Normal X-ray anatomy of the stomach and duodenum

Before taking the contrast mass, there is a small amount of air in the stomach. When the body is in a vertical position, the gas bubble is located in the area of the vault. The rest of the stomach is a ridge with thick and maximally close walls.

The contrast mass swallowed by the patient, in a vertical position of the body, gradually passes from the esophagus into the stomach and descends from the cardiac opening into the body, sinus and antral section. Already after the first small swallows of barium, folds of the gastric mucosa appear - the relief of the internal surface of the organ appears. This folded relief is not constant and reflects the physiological state of the stomach.

In the area of the vault, various variants of the folds' course are observed; usually long and arcuate folds are combined here with transverse and oblique ones. In the body of the stomach, 3-4 longitudinal, slightly sinuous folds are determined. In the outlet part of the stomach, oblique and longitudinal folds predominate. They converge toward the pylorus, continue in its canal and in the bulb of the duodenum. However, starting from the upper bend of the duodenum, the relief of the mucous membrane changes sharply: transverse and oblique short folds appear. Only at the moment of the peristaltic wave's passage do they take a longitudinal direction.

As the stomach is inflated with air, the shape and thickness of the folds change and eventually they disappear. The images show a unique cellular pattern - a fine relief of the inner surface of the stomach. It is formed by oval and rounded elevations of 2-3 mm in size - areolas, or gastric fields. Fine relief differs from folded relief in its constancy.

After the entire contrast mass has been taken, the stomach, when the body is in a vertical position, takes the shape of a hook. It has the following main sections: the vault, body, sinus, antral section, and pylorus. The area around the cardiac opening is called the cardiac part (it has supra- and subcardial sections). The area on the lesser curvature where the body of the stomach passes into its outlet is called the angle of the stomach. A small part of the antral section in front of the pylorus - 2-3 cm long - is called the prepyloric (prepyloric) section. The pyloric canal is visible only when barium passes through it.

The duodenum is divided into the upper, descending and horizontal (lower) parts and three flexures: superior, inferior and duodenojejunum. In the upper part of the intestine, there is an ampulla, or, in radiological terminology, a bulb. In the bulb, there are two pockets - medial and lateral. In the descending part of the intestine, an oval elevation can be identified - a large papilla - the place where the common bile duct and the pancreatic duct (Wirsung's duct) flow into the intestine. Sometimes the Wirsung's duct flows into the intestine on its own. In such cases, radiologically, it is sometimes possible to detect a second oval elevation - the small papilla of the duodenum.

The muscular activity of the stomach is manifested by its contractions and relaxations, which can be recorded in a series of images, as well as peristaltic waves that follow from the cardia to the pylorus at intervals of approximately 20 s. The total duration of the wave's passage along this distance is approximately 20 s; 200 ml of aqueous barium suspension leave the stomach within 1>/2-3 hours. Food remains in the stomach much longer.

More accurate data on the evacuation of contents from the stomach can be obtained by dynamic scintigraphy. On an empty stomach, the patient is offered breakfast with a total weight of 500 g. Its standard composition is: 10% semolina porridge, tea with sugar, a piece of stale white bread. 99mTc colloid with an activity of 10-20 MBq is introduced into this breakfast. Scintigraphy begins immediately after the end of the meal (in a vertical position) and is repeated with a pre-selected frequency for 90 minutes. Then a computer analysis of a series of stomach scintigrams is carried out, the resulting curve is plotted, according to which the period of half-emptying of the stomach from a standard breakfast is determined. In healthy people, its duration is on average 45 minutes.

The gastric mucosa is capable of extracting 99mTc-pertechnetate from the blood and accumulating it. After its intravenous administration, a "hot zone" corresponding to the location of the stomach appears on scintigrams. This property is used to identify areas of ectopic gastric mucosa. Most often, its islets are found in the esophagus (the so-called Berrett esophagus) or in the diverticulum of the ileum (Meckel's diverticulum), located in its distal section. In the esophagus, this pathology can be complicated by inflammation and the development of a peptic ulcer, and in the Meckel's diverticulum - by diverticulitis and bleeding (these complications are more common in children in the first 2 years of life). To identify ectopic mucosa, 10 MBq of 99mTc-pertechnetate is injected into the patient's vein. When it is localized in the Meckel's diverticulum, the scintigram can show an area of RFP accumulation in the right iliac region.

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