Overview
This lecture reviews key concepts in fluoroscopy imaging, focusing on body habitus effects on anatomy position and techniques for interpreting barium studies.
Body Habitus and Organ Position
- Body habitus affects organ placement on imaging, which is crucial for accurate fluoroscopic interpretation.
- Hypersthenic (large/broad) patients have organs pushed upward and outward; gallbladder and duodenal bulb at T11-T12, colon high.
- Sthenic (average) patients have midline organs; gallbladder at T12-L1, duodenal bulb at L1-L2, left colic flexure higher than right.
- Asthenic/hyposthenic (slender) patients have J-shaped, low-lying stomach and gallbladder at L3-L4 near the iliac crest; intestines are also low.
Stomach Position and Fundus Orientation
- The stomach's orientation varies: transverse in hypersthenic, mid in average, J-shaped/vertical in asthenic.
- Fundus is posterior to the stomach body, important for determining air vs. barium location in images.
Patient Positions and Imaging Interpretation
- Common positions: supine (on back), prone (on stomach), RAO (right anterior oblique), LPO (left posterior oblique), and right lateral.
- Degree of rotation for obliques increases with patient size (RAO: 40–70°, LPO: 30–60°).
Imaging Characteristics by Position
- Supine: Barium collects in the fundus (lowest point); air rises to the body.
- Prone: Air in fundus, barium moves to the body.
- Oblique: Use spine appearance (no spinous processes midline, possible "Scotty dogs") and air/barium location to identify position.
- Lateral: Lateral vertebrae seen, emphasis on retrogastric space.
Barium Swallow (Esophagram) Technique
- Primary focus is the RAO position for best esophageal imaging.
- In RAO, esophagus moves between spine and heart shadow; check for proper rotation to avoid overlap.
- Patient swallows barium during exposure to visualize esophagus.
Key Terms & Definitions
- Body Habitus — Patient's body build/type, affecting organ location.
- Fundus — Upper, posterior part of the stomach.
- Barium — Radiopaque contrast agent used to highlight the GI tract in imaging.
- RAO (Right Anterior Oblique) — Patient rotated right front toward the table, used for esophagus imaging.
- LPO (Left Posterior Oblique) — Patient rotated left back toward the table.
- Retrogastric Space — Area behind the stomach.
Action Items / Next Steps
- Review body habitus effects on organ location for image interpretation.
- Practice identifying patient position using air/barium distribution and spine appearance.
- Focus on RAO positioning for barium swallow prep.