Title
Strategies for improved interpretation of computer-aided detections for CT colonography utilizing distributed human intelligence.
Abstract
Computer-aided detection (CAD) systems have been shown to improve the diagnostic performance of CT colonography (CTC) in the detection of premalignant colorectal polyps. Despite the improvement, the overall system is not optimal. CAD annotations on true lesions are incorrectly dismissed, and false positives are misinterpreted as true polyps. Here, we conduct an observer performance study utilizing distributed human intelligence in the form of anonymous knowledge workers (KWs) to investigate human performance in classifying polyp candidates under different presentation strategies. We evaluated 600 polyp candidates from 50 patients, each case having at least one polyp ⩾6mm, from a large database of CTC studies. Each polyp candidate was labeled independently as a true or false polyp by 20KWs and an expert radiologist. We asked each labeler to determine whether the candidate was a true polyp after looking at a single 3D-rendered image of the candidate and after watching a video fly-around of the candidate. We found that distributed human intelligence improved significantly when presented with the additional information in the video fly-around. We noted that performance degraded with increasing interpretation time and increasing difficulty, but distributed human intelligence performed better than our CAD classifier for “easy” and “moderate” polyp candidates. Further, we observed numerous parallels between the expert radiologist and the KWs. Both showed similar improvement in classification moving from single-image to video interpretation. Additionally, difficulty estimates obtained from the KWs using an expectation maximization algorithm correlated well with the difficulty rating assigned by the expert radiologist. Our results suggest that distributed human intelligence is a powerful tool that will aid in the development of CAD for CTC.
Year
DOI
Venue
2012
10.1016/j.media.2012.04.007
Medical Image Analysis
Keywords
Field
DocType
CTC,KW,MTurk,HIT
CAD,Computer vision,Pattern recognition,Computer-aided,Human intelligence,Crowdsourcing,Computed Tomography Colonography,Intestinal polyp,Artificial intelligence,Classifier (linguistics),Medicine,False positive paradox
Journal
Volume
Issue
ISSN
16
6
1361-8415
Citations 
PageRank 
References 
6
0.70
10
Authors
6
Name
Order
Citations
PageRank
Matthew McKenna1192.70
Shijun Wang223922.83
Tan Nguyen3615.22
Joseph E. Burns4899.51
Nicholas Petrick520942.63
Ronald M. Summers689386.16