Today, magnetic resonance imaging is one of the most accurate non-invasive methods for diagnosing diseases. This study allows you to see internal organs, and modern computers create their three-dimensional models. However, in some cases it is necessary to examine a particular internal organ in more detail for a more accurate diagnosis. Then doctors resort to the procedure of conducting an MRI with contrast. A special substance injected into the patient's body is called gadolinium. This product practically does not cause allergies, unlike other iodine-containing drugs.
Features of the impact
Rare earth element, which is the basis of those used by specialists medical supplies, contains molecules held together by chemical bonds. The compound contains a chelating agent, which allows to distribute gadolinium evenly and prevent intoxication associated with the accumulation of dangerous doses of the drug in the body. In our country, doctors use Omniscan, Dotrem, Gadovist and other drugs.
What is contrast MRI and why is a contrast agent administered to the patient? This is an opportunity to increase the information content of diagnostic results and improve the visibility of inflammation, metastases, and neoplasms in the image. early stage. Also introduction special staff simplifies the work of the diagnostician when it is necessary to assess cerebral and cardiac blood flow.
The use of a gadolinium-based product allows you to assess the nature of pathologies and anomalies with maximum accuracy. Carrying out such a study is possible only as prescribed by a radiologist, who determines whether the patient should be prepared for the clearest visualization of changes in the body.
So, what is the difference between an MRI with and without contrast? The procedure, which is preceded by the introduction of a solution with gadolinium, allows you to obtain more detailed information, set boundaries and identify the nature of the pathology more accurately. The area being examined is studied in more detail than during a similar examination, in which no special substance enters the cavity or bloodstream. Most often, this method is used to assess the condition of internal organs, soft tissues, spinal cord and brain.
Progress of the procedure: how to do an MRI with contrast
The contrast agent is administered intravenously using a special syringe or injector that automatically regulates the dose of the drug. On average, the necessary manipulations preceding the actual examination take from 10 to 30 seconds - this is the approximate duration of the injection.
Preparation for the examination and the procedure itself include several stages:
Most often, a drug containing gadolinium is administered after photographs have been taken that do not require the use of contrast. At this moment, the patient is in the MRI room, in the tunnel of the device.
When a laboratory assistant or doctor approaches the tomograph, the table with the patient moves out.
After this, a tourniquet is applied and the substance used when scanning the body with contrast is introduced.
Then the subject again enters the apparatus tunnel.
You have every right to receive information about the peculiarities of conducting magnetic resonance tomography, possible contraindications to MRI with contrast, consequences and the availability of alternative diagnostic methods. A detailed story from the doctor will help you choose best option, allowing you to get accurate results in the most comfortable conditions. If you feel afraid of the injection or the examination itself, inform the specialist in time.
Most patients do not note any discomfort or severe discomfort after such a procedure. Some report nausea, a cold feeling in the arm, or a slight headache. It is worth noting that adverse reactions appear in no more than 1% of all examinations using drugs containing gadolinium salts.
What does an MRI with contrast show?
This method allows you to “highlight” internal organs in the image. This is necessary so that they are visible more clearly, which significantly increases the accuracy of diagnosis. Also, this method makes it possible to determine the size of malignant neoplasms, their structure and the location of tumors and metastases. The solution penetrates into defective cells, making them more visible and making their contours clearer.
MRI with contrast of the brain shows already in the first hours of the development of a stroke the extent of the focus of death nerve cells. IN in this case this method is one of the most informative. One of the most important advantages of such an examination is the natural visibility of the affected area due to the movement of blood.
How is contrast agent administered during MRI?
As mentioned above, in some cases, the magnetic tomography procedure is preceded by the administration of a special solution to the patient. There are 2 options for preparing a person for a gadolinium scan.
In the first case active substance administered intravenously. The injection is performed once before the start of the examination (0.2 mg of solution per 1 kg of the subject’s weight)
The second option involves drip administration of the drug. The amount of drug entering the blood is measured with a special device. This method is called bolus and is widely used when a solution is administered directly during scanning.
Since the contrast agent is administered during MRI in doses, as the diagnosis proceeds, the substance gradually reveals all areas of the organ being examined. Therefore, it is possible to study processes in the body in real time. About 10 ml of the substance is injected at a time. You should then lie still for about an hour before proceeding with the re-diagnosis. All actions of doctors are carried out exclusively with the consent of the patient.
Indications for MRI with contrast
Diagnosis various types malignant neoplasms.
The presence of an unknown infection in the body.
Checking the functioning of blood vessels.
Detection of metastases of the spinal cord and brain. Since these neoplasms are relatively small in size, a gadolinium-based drug helps to see them at an early stage of development.
Determining the stage of multiple sclerosis.
Rehabilitation after surgery on the spine and removal of intervertebral hernias.
More detailed diagnostics a disease detected during resonance imaging without injection of a special drug.
Benefits of MRI with contrast
The advantages and benefits of MRI with contrast have already been listed above. It is more informative than a standard examination performed without the administration of gadolinium salts, which characterizes it as a method that:
determines the degree of malignancy of the tumor;
shows the size of the affected area with extreme accuracy;
makes it possible to identify pathologies at the initial stages of development.
The injected solution is safe for your health in the absence hypersensitivity to its components.
Is contrast agent harmful?
In Russia, magnetic resonance imaging preparations containing intracomplex compounds of the gadolinium ion have been registered and approved for use. These are gadovist, dotarem, primovist and other means used in many countries. All drugs have undergone preliminary clinical trials, which did not reveal complications with the correct administration of the solution and proper calculation of the optimal dosage.
Diagnostic imaging is a field of medicine that uses only proven substances whose safety has been confirmed by specialists. A variety of contrast agents developed for X-ray and CT procedures are successfully used throughout the world. This technology has raised the standards of non-invasive research methods to new level and allowed us to make diagnoses as accurately as possible, guided by optimal image quality when conducting MRI in patients with acute conditions.
If you are asking the question “Is a contrast agent harmful or not,” then these are objective factors that indicate the benefits of using contrast in magnetic resonance imaging. Let's get back to the side effects. Earlier we said that this procedure is safe for most people, but in rare cases it can cause harm to the body of the person being examined. The isotope used as a marker can become toxic if it is difficult to remove the active substance from the body. This is why MRI with contrast is not prescribed to patients with renal failure.
Another side effect that may occur in some cases is an allergic reaction to the active substance of the administered drug. However, such consequences can be avoided by indicating sensitivity to one of the components of the composition at an appointment with a doctor before the procedure. The specialist will find alternative method diagnostics, which will minimize the risk of complications.
Preparing for an MRI with contrast
The patient's actions in preparation for an MRI with contrast, prior to the procedure, depend on which organ will be examined. So, in case of scanning abdominal cavity necessary:
Switch to a low-carbohydrate diet 2-3 days before the magnetic resonance imaging scan and refrain from eating foods containing fiber - they can cause increased gas formation.
Completely avoid morning breakfast (the results of the procedure will be more informative if the diagnosis is carried out on an empty stomach).
It is possible to take an antispasmodic drug.
Over the course of several days (usually 2 days), all foods that cause flatulence are excluded from the patient’s diet (as in the case discussed above). This precaution is necessary when scanning the abdominal cavity, lumbar region spine, Bladder, uterus, etc.
You cannot eat 5 hours before the procedure.
Any drinks are prohibited 3 hours before. An exception is a pelvic examination (doctors do not recommend emptying your bladder before the scan).
Otherwise, preparing the patient for MRI with contrast is completely the same as similar actions when performing tomography without administering a drug based on the rare earth element gadolinium. It is necessary to leave metal jewelry and accessories outside the office, remove all objects that could distort the image in the photo (jewelry, hairpins, glasses, Hearing Aids, removable dentures)and get ready for the procedure. The patient must bring a passport, a referral and medical card with the results of previous examinations.
Contraindications for MRI with contrast
thickening of the skin;
kidney pathologies;
various types of asthma;
anemia and other blood diseases;
pregnancy in the first trimester;
lactation.
Although gadolinium is the safest metal in contrast media, there is a minimal risk of side effects.
skin irritation;
Mild itching;
slight decrease in blood pressure.
These complications occur in 2% of patients. Their occurrence is associated with individual intolerance to the components of the contrast agent.
Magnetic resonance imaging with contrast is an advanced method in diagnosing and studying many diseases. It is distinguished by its safety and variability of the procedure. There is a small number of contraindications and side effects (sensitivity to the components of the drug, renal failure, allergies, slight decrease in blood pressure), which the doctor must report during preliminary consultation. In most cases, the procedure goes without complications, allowing you to identify initial stages development of pathologies, carry out maximum accurate diagnosis and prescribe the right treatment.
Diagnosis of diseases is one of the most important stages treatment that determines the effectiveness of the chosen course. In the event of excruciating pain and discomfort with insufficient description of the symptoms, most likely, the attending physician will send the patient for a procedure to examine the abdominal cavity using computed tomography.
What is a CT scan and what does it show? What is the information content of the diagnosis and are there any contraindications? How is a CT scan performed and how much does the examination cost? How to remove contrast agent from the body? How often can a CT scan be done and what are the indications for the procedure? We will look at the answers to all these questions in the article below.
Computed tomography of the peritoneal organs with contrast - what is it?
Computed tomography is in a modern way diagnostics, which clearly reflects the current state of human internal organs. The main advantage of using this method is obtaining a three-dimensional image. Organs and tissues are not superimposed on each other, as happens when using x-rays, but are visible in a section.
CT scans are used when it is necessary to diagnose diseases of the gastrointestinal tract. Availability foreign bodies, education cancerous tumors, the appearance of stones and various cysts, the development of atherosclerosis, viral diseases and cirrhosis of the liver tissue - this is only a small list of pathologies for which computed tomography of the abdominal cavity is prescribed.
The frequency of this study depends on the total radiation exposure and is determined by the attending physician. Below is a photo of the results of a chest CT scan.
The main qualitative characteristics of a CT study include:
Indications for examination
SCT is prescribed by the attending physician in cases of chronic symptoms diseases of the internal organs of the abdominal cavity, when other research methods do not provide suitable explanations. In addition, CT is performed in case of a rather sharp loss of body weight, unexplained jaundice, or acute abdominal trauma. This study can be carried out in preparation before surgical intervention, and also as a control over the current course of treatment.
Contraindications for CT scan of the abdomen
Computed tomography of the abdominal cavity and chest is a very safe method The study, however, has a number of limitations:
- Pregnant or breastfeeding women would be better suited Magnetic resonance imaging. Also, CT scans should not be performed on patients with diabetes.
- In certain situations, the health risks from using contrast agents may outweigh the need for the test.
- If you have diseases of the heart, liver, kidneys, bronchial asthma, allergic reaction For seafood and iodine, CT is prescribed on an individual basis.
- Relative restrictions for this procedure are the patient’s overweight (more than 120 kg) and insufficient age (the subject must be over 14 years old).
Preparation and plan for the diagnostic procedure
To undergo a computed tomography scan of the abdominal cavity, the patient should carefully prepare.
48 hours before the test, you must give up soda, dairy products, baked goods and brown bread, cabbage, dishes with peas and beans, as well as other food products that contribute to the formation of excessive concentrations of gases in the intestines.
8 hours before a CT scan of the abdominal cavity, you should completely stop eating. On the eve of the study, the patient needs to cleanse the intestines by using an enema or the drug Fortrans, and a couple of hours before the CT scan, take a solution of Urografin. If a person takes any medical supplies, you should tell your doctor about this, as they may affect the results of the study.
The procedure itself cannot be called uncomfortable: the patient sits on the tomograph couch, and a scanner circles around him, taking pictures. All that is required of the subject is to remove objects made with metal inclusions (hairpins, piercings, brassiere with metal underwires, etc.) and lie still. The duration of the procedure is about 15 minutes, and with the introduction of contrast it takes about half an hour. The conclusion in most cases is ready 2-3 hours after the end of the study.
What can be revealed on CT images of the abdominal cavity and retroperitoneum?
CT results help the doctor evaluate the functionality of the internal organs and tissues of the abdominal cavity and retroperitoneal space, as well as the effectiveness of the chosen treatment. CT can also reveal:
Features of SCT of the abdominal cavity with bolus contrast
The drug can be administered intravenously, orally or rectally. For research upper sections The gastrointestinal tract of the patient is asked to drink a special liquid. In order to contrast the large intestine, an enema with a contrast agent is used. The bolus method is used to visualize the abdominal organs.
Computed tomography with bolus contrast is characterized by the introduction of a special substance by an automated injector at a programmed speed and time of delivery of the drug. In this case, the doctor conducting the study must take into account the clinical task, the number of years and body weight of the person, as well as other features.
Bolus contrast allows you to clearly identify and delimit tumor neoplasms, assess the extent of spread of a malignant tumor and its resectability, identify metastases in the lymph nodes and parenchymal organs.
Information content of CT without contrast
Unlike CT without contrast, a study with the introduction of a special drug allows you to most accurately determine the condition of soft tissues, examine the arterial and venous beds, examine the vessels supplying blood to the kidney tissue, gastrointestinal tract organs and other internal organs. The use of a contrast agent makes it possible to study lymphatic system, examine the rectum and colon, and also carefully examine any parenchymal area.
Consequences and complications after computed tomography
An iodine-based drug is used as a contrast agent. After entering the blood, the accumulation of contrast stains the tissue, and thereby displays the area being studied in the images. Contrast drugs are completely eliminated from the patient’s body within 48 hours, and their volume depends on the body weight of the patient. To quickly remove the contrast, doctors recommend drinking as much fluid as possible.
The examination of the abdominal cavity itself does not provide serious complications and side effects. However, a number of patients complain of dizziness or attacks of nausea when rotating the scanner, similar to the state of motion sickness on a carousel in a theme park. After the procedure is completed, the unpleasant sensations disappear.
When using the bolus diagnostic method, people with sensitive skin may feel itching or notice redness at the site of the needle injection. When administering the drug orally, a taste of iodine may appear.
Also, do not worry if the patient feels cold or hot during the contrast injection. These signs do not require intervention medical worker and they will pass on their own.
More Negative influence A CT scan of a patient's body may appear when the person did not know that he was suffering from an allergy to iodine. In this case, the help of a doctor and the use of antihistamines are necessary. If the patient begins to experience difficulty breathing, a cough appears, or a rash and swelling develop on the skin, you must immediately inform the doctor.
Cost of examination
The price for examining the abdominal cavity and retroperitoneal space depends on the area being examined. The more images required for diagnosis, the higher the cost. Computed tomography without contrast is cheaper, since a special substance is not required to be injected into the patient's body. On average, the price of chest diagnostics using CT in Moscow clinics starts from 4 thousand rubles.
CT with contrast is not prescribed in every case of using computed tomography techniques. This examination method is very accurate, allowing you to examine even the smallest tumors, blood clots and hematomas, and is used when it is necessary to detail the picture of the disease.
CT with contrast is a study that involves the use of X-ray radiation in minimal doses, and is also accompanied by the introduction of a special substance to enhance the contrast of healthy and pathologically altered tissues. CT with contrast is performed in cases where it is necessary to very clearly distinguish between normal and abnormal structures in the human body. This differentiation is achieved by enhancing the signal from diseased tissues.
The effect of contrast in CT is based on the fact that most tumors, especially malignant ones, are better supplied with blood than healthy tissue. Therefore, the contrast agent will accumulate in them, giving a picture of difference from other tissues. In addition, contrast is necessary to study the condition of blood vessels - veins, arteries. In CT images, the contrast will be highlighted in white, which will allow you to clearly study this area.
CT with contrast and oncology
- Tumors of parenchymal organs of the abdominal cavity and retroperitoneal space (kidney cancer, carcinoma of the liver, pancreas, spleen).
- Cancer of the hollow organs of the peritoneum - intestines, gall bladder.
- Formations of the chest - lungs, mediastinum, heart.
- Tumors of the brain and base of the skull.
- Neoplasms of the musculoskeletal system - bones, ligaments, joints, spine.
Tomography with contrast will allow you to distinguish a common and common kidney cyst from renal cell carcinoma or benign lipoma, angioma. When studying the condition of the liver, CT will help differentiate between cirrhosis of the liver, benign tumors and hepatocellular cancer.
The study is used for lymphomas - to distinguish them from another cancer (lymphogranulomatosis) or from simple lymphadenitis. Contrasting will allow us to determine the degree of cancer, its prevalence, damage to regional lymph nodes, and the presence of metastases. CT scans are also often prescribed for malignancy. benign tumors, which will be noticeable in the series specific signs(vascularization, increase in size, etc.).
Other indications for CT with contrast agent
The procedure is very informative in the diagnosis of intraluminal blood clots, as well as thrombosed aneurysms, areas of narrowing of the aorta by blood clots. The contrast will also allow for a detailed study of vascular malformations, including before surgery to remove them. The examination will give a complete picture of thinning vein walls, deep vein varicose veins and thrombophlebitis, as well as atherosclerosis of the arteries.
What else will a contrast-enhanced tomography show? These are any diseases of the following areas of the body:
- Hollow organs - stomach, intestines, esophagus.
- Lungs, bronchi and trachea.
- Larynx and vocal cords.
- Brain, spinal cord.
- Base of the skull.
- All parts of the spine.
- Bones.
- Jaws.
- Nose and sinuses.
Contrast agent and method of its administration
For the procedure apply various drugs– ionic and non-ionic, containing iodine. It is iodine that increases the intensity of the image, while there is practically no harm from its penetration into the body. The most common are ionic drugs, but non-ionic ones are even more preferable (their toxicity is zero). Ionic agents include Metrizoate, Diatrizoate, Ioxaglat, non-ionic agents include Iopromide, Iopamidol, Iohexol and others.
Before administering the drug, the doctor must clarify the presence of certain diseases and conditions in the patient, which may become contraindications to the procedure. Also, in most clinics, before the examination, the patient must pass a series of laboratory tests(blood biochemistry, general analysis, liver and kidney tests). The amount of contrast agent is calculated based on the person’s weight.
Eat different ways administration of contrast, the main ones are:
- Bolus. With the bolus method of administration, a syringe injector is installed into the ulnar or other vein, which has a standardized delivery rate of the drug.
- Intravenous single dose. The drug is injected into a vein once with a regular syringe.
- Oral. In this case, the drug is taken orally.
- Rectal. To scan the intestines, a contrast agent is injected through the rectum once.
CT scan with contrast – all contraindications
The administration of iodine-containing drugs is prohibited when:
- Severe form of bronchial asthma and diabetes mellitus
- Allergies to contrast media
- Hyperthyroidism and a number of other thyroid diseases
- Severe renal failure
- Myeloma
A strict contraindication to any CT scan is pregnancy, because the study involves the use of X-rays. Relative contraindication – breast-feeding: After the procedure, breastfeeding should be avoided for 1-2 days. The tomograph has a limitation on the patient’s weight, and when performing a CT scan in people weighing more than 200 kg, difficulties may arise.
How often can I have a CT scan using contrast?
It is generally recommended not to perform the procedure more than once every 6 months. This limitation is not due to the use of contrast, but to the radiation exposure received during CT. However, this load is minimal, and vital signs CT scans may be performed more frequently.
It should be remembered that a number of patients (1-3%) experience pathological reactions to the administration of a contrast agent, which may also limit the frequency of the procedure. Such reactions include:
- Facial swelling
- Dyspnea
- Rash on the body
- Hives
- Itchy skin
- Bronchospasm
- Reduced pressure
- Nausea
- Vomiting, etc.
Such reactions are considered signs of an allergy to the contrast agent and require medical care. Only mild are normal metallic taste in the mouth, pain in the injection area, feeling of warmth in the body.
How the research is carried out
Preparing for a CT scan with contrast enhancement includes the following measures:
- Do not eat for 4-8 hours before the procedure (depending on the specific study area)
- Take a drug to reduce gas formation (during examination of the gastrointestinal tract)
- Come in comfortable, loose clothing
- Remove all metal jewelry and removable medical devices
The patient is placed on a couch, a contrast agent is injected into him, or a syringe injector is installed. After a certain period of time, the scanning procedure begins - they roll the person under the arc of the tomograph and take a series of images. The further the organ being studied is located from the heart, the longer it takes contrast to stain it.
CT scan with or without contrast: main differences
When examining hollow organs, a conventional native CT scan without contrast will show them as a homogeneous gray mass without highlighting. If you introduce a contrast agent, the walls of the organs will become colored, which will make it possible to examine any diseases of their mucous membrane and muscle layer.
During the study of vessels, only the penetration of a contrast agent into them will make it possible to identify blood clots and plaques of atherosclerosis, as well as to detail the boundaries of aneurysms, narrowings and plexuses of vessels among themselves. Native CT will not provide such accurate information even when the “vascular mode” is connected.
When diagnosing cancerous tumors, the differences between the procedure with and without contrast are most pronounced. Exactly malignant neoplasms eat the largest number vessels, therefore they are colored clearly, brightly, with visible boundaries. Therefore, often after a native CT scan, which reveals a tumor, a CT scan with contrast is recommended to clarify the diagnosis.
In general, the differences between the procedures are as follows:
- Contrast-enhanced CT provides much more information to the physician in one examination.
- Computed tomography with contrast makes images of individual anatomical areas more detailed and clear.
Diseases for which computed tomography with contrast is used:
- Cancerous tumors
- Polyps
- Cysts
- Adenomas
- Lipomas
- Blood clots
- Vascular malformations
- Aneurysms
- Ulcers and erosions
- Stenosis of veins and arteries
- Aortic stenosis
- Aortic dissection
- Vascular atherosclerosis
- Bronchial asthma
- Bronchiectasis
- Abscesses
- Cellulitis
CT – modern research which will help you find various pathologies in the body, often not detected by other methods. The contrast agent during CT will allow you to clearly visualize all abnormalities and diseases in a quick and non-invasive way.
Computed tomography with contrast is different from traditional method the fact that during the study there is a change in the color of the tissue in relation to each other. Special components are introduced into the patient’s circulatory system, which react to the action of the device by changing the contrast. Advanced scanning allows you to see the area of interest in color. This contributes to the most accurate diagnosis.
Methods of administration
Computed tomography with contrast is conventionally divided into 2 types, the use of which is prescribed depending on the tissue being diagnosed. Angiography is commonly used to examine cardiovascular diseases. It allows you to obtain a three-dimensional picture of the hematopoietic system. Prescribed for the diagnosis of thrombosis, pre-infarction condition, heart attack, atherosclerosis, aneurysm.
Perfusion diagnoses the presence of a cancerous, functional, infectious, or traumatic process. This study is prescribed to detect pathological foci in the brain, spinal cord, and digestive glands. It allows you to identify neoplasms and changes that are caused by a failure of blood circulation. In addition, there are types of studies that differ in the method of introducing the contrast component.
Most often used intravenous administration. It is used for the above methods.
The contrast agent is administered intravenously in the following ways:
- Bolus. A special pump or catheter is used for this. The drug is supplied to the patient’s circulatory system over a long period of time. Not only before the scan starts, but also during it. This method allows you to maintain the required concentration of contrast agent in the area under study.
- Classic. The contrast is given by dropper or syringe. The coloring component is injected in the required volume once before scanning begins.
If there is a need to examine the brain or spinal cord, the condition coronary vessels, then a bolus injection of contrast is prescribed
Oral administration
If diagnostics of the stomach is required, an oral administration of the dye is usually recommended. It helps improve the image. For this, two types of substances are used:
- Barium sulfate has the consistency milkshake.
- Gastrografin, which appears to be a solution of iodine and gives a bitter taste.
These components appear to be substances that weaken the effects of X-rays. After swallowing, the drug enters the stomach, then into intestinal tract. During the procedure, the radiation passing through the organs is weakened. In this case, the area under study, which is filled with contrast, stands out and appears as a highlighted area in the image.
Oral contrast agents do not pose a danger to the body; they move throughout gastric tract, like incoming food. In some cases, constipation may occur. Contrast should not be administered in this way to people with perforated ulcer. In addition, there are cases of allergic reactions to the flavorings that are part of the component.
Rectal contrasts
The dyes used to examine the intestines are administered rectally. For this purpose the same medications, as for oral administration, only at a different concentration. The patient is placed on his side and a rectal substance is administered as an enema. Moreover, its tip is located in the rectum. It is connected by a tube to a bag filled with contrast.
The drug then fills the lower intestinal tract. At this time, the patient feels some discomfort, fullness, and cold. The rectal substance increases sensitivity to examination in the bladder, uterus, and intestinal tract. Oral components also have a weakening effect on x-rays. The preparatory period, in addition to abstaining from food intake, includes cleansing the intestinal tract. To do this, use a flow enema the day before.
Application
Multislice computed tomography is most often used when an oncological process is suspected, to separate benign from malignant formations. MRI, CT scan with dye guidance recommend:
- at tumor processes abdominal cavity. This method prescribed for oncology of the liver, spleen, pancreas;
- oncology of the intestine, gall bladder;
- malignant formation lungs, heart;
- brain cancer;
- articular, ligamentous, bone oncologies.
Contrast enhancement makes it possible to distinguish lymphadenitis from cancer and establishes the degree of oncology. In addition, it allows you to determine the prevalence of the process, the presence of lesions lymph nodes, metastasis. This procedure shows the informative value of studying an intraluminal thrombus, aneurysm, or area of narrowing of the aorta by blood clots.
Contrast agent allows for clearer images
The contrast component studies vascular changes in detail. Often used before surgery. This study provides full information about the presence of thinning of the venous walls, varicose veins veins, arterial atherosclerosis, thrombophlebitis.
Contrast scanning also shows the condition:
- bronchi;
- stomach;
- larynx;
- spinal cord;
- cranium;
- jaws;
- sinuses.
Types of contrasts
Cannot be used for scanning universal remedy, since the study of each organ and tissue requires a special approach. To obtain the necessary information, many varieties have been invented medicines. They are divided into the following groups:
- Positive drugs that enhance the absorption of x-ray radiation. The radiopaque component includes agents including barium and iodine. With their help, the pituitary gland, OBP, pelvic bones, rib cage.
- Negative, which weaken the absorption of x-ray radiation. This type includes medications with gas mixtures and air. These drugs are used to examine the bladder.
For your information, positive contrasts are divided into non-ionic and ionic. The first types of medications pose the least danger to patients.
In addition to the listed types of contrast components, there are the following types medications containing barium or iodine. The first three types of iodine-containing contrast injections are:
- Water soluble. Used to examine lymph nodes, urinary system organs, circulatory system. These components leave the patient's body through the kidneys.
- Fat soluble. Used to diagnose the spine, respiratory system, brain, spinal cord, canals located in the area of the skull, neck. Excreted through the urinary system.
- Alcohol-soluble. Used to examine the spinal and intracranial canals. These substances are excreted not only by the kidneys, but also by the intestines.
- Insoluble contrasts consist of barium sulfate. Used to examine the intestinal lumen. Excretion is carried out by the intestinal section.
The type of contrast agent is selected exclusively by the doctor. Taking into account general condition patient, presence of allergic reactions to the administered substance.
Contraindications
Despite the high effectiveness of advanced diagnostics, there are some contraindications to this procedure. Which include:
- the presence of an allergic reaction to the administered substance. However, if the component introduced during radiology gave the presence of hypersensitivity, this does not mean that enhanced magnetic resonance imaging will entail a similar result;
- presence of pregnancy;
- presence of transferred surgical intervention on vessels. Since after some of them it is prohibited to carry out this procedure;
- renal failure. Since contrast is mainly excreted through the urinary system, its failure can cause poisoning of the body.
It is important to clarify the presence of contraindications before performing diagnostics.
Side effects
Despite a thorough examination by a doctor and collection of tests before the tomography, there is a risk of developing side effects. Which most often manifest themselves in the form of: shortness of breath, allergic reaction, dizziness, hives, sneezing, itchy eyes. Even if such phenomena occur, they usually manifest themselves in a mild form and are easily eliminated when prescribed adequate therapy, reducing the occurrence of complications to a minimum.
Preparation
If a patient is indicated for a study with the introduction of a contrast component, then he needs to undergo some preparatory activities. First of all, 2-3 days before the proposed examination, you should come for a consultation with the doctor who will conduct the diagnosis. He will collect a detailed medical history of the patient.
Important! If diagnostics with contrast were performed within 24 hours, then enhanced tomography is prohibited.
If no contraindications are identified, then on the day of the procedure you must arrive 30 minutes earlier than the appointed time for the hypersensitivity test. You are prohibited from eating 5 hours before the examination. These measures will help avoid the risk of nausea and vomiting. If tomography of the pelvic tissues is performed, then to obtain more exact result you need to drink 1 liter of water an hour before the procedure. Tomography with a contrast agent allows you to most accurately determine the presence of a pathological focus at the very beginning of its development.
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