Cholecystography

Cholecystography is a unique method for diagnosing the condition of the gallbladder and bile ducts using x-rays. Thanks to this approach, it is possible to visualize the hollow bladder and its ducts in the images more clearly and in detail than, for example, with ultrasound, due to the introduction of a contrast agent, a substance containing iodine, to the patient. This diagnostic method, although not absolutely safe, is often used if a patient has suspected diseases of the biliary tract or bladder, the presence of stones, neoplasms, inflammation or other pathologies in them.

Cholecystography – the essence and objectives of the study

Diagnostic methods using X-rays to obtain images of human internal organs began to be used in medicine in the first half of the 20th century. Thanks to the discovery of X-rays in 1895, medicine received a powerful tool for studying bone, muscle, connective and other types of tissues, as well as organs and the vascular system without the use of surgical intervention.

Radiography of the gallbladder using contrast was first experimentally carried out in 1923-1924. Then the scientists intravenously administered the sodium salt of tetraiodphenolphthalein to dogs, after which they fixed the image of the organ in the pictures. Many theorists and practitioners of medicine carried out the development of this method in the future, making every effort to ensure that the experiment conducted on animals became a full-fledged way to examine the human biliary tract and bladder. Ya.G. Dillon, A.A. Lemberg, N.E. Stern, N.F. Mordvinkin and other scientists worked towards studying the possibilities of contrast radiography of the gallbladder and bile ducts.

With the invention in 1946 of a special contrast agent – a diiodinated derivative of a-phenylpropionic acid – the procedure became a little safer for human health. Bilitrast, as well as later synthesized vesipak, triodan, cystobil, telepak, can increase the percentage of positive cholecystography: approximately 50-70% of studies can achieve a high-quality image of the intrahepatic bile ducts.

For what purposes can the attending physician prescribe the procedure? The survey is carried out for:

• establishing the size and contours of the gallbladder;
• assessment of the contractility of the walls of the organ;
• displaying the dimensions and contours of the bile ducts;
• detection of stones in the bladder and ducts;
• confirmation of the presence of inflammatory or neoplastic processes.

Gallbladder and bile ducts: anatomy and function

The gallbladder looks like a small pear-shaped sac. Its main function is the accumulation of bile produced by the liver. Anatomically, in the bladder, the bottom, walls or middle part, and the neck are distinguished, while the bottom has a wider diameter, and then the walls and neck gradually narrow. The length of the bubble is from 8 to 12 centimeters, the width is 3-5 centimeters. The walls of the gallbladder are thin.

From the proximal narrow part – the neck of the bladder – the cystic duct departs, having the form of a hollow tube. Connecting with the hepatic duct, it forms the common bile duct.

The bubble is located on the visceral side of the liver, it lies in a special hole in the organ. This depression separates the anterior section of the right lobe of the liver and the quadrate lobe. The bottom of the bubble is directed to the lower edge of the liver, the neck looks towards the hepatic gate. In the place where the body of the bubble passes into the neck, there is usually a functional bend, and the neck is located at some angle to the body.

The bladder is adjacent to the fossa with its anterior surface, where it connects to the fibrous membrane of the liver. Its surface, directed towards the abdominal cavity, is covered with a visceral peritoneum, which passes from the liver to the bladder.

The walls of the gallbladder are made up of three layers:

• external serous;
• muscular;
• internal mucosa.

In the area of ​​the peritoneum, the wall is covered with a loose thin connective tissue layer – the subserous base.

There are three intrahepatic bile ducts:

• common hepatic;
• vesicular;
• common bile.

The first of them is located at the gates of the liver, consists of two other hepatic ducts – left and right. Descending in the hepatoduodenal ligament, the common hepatic duct passes into the cystic duct, which originates from the neck of the bladder, forming the common bile duct.

The main function of the gallbladder is to work inextricably with the liver. The bile produced by the liver accumulates in the sac until food enters the body. To process fatty and high-calorie foods, the bladder releases a supply of bile into the duodenum, which, together with pancreatic and intestinal enzymes, processes the food bolus. In turn, the bile ducts transport the accumulated bile to the intestines.

Varieties of cholecystography

The main feature by which doctors differentiate the procedure of cholecystography or cholegraphy is the way the contrast agent enters the patient’s body. According to the method of administration of the contrast agent, the following types of X-ray examination of the gallbladder are distinguished:

• intravenous cholecystography, when contrast is injected through the vascular system by jet using a syringe;
• oral procedure: in this case, the subject drinks a special solution containing a contrast agent;
• infusion cholegraphy: the contrast agent is very slowly injected intravenously with a special catheter;
• percutaneous: the method is used if the patient has diagnosed liver dysfunction, while the contrast is injected into the gallbladder and ducts by puncture.

It should be noted that the latter diagnostic method is practically not used now, as it often causes complications – sepsis, allergies, in some cases – death.

Indications for the procedure, possible contraindications

Considering that cholecystography directly uses the properties of X-rays, and a contrast agent must be injected to the patient to obtain an image, there must be objective reasons for the appointment of such an examination – indications for conducting.

Among such indications is the need to confirm one of the possible diagnoses:

• suspicion of cholecystitis;
• tumor diseases of the organ;
• dyskinesia;
• stones in the ducts or gallbladder.

Also, diagnostics can be prescribed if the patient has some of the following symptoms:

• pain in the right hypochondrium;
• bitterness in the mouth;
• belching, nausea, vomiting, heaviness in the right side, especially after eating;
• discoloration of the feces, accompanied by a significant darkening of the urine.

As for the prohibitions on the appointment of diagnostics, they are mainly associated with the introduction of contrast into the body. Contraindications can be absolute or relative. The former make the procedure completely impossible due to the level of risk for the subject. Cholecystography is contraindicated in patients with:

• liver failure;
• allergy to contrast agents;
• cardiovascular insufficiency;
• acute inflammatory diseases of the liver.

Relative contraindications require the decision of the attending physician in each specific case – if the need for diagnosis and the benefits of it outweigh the potential harm, the doctor may prescribe cholecystography at his own responsibility.

Relative contraindications are:

• acute cholangitis;
• cirrhosis of the liver
• pregnancy, breast-feeding;
• jaundice.

How to prepare for an examination

When prescribing cholegraphy, doctors focus on the fact that the quality of diagnostic results directly depends on how responsibly the subject follows the preparation rules.

The patient preparation algorithm includes a mandatory slag-free diet. Five days before the appointed date, it is necessary to exclude from the diet all foods that increase gas formation in the intestines:

• bread, especially black, confectionery;
• beans;
• carbonated and alcoholic drinks;
• milk and dairy products;
• fatty meat and fish;
• vegetables and fruits rich in coarse fiber.

During the day, the doctor can test a person for sensitivity to bilitrast. To do this, he is intravenously injected with 1 milliliter of the drug, diluted with 10 milliliters of saline.

On the day before the examination, it is also necessary to comply with some requirements for the menu. In the first half of the day, it is allowed to eat dense, ordinary food, with the exception of the above products. This is necessary so that the bile that has already accumulated in the bladder comes out of it. Lunch, snacks and dinner should already be as light and fat free as possible so as not to cause a contraction of the bladder.

In the morning before the procedure, it is forbidden to eat and drink – cholecystography is carried out strictly on an empty stomach.

As part of preparation for oral cholecystography, the patient must drink the drug with a contrast 12-14 hours in advance. The dosage of the substance is calculated by the attending physician, focusing on the weight of the subject. After using the drug, a person needs to lie down on his right side so that the liquid is better absorbed. Before going to bed, a cleansing enema is placed, and in the morning before cholecystography it can be repeated. The contrast agent may cause nausea and loose stools. After that, the subject is also forbidden to drink, chew gum and smoke.

The procedure for diagnosing the gallbladder

Before the examination, the doctor-diagnostician makes a survey radiography of the right hypochondrium to assess the degree of readiness of the digestive organs. Also, the image taken will help identify shadow formations that may indicate the presence of stones, gas, and lime deposits in the bile ducts.

The algorithm of the procedure consists of two stages: first, an image of the filled organ is recorded, then pictures of the bladder are taken after emptying.

The patient is placed on a special couch for imaging with contrast, first in the “prone” position. Next, the doctor asks the subject to move to the left side, stand up straight, while paying attention to the delamination of the contents of the bladder or the presence of mobile filling defects.

The shadow of the contrasted gallbladder is displayed on the center of the screen, and in the absence of a contrast image, on the area of ​​its projection. The projection point of the organ is located at the intersection of the outer edge of the right abdominal muscle and the arch of the ribs. Given the differences in the size and position of the gallbladder and liver, the projection site may differ.

In the pictures, the bubble can be reduced or enlarged, deformed, wrinkled, located in the upper part of the right hypochondrium, or extending into the pelvic cavity. Also, the organ can deviate to the left or right, while its shadow will be superimposed on the right kidney or vertebrae.

If the subject has a blockade of the gallbladder (obstruction of the cystic duct), his shadow will not be visualized on the picture. In addition, the incompleteness of the organ with contrast can also be explained by functional disorders, for example, a deterioration in the excretory function of the liver.

The second stage of diagnosis begins after the patient is given choleretic food or medicine – this is how the phase of contraction and emptying of the bladder begins. During this stage, the doctor can evaluate the so-called evacuation function of the organ, and as the contrasted bile decreases from it, determine the size and location of stones, scars or neoplasms in the walls.

The common bile duct is visualized on images taken after 15 and 30 minutes. If the emptying function is slow, the last image is taken after 60 minutes.

Holography for children

The general requirements for the preparation of a child and the implementation of diagnostics in children are similar to the rules for adults.

The child should be fed on a slag-free diet, gradually removing forbidden foods from his diet. To cleanse the intestines, the doctor may recommend doing an enema the day before the procedure.

Contrast preparations for a child are prescribed at the rate of 0,1 – 0,3 grams per kilogram of body weight.

Features of the interpretation of the results of the study

The image obtained during the diagnostics is studied by a doctor-radiologist. The transcript of the results is issued in the form of a medical report.

Normally, in the pictures of the first stage of the study, the bladder is completely filled with contrasting bile. It has thin, smooth walls and a pear shape. Sizes may vary, but do not exceed 10-12 centimeters in length, 5 centimeters in width. At the same time, the picture should clearly visualize all parts of the organ – the bottom, neck, walls.

If, during normal filling of the gallbladder, mobile contrast defects are present, this indicates the presence of stones in the organ cavity. Fixed contrast defects that are not mobile in nature indicate the location of polyps or neoplasms.

Incomplete filling of the organ with contrast bile is also a deviation from the norm. Usually the cause of such a violation is an inflammatory pathology (calculous or acalculous cholecystitis). Due to inflammation, the patency of the bile ducts is disturbed, and bile cannot normally enter the organ.

If the subject has a violation of the contractile activity of the bladder after ingestion of choleretic food, this may indicate cholecystitis or mechanical obstruction of the ducts.

During the deciphering process, the doctor must take into account that the accuracy of the results can be influenced by several factors, for example, the movement of the patient during the picture, insufficient dose of contrast, incorrect or incomplete preparation, insufficient absorption of the contrast agent in the small intestine, as well as impaired liver function, which directly affects the flow of contrast into bile.

Cholegraphy, along with ultrasound of the gallbladder, is one of the most commonly prescribed methods for examining patients with pathologies of this organ. Thanks to the introduction of a contrast agent, x-rays can detect congestive processes in the gallbladder, polyps, neoplasms, stones in the ducts and gallbladder.

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