An MRI comparison of /s/ production in four subject conditions

Abstract

This study examined a control subject and three patients who had surgery to remove tongue cancer. One patient’s surgery was closed with sutures, one with a radial forearm free flap reconstruction, and one with sutures plus radiation. This study aims to ascertain the effects of these traumas on internal and surface tongue motion during speech. The flap consists of soft tissue that is vascularized, but not innervated; it increases tongue bulk, but has no direct motor control. The other two patients have missing tissue and a scar where the cut regions were sewn together. This morphological change may increase difficulty creating properly formed palatal contacts. The supplemental radiation treatment may cause additional muscle stiffness due to fibrosis. The cine and tagged datasets were recorded in axial, coronal, and sagittal orientations using identical parameters so their data could be overlaid. Each dataset was reconstructed into 3D volumes, one for each time-frame in the word. From each cine-MRI volume, the 3D tongue surface was segmented and used as a “mask” in the tagged-MRI volume. Inthe tagged-MRI volumes, 3D displacement fields were calculated to show motion of each tissue point inside the tongue mask during the speech task.