Normal X-ray anatomy of the small intestine
Last reviewed: 23.04.2024
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Normal small intestine
The most physiological method of artificial contrasting of the small intestine is oral contrasting, achieved by taking an aqueous suspension of barium sulfate inside. Passing the stomach and duodenum, the contrast mass enters the skinny and then into the ileum. After 10-15 minutes after taking barium, the shadow of the first loops of the jejunum is determined, and in 1-2 hours the remaining parts of the small intestine are determined.
The phases of filling the small intestine are fixed on radiographs. If it is necessary to accelerate the progress of the contrast mass, then use strongly chilled barium, which is taken in separate portions, or additionally an ice isotonic sodium chloride solution. The effect of accelerating the passage of barium is also observed under the influence of subcutaneous injection of 0.5 mg of prostigmine or intramuscular injection of 20 mg of metoclopramide. Disadvantages of this method of research of the small intestine are the long duration of the procedure and the relatively high radiation load.
All oral methods of artificial contrasting have a significant disadvantage: the filling of the gut is uneven, fragmentary, individual segments of it are not visible at all on radiographs. As a result, according to the results of oral contrasting, only an approximate idea of the morphological state of the small intestine can be made.
The main method of X-ray examination (X-ray) of the small intestine is radiocontrast enterocolism.
In this study, an elongated intestinal tube (or special catheter) is inserted into the duodenum in order to uniformly tightly fill the small intestine in conditions of artificial medication hypotension of the intestine. 600-800 ml of an aqueous suspension of barium sulphate is poured through the probe. Normally, within 10-15 minutes, the contrast mass fills the entire small intestine and begins to enter the blind. This makes it possible to study the morphological features of the jejunum and ileum. To improve visualization of the intestinal wall after the barium suspension through the catheter into the intestine, air is dosed, i. E. Perform a double contrasting of the small intestine.
The jejunal loops are located mainly in the central parts of the abdominal cavity. They have the form of narrow ribbons with a width of 1.5-2 cm, the contours of the intestine are dentate, since narrow dents are uniformly distributed on them - a reflection of the circular (kerkring) folds of the mucous membrane. The creases themselves are distinguished as gentle transversely and obliquely directed strips, the arrangement and shape of which vary with various movements of the intestinal loops. At the time of the passage of circular waves, the folds take a longitudinal direction. In general, for the jejunum, the so-called pinnate relief pattern of the inner surface is considered to be characteristic. The loops of the ileum are lower, often in the pelvic region. In the course of the ileum, the serration of the contours becomes less and eventually disappears. Caliber of wrinkles decreases from 2-3 mm in the intestine to 1-2 mm in the ileum.
The last loop of the ileum empties into the cecum. On the site of the confluence there is an ileocecal valve (Bauginia flap), its edges appear as semi-oval recesses on the contour of the cecum. Observing the intestinal loops with the help of fluoroscopy, one can see their various movements that promote the movement and mixing of the contents: tonic contractions and relaxations, peristalsis, rhythmic segmentation, pendulum movements. In the ileum, as a rule, its segmentation is noted.
Suction processes in the small intestine are studied using radionuclide techniques. If suspected of pernicious anemia, examine the absorption of vitamin B 12 in the intestine. For this, the patient takes inside the RFP: Co-B 12, while one of them is associated with an internal gastric factor (VGF), which is secreted by the gastric mucosa. In his absence or with a deficiency, absorption of vitamin B 12 is impaired . Then the patient is parenterally administered a large amount of unlabeled vitamin B 12 - about 1000 mcg. Stable vitamin blocks the liver, and its radioactive analogues are excreted in the urine. By collecting the urine released per day and determining its radioactivity, it is possible to calculate the percentage of absorbed B 12. Normally, the excretion of this vitamin with urine is 10-50% of the dose administered. As noted above, the patient takes two RFPs. Since the emissions of two cobalt radionuclides differ in their characteristics, this makes it possible to find out what is the basis for poor absorption of the vitamin-lack of VFD or other causes (impaired absorption in the intestine, genetically altered transport of vitamin B 12 by blood proteins, etc.).
Absorption of neutral fat and fatty acid in the small intestine is evaluated after the patient's intake of labeled trioleate-glycerol and oleic acid. Most often this is used to establish the cause of the steatorrhoea, i.e. Increased fat content in stool. A decrease in the absorption of trioleate-glycerin indicates that steatorrhea is associated with an inadequate release of lipase, a pancreatic enzyme. The absorption of oleic acid is not disturbed. In diseases of the intestine, the absorption of both trioleate-glycerin and oleic acid is impaired.
After taking these drugs, radiometry of the whole body of the patient is made twice: first without a screen, and then with a lead shield over the stomach and intestines. The radiometry is repeated after 2 and 24 hours. The assimilation of trioleate-glycerol and oleic acid is judged by their content in the tissues.
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