Computer-Aided Nodule Assessment and Risk Yield (CANARY) is a novel computed tomography (CT) tool developed at Mayo Clinic (Rochester, MN) that characterizes early lung adenocarcinoma by detecting nine distinct voxel classes, representing a spectrum of lepidic to invasive growth, within an adenocarcinoma. CANARY characterization has been shown to correlate with ADC histology and patient outcomes.This protocol provides basic instructions for segmentation of lung adenocarcinoma on CT imaging. CANARY has been validated in lung adenocarcinomas less than 3cm in diameter