L'abdominal ultrasound or echo abdomen, less commonly known as ultrasonography or abdominal ultrasound, is a first level examination based on the use of ultrasound probes to study the anatomy and alterations of the abdominal organs.
For the physical principles ofultrasound, please refer to the relevant page onultrasound.
Preparation and diet
Even to perform a simple abdominal ultrasound, it is good to follow some simple preparation rules. How to prepare for an echo abdomen?
In the morning before you arrive for the exam, it is important to stay fast. What to eat? It is okay to take liquids, such as tea or milk, coffee and solid foods should be avoided. This is because taking food or coffee for breakfast causes the gallbladder or gallbladder to contract and consequently empty. It is a hollow organ in which bile accumulates. The empty gallbladder without bile cannot be visualized with ultrasound.
In patients suffering from abdominal bloating, it may be necessary to observe certain precautions, following a diet for abdomen ultrasound for a couple of days before the examination. It's about a slag-free diet, you should avoid foods rich in slag or fiber, such as pasta and cereals, especially if wholemeal, vegetables, carbonated drinks. You can eat meat and fish, vegetables in moderate quantities as long as they are peeled and without seeds. In case of abundant meteorism in addition to the slag-free diet the general practitioner may recommend taking some charcoal tablets, a useful substance because it binds, in the intestine, to liquid and gaseous substances, allowing the elimination of intestinal gas.
Another important rule is to present with a full bladder, if an ultrasound is performed on the lower abdomen or in the complete abdomen echo. It is therefore necessary to try not to urinate for a few hours before the exam. This is because the bladder, like the gallbladder, if empty, with no fluid inside, cannot be visualized. In addition, bladder emptying may not allow visualization of the prostate in men, the uterus and ovaries in women. In the upper abdomen ultrasound, however, these organs are not studied, so it is not necessary to show up with a full bladder.
Failure to observe these simple preparation tips does not compromise the execution of the exam, so the ultrasound will still take place. However, the gallbladder and bladder may not be visible.
How is the ultrasound performed?
The radiologist or sonographer, using an ultrasound system and a rounded surface “convex” ultrasound probe, examines the various organs of the abdomen and pelvis. The examination usually begins with the patient lying on his stomach, but it may be necessary to move the patient to both hips to better see some organs. During the examination the doctor, while examining with the probe the patient's abdomen will ask to take deep breaths and hold their breath. This is important because it helps the doctor to better visualize the organs, which move with breathing and remain still during apnea.
There are various indications for performing this examination. Ultrasound may be necessary following abdominal pain, such as in renal or biliary colic, or in case of alteration of some blood test values, such as liver transaminases. The doctor may request an ultrasound of the abdomen following a visit if he finds enlargement of the spleen or liver after palpating the patient. It can sometimes be considered a routine examination in preparation for some surgical procedure, such as organ donation or bone marrow donation. It may be necessary to perform annual ultrasound scans to check some already known benign lesions, for example renal or hepatic cysts, especially if very large, angiomas, stones. L'abdomen ultrasound it is performed as a control in patients with various types of cancer, including breast or lung, to be sure, for example, that there are no metastases, or to verify the regression of already known malignant lesions that may have undergone chemotherapy.
What is the abdomen echo used for?
The ultrasound of the abdomen is used to investigate the abdomen in a non-invasive, rapid, repeatable, economical and free of x-rays or other ionizing radiation. It can be performed in an emergency regime, in the presence of suspected acute abdominal diseases such as biliary and renal colic, pancreatitis or other acute symptoms. It can be done as a checkup for patients who already know they have abdominal organ diseases. It can be done simply to check the abdomen in a patient with altered blood tests (e.g. high transaminases, hyperbilirubinemia, elevated amylase and lipase, high creatinine, increased PSA).
What do you see during the exam?
In theecho upper abdomen, the following abdominal organs are studied:
- the liver, by far the largest organ in the abdomen, as well as in the human body. Various liver diseases or lesions can thus be recognized, including fatty liver (fatty liver), hepatitis, cirrhosis, liver tumors or cysts. The biliary tract and hepatic blood vessels are also studied, with the use of Doppler, a system for visualizing the vessels now integrated in all ultrasound scanners.
- the gallbladder, so you can see any gallstones or adenomas. The one can be distinguished from the other, because the stones move when the patient changes position, for example putting himself on his side. An adenoma is a small polyp that originates from the walls of the gallbladder and therefore does not move within it if the patient moves.
- the pancreas. It is a very deep organ in theabdomen, not always clearly visible. The presence of abdominal bloating, i.e. large amounts of intestinal gas, can prevent the doctor from seeing this organ. This is because the air contained in the intestine cannot be crossed by ultrasound. In very thin patients it is more easily studied, the pancreatic duct of Wirsung can sometimes be observed, which expels the pancreatic juice, essential for digestion, in the intestine. The part of the pancreas that is usually most easily seen is the head, along with the body. These are the areas that most frequently undergo neoplasia. The tail is often difficult to investigate.
- kidneys. Its size is measured, its appearance is seen, because small, thin kidneys are often poorly functioning, suggesting kidney failure. Cysts, stones or angiomyolipomas can be studied, all benign lesions of the kidney. It is evaluated if there is dilation of the urinary tract, as in the case of renal colic. Dilation may indicate that the urinary tract is blocked.
- the spleen. Its structure and size are evaluated. In some infectious or immune diseases the spleen can enlarge, which is why it is always measured. The presence of enlargement of the spleen is defined as splenomegaly, and may require a new check with ultrasound, at a variable distance depending on the doctor's opinion. Following trauma, the spleen can rupture, this type of injury can also be recognized. Angiomas of the spleen may be present.
- the abdominal aorta, the largest arterial vessel in the body, which originates directly from the heart and carries blood to the body. Small dilations (ectasias) or very large dilations, called aneurysms, can be seen. Often the aorta becomes calcified with aging.
- the abdominal lymph nodes. Normally they are not visible or can be seen with difficulty, but they can enlarge until they become measurable in infectious, lymphomatous or tumor pathologies.
In theecho lower abdomeninstead, they are studied (with a full bladder):
- the bladder, which can only be seen when its walls are distended by urine, so it must be full. You can observe stones inside it, or alterations of the walls such as diverticula or vegetative formations that can be tumors. The bladder should always be visualized on ultrasound of the lower abdomen in case of haematuria, i.e. if there is blood in the urine.
- the uterus and ovaries in women. External pelvic echo is not the best and most accurate way to evaluate these structures, which can only be accurately studied by transvaginal ultrasound. Cysts, polyps, myomas and fibroids of the uterus can be recognized, while the ovary can have cysts, follicles or corpora lutei depending on the phase of the menstrual cycle. It can also present multiple small cysts in case of polycystic ovary syndrome, for which further investigations are required, including blood tests.
- the prostate, in men. It should always be measured to see if it is enlarged. Often with aging it increases in size and has calcifications inside, these are not necessarily alarming elements. The most accurate evaluation of the prostate can only be obtained with transrectal ultrasound.
In theultrasound of the complete abdomeninstead, all the structures of the upper and lower abdomen are studied.
Comparison with other exams
Ultrasound of the abdomen is the most useful and effective low-cost investigation for the study of the abdomen and pelvis. The radiography of the abdomen does not allow to evaluate the various organs as precisely. The CT or CT scan of the abdomen is indeed a useful examination, but it has high costs, exposes the patient to ionizing radiation and may require contrast medium. The resonance of the abdomen also allows a superior visualization of the abdominal organs to ultrasound, but it has high costs and long times. CT and resonance are second level examinations, which can be indicated by the doctor or radiologist if necessary to investigate alterations that have been detected on ultrasound.
Ultrasound of the abdomen must be distinguished from FAST echo (from English, Focused Assessment with Sonography in Trauma). The latter is a particular type of ultrasound, designed by those who deal with emergency medicine, to see only some focal alterations of the abdominal organs linked to trauma or emergency situations, in order to quickly guide diagnosis and therapy. Unlike ultrasound of the normal abdomen, this is not a complete and in-depth study of all the abdominal organs.
Abdomen ultrasound is a widely used exam due to its usefulness and relatively low cost. However, it requires good cooperation from the patient, who must follow the doctor's instructions before and during the examination. In patients who have difficulty holding their breath, the examination may be more difficult. In overweight patients, abdominal fat can make some organs difficult to see. Intestinal bloating can also hide the pancreas, as well as some portions of the liver or kidneys.
The price of an abdominal ultrasound varies by performance and center.
In the public, the cost of ultrasound varies depending on the income bracket, ranging between 40 euros and 70 euros for an ultrasound of the complete abdomen.
In clinics and private centers, the cost of a full abdomen ultrasound is higher and can exceed 80 euros.
Ultrasound teaching manual, the basics of performing and interpreting ultrasound scans, Mattias Hofer, 1999
Tags: Abdomen Radiology