Constrained region-based segmentation of pleural effusion in thin-slice CT

A pleural effusion is excess fluid that collects in the pleu-ral cavity, the fluid-filled space that surrounds the lungs. Surplus amounts of such fluid can impair breathing by limiting the expansion of the lungs during inhalation. Measuring the fluid volume is indicative of the effectiveness of any treatment but, due to the similarity to surround regions, fragments of collapsed lung present and topological changes; accurate quantification of the effusion volume is a difficult imaging problem. A novel slice-by-slice code is presented which performs conditional region growth to accurately segment the effusion shape. We demonstrate the applicability of our technique in the segmentation of pleu-ral effusion and pulmonary masses.