Normal radiographic anatomy of the esophagus

On an empty stomach, the esophagus is a narrow tube with collapsed walls. It is not visible on conventional radiographs. During the act of swallowing, air bubbles swallowed with food can be seen moving along the esophagus, but the walls of the esophagus still do not provide an image, so the basis of the radiological examination is artificial contrasting with an aqueous suspension of barium sulfate. Even observing the first small portion of liquid aqueous suspension allows for a rough assessment of the act of swallowing, the movement of the contrast mass along the esophagus, the function of the esophageal-gastric junction, and the entry of barium into the stomach. The patient's intake of a thick aqueous suspension (paste) of barium sulfate makes it possible to leisurely examine all segments of the esophagus in various projections and in different body positions and, in addition to fluoroscopy, to take all the necessary pictures or video recording.

The esophagus filled with a contrast mass causes an intense ribbon-like shadow on radiographs with a diameter in different sections from 1 to 3 cm. The shadow begins at the level of CVI, where a flat depression caused by the cricopharyngeal muscle is noticeable on its posterior contour. This is the first physiological narrowing of the esophagus (the first esophageal sphincter). At the level of the aortic arch, a flat depression is determined on the left contour of the esophageal shadow (the second physiological narrowing) and slightly lower - a shallow depression from the left main bronchus (the third physiological narrowing). Above the diaphragm, on inspiration, especially in a horizontal position, the esophagus forms a pear-shaped expansion - the esophageal ampulla.

On inspiration, the advancement of the contrast mass stops at the level of the esophageal opening of the diaphragm; the shadow of the esophagus is interrupted at this point. The length of the intradiaphragmatic segment of the esophagus is 1-1.5 cm. The supra-, intra- and subdiaphragmatic segments form the so-called esophagogastric junction, or vestibule. They are considered the lower esophageal sphincter (the fourth physiological narrowing). The right contour of the subdiaphragmatic segment directly continues with the lesser curvature of the stomach, and the left contour forms a cardiac notch (angle of His) with the contour of the fornix of the stomach. In healthy people, the angle of His is always less than 90°.

The contours of the esophagus shadow are always smooth. Peristaltic contractions cause waves moving along the contours (at a speed of 2-4 cm per 1 sec). After the main part of the contrast mass has passed into the stomach, a barium sulfate coating remains in the interfold spaces of the esophagus. Due to this, the folds (normally 3-4) of the mucous membrane are visible in the images. They have a longitudinal direction, wavy outlines, and change at the moment of passage of peristaltic waves.

X-ray examination allows to evaluate all phases of esophageal activity: its relaxation upon receipt of contrast agent, subsequent contractions and, finally, the phase of complete collapse (motor pause). At the same time, the function of the upper and lower esophageal sphincters is determined. Esophageal motility can also be studied using dynamic scintigraphy. For this, the patient is asked to swallow 10 ml of water containing a colloid labeled with 99mTc, with an activity of 20 MBq. The movement of the radioactive bolus is recorded on a gamma camera. Normally, the colloid passes through the esophagus in less than 15 s.

Foreign bodies of the pharynx and esophagus

Each patient who has swallowed a foreign body should be under medical supervision until it is removed or exits through natural passages. Metallic foreign bodies and large bones are detected by fluoroscopy, radiographs and CT scans. It is easy to determine their nature and localization. Sharp objects (needles, nails, pieces of bone) can get stuck in the lower parts of the pharynx and piriform sinus. If they are low-contrast, then an indirect symptom is deformation of the pharyngeal lumen due to soft tissue edema. An increase in the volume of prevertebral tissue is observed when a foreign body perforates the wall of the cervical esophagus. Sonography and AT facilitate the detection of this lesion (foreign body shadow, small air bubbles in soft tissues, fluid accumulation in them).

If the X-ray does not reveal a foreign body in the pharynx and esophagus, images of the abdominal organs are taken, since the foreign body could have moved into the stomach or small intestine. If it is assumed that a foreign body, invisible on the X-ray, is still in the esophagus, the patient is asked to drink a full teaspoon of thick barium sulfate suspension, and then two or three sips of water. Normally, water washes away the contrast mass, but if there is a foreign body, it partially lingers on it. Particular attention is paid to the areas of physiological constrictions, since most foreign bodies get stuck there.

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