Automatic Segmentation of Muscles of Mastication from Magnetic Resonance Images Using Prior Knowledge

We propose a knowledge-based, fully automatic methodology for segmenting muscles of mastication from 2-D magnetic resonance (MR) images. To the best of our knowledge, there is currently no methodology which automatically segment muscles of mastication. In our approach, MR images with muscles of interest that have been manually segmented by medical experts are used to train the system to identify a relationship between the region of interest (ROI) of the head and ROI of the muscle. Anisotropic diffusion is used to smooth the ROI of the latter. Neighboring regions of the muscle are removed by thresholding. A template of the muscle, from the manual tracings, is used to obtain an initial segmentation of the muscle. Small unwanted regions in the ROI are removed via connected components labeling. A gradient vector flow (GVF) snake, using the initial segmentation as initialization, is used to refine the initial segmentation. We performed 2D segmentation of the medial and lateral pterygoids on a total of 50 MR images, in the mid-facial region through the mandible with accuracy ranging from 85% to 98%