Computed tomography, or CT, is an image exam that uses X-rays to generate images of the body that are processed by a computer, which can be of bones, organs or tissues. This test does not cause pain and anyone can perform it, however, pregnant women should preferably do other tests as an alternative to computed tomography, such as ultrasound or magnetic resonance, as radiation exposure is greater on tomography.
Tomography can be performed with or without the use of contrast, which is a type of liquid that can be swallowed, injected into the vein or inserted into the rectum during the exam to facilitate the visualization of certain parts of the body.
The price of computed tomography varies between R $ 200 and R $ 700.00, however this exam is available from SUS, without any cost. Computed tomography should only be performed under medical guidance, as it involves exposure to radiation, which can be harmful to health when you do not have adequate guidance.
What is it for
Computed tomography is used to help diagnose muscle and bone diseases, identify the location of a tumor, infection or clot, in addition to detecting and monitoring diseases and injuries. The main types of CT scans are:
- Skull tomography: Indicated for the investigation of trauma, infections, hemorrhage, hydrocephalus or aneurysms. Learn more about this exam; Tomography of the abdomen and pelvis: Requested to assess the evolution of tumors and abscesses, in addition to verifying the occurrence of appendicitis, lithiasis, renal malformation, pancreatitis, pseudocysts, liver damage, cirrhosis and hemangioma. Tomography of upper and lower limbs: Used for muscle injuries, fractures, tumors and infections; Chest tomography: Indicated for investigation of infections, vascular diseases, tumor tracking and evaluation of tumor evolution.
Normally, CT scans of the skull, chest and abdomen are performed with contrast so that there is a better visualization of the structures and it is possible to easily distinguish the different types of tissue.
Computed tomography is usually not the first option for diagnostic examination, since radiation is used to generate images. Most of the times the doctor recommends, depending on the location of the body, other tests such as an X-ray, for example.
How to prepare for the exam
Before the tomography is performed, it is important to fast according to the doctor's guidance, which can be 4 to 6 hours, so that the contrast is better absorbed. In addition, it is important to suspend the use of the drug metformin, if used, 24 hours before and 48 hours after the exam, as there may be a reaction with the contrast.
During the exam the person is lying on a table and enters a kind of tunnel, the tomograph, for 15 minutes. This examination does not hurt and does not cause distress, as the equipment is opened.
Advantages and disadvantages of CT
Computed tomography is an exam widely used to aid in the diagnosis of various diseases because it allows to evaluate sections (parts) of the body, providing sharper images and promoting the distinction of different tissues. Because it is a versatile test, CT is considered the test of choice for the investigation of brain or lung nodules or tumors.
The disadvantage of CT is the fact that the examination is done by emitting radiation, the X-ray, which, even though it is not present in large quantities, can have harmful effects on health when the person is constantly exposed to this type of radiation. In addition, depending on the purpose of the test, the doctor may recommend that contrast can be used, which may have some risks depending on the person, such as allergic reactions or toxic effects on the body. See what are the possible risks of exams with contrast.
