Normal X-ray anatomy of the colon and rectum

In normal pictures, there is no clear image of the colon and rectum. If you take pictures after taking the patient's aqueous suspension of barium sulfate inside, you can register a passage of contrast mass through the digestive canal. From the terminal loop of the ileum, the barium passes into the cecum and then subsequently moves to the remaining parts of the large intestine. This method - the method of "contrasting breakfast" - is used only to assess the motor function of the colon, but not to study its morphology. The fact is that the contrast content is distributed unevenly in the intestine, mixed with food slags, and the mucosal relief is not displayed at all.

The main ray method of research of the colon and rectum is their retrograde filling with contrasting mass - irrigoscopy.

In this study, careful preparation of the patient for irrigoscopy is very important: a slag-free diet for 2-3 days, intake of laxatives - one tablespoon of castor oil on the day before, a series of cleansing enemas - the night before and early in the morning on the day of the study. Some radiologists prefer the preparation with the help of special tablets, for example, contact laxatives, which promote the rejection of fecal matter from the intestinal mucosa, as well as the use of laxative suppositories and magnesium sulfate.

The aqueous barium suspension is introduced through the anus with a Bobrov apparatus in an amount of 600-800 ml. Assess the position, shape, size, outlines, displacement of all parts of the colon and rectum. Then the patient is offered to empty the large intestine. As a result, the bulk of the contrast suspension is removed from the intestine, and the plaque of barium remains on the mucosa and outlines its folds.

After studying the relief of the mucous membrane in the large intestine, under the control of fluoroscopy, up to 1 liter of air is injected. This makes it possible to assess the extensibility (elasticity) of the intestinal wall. In addition, against the background of stretched folds of the mucous membrane, the slightest irregularities are better, for example granulation, polyps, small cancers. A similar technique is called double contrasting of the large intestine.

In recent years, the method of simultaneous double contrasting of the colon has become widespread. In this study, a relatively small amount of contrast mass, about 200-300 ml, is first introduced into the intestine, and then under airflow control, air is dosed and carefully injected, thus pushing in the air column the bolus of the barium suspension introduced earlier, proximally, up to the ileocecal valve. Then a series of survey radiographs of the abdominal organs are made in standard positions, supplementing them with separate pictures of the intestinal portion of the intestine. An obligatory condition for carrying out the research on the method of primary double contrasting is preliminary medication hypotonia of the intestine.

The large intestine occupies mainly the peripheral parts of the abdominal cavity. In the right ileal region is the cecum. At its lower pole, the vermiform appendix is often filled with a contrasting mass in the form of a narrow canal 6-10 cm in length. The cecum without sharp boundaries passes into the ascending colon, which rises to the liver, forms a right bend and continues into the transverse colon. The latter goes to the left, forms a left bend, from which along the left side wall of the abdominal cavity the descending colon proceeds. In the left iliac region, it passes into the sigmoid colon, forming one or two bends. Its continuation is the rectum, which has two bends: sacral, convex toward posterior, and perineal - convex anteriorly.

The largest diameter is the cecum; in the distal direction, the diameter of the large intestine generally decreases, again increasing when passing into the rectum. The contours of the large intestine are wavy because of the Gaustral constrictions, or the caustic. When oral colon is filled, the Hausters are relatively evenly distributed, with smooth, rounded outlines. However, the distribution, depth and shape of the caustic changes in connection with the movement of intestinal contents and movements of the intestinal wall. At an irrigoscopy gaustrace is less deep, and in places it is imperceptible. On the inner surface of the gut, the half-moon folds of the mucosa correspond to the gaustres. In those departments where the contents stay longer, oblique and transverse folds prevail, and in those departments that serve to excrete stool masses, narrow longitudinal folds are more often visible. Normally the relief of the intestinal mucosa is variable.

[1], [2], [3]