Computed tomography of the lungs enables the diagnosis and detailed assessment of any abnormalities in the respiratory tract. Additionally, it also allows the doctor to evaluate other organs in the chest. How is lung tomography done and when does the doctor order it?
Computed tomography of the lungsis a test that allows for layered imaging of the elements of the respiratory system located in the chest. As standard, computed tomography is performed, which allows for saving and transforming images in such a way as to give the collected data the greatest diagnostic value.
The dose of rays the patient receives during the examination is higher than in a traditional X-ray, but the examination gives much more information than a simple X-ray. The test can be performed with or without contrasting.
Computed tomography of the lungs is ordered when serious diseases of the respiratory system are suspected, including the presence of lung cancer, both primary and metastatic. The test may also be recommended when the doctor wants to check the patient's progress in treatment.
A referral for lung computed tomography , just like for all other imaging tests, can only be issued by a doctor.
When do I need a lung CT scan?
The tomographic examination is the simplest and the most frequently used imaging diagnostic method, which allows to evaluate the layered sections of organs.
In about 50% of patients it allows to make a correct and final diagnosis, in 30% of cases it is of auxiliary importance, in 20% of patients it completes the diagnosis process.
They are also often performed to determine the necessity of an operation.
Lung tomography: preparation for the examination
People who undergo computed tomography of the lungs without administering a contrast agent do not have to prepare for the examination in any way. People undergoing computed tomography with contrast agent should:
- fasting 4-6 hours before testing
- drink plenty of non-carbonated fluids beforehand, after the test it is also recommended to drink plenty of fluids (more urine produced reduces the risk of kidney damage by the contrast agent)
- before agreeing to the examination, inform the doctor about the pregnancy,previous reactions to administration of a contrast medium, thyroid and heart diseases, asthma, kidney diseases, diabetes, allergy to drugs and medicines taken chronically
- people who experienced adverse reactions after administration of a contrast agent should receive a glucocorticosteroid and possibly an antihistamine 12 and 2 hours before the examination; the use of a glucocorticosteroid reduces the risk of side effects of administering a contrast agent to less than 1%
Lung tomography: the course of the examination
The test is painless and takes 10 to 30 minutes. During the examination, you lie in a special tunnel formed by the table and the housing of the tomograph itself. Do not move during the examination.
People who suffer from claustrophobia (fear of closed rooms), over-agitated patients and young children are given sleeping pills before the examination.
The patient is placed on the table which is then shifted so that the patient's chest is surrounded by the wide ring of the device.
During the test, the table moves slowly by several centimeters.
Due to the fact that the head is usually outside the tunnel of the device in thoracic examinations, this usually does not cause discomfort for people suffering from claustrophobia.
The test lasts from a few to several minutes (maximum 30 minutes) and is not painful. The actual time during which the patient is exposed to radiation is much shorter and usually amounts to several seconds.
Tomography with contrast agent (contrast)
Before the test, it is necessary to insert a cannula (access the vein). The test is similar to that described above, but during the test, a contrast solution is injected into the vein (usually with an automatic syringe). This can cause a temporary burning sensation in your hand and a hot or strange taste in your mouth which should pass quickly. Should this not be the case, please notify the examining physician.
What does computed tomography of the lungs detect?
Computed tomography of the lungs enables the diagnosis and detailed assessment of anomalies in the respiratory tract. The test detects:
- inflammatory changes
- pulmonary obstruction
- atelectasis
- emphysema
- presence of fluid or adhesions in the pleural cavity
- neoplastic tumors - primary and metastatic
- pulmonary fibrosis and cirrhosis
- developmental defects of the lungs, bronchi and trachea
- post-traumatic changes, foreign bodies and damage to the pulmonary parenchyma (e.g. as a result of contusionlungs on a fall)
The test also provides information about the condition of other organs in the chest, i.e. the heart, large vessels, lymph nodes, and the chest wall.
Computed tomography of the lungs: side effects
Testing without applying a contrast agent is safe.
The dose of ionizing radiation is much higher (often even several dozen times) than in the case of a chest X-ray. Exposure to such a dose of ionizing radiation theoretically increases the risk of developing cancer, but this risk is clearly outweighed by the he alth benefits of obtaining an accurate diagnosis.
On the other hand, after administering a contrast agent, side effects appear in some of the respondents. These are usually:
- nausea and vomiting
- itchy skin, hives, redness of the face
- fever
- shortness of breath from bronchospasm, laryngeal edema or pulmonary edema
- dizziness
- increase or decrease in blood pressure, including shock
- cardiac arrest
Side effects of low intensity occur in up to 1 in 10 people surveyed, and severe in<1 na 1000 (ale ryzyko to zależy od rodzaju stosowanych środków kontrastowych. Bezpieczniejsze dla pacjentów i dające mniej skutków ubocznych są środki niejonowe.
About the author
Anna Jarosz A journalist who has been involved in popularizing he alth education for over 40 years. Winner of many competitions for journalists dealing with medicine and he alth. She received, among others The "Golden OTIS" Trust Award in the "Media and He alth" category, St. Kamil awarded on the occasion of the World Day of the Sick, twice the "Crystal Pen" in the national competition for journalists promoting he alth, and many awards and distinctions in competitions for the "Medical Journalist of the Year" organized by the Polish Association of Journalists for He alth.
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