Identification of tongue muscle fibre group contraction from MR images

Abstract

The tongue is made up of a collection of interwoven families of muscle fibres, but little is known about the function of each of these muscle groups during physiological motions of the tongue. Magnetic resonance imaging (MRI) tissue tagging has been used to observe internal tongue tissue deformation, and estimate possible contractile patterns of the tongue muscles. However, the complex fibrous arrangement and the limited field of view from 2D planar images make it difficult to identify muscle movements in 3D space. This casts doubt on the empirical conclusions drawn from these studies. Here we present a computational modelling framework to estimate the contractile properties of the different muscle groups in the tongue by combining a generic tongue model with anatomical and strain data derived from tagged MR images. Tongue propulsion during dry swallowing was simulated and results were compared with previously published data. The model predicated model results by using empirical conclusion showed that, the co-activation of single intrinsic muscles (transversus, verticalis) cannot explain the most dominate expansion in the posterior tongue body. Contact between the tongue and upper palate and simultaneous contraction with more muscles may also result in anterior–posterior expansion.