Liver ultrasound is an instrumental diagnostic method, during the production of which the doctor evaluates the condition of the organ and identifies its various pathologies based on the image seen on the monitor of the device, resulting from the reflection of ultrasonic waves from biological structures.
What is a liver ultrasound – a brief description
Ultrasound Liver is a study of the body using ultrasound waves emitted and perceived by special devices, called ultrasound scanners. The essence of the study lies in the fact that an ultrasonic wave with an oscillation frequency of more than 20,000 Hz is able to penetrate the tissues to a small depth, pass through them, and then some of the waves are absorbed by the cells, and the other part is reflected with or without refraction. It is such reflected waves that come back to the ultrasound scanner sensor, are captured by it, are converted into electrical impulses and create a picture on the monitor. The doctor on the monitor sees the image of the organ created by the reflected and refracted ultrasonic waves that have passed through the thickness of the tissues.
To obtain ultrasound images on the monitor, one sensor is used, which simultaneously emits and picks up ultrasonic waves. To assess the condition of various organs, it is necessary to use sensors that emit waves of different frequencies, penetrating to different depths.
In order to conduct an ultrasound the liver use sensors with different frequencies of the emitted ultrasonic waves, as it is necessary for the best visualization of the body and identify its pathology. So, currently, for ultrasound examinations of the liver, sensors of 3.5–5 MHz are used, which make it possible to see objects with a diameter of 1-3 mm. Sensors with a frequency of 3.5 MHz allow to obtain images of tissues and organs at a depth of 12 – 28 cm from the sensor surface. That is why such sensors (3.5 MHz) are used to examine adult patients of normal and fat stature. And sensors with a frequency of 5 MHz give an image of objects located at a depth of 4 – 15 cm from the surface of the sensor. Therefore, 5 MHz sensors are used for liver ultrasound in adolescents and thin patients.
The image obtained with the help of reflected ultrasound waves on the monitor makes it possible to assess the size, structure, location of the liver and its parts, to reveal the presence of various additional formations (cysts, tumors, etc.), inflammatory changes, etc. In appearance, size, organ structure, the presence of inflammation in the liver or additional formations, as well as the state of the surrounding tissues, lymphatic and blood vessels, the doctor can diagnose various pathologies, such as hepatitis, cirrhosis, hepatosis, cysts, hemangiomas, adenomas, cancer, liver metastases.
Liver ultrasound is a painless, safe, not uncomfortable, but informative study that is easily tolerated by patients, since the doctor does not have to enter any instruments into different parts of the body to conduct it. Since the ultrasound scan is safe, non-discomforting and well-tolerated by the examination method, it can be carried out without any restrictions for pregnant women, children and the elderly.
Liver ultrasound can be performed for diagnostics existing pathology of the organ, and as one of the methods of preventive examination. In order to diagnose liver ultrasound, it is prescribed when a person has any symptoms suggesting hepatic pathology, such as pain in the epigastrium (in the middle of the abdomen, between the ribs), right or left under the ribs, yellowness of the skin or sclera of the eyes, unexplained skin itching, increased body temperature, and high levels of amylase and bilirubin in the blood. In addition, for the diagnosis of liver damage, ultrasound is prescribed when an abdominal injury occurred. It is compulsory liver ultrasound is carried out with a certain frequency at the already identified liver diseases to assess the condition of the body and monitor the course of the disease, as well as to identify the effectiveness of therapy.
As one of the methods of preventive examination, ultrasound is usually performed once a year. With the preventive purpose, an ultrasound scan is especially recommended for people who have a high risk of developing liver disease, for example, due to alcohol abuse, taking toxic drugs, etc.
What shows liver ultrasound
Ultrasound of the liver allows you to assess the size, structure, location of the organ and its parts, the presence of any formations (cysts, tumors, metastases, etc.), inflammatory changes, pathological foci, traumatic injuries. In addition, liver ultrasound provides an opportunity to assess the surrounding tissue, lymphatic and blood vessels.
The results of ultrasound allow to identify the following liver pathologies:
- Hepatitis (acute and chronic)
- Cirrhosis of the liver
- Hepatosis (fatty liver)
- Pathological foci in the liver (abscess, echinococcosis)
- Benign neoplasms in the liver (cysts, tumors, foci of nodular hyperplasia)
- Malignant neoplasms in the liver (cancer or metastases)
- Changes in the structure and condition of the liver due to heart disease and heart failure.
Indications for liver ultrasound
Contraindications for liver ultrasound
In principle, there are no absolute contraindications to the production of liver ultrasound, since this study is safe and non-invasive (that is, not involving the introduction of tools into any parts of the body). However, if there are burns, wounds, pustular rashes or any damage to the integrity of the skin on the skin of the abdomen and sides, then an ultrasound scan is not recommended, since the pressure and sliding of the sensor can provoke the spread of the existing pathological process over a large area. Therefore, in the presence of wounds or skin diseases in the abdomen, it is recommended to postpone a planned liver ultrasound until the skin is clean. In the case, if the ultrasound of the liver must be done on an emergency basis, then it is carried out, despite the damage and pathological rash of the skin of the abdomen.
In addition, liver ultrasound may be contraindicated for women in the third trimester of pregnancy (from the 27th week to the birth), since during this period the size and weight of the uterus heavily pressed on all organs of the abdominal cavity and "closes" them from the ultrasound scanner, located directly under the abdominal wall.
In cases where a person is worried about sharp pain in the abdomen, due to the presence of which he cannot assume the posture required for the study, liver ultrasound is also contraindicated.
It is advisable to postpone liver ultrasound for several days (3-5 days) after fibrogastroduodenoscopy (FGDS), gastric X-ray with contrast or laparoscopic surgery.
Preparation for liver ultrasound
Routinely, liver ultrasound should preferably be carried out after preparation, which consists of abstaining from food for 8–10 hours and preventing intestinal meteorism.
Ultrasound of the liver is optimally performed on an empty stomach after an 8–10-hour fast. To ensure such an 8–10-hour period of fasting, it is necessary to take away these 8–10 hours from the time at which the liver ultrasound is scheduled, and from this calculated moment not to eat. It is permissible to carry out liver ultrasound at least after a 6-hour fast. If the study is conducted not in the morning, but in the afternoon or in the evening, then in order to avoid too long a hungry period, you can eat dried white bread (crackers without additives, salt, flavor enhancers, flavors, seasonings, etc.) and drink unsweetened tea .
To eliminate and prevent flatulence, it is necessary to abandon the use of products that promote increased gas formation in the intestines, such as sparkling water, whipped cream, nuts, macaroni, honey, mustard, fatty meats and fish, and alcohol, before conducting a study. , vegetables (cabbage, radish, onion, garlic, Bulgarian pepper, etc.), fruits (melon, bananas, sweet apples, etc.), black bread, dairy products, legumes (peas, beans, lentils, etc.) and other high-fiber foods and. During the day before the study, you must also abandon the use of vegetable juices.
If a person suffers from diseases of the intestine or other organs of the digestive system, then, to exclude flatulence, as a preparation for liver ultrasound, in addition to dieting, it is recommended to take medications that eliminate excessive gas formation in the intestines for two or three days before the study (Carbolenum – 9 tablets per day and enzyme preparations (Kreon, Panzinorm, Mezim, etc.), 3-6 tablets per day). In addition to Carbolen and enzyme preparations, to prepare for liver ultrasound in order to eliminate flatulence in the intestine, you can also take simethicone (Espumizan, Disflatil, etc.) 2 capsules 3 times a day, or activated charcoal 2 tablets 3 times a day. Means with simethicone and activated carbon to eliminate flatulence are taken within 2 to 3 days before the liver ultrasound.
Since liver ultrasound is optimally performed against the background of not swollen and empty intestines, on the eve of the study you should drink a mild laxative (for example, Dufalac, Mukofalk) or give an enema or use glycerine candles on the morning of the ultrasound.
When liver ultrasound should be performed on an emergency basis, it is done without any prior preparation. But if in the course of an emergency ultrasound scan, inaccurate data were obtained, then it is necessary to re-conduct the study again in a planned manner with the necessary preliminary preparation.
You need to take paper napkins, toilet paper or a towel to the clinic to wipe off the abdomen gel, which is applied to improve the quality of the image obtained on the ultrasound machine. In addition, if hunger is poorly tolerated by a person, then you can take a dry ration with you to have breakfast immediately after the production of ultrasound.
If a person is constantly taking any medications, then it is not necessary to cancel them before the liver ultrasound.
In children, preparation for liver ultrasound is to abstain from eating any food and drink (including water) for three hours before the study. Of course, such preparation of children is carried out only in those cases when they calmly tolerate fasting and lack of drinking.
How to do a liver ultrasound?
Ultrasound of the liver is carried out in a specially equipped room in which an ultrasound machine, a couch and curtains are installed. The patient for the production of research should expose the stomach, removing or lifting the upper part of the clothes, then sit on the couch in the position indicated by the doctor. Usually liver ultrasound is performed in the supine position, less often – lying on the left side. In some cases, when the patient cannot lie on his back or left side, liver ultrasound is performed in a standing or sitting position.
After taking the necessary position, the doctor applies a special gel to the skin of the abdomen, which is necessary to obtain the best quality image. Next, the doctor drives the ultrasound probe on the surface of the abdomen, obtaining an image of the liver from various angles, which is necessary for a detailed study of the state of all parts and divisions of the organ. During the study, the doctor will ask the patient to breathe in a normal rhythm, and also to make the maximum possible inhale and exhale. The image of the liver in different phases of respiration and against the background of different intensity of respiratory movements allows to obtain the most detailed information about the state of the organ and its structures. In addition, in the process of ultrasound, the doctor may ask you to take any posture, which is also necessary for a comprehensive assessment of the liver or identification of pathological changes.
After completion of the study of the state of the liver and the production of all necessary measurements ultrasound study is considered complete. The doctor removes the sensor from the surface of the abdomen, and the patient can dress and leave.
The procedure of ultrasound examination of the liver is usually short, and takes 10 to 20 minutes, depending on the qualifications of the doctor, the type of ultrasound machine and the patient’s body weight. The thinner the patient, the faster the doctor can assess all the parameters of the liver. In obese patients, on the contrary, the study may be longer, since the subcutaneous fat layer makes it difficult to visualize the organ and makes it necessary to examine the same area several times.
After completing the ultrasound study, the doctor writes a protocol with a mandatory conclusion, which he hands over to the patient.
Norm liver ultrasound
In the process of ultrasound research, it is necessary to determine the size and contours of the liver, assess the state of echostructure (homogeneous, heterogeneous), intrahepatic bile ducts, as well as large vessels. In addition, they reveal the presence of any inclusions and formations uncharacteristic for normal liver echostructure.
If we talk in more detail, then the results of ultrasound of the liver necessarily evaluate the following parameters:
- The shape, contours and anatomical structure of the body
- The size of the entire liver and each lobe
- Liver structure and echogenicity
- The state of the vascular pattern of the body as a whole
- Assessment of the status of large vessels and intrahepatic bile ducts
- Detection of focal changes and pathogenic formations
- Differentiation of various pathological changes from each other with the assumption of which pathological process takes place in a particular case.
Normally, the main indicators evaluated during an ultrasound scan should be as follows:
- The angle of the lower edge of the left lobe of the liver is less than 45 o
- The angle of the lower edge of the right lobe of the liver is less than 75 o
- Oblique vertical size of the right lobe of the liver – up to 150 mm
- The thickness of the right lobe of the liver – up to 140 mm
- Craniocaudal size of the left lobe of the liver – up to 100 mm
- The thickness of the left lobe of the liver – up to 80 mm
- The width of the liver is 230 – 270 mm (23 – 27 cm)
- The length of the liver is 140–200 mm (14–20 cm)
- The transverse size of the liver – 200 – 225 mm (20 – 22.5 cm)
- Portal vein (measured at a distance of 20 mm from the confluence of the mesenteric and splenic veins) – 10-14 mm
- Hepatic veins (measured at a distance of 20 mm from the mouth) – 6 – 10 mm
- Lower vena cava (measured at the level of the caudate lobe of the liver) – 15–25 mm
- Hepatic artery (measured at 20 mm from the gate of the liver) – 4 – 6 mm
- Lobar bile ducts – 2 – 3 mm
- Common bile duct (hepatic) – 4 – 6 mm
- The edges of the liver – normally smooth and clear
- The structure of the parenchyma is normally fine-grained, homogeneous, consisting of a set of uniformly distributed small point and linear structures
- Echogenicity – normally the same or slightly higher than the echogenicity of the cortical substance of the kidneys
- Sound conductivity is normally high (worsens with diffuse changes in the liver tissue, for example, with fibrosis, fatty inclusions with hepatosis, etc.).
The size of the liver by ultrasound
Normally, the total width of the liver is 23 – 27 cm, length – 14 – 20 cm, and the diameter – 20 – 22.5 cm. The thickness of the left lobe of the liver should not exceed 8 cm, and the right lobe – 14 cm. If the size of the liver is enlarged, then such an increase in the organ is called hepatomegaly, which indicates pathology. To understand what kind of pathology in question in a particular case, you can, taking into account the results of other parameters of liver ultrasound.
Normal ultrasound picture of the liver
The liver echogenicity is normally even, and is something between a pancreas echogenicity (which is higher) and a spleen echogenicity (which is lower). In addition, the liver echogenicity is normally the same or slightly higher than the echogenicity of the cortical substance of the kidneys.
Interpretation of liver ultrasound
What do they say changes in various parameters of liver ultrasound
Below we consider the pathologies for which a change in a parameter of liver ultrasound is characteristic.
Increase in size with a homogeneous fine-grained echostructure. When the liver is large, but its structure is normal and homogeneous, this may indicate the following pathologies:
- Heart failure. In addition, advanced ultrasound scans will reveal enlarged hepatic veins, which are normally not visible. The diameter of the inferior vena cava does not change depending on inhalation and exhalation.
- Acute hepatitis. Usually, there are no other specific changes other than an increase in the size of the organ in case of acute hepatitis on ultrasound. The overall picture is quite normal.
- Tropical hepatomegaly. Additionally, a significantly enlarged spleen (splenomegaly) is also detected on ultrasound.
- Schistosomiasis. In addition to increasing the size of the liver, with this disease, an ultrasound shows a thickening of the portal vein and its large branches, and their walls and surrounding tissue are very bright. In some cases, an enlarged splenic vein and the spleen itself are also visible. When an Schistosoma mansoni or Schistosoma japonicum is infected with an ultrasound, fibrosis of the tissue around the portal vein can also be detected.
Increase in size with non-uniform echo structure. An enlarged liver with a heterogeneous structure may indicate the following pathologies:
- If the liver is enlarged, has a heterogeneous structure, but it does not define focal lesions, then this may be a sign of cirrhosis, chronic hepatitis or fatty hepatosis. With these pathologies on ultrasound, in addition to increasing the size and heterogeneous structure of the liver, the increase in its echogenicity (hyperechoic parenchyma) and a decrease in the number of visible branches of the portal vein are recorded. In some cases, sound conduction is significantly reduced, as a result of which deep-lying parts of the liver are not visible at all.
- If the liver is enlarged, has a heterogeneous echogenic structure and shows multiple or single focal lesions of any shape, size and echo structure, then this is a sign of macronodular cirrhosis, abscesses, metastases, lymphomas or hematomas. In case of macronodular cirrhosis, an additional ultrasound shows a modified vascular pattern, a normal stroma and numerous formations of different sizes. In case of abscesses, an increased echogenicity is additionally recorded on the ultrasound and multiple or isolated formations with fuzzy contours are visible. With metastases on ultrasound, formations of various shapes, sizes and echostructures are additionally visible. In lymphoma, multiple hypoechoic (light) structures with fuzzy contours and without distal acoustic amplification are additionally visible. When hematomas on ultrasound visible education with fuzzy contours and distal acoustic amplification.
Liver size reduction may be characteristic of micronodular cirrhosis. At the same time on ultrasound, an increase in echogenicity and organ deformity due to scarring (overgrowth) of the portal and hepatic veins is also recorded. In this case, the portal vein is usually normal or collapsed inside the liver and enlarged outside the liver. Sometimes inside the portal vein there are numerous structures that represent blood clots. Micronodular cirrhosis can be combined with ascites (fluid in the abdominal cavity), portal hypertension (increased pressure in the portal vein of the liver), splenic vein dilation and varicosity, as well as splenomegaly (an increase in the size of the spleen).
Cystic formations in the liver may be different, as provoked by different reasons.
Thus, a solitary cyst can be seen in the liver on an ultrasound, which is an anechoic (light) rounded formation with clear or uneven contours and with a diameter of less than 30 mm. Such cysts usually do not cause any clinical manifestations and are congenital, and therefore non-dangerous. But, unfortunately, a solitary cyst can not always be distinguished from a parasitic cyst, therefore, if such an education is found in the liver, it is recommended to perform a biopsy.
Also, ultrasound can reveal multiple liver cysts, which usually have the appearance of anechoic (light) formations of different diameters with a clear outline and acoustic amplification. Typically, such multiple cysts are a manifestation of congenital polycystic disease, and are very often combined with cysts in the kidneys, spleen and pancreas.
If cysts are complicated, hemorrhages or suppuration occur, then on ultrasound such formations are visible, like abscesses or disintegrating tumors.
Finally, one of the most difficult from the point of view of diagnosis are parasitic (echinococcal) cysts, which are formed due to the penetration of parasites into the liver. Any parasitic cyst on ultrasound can have various echogenic signs, depending on the stage of development of the parasite and the condition of the cystic walls and cavities. Thus, a parasitic cyst may look like a simple bright formation with a clear outline and distal acoustic amplification, similar to a solitary cyst. In other cases, the cyst may have a double wall contour. In the third embodiments, inside the cystic formation visible "parasitic sand" or a septum moving freely in the cyst cavity. In the fourth cases, multiple small cysts and vesicles are seen inside the large cyst, which usually indicates the presence of a live parasite in the liver. When the parasite has already died, the cyst can acquire a clear contour due to calcification (calcification) of its walls.
Single solid formation in the liver may be a hemangioma, abscess, suppurative cyst, metastasis, hepatoma. Unfortunately, it is very difficult to distinguish these formations by ultrasound, therefore, if a serious disease is suspected, a biopsy is recommended. Most often, single solid formations in the liver are represented by hemangiomas (up to 75% of cases).
Ultrasound picture characteristic of various liver diseases
In this section, we consider which ultrasound signs have different liver pathologies.
Cirrhosis. With this pathology, the size of the entire liver or only its left lobe is increased, the organ echogenicity is increased, sound conduction is reduced, its structure is heterogeneous, mosaic, the edges are uneven and uneven, the vascular pattern is disturbed due to the increased diameter of the portal (portal) vein.
Hepatitis. With this pathology, the entire liver is enlarged or only one lobe (right or left), the contours are even and clear, the edges are rounded, the echogenicity is reduced, the sound conduction is increased, the structure is heterogeneous, variegated, the vascular pattern is changed due to the expansion of the portal and splenic veins, as well as contrasting other vessels.
Fatty hepatosis. With this pathology, the size of the liver is increased, the angle of the lower lobe is more than 45 o, the structure is heterogeneous, possibly variegated, echogenicity is increased, sound conduction is reduced, the contours are even but fuzzy, the edges are rounded, and the portal (portal) vein is not visible.
Liver tumors. Ultrasound shows areas with fuzzy contours that are more or less echogenic compared to the rest of the liver tissue. Less echogenic (hypoechoic) tumors are sarcomas, lymphomas, hemangiomas, adenomas, hepatocellular carcinoma, poorly differentiated carcinoma. More echogenic (hyperechoic) tumors are hepatomas and metastases of cancer to the liver. Also, with tumors on ultrasound, an increase in lymph nodes and the displacement of the gallbladder from the normal position are recorded.
Liver cysts. When these pathological formations on the ultrasound visible single or multiple structures with clear edges, which lead to an increase in size or bulges in certain parts of the liver.
Giardiasis. Ultrasound shows areas of calcium salt deposits and areas of low echogenicity, which are areas of parasite accumulation.
Secondary diffuse changes in heart disease. The ultrasound contours of the liver are even and clear, the size of the organ is enlarged, the edge is rounded, the structure is heterogeneous, the echogenicity is increased, sound conduction is reduced, the inferior vena cava and hepatic veins are enlarged.
Abscess. Ultrasound shows round or irregularly shaped formations with a clear wall, different echogenicity and moving contents.
Liver ultrasound – diffuse and focal changes
In a liver diffusion and focal changes can come to light. Diffuse changes that are present throughout the thickness of the body in the form of small heterogeneous structures. Such diffuse changes are characteristic of fatty hepatosis, acute and chronic hepatitis, cirrhosis and heart disease.
Focal changes are called, which are single or multiple clearly defined foci. Such focal changes are characteristic of tumors (hemangiomas, adenomas, cancer and metastases), focal hyperplasia and cysts (true cysts, abscesses, parasitic cysts).
Ultrasound of the baby
Do a liver ultrasound
Liver ultrasound can be done in a regular city municipal clinic, district clinic or in a hospital. Liver ultrasound can also be performed in private medical centers that have the necessary equipment and specialists.
Liver ultrasound – price
Author: Nasedkina A.K. Specialist in conducting research on biomedical problems.