Application of diffusion tensor imaging after glossectomy.

Difficulty in visualizing the intricate architecture of the tongue has limited our understanding of its function during speech, mastication, and swallowing, as well as its adaptation to surgical procedures. Tractography visualization using diffusion tensor imaging (DTI), a semiautomatic technique, can detect and display the spatial distribution of the muscle fiber bundle orientations as three-dimensional (3D) trajectories in human and calf tongues. DTI is a magnetic resonance imaging (MRI) technique that measures the diffusivity of water in different directions and estimates fiber bundle orientation at each voxel, mathematically measuring the spatial distribution of diffusion tensors. It has been successfully applied to the study of neurologic conditions, including stroke, multiple sclerosis, brain tumors, and dementia. We have combined DTI with structural MRI as a means of observing residual tongue anatomy and yielding insight into the tongue’s reconstruction after tumor resection in a glossectomy patient.