The VOLCANO '09 Challenge: Preliminary Results

The VOLCANO\"09 Challenge invited participants to evaluate the change in size of pulmonary nodules in CT images; the challenge data set consisted of 50 pairs of CT scans each scan containing a single nodule. This is the first challenge for CAD methods on pulmonary nodules in which size change rather than volume estimation is the primary endpoint. Responses from 13 teams were received with size change results for a total of 17 different methods. In this paper the challenge data set is described and statistical results computed from the submissions are presented. The dataset consisted of several subgroups: (a) zero-change cases, cases with different slice thickness scans, cases with actual size change and a synthetic nodule case. No statistical difference was found between the methods; a slice thickness change was significant and there was an interesting bias observed for some zero-change nodules