The Use of Magnetic Resonance Imaging (MRI) for the Study of the Velopharynx

Magnetic resonance imaging (MRI) has contributed significantly to our understanding of the velopharyngeal mechanism and is the only imaging modality that allows for visualization of the internal musculature in vivo. Although velopharyngeal dysfunction often can be perceived through indirect assessments such as perceptual ratings, acoustic analysis, and pressure-flow assessment, these indirect methods can fail to identify the underlying cause of hypernasality or velopharyngeal dysfunction due to the inability to visualize the primary muscles responsible for speech. Direct imaging methods, such as nasendoscopy or videofluoroscopy, present drawbacks and are limited in the information that is provided within the oral and nasal cavities, as well as the posterior pharynx. MRI studies have enhanced our knowledge of the velopharyngeal system and offer a foundation to establish the utility of using MRI clinically to improve speech outcomes for children with cleft palate and craniofacial anomalies. The purpose of this paper is to provide an overview of the underlying principles of MRI, describe the advantages and disadvantages of MRI, and discusses a standard protocol for assessing velopharyngeal anatomy.