The usefulness of currently available colon imaging tests, including air contrast barium enema (ACBE), computed tomographic colonography (CTC), and colonoscopy, to detect colon polyps and cancers is uncertain.
Dr Rockey and colleagues undertook a study in order to assess the sensitivity of these 3 imaging tests.
The researchers oversaw 3 separate colon-imaging studies for patients with fecal occult blood, hematochezia, iron-deficiency anemia, or a family history of colon cancer.
The participants underwent ACBE, followed 7-14 days later by CTC and colonoscopy on the same day.
The primary outcome was detection of colonic polyps and cancers.
The researchers assessed outcomes by building an aggregate view of the colon, taking into account results of all 3 tests.
| For lesions 6-9 mm in size, sensitivity was 35% for ACBE, 51% for CTC, and 99% for colonoscopy|
In total, 614 patients completed all 3 imaging tests.
When the research team analyzed the data on a per-patient basis, for lesions 10 mm or larger in size (n=63) and found the sensitivity of ACBE to be 48%, CTC 59% and colonoscopy 98%.
For lesions 6-9 mm in size (n=116), the researchers noted that sensitivity was 35% for ACBE, 51% for CTC, and 99% for colonoscopy.
For lesions of 10 mm or larger in size, the specificity was greater for colonoscopy than for either ACBE or CTC and declined for ACBE and CTC when smaller lesions were considered.
Dr Rockey concluded, "Interpretation Colonoscopy was more sensitive than other tests, as currently undertaken, for detection of colonic polyps and cancers."
"These data have important implications for diagnostic use of colon imaging tests."