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Videofluoroscopic Swallow Study (VFSS)

VFSS, also known as modified barium swallow, is a radiographic procedure that provides a direct, dynamic view of oral, pharyngeal, and upper esophageal function during swallowing. During this procedure, the SLP presents food and liquid mixed with barium. The barium is necessary to view structures via videofluoroscopy during the swallow.

A VFSS is indicated when there is

  • a need to observe oral preparatory, oral transit, pharyngeal, and/or esophageal phases of swallowing;
  • a diagnosed or suspected presence of abnormalities in the anatomy of nasal, oral, pharyngeal, or upper esophageal structures that would preclude endoscopic evaluations;
  • an aversion to having an endoscope inserted;
  • the presence of a respiratory disorder;
  • the presence of a persistent feeding refusal problem for which a swallowing disorder might be a contributing cause; or
  • the need to determine treatment or management strategies to minimize the risk of aspiration and increase swallow efficiency (Arvedson & Lefton-Greif, 1998).

The VFSS shows the characteristics of the swallow and the patterns of bolus movement, including, but not limited to, initiation of the swallow, nasopharyngeal reflux, pharyngeal clearance, and laryngeal penetration and aspiration.

The VFSS can also be used to explore the effectiveness of modifications to improve swallowing safety, including

  • alternating liquids with solids to improve clearance through the hypopharynx and esophagus;
  • changing the child’s position for presentations of food and liquid;
  • using compensatory maneuvers during the swallow such as chin tuck or head turn;  
  • alternating methods of presentation (e.g., modified cups, spoons, alternative nipple to modify flow rate, etc.); and
  • modifying food and liquid consistencies.

Test Protocol

  • The radiologist and SLP work as a team to follow a standard protocol for conducting the study.
  • Types and consistencies of food and liquid to be used are based on results of the clinical evaluation.
  • Test materials (i.e., liquids or solids) are presented in a standardized order. The order of presentation may be modified at the professional’s discretion for optimal cooperation and test success.
  • The child is secured in a seat that offers good head, neck, and torso support.
  • The child is fed by a familiar family member or caregiver, if possible.
  • Every effort is made to maintain the child in a calm, alert state during testing.  

Radiation Safety

Radiation safety is important for all who are present in the room during the procedure. Special care is taken to use the lowest radiation dose possible while producing the best images for evaluation.

Acceptable radiation exposure levels are set by the radiology department and controlled by the radiologist. The SLP and radiologist work together to ensure that the radiation dosage amount is As Low as Reasonably Achievable (ALARA) without affecting the accuracy of the swallowing assessment, as recommended by the International Commission on Radiological Protection (ICRP).

Adults in the fluoroscopy suite wear protective equipment (lead aprons, gloves) to minimize exposure to scattered radiation (although dosage levels for children are generally considered acceptable for adult observers). Pregnant women might not be permitted in the examining room during the study. If permitted, a pregnancy-specific lead apron is worn—be aware of facility guidelines.

Dosimeter badges are worn by the radiologist and SLP who typically conduct these studies. The badges record radiation exposure and are used in most hospitals. See ASHA’s resource on radiation safety for the SLP. See also Video Fluoroscopic Swallowing Exam (VFSE) for consumer-friendly information about this procedure.  


Arvedson, J. C., & Lefton-Greif, M. A. (1998). Pediatric videofluoroscopic swallow studies: A professional manual with caregiver guidelines. San Antonio, TX: Communication Skill Builders.

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