Effect of computer-aided detection as a second reader in multidetector-row CT colonography

Abstract

Our purpose was to assess the effect of computer-aided detection (CAD) on lesion detection as a second reader in computed tomographic colonography, and to compare the influence of CAD on the performance of readers with different levels of expertise. Fifty-two CT colonography patient data-sets (37 patients: 55 endoscopically confirmed polyps > or =0.5 cm, seven cancers; 15 patients: no abnormalities) were retrospectively reviewed by four radiologists (two expert, two nonexpert). After primary data evaluation, a second reading augmented with findings of CAD (polyp-enhanced view, Siemens) was performed. Sensitivities and reading time were calculated for each reader without CAD and supported by CAD findings. The sensitivity of expert readers was 91% each, and of nonexpert readers, 76% and 75%, respectively, for polyp detection. CAD increased the sensitivity of expert readers to 96% (P = 0.25) and 93% (P = 1), and that of nonexpert readers to 91% (P = 0.008) and 95% (P = 0.001), respectively. All four readers diagnosed 100% of cancers, but CAD alone only 43%. CAD increased reading time by 2.1 min (mean). CAD as a second reader significantly improves sensitivity for polyp detection in a high disease prevalence population for nonexpert readers. CAD causes a modest increase in reading time. CAD is of limited value in the detection of cancer.

Does a computer-aided detection algorithm in a second read paradigm enhance the performance of experienced computed tomography colonography readers in a population of increased risk?

“…It is likely that the additional value of CAD would be larger if the data were read by a relatively inexperienced reader group [35,36]. Therefore, our conclusion may not apply to relatively untrained readers.…”

“…Several CTC studies in which the additional value of CAD was evaluated (after the interaction with the observer) have reported good results in terms of polyp detection [12,[25][26][27]. All concluded that the observers detected statistically more polyps with CAD.…”

“…Since there is good evidence that experience in CTC results in less false-negative findings [28,29], it is logical that it is more difficult to substantially increase the sensitivity of the observer with CAD. In studies that report data about the additional value of CAD on experienced observers [30,31], experienced observers benefited proportionately less from CAD when compared with the inexperienced readers. This finding is supported by the results of this study.…”

“…Recent studies concluded that in a selected population CAD significantly improved per-polyp sensitivity for less experienced observers [10][11][12][13]. Though experienced observers benefited proportionally less from CAD [14,15].…”

“…Though experienced observers benefited proportionally less from CAD [14,15]. Therefore, the potential increase by CAD in accuracy for experienced observers is still controversial.…”