Usefulness of computerized scheme for differentiating benign from malignant lung nodules on high-resolution CT

Abstract A computer-aided diagnosis (CAD) scheme for determination of the likelihood of malignancy of 244 nodules on high-resolution CT (HRCT) was developed. The performance (Az) for 16 radiologists was improved from 0.785 to 0.853 (P=0.02) with the aid of the CAD scheme by use of 56 nodules, including 28 cancerous and 28 benign nodules which were matched in size and pattern to the cancers. Our purpose in this study was to investigate further whether a CAD scheme can assist radiologists in distinguishing benign from malignant nodules in different groups. The results indicated that Az values for radiologists without and with the CAD scheme were improved from 0.770 to 0.855 for general radiologists (P=0.01) and from 0.805 to 0.850 for chest radiologists (P=0.12); from 0.717 to 0.821 for nodules at 6–10 mm (P=0.04) and from 0.837 to 0.901 for nodules at 11–20 mm (P=0.04); and from 0.812 to 0.892 for nodules with pure ground-glass opacity (GGO) (P=0.149), from 0.819 to 0.863 for nodules with mixed GGO (P=0.196), and from 0.784 to 0.844 for solid nodules (P=0.334). CAD has the potential to improve the diagnostic accuracy in distinguishing benign nodules from malignant ones in different groups on HRCT.