Using real time magnetic resonance imaging to measure changes in articulatory behavior due to partial glossectomy

Abstract

Real time MRI presents an exciting new method for studying speech articulation, providing the ability to capture articulatory kinematics and coordination. The current study utilizes real time MRI to document the speech of a patient who has undergone partial glossectomy at both preoperative and postoperative time points. While previous work has studied and evaluated postoperative outcomes, the comparison of individual speakers preoperatively and postoperatively is lacking. The possibility of compensation for the pathological articulator by other articulators necessitates the ability to image multiple articulators simultaneously to observe changes in articulatory coordination. In this paper, we present a method for quantifying changes in articulatory behavior, such as compensation for pathology, between two points in time. We find no significant changes in the patient's articulatory coordination that would indicate compensation for pathology. We attribute this to the relatively high degree of speech intelligibility preserved postoperatively for this particular patient. We do observe differences in vocal tract morphology as well as changes in the variability and principle axes of movement for the tongue. The methods we present here provide a means not only for measuring individual morphological changes, but also for observing the relationship between changes in morphology and changes in articulatory behavior.