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Computed tomography of the liver is a non-invasive and painless procedure for examining this organ. Having received a tomographic report from a radiologist, the attending physician can assess the general condition, structural features, development and functioning of the liver. In a short period of scanning time, special X-ray equipment makes it possible to obtain high-precision images of the organ in different projections in layers. The whole principle of operation of the tomograph is based on the use of the properties of x-rays, while this method of examining the body is considered safer than the usual x-ray, due to the lower level of radiation received by the patient in the process.
Computed tomography: what is it, why do it
Tomographic scanning is the process of passing X-rays through the human body at certain intervals. Specialized equipment – a tomograph ring – rotating around the patient, manages to make a series of images of the organ in sections with a step of 0,5 to 10 mm in one cycle lasting one second. A series of images recorded by a tomograph enters a computer, where the corresponding program makes up a three-dimensional, three-dimensional picture of the liver and all its deep tissues from it.
To visualize in more detail the network of blood and lymphatic vessels, as well as neoplasms of any etiology, the method of computed tomography of the liver with contrast is used. The subject is injected with a dye that contains iodine. The drug does not transmit X-rays, therefore, in the pictures it has a characteristic contrast appearance. According to the peculiarities of its distribution in the organ, the radiologist can judge the presence of narrowing or other pathologies in the vessels of the liver, the degree of spread of metastases, the possible presence of neoplasms when they are at the initial stage of their development.
Self-medication has never been welcomed by doctors, and the same statement is true for such specific diagnostic methods as CT. To do a computed tomography of the liver, you must first consult a general practitioner or specialist, and get the appropriate referral. Tomography is practically not carried out as a preventive manipulation – ultrasound is enough for these purposes.
If the doctor has decided on the need for computed tomography of the liver, then he sees an objective need:
- assess the state of the organ and related tissues, structures;
- determine tumors, lesions, injuries, bleeding, abscesses, other types of disorders in the liver, if radiography or ultrasound cannot provide enough information to make a diagnosis and prescribe treatment;
- to carry out preparatory measures for aspiration or biopsy of liver tissue;
- analyze the effectiveness of the applied treatment or surgical intervention;
- clarify the condition of the liver if previous test results, such as liver tests, are unsatisfactory.
Indications and contraindications CT liver
An unpleasant feature of the development of liver diseases is the fact that there are a small number of nerve endings in it, so a person cannot always feel that something abnormal is happening to the organ. However, if the patient often complains about the appearance of pain and heaviness in the liver, bloating, metallic taste, nausea and bitterness in the mouth, such symptoms are an indication for the appointment of an ultrasound scan, based on which the doctor can prescribe a referral for computed tomography.
Other indications for liver CT include:
- detection of organ enlargement for unknown reasons;
- the need to clarify the preliminary diagnosis, for example, cirrhosis or hepatitis;
- identification of pathological formations, the need to clarify their size and extent of distribution;
- suspicion of tumor diseases, the appearance of metastases;
- the presence of violations in the work of the vessels of the liver;
- surgical interventions: surgeons prescribe a CT scan before surgery, in preparation for it, and after to evaluate its effectiveness;
- violation of blood flow and thrombosis in this part of the body;
- infectious and inflammatory processes, polycystic liver;
- chronic alcoholism, which, as you know, often provokes irreversible processes in the liver;
- past trauma to the abdominal cavity.
There are also situations where the potential risks of performing tomography are higher than the likely value of the data obtained in the process, or when, due to the nature of the work of the human body, the information content of the study will be too low. In the presence of certain diseases and conditions, CT can generally harm a person. Tomographic scanning of the liver is prohibited:
- for pregnant women and nursing mothers, due to the risk of irradiation of the fetus;
- for children under 3 years old, so as not to expose a very young organism to X-ray exposure;
- with diabetes mellitus, acute forms of bronchial asthma;
- in the presence of iodine intolerance, renal or hepatic insufficiency, if we are talking about computed tomography with contrast;
- in case of a severe general condition of the patient, for example, if he is connected to life support devices;
- in diseases and pathologies associated with the manifestation of hyperkinesis: in such cases, the patient will not be able to ensure complete immobility during the scan, due to which the value of the obtained images will be almost zero.
For obese patients, liver CT remains a challenge. On the one hand, it is known that ultrasound is practically uninformative for them, since it poorly visualizes the organ due to the presence of a pronounced subcutaneous fat layer. On the other hand, CT scanners, in general, are simply not designed for a weight of more than 140-180 kilograms. In such cases, the doctor decides at his discretion how the patient will be examined.
What pathologies can be detected by computed tomography of the liver
The results of CT scan of the liver are pictures and images, analyzing and studying which, the radiologist can identify such diffuse changes in the liver:
- various neoplasms: cancer, hemangioma, adenoma, other types of tumors;
- liver abscess – purulent inflammation that affects the tissues of the organ, and leads to the formation of a purulent cavity in it;
- signs of liver cysts, the appearance of which may be associated with injury (hematoma, seroma and liver beat) of other types of cysts;
- the presence and extent of spread of metastases;
- echinococcosis is a parasitic lesion of an organ caused by the reproduction of a parasitic infection in it;
- signs of liver cirrhosis;
- signs of infectious or viral lesions, such as hepatitis.
In addition to pathologies and disorders, liver CT also shows the functional characteristics of the organ, as well as the changes found in it – tissue density, size, location of tumors or metastases, their depth.
Do I need to prepare for a CT scan of the liver?
Preparation for computed tomography of the liver has no features that distinguish it from other types of tomography. It is recommended to carry out the examination on an empty stomach, so you should not eat 2-4 hours before it starts. A couple of days before the examination, you should reduce the use of products that contribute to increased gas formation, and completely exclude alcohol.
Be sure to tell the doctor about all medications used by the patient. Perhaps, for a while before the study, it will be necessary to take a break in their reception.
Patients undergoing contrast-enhanced CT scans will need to have their creatinine tested. In some cases, if the patient cannot give an exact answer about whether he is allergic to iodine or other substances, the doctor may prescribe additional appropriate tests – allergy tests.
How is the process of computed tomography
The person being examined must remove all metal objects, accessories and jewelry from himself, leave them, along with all gadgets, outside the door of the diagnostic room. He changes into special clothes – spacious, comfortable, made of cotton fabric and without metal parts, after which he is placed on the tomography table and assumes a comfortable, relaxed position.
Within 15 minutes (in rare cases – up to half an hour), the patient is under the directed influence of X-rays. All that is required of him is not to move, and strictly follow the instructions of the doctor when he asks to hold his breath.
If the procedure involves the introduction of a contrast agent, then after the first scan, the table with the patient is rolled out of the scanner, a catheter with the substance is placed in the cubital vein, and the patient is re-sent to the tomograph for scanning. In this case, the contrast is introduced by the X-ray laboratory assistant before the start of the second scan.
In the process, the device buzzes, crackles, makes a characteristic noise. For patients who are uncomfortable with this fact, earplugs or headphones are prepared by the X-ray technician.
The radiologist and the radiologist are located in the next room – from there they monitor the progress of the procedure, they can communicate with the patient. If a person feels in the process of a sharp malaise, pain, deterioration of health, he immediately informs the doctor about it.
A series of images taken during the examination is recorded in computer media and processed by a special program that produces ready-made layered images.
Tomographic scanning of the liver occurs in segments closely related to the duct system, of which there are five in the liver. This technique greatly simplifies the examination, further reading of the results and the conclusion of the radiologist.
Benefits of having a liver exam with a CT scanner
The development of this apparatus at one time became a real breakthrough, and CT is still considered a way to obtain the most clear and informative images of the internal organs of a person and their deep structures. A qualified radiologist can not only detect the presence of diseases and pathologies in the images, but also outline the circle of reasons that led to their appearance.
An examination using a tomograph is non-invasive, painless and more affordable than, for example, an MRI. Its implementation usually does not threaten the patient with any complications if all the preparation requirements have been met, and the absence of contraindications has been determined.
In some emergency cases, the fact that the examination itself takes from 15 minutes plays an important role. If the patient has acute injuries, bleeding and damage, every second of delay becomes deadly for him, so the possibility of obtaining examination results in such a short time is highly valued.
Computed tomography is undoubtedly safer than radiography, as it exposes the patient to much less radiation.
The diagnosis of liver formations has stepped far ahead with the advent of computed tomography. In cases where tests, ultrasound and radiography cannot give the doctor complete and accurate information about the presence, extent and nature of liver lesions, the appointment of CT is a real way out. Computer diagnostics using the properties of X-rays makes it possible to identify pathological processes in the liver even at the early stages of their development, and with minimally noticeable manifestations.