GI Studies
38 Upper GI Series
Anatomy & Pathology
Anatomy
- Esophagus
- Esophagogastric Junction (Cardiac Orifice)
- Cardiac Sphincter
- Cardiac Notch
- Stomach
- Fundus
- Body
- Pylorus (including pyloric orifice & pyloric sphincter)
- Angular Notch
- Greater Curvature
- Lesser Curvature
- Rugae (gastric folds)
- Duodenum
- Duodenal Bulb
- C-loop
Common Pathologies (and Imaging Considerations)
- Peptic Ulcer Disease (PUD) – Localized erosion of the mucosa, usually in the duodenal bulb or lesser curvature.
Imaging Appearance: Crater-like “niche” with contrast collection.
Technical Consideration: Use double-contrast technique for mucosal detail; avoid excessive exposure that washes out the niche. - Hiatal Hernia – Protrusion of the stomach through the esophageal hiatus of the diaphragm.
Imaging Appearance: Fundus projects above diaphragm on AP or LPO; Schatzki ring may be visible.
Technical Consideration: Perform AP or LPO projection including diaphragm; reduce kVp slightly if imaging both thorax and abdomen. - Gastritis – Inflammation and thickening of the gastric mucosa.
Imaging Appearance: Thickened, nodular rugae; poor coating on double-contrast.
Technical Consideration: Use double-contrast with reduced barium volume; moderate kVp (~90 – 100) to enhance mucosal contrast. - Tumors (Neoplasms) – Benign (polyps) or malignant masses that distort stomach contours.
Imaging Appearance: Filling defect with smooth or irregular margins.
Technical Consideration: Use double-contrast, tight collimation, and delayed images to evaluate filling and emptying. - Diverticula – Outpouchings of the stomach wall, commonly near the cardia or pylorus.
Imaging Appearance: Contrast-filled sacculation projecting beyond wall.
Technical Consideration: May require slight oblique angle to separate diverticulum from stomach body. - Bezoars – Mass of undigested material (hair, fiber, etc.) within the stomach.
Imaging Appearance: Intraluminal filling defect with mottled gas pattern.
Technical Consideration: Use single-contrast to evaluate obstruction; may need horizontal beam to demonstrate mobility. - Gastroesophageal Reflux Disease (GERD) – Retrograde flow of gastric contents into the esophagus.
Imaging Appearance: Contrast seen refluxing into esophagus during fluoroscopy.
Technical Consideration: Demonstrated in Trendelenburg or Valsalva maneuver positions; use pulsed fluoro for motion control.
Indications, Contraindications, and Patient Preparation
Indications
- Evaluation of ulcers, tumors, hernias, and gastric motility
- Assessment of epigastric pain, nausea, vomiting, or weight loss
- Post-operative evaluation of gastric anatomy
- Detection of foreign bodies or masses (bezoars)
Contraindications
- Absolute: None
- Relative: Avoid barium sulfate if bowel perforation, laceration, or rupture is suspected. Use water-soluble iodinated contrast instead.
Patient Preparation
- NPO for at least 8 hours prior to exam (typically after midnight)
- No smoking or chewing gum during fasting period (to minimize gastric secretions)
- Explain the procedure and expected position changes to reduce anxiety and ensure cooperation
Projections
PA Stomach & Duodenum
CR Location & Positioning
- SID: 40 inches
- Patient position: Prone, midsagittal plane (MSP) centered to IR
- Adjustments: Arms raised near head, legs extended
- CR: Perpendicular to IR, centered at level of L1–L2 (1–2″ above lower rib margin) and 1″ left of MSP
- Patient instructions: Suspend respiration after expiration
- Exposure: On expiration
Evaluation Criteria
- Coverage: Entire stomach and duodenum included from fundus to C-loop.
- Rotation checks: Vertebral column aligned with midline; stomach symmetry indicates no rotation.
- Motion checks: Gastric folds (rugae) and duodenal contour sharp, with no peristaltic blur.
- Technique checks: Appropriate contrast—barium in body/pylorus and air in fundus; visible mucosal detail.
- Clinical aim: Evaluate gastric emptying and distal stomach for ulcers or pyloric obstruction.
RAO Stomach & Duodenum
CR Location & Positioning
- SID: 40 inches
- Patient position: Prone, rotated 40–70° RAO (more rotation for hypersthenic, less for asthenic habitus)
- Adjustments: Right arm down for stability, left arm flexed across chest; right knee bent for comfort
- CR: Perpendicular to IR at level of L1–L2 (1–2″ above lower rib margin), midway between spine and left lateral abdominal border
- Patient instructions: Suspend respiration after expiration
- Exposure: On expiration
Evaluation Criteria
- Coverage: Entire stomach and duodenum, including pyloric canal and duodenal bulb.
- Rotation checks: Duodenal bulb and C-loop open and in profile; no overlap of gastric body.
- Motion checks: Crisp mucosal folds; duodenal outline sharp.
- Technique checks: Barium fills body and pylorus; fundus air-filled; appropriate density and contrast.
- Clinical aim: Optimal view of pylorus and duodenal loop for ulcer, mass, or obstruction assessment.
Right Lateral Stomach
CR Location & Positioning
- SID: 40 inches
- Patient position: Right lateral recumbent, midcoronal plane (MCP) perpendicular to IR
- Adjustments: Knees slightly flexed; arms positioned anteriorly for comfort
- CR: Perpendicular to IR at level of L1–L2 (1–2″ above lower rib margin), midway between MCP and anterior abdomen
- Patient instructions: Suspend respiration after expiration
- Exposure: On expiration
Evaluation Criteria
- Coverage: Entire stomach and duodenum from fundus through pylorus and duodenal loop.
- Rotation checks: Posterior ribs and vertebral bodies superimposed; spine straight.
- Motion checks: Duodenal bulb and C-loop sharp with no peristaltic blur.
- Technique checks: Proper contrast—barium in body/pylorus, air in fundus; no cutoff or fogging.
- Clinical aim: Demonstrates posterior anatomy and gastric emptying; shows relationship of stomach to duodenum.
LPO Stomach
CR Location & Positioning
- SID: 40 inches
- Patient position: Supine, rotated 30–60° LPO (more for hypersthenic, less for asthenic habitus)
- Adjustments: Right arm across chest; left arm extended from body; knees flexed slightly for stability
- CR: Perpendicular to IR at level of L1–L2 (1–2″ above lower rib margin), midway between xiphoid tip and lower rib margin, and between spine and left lateral border
- Patient instructions: Suspend respiration after expiration
- Exposure: On expiration
Evaluation Criteria
- Coverage: Entire stomach and duodenum included; diaphragm superiorly if assessing hernia.
- Rotation checks: Fundus barium-filled and free of overlap; pylorus and bulb air-filled and unobscured.
- Motion checks: Sharp fundic and duodenal borders; no motion blur.
- Technique checks: Adequate exposure for mucosal coating and rugae detail; balanced contrast.
- Clinical aim: Demonstrates fundic region and hiatal hernia; used for reflux and fundus pathology evaluation.
AP Stomach
CR Location & Positioning
- SID: 40 inches
- Patient position: Supine, MSP centered to IR
- Adjustments: Arms at sides, legs extended; ensure pelvis not rotated
- CR: Perpendicular to IR, centered at level of L1–L2 (bottom of IR at iliac crest) and to MSP
- Patient instructions: Suspend respiration after expiration
- Exposure: On expiration
Evaluation Criteria
- Coverage: Entire stomach and duodenum, including diaphragm for hernia evaluation.
- Rotation checks: Symmetric gastric outline; spine centered over sacrum.
- Motion checks: No blur of gastric folds or diaphragm.
- Technique checks: Fundus barium-filled; body and pylorus air-filled; uniform contrast and density.
- Clinical aim: Shows overall gastric shape, position, and hiatal hernia; evaluates reflux or retained contrast.
Procedure Adaptation
- Body Habitus
Hypersthenic → stomach higher and transverse; increase rotation for obliques
Asthenic → stomach lower, J-shaped; decrease rotation - Pediatric Patients
Smaller contrast volume and shorter exposure time - Pathology-Specific Modifications
Ulcer study → use double-contrast and short exposure
Hiatal hernia → include diaphragm on AP/LPO
Gastritis → double-contrast with low barium volume
Tumor or diverticulum → tight collimation and oblique views - Limited Mobility Patients
Use decubitus or semi-erect position if unable to rotate adequately
Exposure Factors & Technical Considerations
- kVp: 100–125 for single-contrast; 90–100 for double-contrast
- mAs: Moderate, short exposure to minimize motion
- SID: 40 inches
- Collimation: To stomach and proximal duodenum region
- Shielding: Gonadal shielding when possible
- Contrast media:
- Barium sulfate (thin for motility studies, thick for mucosal coating)
- Water-soluble iodinated contrast (Gastrografin) if perforation suspected
Memory Aids
| Projection | Body Region Best Shown | Barium Location | Air Location |
|---|---|---|---|
| PA | Body and Pylorus | Body & Pylorus | Fundus |
| RAO | Duodenal Bulb and C-loop | Body & Pylorus | Fundus |
| Right Lateral | Pylorus and C-loop | Body & Pylorus | Fundus |
| LPO | Fundus | Fundus | Body & Pylorus |
| AP | Entire stomach & diaphragm (hiatal hernia) | Fundus | Body & Pylorus |
Hows & Whys of UGI Radiography
Anatomy
- What are the major regions of the stomach?
The fundus, body, and pylorus — responsible for storage, mechanical digestion, and emptying into the duodenum. - How does stomach position vary by body habitus?
It’s high and transverse in hypersthenic patients and low and J-shaped in asthenic or hyposthenic patients. - What structure connects the esophagus to the stomach?
The esophagogastric junction, controlled by the cardiac sphincter. - What part of the stomach joins the duodenum?
The pylorus, ending at the pyloric orifice and sphincter. - What is the duodenal bulb and C-loop?
The bulb is the widened first portion; the C-loop curves around the pancreatic head and is the primary site for duodenal ulcers.
Positioning
- Why is the PA projection performed with the patient prone?
Prone positioning spreads the stomach and uses gravity to fill the body and pylorus with barium while leaving the fundus air-filled. - Why is the patient rotated 40–70° for the RAO projection?
This angle opens the duodenal bulb and C-loop in profile and demonstrates gastric emptying dynamics. - Why is the Right Lateral projection obtained?
It shows the posterior stomach, pylorus, and C-loop without superimposition and evaluates motility toward the duodenum. - Why is the LPO position used?
It fills the fundus with barium and the body/pylorus with air, revealing fundic lesions and hiatal hernias. - Why is the AP projection obtained?
It demonstrates the entire stomach and duodenum with the diaphragm included to assess hiatal hernia or reflux. - Why should respiration be suspended after expiration?
To minimize motion, elevate the diaphragm slightly for consistent organ positioning, and reduce the amount of lung tissue included in the image, making the overall radiographic contrast more uniform across the stomach and duodenum. - Why must the degree of rotation vary with body habitus?
Hypersthenic patients require greater rotation (up to 70°) to separate stomach structures, while asthenic patients need less (about 40°). - Why must the CR center be adjusted to the level of L1–L2 for most projections?
Because the stomach lies near this level in average patients; shifting the CR ensures coverage of the duodenal bulb and gastric body. - Why should the patient’s right side be down for the RAO?
Gravity directs the contrast through the pylorus into the duodenum, outlining the C-loop optimally. - Why is a pillow or support used under the knees for supine positions?
It relaxes abdominal muscles, reducing lumbar lordosis and improving comfort and gastric positioning. - Why are feet and legs extended for PA or AP positions?
To prevent pelvic rotation that could obscure gastric orientation. - Why is NPO status required for at least 8 hours?
Food, fluid, and smoking stimulate gastric secretions that obscure barium coating and distort results. - Why must patients avoid chewing gum or smoking before the exam?
Both increase saliva and gastric acid, diluting the contrast and interfering with mucosal visualization.
Technique & Image Evaluation
- What does an upper GI study evaluate?
The form and function of the distal esophagus, stomach, and duodenum. - What type of contrast media is typically used?
Barium sulfate — thin for motility studies, thick for mucosal coating in double-contrast exams. - When is a double-contrast study preferred?
When evaluating ulcers, polyps, diverticula, or small mucosal lesions. - Why is barium contraindicated in suspected perforation?
Because it is not absorbed and may require surgical removal if it leaks into the peritoneal cavity. - What contrast is used if barium is contraindicated?
A water-soluble iodinated agent such as Gastrografin. - What allergies must be assessed before using iodinated contrast?
Iodine, seafood, or prior reactions to contrast dye. - How can you confirm proper positioning on each projection?
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PA: Pylorus centered; barium in body/pylorus, air in fundus.
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RAO: Duodenal bulb and C-loop open in profile.
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Right Lateral: Posterior ribs superimposed, pylorus clearly outlined.
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LPO: Fundus barium-filled, bulb and pylorus air-filled.
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AP: Stomach and diaphragm fully included, rugae visible.
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- How do you know if the degree of rotation was appropriate on oblique projections?
Over-rotation foreshortens the bulb; under-rotation leaves it partly behind the spine. - How can you verify that exposure was correct?
Sharp gastric folds and trabecular bone pattern with visible contrast layering; no motion or fog. - How should kVp be adjusted for double-contrast exams?
Use slightly lower kVp (90–100) to enhance mucosal coating and air contrast. - How do you detect motion blur?
Loss of rugal detail and hazy margins around the duodenal loop. - How can you evaluate peristalsis fluoroscopically?
By watching rhythmic contractions that propel contrast through the pylorus into the duodenum.
Clinical Applications
- What are the common indications for an upper GI study?
Peptic ulcers, hiatal hernia, gastritis, tumors, diverticula, bezoars, or unexplained upper abdominal pain. - What are peptic ulcers, and what happens if untreated?
Erosions of the gastric or duodenal mucosa that may perforate, causing peritonitis. - What is a hiatal hernia?
Protrusion of part of the stomach through the diaphragm’s esophageal hiatus into the thorax. - What is gastritis?
Inflammation of the stomach lining that may appear as thickened, nodular rugae on double-contrast imaging. - What are stomach polyps, and can they be cancerous?
Small mucosal growths that can be benign or malignant; appear as smooth filling defects. - What are diverticula?
Outpouchings of the gastric wall that fill with contrast, usually near the cardia or pylorus. - What are bezoars?
Masses of indigestible material producing mottled filling defects within the stomach. - How can hiatal hernia be best demonstrated?
AP or LPO projections including the diaphragm, with fundus barium-filled. - How does gastritis alter technical approach?
Use double-contrast to visualize mucosal irregularities and avoid overexposure that masks fine detail. - How can ulcer disease be best demonstrated?
In RAO or Right Lateral positions, using double-contrast for crater visualization and mucosal fold convergence. - How can reflux be provoked or confirmed?
With the Valsalva maneuver or slight Trendelenburg position during fluoroscopy.
