From the Guidelines
The MBSS (Modified Barium Swallow Study) is a video fluoroscopic procedure used to evaluate a patient's oropharyngeal swallow and assess abnormalities in the oral and pharyngeal phases of swallowing 1.
Key Components of MBSS
- The test focuses on the oral cavity, pharynx, and cervical esophagus to assess difficulties in propelling the bolus, laryngeal penetration, tracheal aspiration, and cricopharyngeal dysfunction 1.
- It involves dynamic evaluation of swallowing function, assessing bolus manipulation, tongue motion, hyoid, laryngeal, pharyngeal elevation, soft-palate elevation, pharyngeal constrictor motion, epiglottic tilt, laryngeal penetration, and cricopharyngeus muscle function 1.
- The patient is given varying consistencies of barium and barium-impregnated food to assess their ability to swallow, which can help identify the cause of dysphagia in a significant percentage of patients 1.
Clinical Application
The MBSS is particularly beneficial when structural abnormalities have been excluded by direct endoscopic visualization, and it can accurately localize videofluoroscopic findings to the site of the patient's symptoms, especially when the finding is structural 1.
From the Research
Definition and Purpose of Modified Barium Swallow Study (MBSS)
- The Modified Barium Swallow Study (MBSS) is a videofluoroscopic evaluation of oropharyngeal swallow function 2, 3, 4.
- It is used to assess the functional anatomy and physiology of swallowing, permitting visualization of bolus flow throughout the upper aerodigestive tract in real time 3.
- The primary goal of MBSS is to identify and distinguish the type and severity of swallowing impairment, determine the safety of oral intake, and formulate oral intake recommendations and treatment planning 3.
Components and Procedure of MBSS
- MBSS involves the use of a barium swallow, which is a radiographic contrast agent, to visualize the swallowing process 2, 3.
- The study typically includes a series of swallows with different consistencies and volumes of barium, which are recorded using videofluoroscopy 3.
- The recordings are then analyzed to assess the swallowing physiology, including the movement of the bolus through the pharynx and esophagus, and the presence of any swallowing impairments 2, 3.
Esophageal Imaging in MBSS
- Esophageal imaging is not routinely performed during an MBSS, but it can be included as part of the study to assess esophageal function 2.
- The inclusion of esophageal imaging in MBSS can help identify esophageal disorders and improve patient outcomes 2, 4.
- However, there is variability in the practice of esophageal imaging during MBSS, and a standardized protocol is needed to ensure consistency and accuracy 4.
Diagnostic Accuracy and Clinical Utility of MBSS
- MBSS has been shown to be a reliable and valid tool for assessing swallowing function and identifying swallowing impairments 3, 5.
- The diagnostic accuracy of MBSS can be affected by factors such as the pulse rate of the fluoroscopy, with higher pulse rates providing better temporal resolution and diagnostic accuracy 6.
- MBSS is considered a gold standard for evaluating swallow function, along with the functional endoscopic evaluation of swallowing (FEES) 5.