Real-time magnetic resonance imaging (rtMRI) is becoming a practical tool in speech production research and language pathology observation. It is still a challenge to extract the tongue contour accurately in rtMRI sequences, since tongue is a soft tissue and often touches other organs such as lips and upper mandible. This paper proposes a novel semiautomatic tongue contour extraction method from rtMRI sequences. The initial boundary image is obtained by combined multi-directional Sobel operators in tongue movement region; then a boundary intensity map is constructed to find the most probable tongue contour points by searching for the optimal boundary route with Viterbi algorithm; finally the tongue contour is obtained using B-Spline approximation. The proposed method could obtain accurate tongue contour from rtMRI sequences, even in the cases that some parts of tongue touch other organs. Experiments demonstrate the robustness of the proposed method.
['Dawei Zhang', 'Minghao Yang', 'Jianhua Tao', 'Yang Wang', 'Bin Liu', 'Danish Bukhari']
Extraction of tongue contour in real-time magnetic resonance imaging sequences