Comparison of standard reading and computer aided detection (CAD) on a national proficiency test of screening mammography

Abstract

Objective: To evaluate the role of computer aided detection (CAD) in improving the interpretation of screening mammograms Material and methods: Ten radiologists underwent a proficiency test of screening mammography first by conventional reading and then with the help of CAD. Radiologists were blinded to test results for the whole study duration. Results of conventional and CAD reading were compared in terms of sensitivity and recall rate. Double reading was simulated combining conventional readings of four expert radiologists and compared with CAD reading. Results: Considering all ten readings, cancer was identified in 146 or 153 of 170 cases (85.8 vs. 90.0%; χ 2=0.99, df=1, P=0.31) and recalls were 106 or 152 of 1330 cases (7.9 vs. 11.4%; χ 2=8.69, df=1, P=0.003) at conventional or CAD reading, respectively. CAD reading was essentially the same (sensitivity 97.0 vs. 96.0%; χ 2=7.1, df=1, P=0.93; recall rate 10.7 vs. 10.6%; χ 2=1.5, df=1, P=0.96) as compared with simulated conventional double reading. Conclusion: CAD reading seems to improve the sensitivity of conventional reading while reducing specificity, both effects being of limited size. CAD reading had almost the same performance of simulated conventional double reading, suggesting a possible use of CAD which needs to be confirmed by further studies inclusive of cost-effective analysis.