Automated tumor size assessment: Consistency of computer measurements with an expert panel.

7566 Background: Manual tumor measurements for use in diagnosis and longitudinal assessment suffer from intra- and inter-observer variability. In practice they are also limited to 1-dimensional diameter measurements because manual contouring of 3D tumor boundaries is impractical. In this work we evaluated a fully automated tumor assessment system in the setting of lung nodules on CT by comparing its tumor size and density measurements against independent measurements made by an expert panel of radiologists. Methods: A new computer-aided detection (CAD) system has been developed that performs fully automated lung nodule detection and measurement. In order to identify the nodule boundary in 3D the system performs automated intensity thresholding, a Euclidean Distance Transformation, and segmentation based on watersheds. The system computes nodule diameter, volume, and mean density in Hounsfield Units (HU). The automated measurements were evaluated against data from the publically available Lung Imaging Data...