Real-time magnetic resonance imaging of normal swallowing

Purpose: To evaluate the use of a novel real-time magnetic resonance imaging (MRI) technique for the assessment of normal swallowing dynamics. Materials and Methods: In a cohort of 10 healthy subjects, real-time MRI movies at 24.3 frames per second were obtained in sagittal, coronal, and axial orientation during self-controlled swallows of 5 mL pineapple juice as oral contrast bolus. All studies were performed with the use of a commercial MRI system at 3 T combining two sets of radiofrequency receiver coils. Real-time movies relied on a fast low-angle shot (FLASH) MRI sequence with radial undersampling and image reconstruction by nonlinear inversion yielding 41.23 msec acquisition time for an in-plane resolution of 1.5 mm. Evaluations focused on clinical image quality as well as visualization and temporal quantification of distinct swallowing functions. Results: Throughout the entire process, the swallowing dynamics were well depicted and characterized with almost no visible image artifacts in all subjects. The mid-sagittal plane turned out to be most valuable. The movies allowed for a quantitative determination of the temporal pattern of all swallowing events. Conclusion: The proposed real-time MRI technique yields noninvasive, robust, and quantitative access to the physiology of normal swallowing in healthy subjects at high temporal resolution and image quality. J. Magn. Reson. Imaging 2012;. (c) 2012 Wiley Periodicals, Inc.