Images used in this study were acquired on four different CT scanners from four different vendors in four different hospitals using standard parameters for calcium scoring in cardiac CT. For each patient, both a non-contrast enhanced CT and a contrast-enhanced CTA image are provided.

The training set consists of images of 32 patients. Initially, the test set for web-based evaluation consisted of images of 32 patients. For the on-site analysis, a set of eight patient images was provided. After the event, these images have been merged to one test set for the web-based analysis.

Images are available from the Download page.

Reference standard

The reference standard for all non-contrast enhanced CT images was set independently by two experts using a custom-built tool. Following the standard protocol provided by commercial vendors, image voxels with intensities greater than 130 HU were highlighted. Individual lesions were identified in 3-D using 6-connectivity. Calcifications were manually labeled as belonging to either the left anterior descending (LAD), left circumflex (LCX) or right coronary artery (RCA). For this challenge, calcifications in the left main coronary artery were labeled as LAD calcifications. In the labeled images with reference annotations, calcifications are labeled as 1 (LAD), 2 (LCX) or 3 (RCA).

Subsequently, lesions on which the experts disagreed were again presented and resolved in consensus. This consensus reading presented the reference standard.

The following image shows an example of coronary calcification marked by the experts. Coronary calcifications in the LAD are shown in green, calcifications in the LCX are shown in blue and calcifications in the RCA are shown in red. You can scroll and zoom through the slices by using your mouse or the controls at the bottom.