Automatic segmentation of the internal carotid arteries through the skull base

An automatic method is presented to segment the internal carotid arteries through the difficult part of the skull base in CT angiography. The method uses the entropy per slice to select a cross sectional plane below the skull base. In this plane 2D circular structures are detected by the Hough transform. The center points are used to initialize a level set which evolves with a prior shape constraint on its topology. In contrast with some related vessel segmentation methods, our approach does not require the acquisition of an additional CT scan for bone masking. Experiments on twenty internal carotids in ten patients show that 19 seed points are correctly identified (95%) and 18 carotids (90%) are successfully segmented without any human interaction.