Videofluoroscopic Swallowing Study (VFSS)

How to Cite This Chapter: Gandhi P, Steele CM. Videofluoroscopic Swallowing Study (VFSS). McMaster Textbook of Internal Medicine. Kraków: Medycyna Praktyczna. Accessed April 21, 2024.
Last Updated: June 19, 2019
Last Reviewed: June 6, 2020
Chapter Information

The videofluoroscopic swallowing study (VFSS) is a commonly used instrumental swallowing assessment procedure in Canada. This procedure may also be referred to as videofluoroscopic (special) swallowing study, videofluoroscopic evaluation of swallowing (VFES), modified barium swallow (MBS), cookie swallow, cine esophagram, or palatopharyngeal analysis (PPA).


Videofluoroscopy is a digitized dynamic fluoroscopic image that captures the oral, pharyngeal, laryngeal, and upper esophageal swallow physiology and integrates compensatory treatment strategies (eg, swallowing maneuvers, patient positioning, texture modification). Videofluoroscopic swallowing studies allow the clinician to:

1) Assess various components of swallowing physiology and detect abnormalities.

2) Determine the presence, cause, and severity of dysphagia by visualizing liquid or solid bolus control, flow and timing of the bolus, and the individual’s response to bolus misdirection and residue.

3) Visualize the presence, location, and amount of secretions in the upper aerodigestive tract as well as the patient’s sensitivity and ability to clear the secretions.

4) Determine the presence and response to laryngeal penetration or aspiration.

5) Determine the safety and efficiency of different bolus consistencies and volumes.


1. Identification of impaired swallowing physiology to guide management and treatment.

2. Presence of a medical condition or diagnosis associated with a high risk of dysphagia.

3. Evaluation of the effects of rehabilitation techniques on swallowing function, such as sensory enhancement, postural changes, and behavioral maneuvers.

4. Inconsistent signs and symptoms in the findings from clinical bedside examination.

5. Evaluation of concerns regarding the safety and efficiency of swallow.

6. Identification of changes in swallowing safety and efficiency as a function of food or fluid consistency.


1. The patient is medically unstable and cannot tolerate the procedure.

2. The patient is not able to participate in investigations involving instrumentation (eg, reduced level of alertness, attentional deficits, cognitive difficulties).


Videofluoroscopy recordings are captured either on a videotape or using a digital capture device to allow postexamination analysis by the speech-language pathologist and radiologist.

The radiographic image should have a minimum spatial resolution of 400 lines. The pulse rate of videofluoroscopy should be determined in consultation with radiological personnel, balancing the concerns of radiation exposure with the need to capture a comprehensive dynamic recording of swallowing. Current research evidence has not definitively identified the minimum pulse rate necessary for imaging of the oropharyngeal swallow; however, it is suggested that pulse rates <15 pulses per second may be insufficient to capture key events in swallowing. The video or digital recording of the dynamic swallowing study should be captured and archived at a minimum temporal resolution of 30 frames per second, so that adequate information regarding the swallow is available for later analysis.


VFSSs are typically performed with both a speech-language pathologist and radiologist present, allowing for professional collaboration. The speech-language pathologist focuses on swallowing physiology and functioning while the radiologist makes medical diagnoses.

At minimum, a VFSS includes the following protocols:

1) Educating the patient and caregiver on the rationale and radiation safety of the VFSS.

2) Positioning the patient upright or in the typical eating position, if possible, to simulate normal ingestion.

3) Using postural supports (eg, head, trunk) if necessary.

4) Identifying the relevant anatomical structures visible on fluoroscopy.

5) Obtaining lateral and anterior-posterior views of the oral cavity, pharynx, and upper esophagus, as needed, for each of the liquid or solid bolus types.

6) Evaluating the oral phase of swallowing.

7) Studying the pharyngeal components of swallowing and related physiologic events.

8) Assessing the influence and effectiveness in altering liquid/solid bolus delivery and the use of rehabilitative or compensatory techniques on swallowing.

9) Visually identifying the presence and effectiveness of swallow function and sensory awareness.

10) Assessing the presence and effectiveness of the patient’s response to laryngeal penetration, aspiration, and/or residue.

Clinicians select bolus type (eg, consistency, volume) for each trial carefully, as some consistencies and volumes may influence the clinician’s overall impression of swallow function. In addition, clinicians assess the impact of the method and rate of food introduction, such as when the patient is fed by the examiner, self-fed, or fed by a caregiver, and when solids and liquids are alternated. Clinicians also note any differences in swallow function when the patient is instructed to swallow as compared with spontaneous swallows.

A VFSS requires the patient to make an adequate number of swallowing attempts to ensure clinically informed decisions about route of intake, consistency of oral diet, and maneuvers to improve swallowing function and to determine the need for additional assessments or interventions through interprofessional team referrals.

Clinicians record the individual’s tolerance of and response to the examination (eg, ability to follow directions, fatigue, ability to repeat therapeutic interventions, signs of stress due to medical complexity of condition). Indications of an adverse reaction to the assessment may include agitation, changes in breathing pattern, fluctuations in alertness, changes in coloring, nausea and vomiting, and changes in the overall medical status.

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