. Author manuscript; available in PMC: 2011 Aug 1.

Published in final edited form as: Acad Radiol. 2010 Jun 12;17(8):948–959. doi: 10.1016/j.acra.2010.03.024

Table 4.

Reasons for False Negative Polyps

Reason Given by Radiologist for Not Calling Polyp	Single-mark Cases (n=34)	Double-mark Cases (n=62)
Stool	15 (44.1%)	20 (32.3%)
Normal Mucosa	8 (23.5%)	14 (22.6%)
Fluid	6 (17.6%)	7 (11.3%)
Fold	3 (8.8%)	10 (16.1%)
Not Viewable	2 (5.9%)	5 (8.1%)
Scan Artifact	0 (0%)	2 (3.2%)
Rectal Tube	0 (0%)	1 (1.6%)
Air Bubble	0 (0%)	1 (1.6%)
Other	0 (0%)	1 (1.6%)

Data are numbers of false negative polyps (%) according to the reasons the radiologists gave for not calling the CAD finding a polyp. These are CAD marks on polyps that were mischaracterized by the radiologists. “Not viewable” means CAD mark was not visible on colonic surface when radiologist clicked on that entry in list of CAD marks.