What the practicing radiologist needs to know about the pharynx and dysphagia

The number of persons with impaired swallowing in our population is substantial. In the United States alone, an estimated 8,000-10,000 individuals die from choking each year. In nursing homes, 35%-40% of the residents are affected to some degree. The semingly simple act of swallowing requires the successful coordination of several cranial nerves and 26 muscles of the mouth, pharynx, and esophagus. The system can be affected by many abnormalities including developmental abnormalities, neurologic and neuromuscular disease, head and neck injuries or surgery, structural lesions including cancer, and gastrointestinal disorders, to mention just a few. The resulting impairment can range from mild discomfort to life-threatening disability. This paper focuses on dynamic imaging of the pharynx: how to perform and interpret dynamic studies. Pertinent radiographic anatomy and the physiology of normal and abnormal swallowing are addressed. The importance of a multidisciplinary approach to the patient with dysphagia is discussed