Deformable models for random small-size objects: Case of lung nodules in CT tomography

Deformable models are common in image modeling and analysis. Random objects provide major challenges as shapes and appearances are hard to quantify; hence, formulation of deformable models are much harder to construct and validate. In this paper, we examine the effect of randomness on building the shape and appearance models for small-size lung nodules (≤ 1cm) which appear in computed tomography (CT) of the human chest. We devise an approach for annotation, which lends a standard mechanism for building traditional active appearance (AAM), active shape (ASM) and active tensor models (ATM). We illustrate the effectiveness of AAM for nodule detection.