Pulmonary embolism (PE) can be detected by checking the shape of pulmonary arteries in three-dimensional CTA images, since PE has darker gray colors in CTA images than normal arteries and it makes the irregular shape of pulmonary arteries. Some locations of pulmonary artery containing PE look like squashed blood vessel. Therefore, artery-vein separation and correct boundary detection are important steps to detect PE from three-dimensional CTA images. Intensity-based boundary detection may not be good idea for PE detection, because of the partial volume effect, in which several materials are mixed within a voxel. In this project, we distinguish pulmonary arteries and veins and extract the blood vessel boundaries using 1st and 2nd derivatives as well as intensity values.
|1st step: Voxel classification and labeling|
|3rd step: Pulmonary artery detection and visualization|
|Graph representation of the whole trees.||The heart and blood vessel boundaries are extracted using 2nd directional derivatives.|
|4th step: Detecting abnormalities of pulmonary arteries (ongoing).|