X-ray examination of the stomach

X-ray contrast examination techniques

Despite the rapid advancement of endoscopy and cross-sectional imaging, fluoroscopy (fluoroscopy) remains a critical diagnostic method. There are three main approaches to contrast administration:

1. Double-contrast examination. This method is essential for examining the finest details of the mucosal lining. The patient ingests an effervescent gas-producing agent followed by 100–150 ml of a high-density barium suspension. To evenly coat the entire mucosa, the patient is rotated 360 degrees. Antiperistaltic agents are sometimes administered additionally to eliminate motion artifacts. Targeted radiographs in various projections are acquired during the procedure.
2. Single-contrast examination. Used to evaluate full gastric filling, compression, and coarse mucosal relief. Images are taken in the upright (upright), supine (supine), and prone (prone) positions. This examination is usually combined with the evaluation of the esophagus and duodenum up to the ligament of Treitz.
3. Water-soluble contrast. Used exclusively under strict indications: suspected perforation (e.g., in peptic ulcer disease) or to check for anastomotic leakage after surgery. Barium suspension is strictly contraindicated in such cases, as its entry into the peritoneal cavity causes peritoneal fibrosis and granuloma formation. Water-soluble contrast is safe because it is easily absorbed by the peritoneum and excreted by the kidneys.

Effect of patient positioning on visualization

For quality contouring of the parts of the stomach, it is critically important to understand their spatial orientation in different postures:

• Supine position: In this position, the fundus (fundus) becomes the most posterior part of the stomach, and the lesser curvature forms its posterior wall. The antrum (antrum) projects anteriorly, and the greater curvature forms the anterior wall. Early filling of the duodenum is noted. In 10% of individuals, fine transverse folds of the antrum (gastric striae) may be visualized.
• Upright position: Optimal for creating double-contrast conditions of the gastric fundus.
• Right proximal oblique projection: Allows visualization of the proximal body of the stomach. With a semi-upright table tilt, the cardia and fundus are clearly traced.
• Flow technique: Fluoroscopic observation of a thin layer of barium bathing the mucosa during rotation. On the dependent wall, normal folds (rugal folds) appear as linear protrusions in a small pool of barium. On the non-dependent wall, the folds are outlined by a thin line of contrast, creating a "white-etched" effect.

Radiation anatomy and histological structure

The esophagus connects to the stomach at the esophagogastric junction (OGJ), whose barrier function is ensured by the lower esophageal sphincter and the crura of the diaphragm. Anatomically, the stomach is divided into several parts:

• Cardia: the junction zone between the esophagus and the stomach, located near the left dome of the diaphragm.
• Fundus: the rounded portion located superior and posterior to the cardia. This is predominantly the site of ghrelin-secreting cells, as well as parietal and chief cells.
• Body: the largest part, extending to the angular notch (incisura angularis) on the lesser curvature. Contains cells that produce hydrochloric acid and pepsin precursors.
• Antrum: separated from the body by a line drawn from the angular notch. Contains gastrin-producing cells.
• Pylorus: the muscular channel connecting the stomach to the duodenum.

Histological layers of the gastric wall:

1. Mucosa (mucosa): features invaginations (gastric pits). Includes the lamina propria (lamina propria) with blood vessels and lymphoid follicles, as well as the muscularis mucosae (muscularis mucosae).
2. Submucosa (submucosa): loose connective tissue containing blood vessels and nerve plexuses.
3. Muscularis propria (muscularis propria): consists of three layers: inner oblique, middle circular (forming the pyloric sphincter), and outer longitudinal.
4. Serosa (serosa): the outer layer, transitioning into the gastrocolic, gastrosplenic, and gastropancreatic/hepatogastric ligaments.

Note: The position of the stomach in the abdominal cavity varies. In muscular or obese patients, it lies more horizontally, whereas in asthenic (slender) and elderly individuals, it is more vertical.

Cross-sectional imaging (MSCT)

Multislice computed tomography (MSCT / MDCT) plays a leading role in modern oncology and is the gold standard for preoperative staging of gastric malignancies.

Thin section collimation provides isotropic visualization and enables multiplanar reconstruction. For targeted evaluation of the organ, CT gastrography (CT gastrography) is used. The success of this technique directly depends on adequate gastric wall distension (the patient needs to drink 1–1.5 liters of water and ingest effervescent granules) and correctly timed scanning following intravenous contrast administration. The examination is most often performed with the patient in the prone position (prone position).

Class and exam questions

What else to study on this topic

• Fluoroscopic examination of the esophagus and diagnosis of achalasia
• Esophagogastroduodenoscopy (EGD) and endoscopic mucosal resection (EMR)
• CT diagnosis of intestinal volvulus: "whirlpool" and "target" signs
• MRI and radiographic manifestations of gastrointestinal endometriosis
• Features of the MRI presentation of acute appendicitis in children

Other topics in the section "Diagnostic Radiology of the Abdominal Organs"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.