False Positive Reduction in CT Colonography using Spectral Compression and Curvature Tensor Smoothing of Surface Geometry

Abstract

Existing polyp detection methods rely heavily on curvaturebased characteristics to differentiate between lesions. However, as curvature is a local feature and a second order differential quantity, noise caused by small bumpy structures and incoherent curvature fields of a discretized volume or surface can greatly increase the number of false positives (FPs) detected. This paper investigates a spectral compression and curvature tensor smoothing algorithm with the aim to reduce the number of FPs detected while preserving true positives. Simulation results give 96% sensitivity for polyps >10mm while reducing FPs by 92%.