optimized if this procedure was performed with contrast enhancement in symptomatic older subjects," the authors wrote.