GI Studies
Swallowing Dysfunction Study (Modified Barium Swallow)
Anatomy
Students should be able to identify the following structures on radiographic images:
Oral cavity, Pharynx (nasopharynx, oropharynx, and laryngopharynx), Larynx, Epiglottis, Vocal folds (cords), Trachea, Esophagus, Upper esophageal sphincter (UES)
Indications, Contraindications, and Patient Preparation
Indications
Evaluation of swallowing function in patients with:
- Stroke or neurological disorders (e.g., Parkinson’s disease, ALS, MS)
- Head/neck cancers or surgery
- Dysphagia (difficulty swallowing)
- Recurrent aspiration pneumonia
- Developmental or congenital swallowing problems (pediatrics)
Contraindications
- Severe aspiration risk (determined by physician/Speech-Language Pathologist [SLP])
- Inability to sit upright for study (unless modifications possible)
- Barium contraindicated if suspected perforation — water-soluble contrast may be used
Patient Preparation
- No specific dietary restrictions (unlike UGI or esophagram)
- Patient may need to bring dentures if normally worn for eating
- Explain the exam: patient will swallow small amounts of barium-coated food/liquids while imaging is recorded
- Performed in collaboration with a Speech-Language Pathologist (SLP), who prepares consistencies and directs swallowing tasks
Routine Projections (ARRT Required)
Lateral Projection
CR Location & Positioning
- SID: 40–48 inches
- Patient position: Upright, seated laterally to the IR or fluoroscopic tower
- Adjustments: Chin slightly elevated; midsagittal plane parallel to IR; arms relaxed at sides
- CR: Perpendicular, directed to oropharyngeal region at level of C4–C6
- Patient instructions: Swallow on command when given food or liquid bolus
- Exposure: Continuous fluoroscopic recording during swallowing
Evaluation Criteria
- Coverage (what anatomy must be included and how you verify it’s complete): Oral cavity, pharynx, larynx, trachea, and cervical esophagus included.
- Rotation checks (how symmetry or alignment tells you if positioning is correct): Mandible and vertebral bodies superimposed; shoulders aligned.
- Motion checks (how sharpness confirms patient cooperation/exposure timing): Sharp anatomic detail of epiglottis, tongue, and bolus; minimal blur.
- Technique checks (what contrast, density, soft tissue visibility, and artifacts to look for): Adequate contrast for soft-tissue visualization; bolus clearly outlined.
- Clinical aim (when applicable, e.g., reflux, obstruction, displacement, etc.): Evaluate swallowing sequence, penetration, and aspiration risk in real time.
Supplemental Projections
AP Projection
CR Location & Positioning
- SID: 40 inches
- Patient position: Upright, facing the x-ray tube with back against upright detector
- Adjustments: Midsagittal plane centered; chin slightly elevated; shoulders relaxed
- CR: Perpendicular at C4–C6
- Patient instructions: Swallow on command when directed
- Exposure: Fluoroscopic recording during swallowing
Evaluation Criteria
- Coverage: Pharynx, larynx, and upper esophagus visible.
- Rotation checks: Trachea midline; mandible and hyoid symmetric.
- Motion checks: Bolus path and soft-tissue movement sharply visualized.
- Technique checks: Proper kVp to demonstrate soft tissues and airway; no overexposure.
- Clinical aim: Assess symmetry of bolus passage and pharyngeal wall motion.
Procedure Adaptation
- Pediatrics: Use small bolus volumes and thickened consistencies; maintain child comfort and cooperation.
- Geriatrics: Minimize study length due to fatigue; provide seating support.
- Tracheostomy patients: Use suction precautions and modified bolus as directed by SLP.
- Non-ambulatory patients: Perform in wheelchair or stretcher using lateral orientation.
Exposure Factors & Technical Considerations
- SID: 40–48 inches
- kVp: 80–100 (lower than UGI to enhance soft tissue and airway visualization)
- mAs: Very low — fluoroscopic recording captures motion
- Contrast:
- Thin liquid barium
- Thickened barium (nectar, honey consistency)
- Barium-coated semisolids (applesauce, cookie, cracker)
- Collimation: Include oral cavity through cervical esophagus
- Recording: Digital video capture is standard for SLP review
⚠️ Safety Note:
Barium is non-toxic to the respiratory system. If aspirated, it is less likely to cause pneumonia than water-soluble iodinated contrast. For this reason, barium is preferred for swallowing studies, except in cases where perforation is suspected, in which case iodinated contrast must be used.
Memory Aids
- “Lateral for Larynx” – The lateral view shows airway protection and aspiration clearly.
- “SLP Leads” – The Speech-Language Pathologist directs bolus size, texture, and timing.
- “Barium Bright, Airway Light” – Barium shows as bright contrast; airway remains radiolucent.
- “C4–C6 Centering Rule” – CR centered at the pharyngeal level of C4–C6 for all projections.
Hows & Whys of Swallowing Dysfunction Studies
Anatomy
- What is dysphagia?
Difficulty swallowing due to neurological, structural, or muscular causes that interfere with the normal passage of food or liquid. - Which structures are primarily evaluated during a swallowing study?
The oral cavity, pharynx, larynx (including the epiglottis and vocal folds), and upper esophagus. - What is the role of the epiglottis during swallowing?
It folds downward to cover the laryngeal inlet and prevent food or liquid from entering the airway. - How can aspiration be identified on fluoroscopy?
Contrast enters the trachea below the vocal cords rather than passing into the esophagus. - How can penetration be distinguished from aspiration?
Penetration stops above the vocal cords, while aspiration passes below them.
Positioning
- Why is the lateral projection preferred?
It demonstrates the entire swallowing sequence and provides the clearest view of potential aspiration into the trachea. - Why must the patient remain upright during the study?
The upright position simulates normal eating conditions and allows gravity to assist bolus movement. - Why is the chin slightly elevated during imaging?
It aligns the oropharynx and upper esophagus, allowing an unobstructed view of bolus movement. - Why is the study performed dynamically under fluoroscopy?
Swallowing is a rapid, coordinated motion that must be recorded in real time to assess timing, coordination, and aspiration risk.
Technique & Image Evaluation
- Why is barium used in swallowing studies?
Barium coats the food or liquid bolus, making its movement visible under fluoroscopy. It is non-toxic to the respiratory system, so if aspirated, it is less likely to cause chemical pneumonia than iodinated contrast. - Why are multiple consistencies of barium used?
Different viscosities—thin liquid, nectar, honey, pudding, and solid—test the patient’s ability to swallow safely under various conditions. - Why is video recording essential?
Frame-by-frame review allows the Speech-Language Pathologist (SLP) to analyze swallowing mechanics and recommend therapeutic or dietary adjustments. - How can correct lateral positioning be confirmed?
The mandible and cervical vertebrae are superimposed, and the shoulders appear aligned without rotation. - How can adequate exposure be evaluated?
Soft tissues of the pharynx, larynx, and upper esophagus are clearly visible with proper contrast and no motion blur. - How can the effectiveness of swallowing maneuvers be determined?
By comparing pre- and post-maneuver recordings to see if bolus transit and airway protection improve. - How can delayed swallowing be recognized?
Contrast pools in the vallecula or pyriform sinuses before the swallow reflex initiates. - How can aspiration or penetration be documented accurately?
By reviewing the recorded video to identify when and how deeply the contrast enters the airway.
Clinical Applications
- Who directs the swallowing tasks during the exam?
A Speech-Language Pathologist (SLP) in collaboration with the radiologist, while the radiographer manages imaging and technical factors. - Why might water-soluble contrast be substituted for barium?
If perforation is suspected, iodinated contrast is used because it can be absorbed by the body and poses less risk if leakage occurs. - Why is no patient preparation required?
The purpose is to simulate a natural eating environment so swallowing behavior reflects normal conditions. - Why is aspiration a major concern during this study?
If contrast enters the trachea or lungs, it may cause inflammation or aspiration pneumonia, particularly with large volumes or thin liquids. - How do variations in contrast consistency aid diagnosis?
They reveal which textures or viscosities the patient can swallow safely and which pose the greatest aspiration risk. - How should findings be recorded and reported?
Digital video documentation should accompany the radiologist’s and SLP’s written evaluation to guide treatment and dietary recommendations.