Computed tomography – course, indications, preparation for surgery, contraindications. Types of computed tomography

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Computed tomography is one of the basic diagnostic methods included in the so-called imaging tests. It is readily available and common, and is widely used in the diagnosis of many serious medical conditions. What is worth knowing about this study?

Computed tomography – what is this test?

Computed tomography uses computer technologies and X-ray machines to create cross-sectional images of the body. These images provide more detailed information than regular X-ray images. Computed tomography is much more accurate as it shows soft tissues, blood vessels and bones in various parts of the body. Computed tomography can be used to visualize:

1. head,
2. arms,
3. spine,
4. hearts,
5. abdominal cavity,
6. skeletal system,
7. chest.

During computed tomography, you lie in a tunnel-like machine while the inside of the machine rotates and takes a series of x-rays from different angles. These images are then transferred to a computer where they are combined to create images of the body. They can also be combined to create a three-dimensional image of a specific area of ​​the body.

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Computed tomography – application

Computed tomography has many uses, but is especially important for diagnosing disease and assessing injuries. An imaging technique such as a CT scan helps:

1. diagnose infections, muscle disorders and bone fractures,
2. indicate the location of tumors and neoplasms,
3. examine blood vessels and other internal structures,
4. assess the extent of internal injuries and internal bleeding,
5. monitor the effectiveness of treatment for certain diseases, including cancer and heart disease.

Computed tomography is minimally invasive and safe for the patient.

Computed tomography – what is it?

A computed tomography scan consists of taking several pictures using X-rays. The head of the tomographic machine circulates around specific parts of the patient’s body, generating radiation. It gives the possibility of taking many photos on various planes and layers. The obtained image is then transferred to a computer with specialized software. The photographed part of the patient’s body is visible in the 2D or 3D technique.

It is worth knowing that it is important to remain motionless while performing computed tomography. Otherwise, the resulting artifacts may affect the correct assessment and the test result itself.

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Computed tomography – preparation

In order for the CT scan to run properly, you need to prepare properly. People ordered to have a CT scan should eat their last meal at least six hours before the scan. What’s more – you should drink large amounts of fluids a day or two hours before the tomography. You should bring the current test results with you for the examination, including the previously performed tomography.

The examination itself does not take too long – usually 10-15 minutes.

Computed tomography – contrast

As with all X-rays, dense structures in the body – such as bones – are easy to visualize, while soft tissues have a different ability to trap X-rays and can therefore be weak or difficult to see. For this reason, intravenous (IV) contrast agents have been developed that are clearly visible on X-rays or CT scans and are safe to use in patients.

Contrast agents contain substances that better block x-rays, making them more visible on an x-ray image. For example, to examine the circulatory system, an iodine-based contrast agent is injected into the bloodstream to help illuminate the blood vessels. This type of test is used to look for possible blockages of blood vessels, including in the heart. Oral contrast agents such as barium-based compounds are used to image the digestive system, including the esophagus, stomach, and digestive tract.

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Computed tomography of the head – indications and course

Computed tomography of the head is marked with CT or CT skins. It is an x-ray examination that is used in cases such as:

1. cerebral vascular stroke,
2. all kinds of craniocerebral injuries,
3. suspicion of ischemic changes in the brain or brain tumors,
4. brain atrophy
5. suspicion of malformations of the outer and middle ear,
6. suspicion of chronic otitis media,
7. Alzheimer’s disease,
8. postoperative control,
9. cancer of the salivary glands,
10. sinusitis, polyps, injuries.
11. neoplasms, such as glioma, astrocytoma, lymphoma or tumor metastases,
12. head injuries, such as hematomas, contusions of the brain, fractures of the skull bones,
13. suspicions of malformations in children
14. cerebral ischemia,
15. intracerebral hemorrhage,
16. chronic strokes
17. bone changes.

Computed tomography of the head with contrast

In some patients, a contrast agent must be administered during computed tomography, the purpose of which is to better visualize the obtained image. The contrast agent most often consists of iodine and can be administered intravenously or orally.

Computed tomography of the head – price

The price of a head CT scan may vary. It depends on the center performing the test and whether or not a contrast agent has been administered. The price of a head CT scan ranges from approx. PLN 170 to PLN 500.

Computed tomography of the abdominal cavity – indications and course

Computed tomography of the abdominal cavity is an examination thanks to which it is possible to visualize the organs located in the abdominal cavity, and more precisely their cross sections.

The most common indications for abdominal computed tomography:

1. kidney problems, e.g. kidney stones, kidney calcification, inflammation of the kidneys,
2. cancer of the pancreas or liver
3. inflammation of the pancreas,
4. diverticulitis of the large intestine,
5. appendicitis,
6. gastrointestinal obstruction,
7. abdominal injuries,
8. hepatic vein thrombosis,
9. gastrointestinal bleeding.

Contraindications for performing computed tomography of the abdominal cavity:

1. hemorrhagic diathesis,
2. pregnancy,
3. allergy to contrast agents,
4. claustrophobia

The patient must go to the abdominal cavity for a CT scan (he can only drink still water). You should take the current creatinine result with you for the test, because the result above or below the norm is automatically a contraindication to the test. In addition, before the examination, it is recommended to drink 1,5 liters of non-carbonated water and stay for the time of tomography with a full bladder.

During the examination, the patient is given a contrast agent to drink and, in some cases, preparations that inhibit intestinal peristalsis. Before the examination, young children are given a sedative and sometimes even general anesthesia. Abdominal computed tomography takes several or several dozen minutes, and the radiation dose during the examination is so high that it should not be performed too often.

The patient must remain still during the examination. After the examination, you should drink a large amount of liquid to rinse out the contrast.

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Computed tomography of the sinuses – indications and course

Computed tomography of the sinuses is a very precise examination. It is performed not only before the use of pharmacological treatment, but also before the sinus restoration procedure and the operation itself. This examination is currently considered the most accurate imaging test.

It is performed with the use of ionizing radiation, the beam of which is passed through the body of the examined person. The device used for the examination is a computer tomograph, which consists of a scanner, a table on which the patient is lying and a console located in a separate room, intended for the machine operator.

The indications for the computed tomography of the sinuses include:

1. chronic and acute sinusitis,
2. tumors of the sinuses and nasal cavity (benign and malignant),
3. bay area injuries
4. assessment of the patency of each nasal cavity,
5. unclear result, e.g. sinus X-ray
6. sinus disease treatment evaluation.

Before carrying out the test, inform your doctor about the pregnancy or possible conception, which may have occurred recently. All current diseases should also be mentioned, especially if they are kidney diseases, circulatory failure, thyroid disease, asthma or diabetes. Such diseases may be a contraindication to performing computed tomography of the sinuses, especially with the use of a contrast agent. Appropriate safety precautions are taken in people suffering from these diseases. People suffering from claustrophobia should also inform their doctor.

In addition, the doctor should be informed about possible claustrophobia (fear of small spaces; in this case, and in case of increased anxiety, sedatives will be given).

If the computed tomography of the sinuses will be performed with the use of a contrast agent, it should be on an empty stomach. Otherwise, it is not necessary, unless your doctor tells you otherwise. Before performing a tomography, remove any metal objects from clothes and body that may affect the quality of the obtained images.

Computed tomography of the chest – indications and course

Computed tomography of the chest allows you to visualize the structures of this area, from the heart and vessels, through the lungs, bronchi and pleura, to the esophagus, diaphragm, muscles, ribs, sternum, spine and lymph nodes. As with other radiographic examinations, computed tomography of the chest uses ionizing radiation.

The most common indications for chest computed tomography:

Computed tomography is performed to assess the above-mentioned organs, so it is difficult to list all indications for the examination. It is certainly performed routinely in the case of unclear results of other tests. eg chest or trauma X-ray to assess the extent of possible internal injuries.

Other indications include:

1. thoracic aortic aneurysm
2. suspicion of developmental defects,
3. the appearance of symptoms of pneumonia,
4. determining the location and shape of the neoplasm in the chest,
5. assessment of tumor metastases,
6. assessment of the stage of the neoplastic disease (helps to choose the treatment),
7. replacing more invasive tests, e.g. examining the arteries of the heart.

Contraindications for chest computed tomography:

1. fresh bleeding into the brain
2. toxic goiter of the thyroid gland,
3. liver / kidney failure,
4. respiratory system diseases,
5. cardiovascular disease,
6. asthma,
7. multiple myeloma,
8. patients over 65 and under 10,
9. history of a reaction to the contrast medium administered
10. allergy to iodine contrast agents,
11. taking meltformin (an anti-diabetes preparation).

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Computed tomography of the spine – indications and course

Computed tomography of the spine is a type of X-ray examination that uses it to obtain multiple images of the spine and also, if necessary, three-dimensional images. Images obtained with computed tomography are much more detailed than those obtained with a conventional X-ray machine.

In addition, computed tomography is a very useful diagnostic method as it can visualize and distinguish many different types of tissue in the same region, including bones, muscles, soft tissues and blood vessels. The bone structure of the vertebrae is clearly and accurately shown on computed tomography, as are the intervertebral discs and, to some extent, the spinal cord.

Some of the common uses for spine computed tomography include:

1. detection or exclusion of spinal injuries in people with a history of injuries,
2. condition of the spine before and after surgery,
3. detecting different types of tumors in the spine, including those that have spread there from another area of ​​the body. Some cancers that arise elsewhere are first identified by finding deposits of malignant cells (metastases) in the vertebrae; an example is prostate cancer,
4. To detect spinal stenosis, vertebral fractures, infection, or a degenerative disease such as arthritis, computed tomography of the spine can provide important information when done alone or in addition to magnetic resonance imaging (MRI). One of the most common causes of back pain that can be diagnosed with computed tomography is a herniated intervertebral disc.

Computed tomography of the spine is performed with the patient lying on his back. The technician performing the test will make sure that you are properly positioned and can use pillows to help you maintain proper posture during the test. If indicated, contrast material will be injected into your arm’s vein during the procedure to sharpen images of various tissues.

A scan of the lower spine can also be done after injecting contrast material into the spinal canal surrounding the spinal cord during a lumbar puncture. This will help detect tumors or locate areas of inflammation or pressure on the nerves.

Computed tomography of the spine is a painless procedure, except for inserting a needle in the event of an intravenous injection. The discomfort is mainly due to the need to lie down on the operating table for some time. The injection of the contrast material may cause a slight burning sensation in the arm, a metallic taste and a warm reddening of the entire body. These are all normal reactions and usually end within seconds.

Computed tomography – price

Computed tomography, depending on the examined area of ​​the body, differs in terms of price. For example, a head examination costs from 170 to 500 PLN. Tomography, which uses contrast, is also more expensive.

Computed tomography – risks and complications

During computed tomography, we are exposed to ionizing radiation for a while. The amount of radiation is greater than during a regular X-ray examination because CT scans collect more detailed information. Radiation doses used in computed tomography have not been shown to have long-term consequences in the bodyalthough there may be a slight increase in the potential risk of cancer development at much higher doses.

Computed tomography uses the lowest possible dose of radiation to get the medical information you need. In addition, newer, faster machines and techniques require less radiation than was used in previous years.

Before having a CT scan, tell your doctor if you are pregnant. While the radiation from a CT scan is unlikely to cause any negative consequences for your baby, your doctor may recommend another type of scan, such as an ultrasound or MRI scan, to avoid your baby’s exposure to radiation. At the low doses of radiation used in computed tomography imaging, no negative effects were observed in pregnant women and their children.

In some cases of computed tomography, your doctor may recommend that you get a special dye called contrast material. Usually administered intravenously, the contrast material can cause medical problems or allergic reactions.

Most allergic reactions are mild and cause a rash. In rare cases, an allergic reaction can be serious or even life-threatening.