Liver Ultrasound: Indications, Diet, Preparation
What is it and how is it performed?
Hepatic ultrasound is based on the principle of ultrasonography. Through this technique, a beam of ultrasounds (so called because they cannot be heard by the human ear) is projected onto the body area to be examined, thanks to a special probe. At this point the tissues affected by sound waves reflect them in varying degrees depending on their consistency; therefore, by picking up the ultrasounds reflected by the same probe that generated them, and converting them into electrical signals, it is possible to process them informally to reconstruct the morphology of the tissues and organs studied.
According to the above, hepatic ultrasound is performed to describe or better delineate the architecture of the liver, especially in the presence of suspected symptoms or clinical examinations. It is possible, for example, to evaluate the consistency of the organ and blood circulation, as well as to search for the presence of cysts, abnormal and fibrous formations, and pockets of infection.
The symptoms most commonly associated with liver disease include:
- jaundice (yellowish coloring of the skin and ocular sclerae);
- loss of appetite;
- fatigue, malaise and significant weight loss;
- dark coloration of the urine or clear of the stool.
Other symptoms common to various liver diseases are: nausea, vomiting, diarrhea, varicose veins, hypoglycemia, low-grade fever, muscle pain and loss of sexual desire.
The pain in the liver, perceived in the center-upper right abdominal region, generally occurs only in an advanced phase of the morbid process; this symptom is in fact associated with the volumetric increase of the organ, especially when it occurs abruptly (acute hepatitis).
Among the blood tests that investigate the health of the liver we remember the dosage of:
- enzymes of hepatocytic origin (transaminases - AST, ALT - ALP and GGT); ↑↑↑
- direct and indirect bilirubin (also urine dosage important) ↑↑↑
- plasma proteins (total amount, albumin and / or globulins) ↓↓↓
- coagulation factors (prothrombin time ↑↑↑) ↓↓↓
Risk factors for developing liver disease include:
- presence of metabolic diseases, such as diabetes mellitus
- drug use
- unprotected sex
- prolonged drug therapies (including the use of high dose anabolic steroids)
- intoxication (arsenic, poisonous fungi, mycotoxins)
Another classic application of hepatic ultrasound is the diagnosis of steatosis, a condition characterized by excessive accumulation of fat in hepatocytes (so called liver cells). At the same time, during hepatic ultrasound it is possible to extend the study to other abdominal organs, for example to assess the presence of stones inside the gall bladder or biliary tract, or the state of health of the pancreas. Furthermore, the so-called operative hepatic ultrasound can be performed with diagnostic or therapeutic purposes, for example to guide the needle route during a biopsy, a liver drain or the treatment of liver tumors by radiofrequency hyperthermia or laser.
We have therefore seen how broad the range of indications for hepatic ultrasound is, while in the table to the side the symptoms and the clinical exams are theoretically deserving of deepening through hepatic echography. What remains quite similar in various cases is the preparation required by the doctor in view of the ultrasound examination of the liver.
Preparation diet for hepatic ultrasound
Since the excessive presence of intestinal gas can limit the accuracy of the diagnostic examination, in the two / three days prior to the ultrasound the patient must limit the consumption of all those foods that can cause problems of meteorism and flatulence (such as those rich in fiber and slag). He must therefore refrain from the consumption of legumes (lentils, beans, broad beans, chickpeas, peas), milk and dairy products, vegetables, tubers, grapes, various cheeses, bread and pasta (both allowed with extreme parsimony), whole grain products and fermented foods. These days you should also avoid carbonated drinks, limited nervine drinks (tea, coffee, hot chocolate) and of course abolished the consumption of alcohol. In the approach to hepatic ultrasound is instead allowed the consumption of meat, fish, eggs, fruit without peel (with the exception of grapes), seasoned cheeses with moderation and smooth mineral water.
On the day of the exam, the patient must have been in the fasting clinic for at least eight hours, during which time he can only drink non-carbonated water.