1. A method for detecting a trachea of a patient, the method comprising: obtaining a three-dimensional (3D) model of a chest of the patient; generating slice images of the 3D model along an axial direction; identifying a potential connected component in a first slice image of the generated slice images; identifying a potential connected component in a second slice image of the generated slice images, wherein the second slice image is immediately subsequent to the first generated slice image; confirming that the potential connected component of the first and second slice images are connected; labeling the potential connected component as a connected component; labeling the first slice image as a top slice image of the generated slice images; labeling the connected component in the top slice image as an active object; associating each connected component in a current slice image of the generated slice images with a corresponding connected component in a previous slice image based on a connectivity criterion; labeling each connected component in the current slice image associated with a connected component of the preceding slice image as the active object; and identifying the active object as the trachea, based on a length of the active object.