Harmful if CT (computed tomography)?
Based on the results of many polls, it’s safe to say that CT is one of the most important inventions of mankind. In the late 70-ies of the last century the revolution in medicine, did a CT scan the most important method of diagnosis of human diseases, and scientists who developed computer tomography, was awarded the Nobel prize.
At the end of the last two decades of the 20th century the interest of the physicians moved between computed tomography and magnetic resonance. CT has evolved at a moderate pace, in contrast to MRI, which addressed the views of practitioners. But in 1988, thanks to the invention of computed tomography, this method has regained its former popularity: increased speed of examination and the accuracy of the results. Today with CT you can get up to 70% of diagnostic information about the patient’s health, which explains its widespread use in clinical practice.
CT is a safe method, the harmful effects of the use of which has not been proved. Its purpose there is no absolute contraindication, it means that theoretically the method can be used to diagnose all types of patients. However, there are relative contraindications associated with radiation exposure and individual sensitivity to the contrast.
For patients who are not recommended to do a CT scan are pregnant women and children. This is due to the fact that even small doses of radiation affecting the body during a CT scan, can have a detrimental effect on the health of a growing body both the fetus and the child, which can lead to undesirable consequences. And although over the last decade, improvements in CT devices allowed reducing the average radiation dose to 4-8 mSv, pregnant women and children the survey can be done only under strict indications. If possible the diagnostic beam method, a CT scan is not carried out.
However, in cases where there is no possibility to refuse the CT, there are three principles of protection from harmful radiation: protection by time, distance and shielding.
Protection time reduces study duration that can be achieved by avoiding a CT scan in two projections, reducing the x-ray tube current, the use of fast imaging, reducing the number of phases of imaging. In the case of children, the use of sedatives in the hours before the test helps small patients to lie still, which greatly accelerates the research process and allows to obtain images of good quality.
In recent times it has become a widely used CT using bismuth screens (for example, breast examination), they reduce harmful radiation exposure and no significant impact on the quality of the pictures.
Contrast study – is there a risk of an allergic reaction?
Today, a CT scan is conducted, as a rule, with the introduction of contrast media, and most of these iodine-containing drugs. Light the adverse reaction occur in only 1-3% of people, it is symptoms such as nausea, vomiting, itching, hives, change in taste. They do not require treatment and are no harm to health.
Reaction moderate (angioedema, bronchospasm, dyspnea, laryngospasm) develop in isolated cases, but require medical intervention. Reaction severe are extremely rare and occur in patients with severe Allergy to iodine or other substances in history, and require resuscitation. Serious adverse reactions may include shock, collapse, respiratory arrest, or cardiac arrest.
A lot depends on how you introduced the contrast bolus in the introduction, the frequency of side effects is much less than with the drip. Patients who have in the past had the experience of a negative reaction to iodine-containing drugs are mild, you can enter anti-allergic medicines before using contrast. Sometimes staging is carried out Allergy tests to establish how a substance reacts. Patients with severe allergies to iodine CT scan with contrast is strictly contraindicated.
The future of the method in its safety and effectiveness
It’s safe to say that in modern medicine there is a method that as CT, would combine the high sensitivity of magnetic resonance imaging, ultrasound functionality and availability of radiography. And the ability to create multiplanar and three-dimensional images, computer simulations of surgical operations make this method one of a kind.