Ultrasound signs of pathology of the gallbladder and biliary tract

Nonvisualizable gallbladder

There are several reasons why the gallbladder is not visualized by ultrasound:

1. The patient is not examined on an empty stomach: repeated examination is necessary after 6 hours of abstinence from ingestion of food and water.
2. Abnormal location of the gallbladder.
   • Scan down the right side of the abdomen until the pelvic area.
   • Scan to the left of the midline in the patient's position on the right side.
   • Scan above the edge of the costal arch.
3. Congenital hypoplasia or agenesis of the gallbladder.
4. The wrinkling of the gallbladder with full filling of the cavity with stones with an accompanying acoustic shadow.
5. The gallbladder is quickly removed: try to find scars on the skin or ask the patient (or the patient's relatives).
6. The researcher is not sufficiently trained or does not have relevant experience: ask a colleague to examine the patient.

There are only a few pathological conditions (except congenital agenesis or surgical removal) that lead to a reproducible lack of visualization of the gallbladder during ultrasound examination.

You can not put a clinical diagnosis in the absence of visualization of the gallbladder, even when exploring in different positions.

Enlarged (dilated) gallbladder

The gallbladder is considered enlarged if its width (transverse diameter) exceeds 4 cm.

A normal gallbladder looks stretched when the patient dehydrates, with a diet low in fat or parenteral nutrition, or when the patient is immobilized for some time. If there are no clinical symptoms of cholecystitis and thickening of the gallbladder wall, give the patient fatty foods and repeat the test 45 minutes or 1 hour later.

In the absence of shortening, look for:

1. A stone or other cause of obstruction of the bladder duct. In this case the hepatic and bile ducts will be normal. If there is no internal obstruction, there may be an obstruction caused by the lymph node compression of the duct from the outside.
2. A stone or other cause of obstruction in the common bile duct. The common hepatic duct will be expanded (over 5 mm). Investigate the common bile duct for ascaris: on the cross sections, the tubular structure inside another tubular structure - the symptom of the "target" - will be determined. Look for ascaris in the stomach or small intestine. Obstruction can be caused by a pancreatic head tumor (echogenic formation), and in endemic areas with echinococcus - cystic membranes in the common bile duct. (Examine also the liver and abdominal cavity for the detection of cysts, perform a chest X-ray.)
3. If the gallbladder is stretched and filled with fluid, with thickened over 5 mm walls, there may be empyema: this will determine the local tenderness when pressing. Conduct a clinical examination of the patient.
4. In the presence of an extended gallbladder, filled with fluid, with thin walls, the presence of mucocele is likely. Mukocele usually does not give local soreness with pressure.

Acute cholecystitis

Clinically acute cholecystitis is usually accompanied by the appearance of pain in the upper right quadrant of the abdomen with local soreness with (careful) movement of the sensor in the projection of the gallbladder. One or more concrements can be detected, with the presence of a stone in the neck of the gallbladder or in the bladder duct. The walls of the gallbladder are usually thickened and swollen, although the gallbladder may be unstretched. When the perforation of the gallbladder near it is determined by the accumulation of fluid.

Concrements in the gallbladder do not always give clinical symptoms: you must also exclude other diseases, even if you find stones in the gallbladder.

Internal ehostruktury in the cavity of the gallbladder

Shifted internal echo structures with acoustic shadow

1. Concrements of the gallbladder are defined in the lumen as bright hyperechoic structures with an acoustic shadow. Concrements can be single or multiple, small or large, calcined or not. The walls of the gallbladder can be thickened, but may not be thickened.
2. If there is a suspicion of concrements, but the concrements are not clearly detectable during normal scanning, repeat the study in an inclined position or in a vertical position of the patient. Most stones will change their position when the patient moves.
3. If there are still doubts, put the patient on all fours. The stones should move anteriorly. This position of the patient can be useful in the presence of pronounced meteorism in the intestine.

Ultrasound examination allows to identify with high accuracy gallstones in the gallbladder.

Ultrasound examination does not always clearly identify the stones in the bile ducts.

Stones of the gallbladder do not always give clinical symptoms: you need to exclude other diseases, even if you identify gallstones.

Shifted internal echo structures without shadow

Scanning must be done in different positions. Most often, such ehostruktury appear as a result of the presence of:

1. Gallstones. Keep in mind that if the stones are very small (smaller than the length of the ultrasonic wave), then the acoustic shadow will not be detected.
2. Hyperchogenic bile (sediment). It is a thickened bile that produces a distinctly defined echostructure that moves slowly when the patient's position changes, unlike concrements that move quickly.
3. Piogenic suspension.
4. Blood clots.
5. The daughter cells are a parasitic cyst. It is also necessary to perform a liver test to detect cysts.
6. Ascaris and other parasites. It is rare that worms, such as ascarids, get into the gallbladder, more often they can be seen in the bile ducts. With clonorhozes, the hepatic ducts will be enlarged. They are convoluted, in the lumen of their suspension will be determined.

Non-displaced internal echo structures with acoustic shadow

The most common cause is a pitted stone: look for other concrements. The cause can also be kalidifikatsiya wall of the gallbladder: in the presence of wall thickening it can be acute or chronic cholecystitis, but it can be difficult to exclude concomitant cancer.

Non-displaced internal echo structures without shadow

1. The most frequent reason for the appearance of such a structure is the polyp. Sometimes you can identify the foot of a polyp when scanning in different projections. The acoustic shadow is not detected, changing the position of the patient's body does not shift the polyp, but its shape may change. A malignant tumor can look like a polyp, but it often combines with a thickening of the gallbladder wall and does not have a leg. A malignant tumor is much less likely to change its shape as the patient moves.
2. Constriction or kink of the gallbladder usually has no clinical significance.
3. Malignant tumor.

Thickening the walls of the gallbladder total thickening

The normal thickness of the gallbladder wall is less than 3 mm and rarely exceeds 5 mm. When the thickness of the wall is 3-5 mm, it is necessary to correlate this echographic picture with the clinic. The general thickening of the gallbladder walls can occur in the following cases:

1. Acute cholecystitis. This can be combined with the appearance of an anechoic streak in the wall or local accumulation of fluid. You can identify stones: carefully examine the cervix of the gallbladder.
2. Chronic cholecystitis. Also, stones can be detected.
3. Hypoalbuminemia in liver cirrhosis. Try to identify ascites, an enlarged portal vein and splenomegaly.
4. Congestive heart failure. Try to identify ascites, effusion in the pleural cavities, dilated inferior vena cava and hepatic vein. Examine the patient.
5. Chronic renal failure. Examine the kidneys and do urine tests.
6. Multiple myeloma. It is necessary to conduct laboratory research.
7. Hyperplastic cholecystosis. Sinuses Ashota-Rokitansky better identified with oral cholecystography, rarely with the help of ultrasound.
8. Acute hepatitis.
9. Lymphoma.

Local thickening

Local thickening of the gallbladder wall can occur as a result of the following reasons:

1. Bracers formed from the mucous layer. They can be several in one bubble. Scan in different positions: the pathological thickening (more than 5 mm in all areas) will not disappear when the patient's position changes, and the constrictions change their shape and thickness.
2. Polyp. It does not shift when the patient changes position, but can change its shape.
3. Primary or secondary cancers of the gallbladder. It looks like a thick, with an uneven contour, a solid intraluminal formation, fixed and not changing the position when the position of the patient's body changes).

Small gallbladder

1. Probably, the patient ate fatty food and the gallbladder contracted.
2. Chronic cholecystitis: check - whether the wall of the gallbladder is thickened and whether there are concrements in the gallbladder.

If the gallbladder is small, repeat the test after 6-8 hours (without giving the patient food or water) for a differential diagnosis between an empty (empty) gallbladder and a contracted gallbladder. A normal gallbladder will be filled in a few hours and will be of normal size.

Jaundice

When a patient has jaundice, ultrasound usually helps to differentiate the non-obstructive and obstructive form by determining whether the biliary tract is obstructed or not. Nevertheless, it happens that it is difficult to establish the exact cause of jaundice.

If the patient has jaundice, ultrasound provides information about the state of the gallbladder and biliary tract and usually helps to differentiate the obstructive and non-obstructive form of jaundice, but does not always accurately identify the cause of jaundice.

Each patient with jaundice needs to examine the liver, biliary tract and both halves of the upper abdomen.

Equipment

The patient should be on his back with a slightly raised right side. Ask the patient to take a deep breath and hold his breath while scanning.

For adults, use a 3.5 MHz sensor. For children and lean adults, use a 5 MHz sensor.

Start with sagittal or slightly inclined slices: find the lower hollow vein and the main trunk of the portal vein lying in front. This will make it easier to find a common hepatic and common bile duct that will be visualized descending at an angle to the liver in front of the portal vein to the pancreas.

In one third of patients, the common bile duct will be visualized lateral to the portal vein and at the same time will be seen better on skew-longitudinal sections.

Normal bile ducts

1. Extrahepatic ducts. It may be difficult to visualize extrahepatic bile ducts, especially if there is a linear sensor. Use, if possible, a convection or sector sensor. In cases where it is necessary to visualize the extrahepatic bile ducts, try to vary the scanning technique as much as possible by conducting research in different positions of the patient.
2. Intrahepatic ducts. Intrahepatic bile ducts are best visualized in the left half of the liver with deep inspiration. It is difficult to visualize normal intrahepatic ducts with ultrasound because they have very small dimensions and thin walls. Nevertheless, if the ducts are enlarged, they are easily visualized and appear as multiple branching crimp structures against the liver parenchyma background (there is a "branching tree" effect) near the portal vein and its branches.

Gallbladder with jaundice

1. If the gallbladder is stretched, obstruction of the common bile duct (eg, concrement, ascarids, a pancreas tumor or acute pancreatitis) is more common. Hepatic ducts will also be enlarged.
2. If the gallbladder is not stretched or small, obstruction is unlikely, or it occurs above the level of the cystic duct (eg, enlarged lymph nodes or swelling near the liver gates).

Bile ducts with jaundice

Maximum diameter of normal bile duct: less than 5 mm

Maximum diameter of normal bile duct: less than 9 mm

small diameter of normal common bile duct after cholecystectomy: 10-12 mm

Sometimes after surgery and in patients older than 70 years, the common bile duct may be several millimeters wider (ie 12-14 mm). Add 1 mm to all measurements with every subsequent decade of patients older than 70 years.

1. If the intrahepatic ducts are moderately dilated, you can suspect obstruction of the biliary tract before the clinical manifestations of jaundice appear.

If at the early stages of jaundice the dilatation of the bile ducts is not determined, repeat the test after 24 hours.

2. If extrahepatic ducts are dilated, and intrahepatic ducts are not, conduct an ultrasound examination of the liver. In the presence of jaundice, this can be caused by cirrhosis of the liver. But it is also necessary to exclude obstruction of the lower parts of the common bile duct.

Expanded intrahepatic ducts are better visualized when scanning under the xiphoid process in the left lobe of the liver. They will be defined as tubular structures parallel to the portal vein, which are located centrally and spread to the peripheral parts of the liver.

If two vessels are detected during scanning, going in parallel, extending to the entire liver, whose diameter is approximately equal to the diameter of the portal vein, then it is most likely that one of them is an enlarged bile duct.

Clonorchosis

In the clonorchosis, the common hepatic and common bile ducts are enlarged, crimped and represented by saccate structures, while in obstructive jaundice without the phenomena of cholangitis they will be evenly expanded without sachet formations. With a clonorchosis, it is possible to visualize the sediment within the ducts, but the parasite itself is too small to be visualized by ultrasound.

If both intra- and extrahepatic bile ducts are enlarged, and in the liver parenchyma there are large cystic formations, the most likely presence of echinococcosis, rather than a clonorchosis.

Ultrasound examination will help to identify the stones in the gallbladder, but not always stones in the common bile duct. Clinical evaluation should be given, especially in patients with jaundice.